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tor/ReleaseNotes
Roger Dingledine 0d46978de6 sorry brits
2015-02-19 09:26:32 -05:00

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This document summarizes new features and bugfixes in each stable release
of Tor. If you want to see more detailed descriptions of the changes in
each development snapshot, see the ChangeLog file.
Changes in version 0.2.5.10 - 2014-10-24
Tor 0.2.5.10 is the first stable release in the 0.2.5 series.
It adds several new security features, including improved
denial-of-service resistance for relays, new compiler hardening
options, and a system-call sandbox for hardened installations on Linux
(requires seccomp2). The controller protocol has several new features,
resolving IPv6 addresses should work better than before, and relays
should be a little more CPU-efficient. We've added support for more
OpenBSD and FreeBSD transparent proxy types. We've improved the build
system and testing infrastructure to allow unit testing of more parts
of the Tor codebase. Finally, we've addressed several nagging pluggable
transport usability issues, and included numerous other small bugfixes
and features mentioned below.
This release marks end-of-life for Tor 0.2.3.x; those Tor versions
have accumulated many known flaws; everyone should upgrade.
o Major features (security):
- The ntor handshake is now on-by-default, no matter what the
directory authorities recommend. Implements ticket 8561.
- Make the "tor-gencert" tool used by directory authority operators
create 2048-bit signing keys by default (rather than 1024-bit, since
1024-bit is uncomfortably small these days). Addresses ticket 10324.
- Warn about attempts to run hidden services and relays in the same
process: that's probably not a good idea. Closes ticket 12908.
- Disable support for SSLv3. All versions of OpenSSL in use with Tor
today support TLS 1.0 or later, so we can safely turn off support
for this old (and insecure) protocol. Fixes bug 13426.
o Major features (relay security, DoS-resistance):
- When deciding whether we have run out of memory and we need to
close circuits, also consider memory allocated in buffers for
streams attached to each circuit.
This change, which extends an anti-DoS feature introduced in
0.2.4.13-alpha and improved in 0.2.4.14-alpha, lets Tor exit relays
better resist more memory-based DoS attacks than before. Since the
MaxMemInCellQueues option now applies to all queues, it is renamed
to MaxMemInQueues. This feature fixes bug 10169.
- Avoid hash-flooding denial-of-service attacks by using the secure
SipHash-2-4 hash function for our hashtables. Without this
feature, an attacker could degrade performance of a targeted
client or server by flooding their data structures with a large
number of entries to be stored at the same hash table position,
thereby slowing down the Tor instance. With this feature, hash
table positions are derived from a randomized cryptographic key,
and an attacker cannot predict which entries will collide. Closes
ticket 4900.
- If you don't specify MaxMemInQueues yourself, Tor now tries to
pick a good value based on your total system memory. Previously,
the default was always 8 GB. You can still override the default by
setting MaxMemInQueues yourself. Resolves ticket 11396.
o Major features (bridges and pluggable transports):
- Add support for passing arguments to managed pluggable transport
proxies. Implements ticket 3594.
- Bridges now track GeoIP information and the number of their users
even when pluggable transports are in use, and report usage
statistics in their extra-info descriptors. Resolves tickets 4773
and 5040.
- Don't launch pluggable transport proxies if we don't have any
bridges configured that would use them. Now we can list many
pluggable transports, and Tor will dynamically start one when it
hears a bridge address that needs it. Resolves ticket 5018.
- The bridge directory authority now assigns status flags (Stable,
Guard, etc) to bridges based on thresholds calculated over all
Running bridges. Now bridgedb can finally make use of its features
to e.g. include at least one Stable bridge in its answers. Fixes
bug 9859.
o Major features (controller):
- Extend ORCONN controller event to include an "ID" parameter,
and add four new controller event types CONN_BW, CIRC_BW,
CELL_STATS, and TB_EMPTY that show connection and circuit usage.
The new events are emitted in private Tor networks only, with the
goal of being able to better track performance and load during
full-network simulations. Implements proposal 218 and ticket 7359.
o Major features (relay performance):
- Speed up server-side lookups of rendezvous and introduction point
circuits by using hashtables instead of linear searches. These
functions previously accounted between 3 and 7% of CPU usage on
some busy relays. Resolves ticket 9841.
- Avoid wasting CPU when extending a circuit over a channel that is
nearly out of circuit IDs. Previously, we would do a linear scan
over possible circuit IDs before finding one or deciding that we
had exhausted our possibilities. Now, we try at most 64 random
circuit IDs before deciding that we probably won't succeed. Fixes
a possible root cause of ticket 11553.
o Major features (seccomp2 sandbox, Linux only):
- Use the seccomp2 syscall filtering facility on Linux to limit
which system calls Tor can invoke. This is an experimental,
Linux-only feature to provide defense-in-depth against unknown
attacks. To try turning it on, set "Sandbox 1" in your torrc
file. Please be ready to report bugs. We hope to add support
for better sandboxing in the future, including more fine-grained
filters, better division of responsibility, and support for more
platforms. This work has been done by Cristian-Matei Toader for
Google Summer of Code. Resolves tickets 11351 and 11465.
o Major features (testing networks):
- Make testing Tor networks bootstrap better: lower directory fetch
retry schedules and maximum interval without directory requests,
and raise maximum download tries. Implements ticket 6752.
- Add make target 'test-network' to run tests on a Chutney network.
Implements ticket 8530.
o Major features (other):
- On some platforms (currently: recent OSX versions, glibc-based
platforms that support the ELF format, and a few other
Unix-like operating systems), Tor can now dump stack traces
when a crash occurs or an assertion fails. By default, traces
are dumped to stderr (if possible) and to any logs that are
reporting errors. Implements ticket 9299.
o Deprecated versions:
- Tor 0.2.3.x has reached end-of-life; it has received no patches or
attention for some while.
o Major bugfixes (security, directory authorities):
- Directory authorities now include a digest of each relay's
identity key as a part of its microdescriptor.
This is a workaround for bug 11743 (reported by "cypherpunks"),
where Tor clients do not support receiving multiple
microdescriptors with the same SHA256 digest in the same
consensus. When clients receive a consensus like this, they only
use one of the relays. Without this fix, a hostile relay could
selectively disable some client use of target relays by
constructing a router descriptor with a different identity and the
same microdescriptor parameters and getting the authorities to
list it in a microdescriptor consensus. This fix prevents an
attacker from causing a microdescriptor collision, because the
router's identity is not forgeable.
o Major bugfixes (openssl bug workaround):
- Avoid crashing when using OpenSSL version 0.9.8zc, 1.0.0o, or
1.0.1j, built with the 'no-ssl3' configuration option. Fixes
bug 13471. This is a workaround for an OpenSSL bug.
o Major bugfixes (client):
- Perform circuit cleanup operations even when circuit
construction operations are disabled (because the network is
disabled, or because there isn't enough directory information).
Previously, when we were not building predictive circuits, we
were not closing expired circuits either. Fixes bug 8387; bugfix on
0.1.1.11-alpha. This bug became visible in 0.2.4.10-alpha when we
became more strict about when we have "enough directory information
to build circuits".
o Major bugfixes (client, pluggable transports):
- When managing pluggable transports, use OS notification facilities
to learn if they have crashed, and don't attempt to kill any
process that has already exited. Fixes bug 8746; bugfix
on 0.2.3.6-alpha.
o Major bugfixes (relay denial of service):
- Instead of writing destroy cells directly to outgoing connection
buffers, queue them and intersperse them with other outgoing cells.
This can prevent a set of resource starvation conditions where too
many pending destroy cells prevent data cells from actually getting
delivered. Reported by "oftc_must_be_destroyed". Fixes bug 7912;
bugfix on 0.2.0.1-alpha.
o Major bugfixes (relay):
- Avoid queuing or sending destroy cells for circuit ID zero when we
fail to send a CREATE cell. Fixes bug 12848; bugfix on 0.0.8pre1.
Found and fixed by "cypherpunks".
- Fix ORPort reachability detection on relays running behind a
proxy, by correctly updating the "local" mark on the controlling
channel when changing the address of an or_connection_t after the
handshake. Fixes bug 12160; bugfix on 0.2.4.4-alpha.
- Use a direct dirport connection when uploading non-anonymous
descriptors to the directory authorities. Previously, relays would
incorrectly use tunnel connections under a fairly wide variety of
circumstances. Fixes bug 11469; bugfix on 0.2.4.3-alpha.
- When a circuit accidentally has the same circuit ID for its
forward and reverse direction, correctly detect the direction of
cells using that circuit. Previously, this bug made roughly one
circuit in a million non-functional. Fixes bug 12195; this is a
bugfix on every version of Tor.
o Minor features (security):
- New --enable-expensive-hardening option to enable security
hardening options that consume nontrivial amounts of CPU and
memory. Right now, this includes AddressSanitizer and UbSan, which
are supported in newer versions of GCC and Clang. Closes ticket
11477.
- Authorities now assign the Guard flag to the fastest 25% of the
network (it used to be the fastest 50%). Also raise the consensus
weight that guarantees the Guard flag from 250 to 2000. For the
current network, this results in about 1100 guards, down from 2500.
This step paves the way for moving the number of entry guards
down to 1 (proposal 236) while still providing reasonable expected
performance for most users. Implements ticket 12690.
o Minor features (security, memory management):
- Memory allocation tricks (mempools and buffer freelists) are now
disabled by default. You can turn them back on with
--enable-mempools and --enable-buf-freelists respectively. We're
disabling these features because malloc performance is good enough
on most platforms, and a similar feature in OpenSSL exacerbated
exploitation of the Heartbleed attack. Resolves ticket 11476.
o Minor features (bridge client):
- Report a more useful failure message when we can't connect to a
bridge because we don't have the right pluggable transport
configured. Resolves ticket 9665. Patch from Fábio J. Bertinatto.
o Minor features (bridge):
- Add an ExtORPortCookieAuthFileGroupReadable option to make the
cookie file for the ExtORPort g+r by default.
o Minor features (bridges, pluggable transports):
- Bridges now write the SHA1 digest of their identity key
fingerprint (that is, a hash of a hash of their public key) to
notice-level logs, and to a new hashed-fingerprint file. This
information will help bridge operators look up their bridge in
Globe and similar tools. Resolves ticket 10884.
- Improve the message that Tor displays when running as a bridge
using pluggable transports without an Extended ORPort listener.
Also, log the message in the log file too. Resolves ticket 11043.
- Add threshold cutoffs to the networkstatus document created by
the Bridge Authority. Fixes bug 1117.
- On Windows, spawn background processes using the CREATE_NO_WINDOW
flag. Now Tor Browser Bundle 3.5 with pluggable transports enabled
doesn't pop up a blank console window. (In Tor Browser Bundle 2.x,
Vidalia set this option for us.) Implements ticket 10297.
o Minor features (build):
- The configure script has a --disable-seccomp option to turn off
support for libseccomp on systems that have it, in case it (or
Tor's use of it) is broken. Resolves ticket 11628.
- Assume that a user using ./configure --host wants to cross-compile,
and give an error if we cannot find a properly named
tool-chain. Add a --disable-tool-name-check option to proceed
nevertheless. Addresses ticket 9869. Patch by Benedikt Gollatz.
- If we run ./configure and the compiler recognizes -fstack-protector
but the linker rejects it, warn the user about a potentially missing
libssp package. Addresses ticket 9948. Patch from Benedikt Gollatz.
- Add support for `--library-versions` flag. Implements ticket 6384.
- Return the "unexpected sendme" warnings to a warn severity, but make
them rate limited, to help diagnose ticket 8093.
- Detect a missing asciidoc, and warn the user about it, during
configure rather than at build time. Fixes issue 6506. Patch from
Arlo Breault.
o Minor features (client):
- Add a new option, PredictedPortsRelevanceTime, to control how long
after having received a request to connect to a given port Tor
will try to keep circuits ready in anticipation of future requests
for that port. Patch from "unixninja92"; implements ticket 9176.
o Minor features (config options and command line):
- Add an --allow-missing-torrc commandline option that tells Tor to
run even if the configuration file specified by -f is not available.
Implements ticket 10060.
- Add support for the TPROXY transparent proxying facility on Linux.
See documentation for the new TransProxyType option for more
details. Implementation by "thomo". Closes ticket 10582.
o Minor features (config options):
- Config (torrc) lines now handle fingerprints which are missing
their initial '$'. Resolves ticket 4341; improvement over 0.0.9pre5.
- Support a --dump-config option to print some or all of the
configured options. Mainly useful for debugging the command-line
option parsing code. Helps resolve ticket 4647.
- Raise awareness of safer logging: notify user of potentially
unsafe config options, like logging more verbosely than severity
"notice" or setting SafeLogging to 0. Resolves ticket 5584.
- Add a new configuration option TestingV3AuthVotingStartOffset
that bootstraps a network faster by changing the timing for
consensus votes. Addresses ticket 8532.
- Add a new torrc option "ServerTransportOptions" that allows
bridge operators to pass configuration parameters to their
pluggable transports. Resolves ticket 8929.
- The config (torrc) file now accepts bandwidth and space limits in
bits as well as bytes. (Anywhere that you can say "2 Kilobytes",
you can now say "16 kilobits", and so on.) Resolves ticket 9214.
Patch by CharlieB.
o Minor features (controller):
- Make the entire exit policy available from the control port via
GETINFO exit-policy/*. Implements enhancement 7952. Patch from
"rl1987".
- Because of the fix for ticket 11396, the real limit for memory
usage may no longer match the configured MaxMemInQueues value. The
real limit is now exposed via GETINFO limits/max-mem-in-queues.
- Add a new "HS_DESC" controller event that reports activities
related to hidden service descriptors. Resolves ticket 8510.
- New "DROPGUARDS" controller command to forget all current entry
guards. Not recommended for ordinary use, since replacing guards
too frequently makes several attacks easier. Resolves ticket 9934;
patch from "ra".
- Implement the TRANSPORT_LAUNCHED control port event that
notifies controllers about new launched pluggable
transports. Resolves ticket 5609.
o Minor features (diagnostic):
- When logging a warning because of bug 7164, additionally check the
hash table for consistency (as proposed on ticket 11737). This may
help diagnose bug 7164.
- When we log a heartbeat, log how many one-hop circuits we have
that are at least 30 minutes old, and log status information about
a few of them. This is an attempt to track down bug 8387.
- When encountering an unexpected CR while writing text to a file on
Windows, log the name of the file. Should help diagnosing
bug 11233.
- Give more specific warnings when a client notices that an onion
handshake has failed. Fixes ticket 9635.
- Add significant new logging code to attempt to diagnose bug 12184,
where relays seem to run out of available circuit IDs.
- Improve the diagnostic log message for bug 8387 even further to
try to improve our odds of figuring out why one-hop directory
circuits sometimes do not get closed.
- Add more log messages to diagnose bug 7164, which causes
intermittent "microdesc_free() called but md was still referenced"
warnings. We now include more information, to figure out why we
might be cleaning a microdescriptor for being too old if it's
still referenced by a live node_t object.
- Log current accounting state (bytes sent and received + remaining
time for the current accounting period) in the relay's heartbeat
message. Implements ticket 5526; patch from Peter Retzlaff.
o Minor features (geoip):
- Update geoip and geoip6 to the August 7 2014 Maxmind GeoLite2
Country database.
o Minor features (interface):
- Generate a warning if any ports are listed in the SocksPolicy,
DirPolicy, AuthDirReject, AuthDirInvalid, AuthDirBadDir, or
AuthDirBadExit options. (These options only support address
ranges.) Fixes part of ticket 11108.
o Minor features (kernel API usage):
- Use the SOCK_NONBLOCK socket type, if supported, to open nonblocking
sockets in a single system call. Implements ticket 5129.
o Minor features (log messages):
- When ServerTransportPlugin is set on a bridge, Tor can write more
useful statistics about bridge use in its extrainfo descriptors,
but only if the Extended ORPort ("ExtORPort") is set too. Add a
log message to inform the user in this case. Resolves ticket 9651.
- When receiving a new controller connection, log the origin address.
Resolves ticket 9698; patch from "sigpipe".
- When logging OpenSSL engine status at startup, log the status of
more engines. Fixes ticket 10043; patch from Joshua Datko.
o Minor features (log verbosity):
- Demote the message that we give when a flushing connection times
out for too long from NOTICE to INFO. It was usually meaningless.
Resolves ticket 5286.
- Don't log so many notice-level bootstrapping messages at startup
about downloading descriptors. Previously, we'd log a notice
whenever we learned about more routers. Now, we only log a notice
at every 5% of progress. Fixes bug 9963.
- Warn less verbosely when receiving a malformed
ESTABLISH_RENDEZVOUS cell. Fixes ticket 11279.
o Minor features (performance):
- If we're using the pure-C 32-bit curve25519_donna implementation
of curve25519, build it with the -fomit-frame-pointer option to
make it go faster on register-starved hosts. This improves our
handshake performance by about 6% on i386 hosts without nacl.
Closes ticket 8109.
o Minor features (relay):
- If a circuit timed out for at least 3 minutes, check if we have a
new external IP address, and publish a new descriptor with the new
IP address if it changed. Resolves ticket 2454.
o Minor features (testing):
- If Python is installed, "make check" now runs extra tests beyond
the unit test scripts.
- When bootstrapping a test network, sometimes very few relays get
the Guard flag. Now a new option "TestingDirAuthVoteGuard" can
specify a set of relays which should be voted Guard regardless of
their uptime or bandwidth. Addresses ticket 9206.
o Minor features (transparent proxy, *BSD):
- Support FreeBSD's ipfw firewall interface for TransPort ports on
FreeBSD. To enable it, set "TransProxyType ipfw". Resolves ticket
10267; patch from "yurivict".
- Support OpenBSD's divert-to rules with the pf firewall for
transparent proxy ports. To enable it, set "TransProxyType
pf-divert". This allows Tor to run a TransPort transparent proxy
port on OpenBSD 4.4 or later without root privileges. See the
pf.conf(5) manual page for information on configuring pf to use
divert-to rules. Closes ticket 10896; patch from Dana Koch.
o Minor bugfixes (bridge client):
- Stop accepting bridge lines containing hostnames. Doing so would
cause clients to perform DNS requests on the hostnames, which was
not sensible behavior. Fixes bug 10801; bugfix on 0.2.0.1-alpha.
o Minor bugfixes (bridges):
- Avoid potential crashes or bad behavior when launching a
server-side managed proxy with ORPort or ExtORPort temporarily
disabled. Fixes bug 9650; bugfix on 0.2.3.16-alpha.
- Fix a bug where the first connection works to a bridge that uses a
pluggable transport with client-side parameters, but we don't send
the client-side parameters on subsequent connections. (We don't
use any pluggable transports with client-side parameters yet,
but ScrambleSuit will soon become the first one.) Fixes bug 9162;
bugfix on 0.2.0.3-alpha. Based on a patch from "rl1987".
o Minor bugfixes (build, auxiliary programs):
- Stop preprocessing the "torify" script with autoconf, since
it no longer refers to LOCALSTATEDIR. Fixes bug 5505; patch
from Guilhem.
- The tor-fw-helper program now follows the standard convention and
exits with status code "0" on success. Fixes bug 9030; bugfix on
0.2.3.1-alpha. Patch by Arlo Breault.
- Corrected ./configure advice for what openssl dev package you should
install on Debian. Fixes bug 9207; bugfix on 0.2.0.1-alpha.
o Minor bugfixes (client):
- Avoid "Tried to open a socket with DisableNetwork set" warnings
when starting a client with bridges configured and DisableNetwork
set. (Tor launcher starts Tor with DisableNetwork set the first
time it runs.) Fixes bug 10405; bugfix on 0.2.3.9-alpha.
- Improve the log message when we can't connect to a hidden service
because all of the hidden service directory nodes hosting its
descriptor are excluded. Improves on our fix for bug 10722, which
was a bugfix on 0.2.0.10-alpha.
- Raise a control port warning when we fail to connect to all of
our bridges. Previously, we didn't inform the controller, and
the bootstrap process would stall. Fixes bug 11069; bugfix on
0.2.1.2-alpha.
- Exit immediately when a process-owning controller exits.
Previously, tor relays would wait for a little while after their
controller exited, as if they had gotten an INT signal -- but this
was problematic, since there was no feedback for the user. To do a
clean shutdown, controllers should send an INT signal and give Tor
a chance to clean up. Fixes bug 10449; bugfix on 0.2.2.28-beta.
- Stop attempting to connect to bridges before our pluggable
transports are configured (harmless but resulted in some erroneous
log messages). Fixes bug 11156; bugfix on 0.2.3.2-alpha.
- Fix connections to IPv6 addresses over SOCKS5. Previously, we were
generating incorrect SOCKS5 responses, and confusing client
applications. Fixes bug 10987; bugfix on 0.2.4.7-alpha.
o Minor bugfixes (client, DNSPort):
- When using DNSPort, try to respond to AAAA requests with AAAA
answers. Previously, we hadn't looked at the request type when
deciding which answer type to prefer. Fixes bug 10468; bugfix on
0.2.4.7-alpha.
- When receiving a DNS query for an unsupported record type, reply
with no answer rather than with a NOTIMPL error. This behavior
isn't correct either, but it will break fewer client programs, we
hope. Fixes bug 10268; bugfix on 0.2.0.1-alpha. Original patch
from "epoch".
o Minor bugfixes (client, logging during bootstrap):
- Only report the first fatal bootstrap error on a given OR
connection. This stops us from telling the controller bogus error
messages like "DONE". Fixes bug 10431; bugfix on 0.2.1.1-alpha.
- Avoid generating spurious warnings when starting with
DisableNetwork enabled. Fixes bug 11200 and bug 10405; bugfix on
0.2.3.9-alpha.
o Minor bugfixes (closing OR connections):
- If write_to_buf() in connection_write_to_buf_impl_() ever fails,
check if it's an or_connection_t and correctly call
connection_or_close_for_error() rather than
connection_mark_for_close() directly. Fixes bug 11304; bugfix on
0.2.4.4-alpha.
- When closing all connections on setting DisableNetwork to 1, use
connection_or_close_normally() rather than closing OR connections
out from under the channel layer. Fixes bug 11306; bugfix on
0.2.4.4-alpha.
o Minor bugfixes (code correctness):
- Previously we used two temporary files when writing descriptors to
disk; now we only use one. Fixes bug 1376.
- Remove an erroneous (but impossible and thus harmless) pointer
comparison that would have allowed compilers to skip a bounds
check in channeltls.c. Fixes bugs 10313 and 9980; bugfix on
0.2.0.10-alpha. Noticed by Jared L Wong and David Fifield.
- Fix an always-true assertion in pluggable transports code so it
actually checks what it was trying to check. Fixes bug 10046;
bugfix on 0.2.3.9-alpha. Found by "dcb".
o Minor bugfixes (command line):
- Use a single command-line parser for parsing torrc options on the
command line and for finding special command-line options to avoid
inconsistent behavior for torrc option arguments that have the same
names as command-line options. Fixes bugs 4647 and 9578; bugfix on
0.0.9pre5.
- No longer allow 'tor --hash-password' with no arguments. Fixes bug
9573; bugfix on 0.0.9pre5.
o Minor bugfixes (compilation):
- Compile correctly with builds and forks of OpenSSL (such as
LibreSSL) that disable compression. Fixes bug 12602; bugfix on
0.2.1.1-alpha. Patch from "dhill".
- Restore the ability to compile Tor with V2_HANDSHAKE_SERVER
turned off (that is, without support for v2 link handshakes). Fixes
bug 4677; bugfix on 0.2.3.2-alpha. Patch from "piet".
- In routerlist_assert_ok(), don't take the address of a
routerinfo's cache_info member unless that routerinfo is non-NULL.
Fixes bug 13096; bugfix on 0.1.1.9-alpha. Patch by "teor".
- Fix a large number of false positive warnings from the clang
analyzer static analysis tool. This should make real warnings
easier for clang analyzer to find. Patch from "teor". Closes
ticket 13036.
- Resolve GCC complaints on OpenBSD about discarding constness in
TO_{ORIGIN,OR}_CIRCUIT functions. Fixes part of bug 11633; bugfix
on 0.1.1.23. Patch from Dana Koch.
- Resolve clang complaints on OpenBSD with -Wshorten-64-to-32 due to
treatment of long and time_t as comparable types. Fixes part of
bug 11633. Patch from Dana Koch.
- When deciding whether to build the 64-bit curve25519
implementation, detect platforms where we can compile 128-bit
arithmetic but cannot link it. Fixes bug 11729; bugfix on
0.2.4.8-alpha. Patch from "conradev".
- Fix compilation when DNS_CACHE_DEBUG is enabled. Fixes bug 11761;
bugfix on 0.2.3.13-alpha. Found by "cypherpunks".
- Fix compilation with dmalloc. Fixes bug 11605; bugfix
on 0.2.4.10-alpha.
- Build and run correctly on systems like OpenBSD-current that have
patched OpenSSL to remove get_cipher_by_char and/or its
implementations. Fixes issue 13325.
o Minor bugfixes (controller and command-line):
- If changing a config option via "setconf" fails in a recoverable
way, we used to nonetheless write our new control ports to the
file described by the "ControlPortWriteToFile" option. Now we only
write out that file if we successfully switch to the new config
option. Fixes bug 5605; bugfix on 0.2.2.26-beta. Patch from "Ryman".
o Minor bugfixes (directory server):
- No longer accept malformed http headers when parsing urls from
headers. Now we reply with Bad Request ("400"). Fixes bug 2767;
bugfix on 0.0.6pre1.
- When sending a compressed set of descriptors or microdescriptors,
make sure to finalize the zlib stream. Previously, we would write
all the compressed data, but if the last descriptor we wanted to
send was missing or too old, we would not mark the stream as
finished. This caused problems for decompression tools. Fixes bug
11648; bugfix on 0.1.1.23.
o Minor bugfixes (hidden service):
- Only retry attempts to connect to a chosen rendezvous point 8
times, not 30. Fixes bug 4241; bugfix on 0.1.0.1-rc.
o Minor bugfixes (interface):
- Reject relative control socket paths and emit a warning. Previously,
single-component control socket paths would be rejected, but Tor
would not log why it could not validate the config. Fixes bug 9258;
bugfix on 0.2.3.16-alpha.
o Minor bugfixes (log messages):
- Fix a bug where clients using bridges would report themselves
as 50% bootstrapped even without a live consensus document.
Fixes bug 9922; bugfix on 0.2.1.1-alpha.
- Suppress a warning where, if there's only one directory authority
in the network, we would complain that votes and signatures cannot
be uploaded to other directory authorities. Fixes bug 10842;
bugfix on 0.2.2.26-beta.
- Report bootstrapping progress correctly when we're downloading
microdescriptors. We had updated our "do we have enough microdescs
to begin building circuits?" logic most recently in 0.2.4.10-alpha
(see bug 5956), but we left the bootstrap status event logic at
"how far through getting 1/4 of them are we?" Fixes bug 9958;
bugfix on 0.2.2.36, which is where they diverged (see bug 5343).
o Minor bugfixes (logging):
- Downgrade "Unexpected onionskin length after decryption" warning
to a protocol-warn, since there's nothing relay operators can do
about a client that sends them a malformed create cell. Resolves
bug 12996; bugfix on 0.0.6rc1.
- Log more specific warnings when we get an ESTABLISH_RENDEZVOUS
cell on a cannibalized or non-OR circuit. Resolves ticket 12997.
- When logging information about an EXTEND2 or EXTENDED2 cell, log
their names correctly. Fixes part of bug 12700; bugfix
on 0.2.4.8-alpha.
- When logging information about a relay cell whose command we don't
recognize, log its command as an integer. Fixes part of bug 12700;
bugfix on 0.2.1.10-alpha.
- Escape all strings from the directory connection before logging
them. Fixes bug 13071; bugfix on 0.1.1.15. Patch from "teor".
- Squelch a spurious LD_BUG message "No origin circuit for
successful SOCKS stream" in certain hidden service failure cases;
fixes bug 10616.
- Downgrade the severity of the 'unexpected sendme cell from client'
from 'warn' to 'protocol warning'. Closes ticket 8093.
o Minor bugfixes (misc code correctness):
- In munge_extrainfo_into_routerinfo(), check the return value of
memchr(). This would have been a serious issue if we ever passed
it a non-extrainfo. Fixes bug 8791; bugfix on 0.2.0.6-alpha. Patch
from Arlo Breault.
- On the chance that somebody manages to build Tor on a
platform where time_t is unsigned, correct the way that
microdesc_add_to_cache() handles negative time arguments.
Fixes bug 8042; bugfix on 0.2.3.1-alpha.
- Fix various instances of undefined behavior in channeltls.c,
tor_memmem(), and eventdns.c that would cause us to construct
pointers to memory outside an allocated object. (These invalid
pointers were not accessed, but C does not even allow them to
exist.) Fixes bug 10363; bugfixes on 0.1.1.1-alpha, 0.1.2.1-alpha,
0.2.0.10-alpha, and 0.2.3.6-alpha. Reported by "bobnomnom".
- Use the AddressSanitizer and Ubsan sanitizers (in clang-3.4) to
fix some miscellaneous errors in our tests and codebase. Fixes bug
11232. Bugfixes on versions back as far as 0.2.1.11-alpha.
- Always check return values for unlink, munmap, UnmapViewOfFile;
check strftime return values more often. In some cases all we can
do is report a warning, but this may help prevent deeper bugs from
going unnoticed. Closes ticket 8787; bugfixes on many, many tor
versions.
- Fix numerous warnings from the clang "scan-build" static analyzer.
Some of these are programming style issues; some of them are false
positives that indicated awkward code; some are undefined behavior
cases related to constructing (but not using) invalid pointers;
some are assumptions about API behavior; some are (harmlessly)
logging sizeof(ptr) bytes from a token when sizeof(*ptr) would be
correct; and one or two are genuine bugs that weren't reachable
from the rest of the program. Fixes bug 8793; bugfixes on many,
many tor versions.
o Minor bugfixes (node selection):
- If ExcludeNodes is set, consider non-excluded hidden service
directory servers before excluded ones. Do not consider excluded
hidden service directory servers at all if StrictNodes is
set. (Previously, we would sometimes decide to connect to those
servers, and then realize before we initiated a connection that
we had excluded them.) Fixes bug 10722; bugfix on 0.2.0.10-alpha.
Reported by "mr-4".
- If we set the ExitNodes option but it doesn't include any nodes
that have the Exit flag, we would choose not to bootstrap. Now we
bootstrap so long as ExitNodes includes nodes which can exit to
some port. Fixes bug 10543; bugfix on 0.2.4.10-alpha.
o Minor bugfixes (performance):
- Avoid a bug where every successful connection made us recompute
the flag telling us whether we have sufficient information to
build circuits. Previously, we would forget our cached value
whenever we successfully opened a channel (or marked a router as
running or not running for any other reason), regardless of
whether we had previously believed the router to be running. This
forced us to run an expensive update operation far too often.
Fixes bug 12170; bugfix on 0.1.2.1-alpha.
- Avoid using tor_memeq() for checking relay cell integrity. This
removes a possible performance bottleneck. Fixes part of bug
12169; bugfix on 0.2.1.31.
o Minor bugfixes (platform-specific):
- When dumping a malformed directory object to disk, save it in
binary mode on Windows, not text mode. Fixes bug 11342; bugfix on
0.2.2.1-alpha.
- Don't report failures from make_socket_reuseable() on incoming
sockets on OSX: this can happen when incoming connections close
early. Fixes bug 10081.
o Minor bugfixes (pluggable transports):
- Avoid another 60-second delay when starting Tor in a pluggable-
transport-using configuration when we already have cached
descriptors for our bridges. Fixes bug 11965; bugfix
on 0.2.3.6-alpha.
o Minor bugfixes (protocol correctness):
- When receiving a VERSIONS cell with an odd number of bytes, close
the connection immediately since the cell is malformed. Fixes bug
10365; bugfix on 0.2.0.10-alpha. Spotted by "bobnomnom"; fix by
"rl1987".
o Minor bugfixes (relay, other):
- We now drop CREATE cells for already-existent circuit IDs and for
zero-valued circuit IDs, regardless of other factors that might
otherwise have called for DESTROY cells. Fixes bug 12191; bugfix
on 0.0.8pre1.
- When rejecting DATA cells for stream_id zero, still count them
against the circuit's deliver window so that we don't fail to send
a SENDME. Fixes bug 11246; bugfix on 0.2.4.10-alpha.
o Minor bugfixes (relay, threading):
- Check return code on spawn_func() in cpuworker code, so that we
don't think we've spawned a nonworking cpuworker and write junk to
it forever. Fix related to bug 4345; bugfix on all released Tor
versions. Found by "skruffy".
- Use a pthread_attr to make sure that spawn_func() cannot return an
error while at the same time launching a thread. Fix related to
bug 4345; bugfix on all released Tor versions. Reported
by "cypherpunks".
o Minor bugfixes (relays and bridges):
- Avoid crashing on a malformed resolv.conf file when running a
relay using Libevent 1. Fixes bug 8788; bugfix on 0.1.1.23.
- Non-exit relays no longer launch mock DNS requests to check for
DNS hijacking. This has been unnecessary since 0.2.1.7-alpha, when
non-exit relays stopped servicing DNS requests. Fixes bug 965;
bugfix on 0.2.1.7-alpha. Patch from Matt Pagan.
- Bridges now report complete directory request statistics. Related
to bug 5824; bugfix on 0.2.2.1-alpha.
- Bridges now never collect statistics that were designed for
relays. Fixes bug 5824; bugfix on 0.2.3.8-alpha.
o Minor bugfixes (testing):
- Fix all valgrind warnings produced by the unit tests. There were
over a thousand memory leak warnings previously, mostly produced
by forgetting to free things in the unit test code. Fixes bug
11618, bugfixes on many versions of Tor.
o Minor bugfixes (tor-fw-helper):
- Give a correct log message when tor-fw-helper fails to launch.
(Previously, we would say something like "tor-fw-helper sent us a
string we could not parse".) Fixes bug 9781; bugfix
on 0.2.4.2-alpha.
o Minor bugfixes (trivial memory leaks):
- Fix a small memory leak when signing a directory object. Fixes bug
11275; bugfix on 0.2.4.13-alpha.
- Resolve some memory leaks found by coverity in the unit tests, on
exit in tor-gencert, and on a failure to compute digests for our
own keys when generating a v3 networkstatus vote. These leaks
should never have affected anyone in practice.
o Code simplification and refactoring:
- Remove some old fallback code designed to keep Tor clients working
in a network with only two working relays. Elsewhere in the code we
have long since stopped supporting such networks, so there wasn't
much point in keeping it around. Addresses ticket 9926.
- Reject 0-length EXTEND2 cells more explicitly. Fixes bug 10536;
bugfix on 0.2.4.8-alpha. Reported by "cypherpunks".
- Extract the common duplicated code for creating a subdirectory
of the data directory and writing to a file in it. Fixes ticket
4282; patch from Peter Retzlaff.
- Since OpenSSL 0.9.7, the i2d_*() functions support allocating output
buffer. Avoid calling twice: i2d_RSAPublicKey(), i2d_DHparams(),
i2d_X509(), and i2d_PublicKey(). Resolves ticket 5170.
- Add a set of accessor functions for the circuit timeout data
structure. Fixes ticket 6153; patch from "piet".
- Clean up exit paths from connection_listener_new(). Closes ticket
8789. Patch from Arlo Breault.
- Since we rely on OpenSSL 0.9.8 now, we can use EVP_PKEY_cmp()
and drop our own custom pkey_eq() implementation. Fixes bug 9043.
- Use a doubly-linked list to implement the global circuit list.
Resolves ticket 9108. Patch from Marek Majkowski.
- Remove contrib/id_to_fp.c since it wasn't used anywhere.
- Remove constants and tests for PKCS1 padding; it's insecure and
shouldn't be used for anything new. Fixes bug 8792; patch
from Arlo Breault.
- Remove instances of strcpy() from the unit tests. They weren't
hurting anything, since they were only in the unit tests, but it's
embarassing to have strcpy() in the code at all, and some analysis
tools don't like it. Fixes bug 8790; bugfix on 0.2.3.6-alpha and
0.2.3.8-alpha. Patch from Arlo Breault.
- Remove is_internal_IP() function. Resolves ticket 4645.
- Remove unused function circuit_dump_by_chan from circuitlist.c.
Closes issue 9107; patch from "marek".
- Change our use of the ENUM_BF macro to avoid declarations that
confuse Doxygen.
- Get rid of router->address, since in all cases it was just the
string representation of router->addr. Resolves ticket 5528.
o Documentation:
- Adjust the URLs in the README to refer to the new locations of
several documents on the website. Fixes bug 12830. Patch from
Matt Pagan.
- Document 'reject6' and 'accept6' ExitPolicy entries. Resolves
ticket 12878.
- Update manpage to describe some of the files you can expect to
find in Tor's DataDirectory. Addresses ticket 9839.
- Clean up several option names in the manpage to match their real
names, add the missing documentation for a couple of testing and
directory authority options, remove the documentation for a
V2-directory fetching option that no longer exists. Resolves
ticket 11634.
- Correct the documenation so that it lists the correct directory
for the stats files. (They are in a subdirectory called "stats",
not "status".)
- In the manpage, move more authority-only options into the
directory authority section so that operators of regular directory
caches don't get confused.
- Fix the layout of the SOCKSPort flags in the manpage. Fixes bug
11061; bugfix on 0.2.4.7-alpha.
- Resolve warnings from Doxygen.
- Document in the manpage that "KBytes" may also be written as
"kilobytes" or "KB", that "Kbits" may also be written as
"kilobits", and so forth. Closes ticket 9222.
- Document that the ClientOnly config option overrides ORPort.
Our old explanation made ClientOnly sound as though it did
nothing at all. Resolves bug 9059.
- Explain that SocksPolicy, DirPolicy, and similar options don't
take port arguments. Fixes the other part of ticket 11108.
- Fix a comment about the rend_server_descriptor_t.protocols field
to more accurately describe its range. Also, make that field
unsigned, to more accurately reflect its usage. Fixes bug 9099;
bugfix on 0.2.1.5-alpha.
- Fix the manpage's description of HiddenServiceAuthorizeClient:
the maximum client name length is 16, not 19. Fixes bug 11118;
bugfix on 0.2.1.6-alpha.
o Package cleanup:
- The contrib directory has been sorted and tidied. Before, it was
an unsorted dumping ground for useful and not-so-useful things.
Now, it is divided based on functionality, and the items which
seemed to be nonfunctional or useless have been removed. Resolves
ticket 8966; based on patches from "rl1987".
o Removed code and features:
- Clients now reject any directory authority certificates lacking
a dir-key-crosscert element. These have been included since
0.2.1.9-alpha, so there's no real reason for them to be optional
any longer. Completes proposal 157. Resolves ticket 10162.
- Remove all code that existed to support the v2 directory system,
since there are no longer any v2 directory authorities. Resolves
ticket 10758.
- Remove the HSAuthoritativeDir and AlternateHSAuthority torrc
options, which were used for designating authorities as "Hidden
service authorities". There has been no use of hidden service
authorities since 0.2.2.1-alpha, when we stopped uploading or
downloading v0 hidden service descriptors. Fixes bug 10881; also
part of a fix for bug 10841.
- Remove /tor/dbg-stability.txt URL that was meant to help debug WFU
and MTBF calculations, but that nobody was using. Fixes bug 11742.
- The TunnelDirConns and PreferTunnelledDirConns options no longer
exist; tunneled directory connections have been available since
0.1.2.5-alpha, and turning them off is not a good idea. This is a
brute-force fix for 10849, where "TunnelDirConns 0" would break
hidden services.
- Remove all code for the long unused v1 directory protocol.
Resolves ticket 11070.
- Remove all remaining code related to version-0 hidden service
descriptors: they have not been in use since 0.2.2.1-alpha. Fixes
the rest of bug 10841.
- Remove migration code from when we renamed the "cached-routers"
file to "cached-descriptors" back in 0.2.0.8-alpha. This
incidentally resolves ticket 6502 by cleaning up the related code
a bit. Patch from Akshay Hebbar.
o Test infrastructure:
- Tor now builds each source file in two modes: a mode that avoids
exposing identifiers needlessly, and another mode that exposes
more identifiers for testing. This lets the compiler do better at
optimizing the production code, while enabling us to take more
radical measures to let the unit tests test things.
- The production builds no longer include functions used only in
the unit tests; all functions exposed from a module only for
unit-testing are now static in production builds.
- Add an --enable-coverage configuration option to make the unit
tests (and a new src/or/tor-cov target) to build with gcov test
coverage support.
- Update to the latest version of tinytest.
- Improve the tinytest implementation of string operation tests so
that comparisons with NULL strings no longer crash the tests; they
now just fail, normally. Fixes bug 9004; bugfix on 0.2.2.4-alpha.
- New macros in test.h to simplify writing mock-functions for unit
tests. Part of ticket 11507. Patch from Dana Koch.
- We now have rudimentary function mocking support that our unit
tests can use to test functions in isolation. Function mocking
lets the tests temporarily replace a function's dependencies with
stub functions, so that the tests can check the function without
invoking the other functions it calls.
o Testing:
- Complete tests for the status.c module. Resolves ticket 11507.
Patch from Dana Koch.
- Add more unit tests for the <circid,channel>->circuit map, and
the destroy-cell-tracking code to fix bug 7912.
- Unit tests for failing cases of the TAP onion handshake.
- More unit tests for address-manipulation functions.
o Distribution (systemd):
- Include a tor.service file in contrib/dist for use with systemd.
Some distributions will be able to use this file unmodified;
others will need to tweak it, or write their own. Patch from Jamie
Nguyen; resolves ticket 8368.
- Verify configuration file via ExecStartPre in the systemd unit
file. Patch from intrigeri; resolves ticket 12730.
- Explicitly disable RunAsDaemon in the systemd unit file. Our
current systemd unit uses "Type = simple", so systemd does not
expect tor to fork. If the user has "RunAsDaemon 1" in their
torrc, then things won't work as expected. This is e.g. the case
on Debian (and derivatives), since there we pass "--defaults-torrc
/usr/share/tor/tor-service-defaults-torrc" (that contains
"RunAsDaemon 1") by default. Patch by intrigeri; resolves
ticket 12731.
Changes in version 0.2.4.25 - 2014-10-20
Tor 0.2.4.25 disables SSL3 in response to the recent "POODLE" attack
(even though POODLE does not affect Tor). It also works around a crash
bug caused by some operating systems' response to the "POODLE" attack
(which does affect Tor).
o Major security fixes (also in 0.2.5.9-rc):
- Disable support for SSLv3. All versions of OpenSSL in use with Tor
today support TLS 1.0 or later, so we can safely turn off support
for this old (and insecure) protocol. Fixes bug 13426.
o Major bugfixes (openssl bug workaround, also in 0.2.5.9-rc):
- Avoid crashing when using OpenSSL version 0.9.8zc, 1.0.0o, or
1.0.1j, built with the 'no-ssl3' configuration option. Fixes bug
13471. This is a workaround for an OpenSSL bug.
Changes in version 0.2.4.24 - 2014-09-22
Tor 0.2.4.24 fixes a bug that affects consistency and speed when
connecting to hidden services, and it updates the location of one of
the directory authorities.
o Major bugfixes:
- Clients now send the correct address for their chosen rendezvous
point when trying to access a hidden service. They used to send
the wrong address, which would still work some of the time because
they also sent the identity digest of the rendezvous point, and if
the hidden service happened to try connecting to the rendezvous
point from a relay that already had a connection open to it,
the relay would reuse that connection. Now connections to hidden
services should be more robust and faster. Also, this bug meant
that clients were leaking to the hidden service whether they were
on a little-endian (common) or big-endian (rare) system, which for
some users might have reduced their anonymity. Fixes bug 13151;
bugfix on 0.2.1.5-alpha.
o Directory authority changes:
- Change IP address for gabelmoo (v3 directory authority).
o Minor features (geoip):
- Update geoip and geoip6 to the August 7 2014 Maxmind GeoLite2
Country database.
Changes in version 0.2.4.23 - 2014-07-28
Tor 0.2.4.23 brings us a big step closer to slowing down the risk from
guard rotation, and also backports several important fixes from the
Tor 0.2.5 alpha release series.
o Major features:
- Clients now look at the "usecreatefast" consensus parameter to
decide whether to use CREATE_FAST or CREATE cells for the first hop
of their circuit. This approach can improve security on connections
where Tor's circuit handshake is stronger than the available TLS
connection security levels, but the tradeoff is more computational
load on guard relays. Implements proposal 221. Resolves ticket 9386.
- Make the number of entry guards configurable via a new
NumEntryGuards consensus parameter, and the number of directory
guards configurable via a new NumDirectoryGuards consensus
parameter. Implements ticket 12688.
o Major bugfixes:
- Fix a bug in the bounds-checking in the 32-bit curve25519-donna
implementation that caused incorrect results on 32-bit
implementations when certain malformed inputs were used along with
a small class of private ntor keys. This bug does not currently
appear to allow an attacker to learn private keys or impersonate a
Tor server, but it could provide a means to distinguish 32-bit Tor
implementations from 64-bit Tor implementations. Fixes bug 12694;
bugfix on 0.2.4.8-alpha. Bug found by Robert Ransom; fix from
Adam Langley.
o Minor bugfixes:
- Warn and drop the circuit if we receive an inbound 'relay early'
cell. Those used to be normal to receive on hidden service circuits
due to bug 1038, but the buggy Tor versions are long gone from
the network so we can afford to resume watching for them. Resolves
the rest of bug 1038; bugfix on 0.2.1.19.
- Correct a confusing error message when trying to extend a circuit
via the control protocol but we don't know a descriptor or
microdescriptor for one of the specified relays. Fixes bug 12718;
bugfix on 0.2.3.1-alpha.
- Avoid an illegal read from stack when initializing the TLS
module using a version of OpenSSL without all of the ciphers
used by the v2 link handshake. Fixes bug 12227; bugfix on
0.2.4.8-alpha. Found by "starlight".
o Minor features:
- Update geoip and geoip6 to the July 10 2014 Maxmind GeoLite2
Country database.
Changes in version 0.2.4.22 - 2014-05-16
Tor 0.2.4.22 backports numerous high-priority fixes from the Tor 0.2.5
alpha release series. These include blocking all authority signing
keys that may have been affected by the OpenSSL "heartbleed" bug,
choosing a far more secure set of TLS ciphersuites by default, closing
a couple of memory leaks that could be used to run a target relay out
of RAM, and several others.
o Major features (security, backport from 0.2.5.4-alpha):
- Block authority signing keys that were used on authorities
vulnerable to the "heartbleed" bug in OpenSSL (CVE-2014-0160). (We
don't have any evidence that these keys _were_ compromised; we're
doing this to be prudent.) Resolves ticket 11464.
o Major bugfixes (security, OOM):
- Fix a memory leak that could occur if a microdescriptor parse
fails during the tokenizing step. This bug could enable a memory
exhaustion attack by directory servers. Fixes bug 11649; bugfix
on 0.2.2.6-alpha.
o Major bugfixes (TLS cipher selection, backport from 0.2.5.4-alpha):
- The relay ciphersuite list is now generated automatically based on
uniform criteria, and includes all OpenSSL ciphersuites with
acceptable strength and forward secrecy. Previously, we had left
some perfectly fine ciphersuites unsupported due to omission or
typo. Resolves bugs 11513, 11492, 11498, 11499. Bugs reported by
'cypherpunks'. Bugfix on 0.2.4.8-alpha.
- Relays now trust themselves to have a better view than clients of
which TLS ciphersuites are better than others. (Thanks to bug
11513, the relay list is now well-considered, whereas the client
list has been chosen mainly for anti-fingerprinting purposes.)
Relays prefer: AES over 3DES; then ECDHE over DHE; then GCM over
CBC; then SHA384 over SHA256 over SHA1; and last, AES256 over
AES128. Resolves ticket 11528.
- Clients now try to advertise the same list of ciphersuites as
Firefox 28. This change enables selection of (fast) GCM
ciphersuites, disables some strange old ciphers, and stops
advertising the ECDH (not to be confused with ECDHE) ciphersuites.
Resolves ticket 11438.
o Minor bugfixes (configuration, security):
- When running a hidden service, do not allow TunneledDirConns 0:
trying to set that option together with a hidden service would
otherwise prevent the hidden service from running, and also make
it publish its descriptors directly over HTTP. Fixes bug 10849;
bugfix on 0.2.1.1-alpha.
o Minor bugfixes (controller, backport from 0.2.5.4-alpha):
- Avoid sending a garbage value to the controller when a circuit is
cannibalized. Fixes bug 11519; bugfix on 0.2.3.11-alpha.
o Minor bugfixes (exit relay, backport from 0.2.5.4-alpha):
- Stop leaking memory when we successfully resolve a PTR record.
Fixes bug 11437; bugfix on 0.2.4.7-alpha.
o Minor bugfixes (bridge client, backport from 0.2.5.4-alpha):
- Avoid 60-second delays in the bootstrapping process when Tor is
launching for a second time while using bridges. Fixes bug 9229;
bugfix on 0.2.0.3-alpha.
o Minor bugfixes (relays and bridges, backport from 0.2.5.4-alpha):
- Give the correct URL in the warning message when trying to run a
relay on an ancient version of Windows. Fixes bug 9393.
o Minor bugfixes (compilation):
- Fix a compilation error when compiling with --disable-curve25519.
Fixes bug 9700; bugfix on 0.2.4.17-rc.
o Minor bugfixes:
- Downgrade the warning severity for the the "md was still
referenced 1 node(s)" warning. Tor 0.2.5.4-alpha has better code
for trying to diagnose this bug, and the current warning in
earlier versions of tor achieves nothing useful. Addresses warning
from bug 7164.
o Minor features (log verbosity, backport from 0.2.5.4-alpha):
- When we run out of usable circuit IDs on a channel, log only one
warning for the whole channel, and describe how many circuits
there were on the channel. Fixes part of ticket 11553.
o Minor features (security, backport from 0.2.5.4-alpha):
- Decrease the lower limit of MaxMemInCellQueues to 256 MBytes (but
leave the default at 8GBytes), to better support Raspberry Pi
users. Fixes bug 9686; bugfix on 0.2.4.14-alpha.
o Documentation (backport from 0.2.5.4-alpha):
- Correctly document that we search for a system torrc file before
looking in ~/.torrc. Fixes documentation side of 9213; bugfix on
0.2.3.18-rc.
Changes in version 0.2.4.21 - 2014-02-28
Tor 0.2.4.21 further improves security against potential adversaries who
find breaking 1024-bit crypto doable, and backports several stability
and robustness patches from the 0.2.5 branch.
o Major features (client security):
- When we choose a path for a 3-hop circuit, make sure it contains
at least one relay that supports the NTor circuit extension
handshake. Otherwise, there is a chance that we're building
a circuit that's worth attacking by an adversary who finds
breaking 1024-bit crypto doable, and that chance changes the game
theory. Implements ticket 9777.
o Major bugfixes:
- Do not treat streams that fail with reason
END_STREAM_REASON_INTERNAL as indicating a definite circuit failure,
since it could also indicate an ENETUNREACH connection error. Fixes
part of bug 10777; bugfix on 0.2.4.8-alpha.
o Code simplification and refactoring:
- Remove data structures which were introduced to implement the
CellStatistics option: they are now redundant with the new timestamp
field in the regular packed_cell_t data structure, which we did
in 0.2.4.18-rc in order to resolve bug 9093. Resolves ticket 10870.
o Minor features:
- Always clear OpenSSL bignums before freeing them -- even bignums
that don't contain secrets. Resolves ticket 10793. Patch by
Florent Daigniere.
- Build without warnings under clang 3.4. (We have some macros that
define static functions only some of which will get used later in
the module. Starting with clang 3.4, these give a warning unless the
unused attribute is set on them.) Resolves ticket 10904.
- Update geoip and geoip6 files to the February 7 2014 Maxmind
GeoLite2 Country database.
o Minor bugfixes:
- Set the listen() backlog limit to the largest actually supported
on the system, not to the value in a header file. Fixes bug 9716;
bugfix on every released Tor.
- Treat ENETUNREACH, EACCES, and EPERM connection failures at an
exit node as a NOROUTE error, not an INTERNAL error, since they
can apparently happen when trying to connect to the wrong sort
of netblocks. Fixes part of bug 10777; bugfix on 0.1.0.1-rc.
- Fix build warnings about missing "a2x" comment when building the
manpages from scratch on OpenBSD; OpenBSD calls it "a2x.py".
Fixes bug 10929; bugfix on 0.2.2.9-alpha. Patch from Dana Koch.
- Avoid a segfault on SIGUSR1, where we had freed a connection but did
not entirely remove it from the connection lists. Fixes bug 9602;
bugfix on 0.2.4.4-alpha.
- Fix a segmentation fault in our benchmark code when running with
Fedora's OpenSSL package, or any other OpenSSL that provides
ECDH but not P224. Fixes bug 10835; bugfix on 0.2.4.8-alpha.
- Turn "circuit handshake stats since last time" log messages into a
heartbeat message. Fixes bug 10485; bugfix on 0.2.4.17-rc.
o Documentation fixes:
- Document that all but one DirPort entry must have the NoAdvertise
flag set. Fixes bug 10470; bugfix on 0.2.3.3-alpha / 0.2.3.16-alpha.
Changes in version 0.2.4.20 - 2013-12-22
Tor 0.2.4.20 fixes potentially poor random number generation for users
who 1) use OpenSSL 1.0.0 or later, 2) set "HardwareAccel 1" in their
torrc file, 3) have "Sandy Bridge" or "Ivy Bridge" Intel processors,
and 4) have no state file in their DataDirectory (as would happen on
first start). Users who generated relay or hidden service identity
keys in such a situation should discard them and generate new ones.
This release also fixes a logic error that caused Tor clients to build
many more preemptive circuits than they actually need.
o Major bugfixes:
- Do not allow OpenSSL engines to replace the PRNG, even when
HardwareAccel is set. The only default builtin PRNG engine uses
the Intel RDRAND instruction to replace the entire PRNG, and
ignores all attempts to seed it with more entropy. That's
cryptographically stupid: the right response to a new alleged
entropy source is never to discard all previously used entropy
sources. Fixes bug 10402; works around behavior introduced in
OpenSSL 1.0.0. Diagnosis and investigation thanks to "coderman"
and "rl1987".
- Fix assertion failure when AutomapHostsOnResolve yields an IPv6
address. Fixes bug 10465; bugfix on 0.2.4.7-alpha.
- Avoid launching spurious extra circuits when a stream is pending.
This fixes a bug where any circuit that _wasn't_ unusable for new
streams would be treated as if it were, causing extra circuits to
be launched. Fixes bug 10456; bugfix on 0.2.4.12-alpha.
o Minor bugfixes:
- Avoid a crash bug when starting with a corrupted microdescriptor
cache file. Fixes bug 10406; bugfix on 0.2.2.6-alpha.
- If we fail to dump a previously cached microdescriptor to disk, avoid
freeing duplicate data later on. Fixes bug 10423; bugfix on
0.2.4.13-alpha. Spotted by "bobnomnom".
Changes in version 0.2.4.19 - 2013-12-11
The Tor 0.2.4 release series is dedicated to the memory of Aaron Swartz
(1986-2013). Aaron worked on diverse projects including helping to guide
Creative Commons, playing a key role in stopping SOPA/PIPA, bringing
transparency to the U.S government's PACER documents, and contributing
design and development for Tor and Tor2Web. Aaron was one of the latest
martyrs in our collective fight for civil liberties and human rights,
and his death is all the more painful because he was one of us.
Tor 0.2.4.19, the first stable release in the 0.2.4 branch, features
a new circuit handshake and link encryption that use ECC to provide
better security and efficiency; makes relays better manage circuit
creation requests; uses "directory guards" to reduce client enumeration
risks; makes bridges collect and report statistics about the pluggable
transports they support; cleans up and improves our geoip database;
gets much closer to IPv6 support for clients, bridges, and relays; makes
directory authorities use measured bandwidths rather than advertised
ones when computing flags and thresholds; disables client-side DNS
caching to reduce tracking risks; and fixes a big bug in bridge
reachability testing. This release introduces two new design
abstractions in the code: a new "channel" abstraction between circuits
and or_connections to allow for implementing alternate relay-to-relay
transports, and a new "circuitmux" abstraction storing the queue of
circuits for a channel. The release also includes many stability,
security, and privacy fixes.
o Major features (new circuit handshake):
- Tor now supports a new circuit extension handshake designed by Ian
Goldberg, Douglas Stebila, and Berkant Ustaoglu. Our original
circuit extension handshake, later called "TAP", was a bit slow
(especially on the relay side), had a fragile security proof, and
used weaker keys than we'd now prefer. The new circuit handshake
uses Dan Bernstein's "curve25519" elliptic-curve Diffie-Hellman
function, making it significantly more secure than the older
handshake, and significantly faster. Tor can use one of two built-in
pure-C curve25519-donna implementations by Adam Langley, or it
can link against the "nacl" library for a tuned version if present.
The built-in version is very fast for 64-bit systems when building
with GCC. The built-in 32-bit version is still faster than the
old TAP protocol, but using libnacl is better on most such hosts.
Implements proposal 216; closes ticket 7202.
o Major features (better link encryption):
- Relays can now enable the ECDHE TLS ciphersuites when available
and appropriate. These ciphersuites let us negotiate forward-secure
TLS secret keys more safely and more efficiently than with our
previous use of Diffie-Hellman modulo a 1024-bit prime. By default,
public relays prefer the (faster) P224 group, and bridges prefer
the (more common) P256 group; you can override this with the
TLSECGroup option.
This feature requires clients running 0.2.3.17-beta or later,
and requires both sides to be running OpenSSL 1.0.0 or later
with ECC support. OpenSSL 1.0.1, with the compile-time option
"enable-ec_nistp_64_gcc_128", is highly recommended.
Implements the relay side of proposal 198; closes ticket 7200.
- Re-enable TLS 1.1 and 1.2 when built with OpenSSL 1.0.1e or later.
Resolves ticket 6055. (OpenSSL before 1.0.1 didn't have TLS 1.1 or
1.2, and OpenSSL from 1.0.1 through 1.0.1d had bugs that prevented
renegotiation from working with TLS 1.1 or 1.2, so we had disabled
them to solve bug 6033.)
o Major features (relay performance):
- Instead of limiting the number of queued onionskins (aka circuit
create requests) to a fixed, hard-to-configure number, we limit
the size of the queue based on how many we expect to be able to
process in a given amount of time. We estimate the time it will
take to process an onionskin based on average processing time
of previous onionskins. Closes ticket 7291. You'll never have to
configure MaxOnionsPending again.
- Relays process the new "NTor" circuit-level handshake requests
with higher priority than the old "TAP" circuit-level handshake
requests. We still process some TAP requests to not totally starve
0.2.3 clients when NTor becomes popular. A new consensus parameter
"NumNTorsPerTAP" lets us tune the balance later if we need to.
Implements ticket 9574.
o Major features (client bootstrapping resilience):
- Add a new "FallbackDir" torrc option to use when we can't use
a directory mirror from the consensus (either because we lack a
consensus, or because they're all down). Currently, all authorities
are fallbacks by default, and there are no other default fallbacks,
but that will change. This option will allow us to give clients a
longer list of servers to try to get a consensus from when first
connecting to the Tor network, and thereby reduce load on the
directory authorities. Implements proposal 206, "Preconfigured
directory sources for bootstrapping". We also removed the old
"FallbackNetworkstatus" option, since we never got it working well
enough to use it. Closes bug 572.
- If we have no circuits open, use a relaxed timeout (the
95th-percentile cutoff) until a circuit succeeds. This heuristic
should allow Tor to succeed at building circuits even when the
network connection drastically changes. Should help with bug 3443.
o Major features (use of guards):
- Support directory guards (proposal 207): when possible, clients now
use their entry guards for non-anonymous directory requests. This
can help prevent client enumeration. Note that this behavior only
works when we have a usable consensus directory, and when options
about what to download are more or less standard. In the future we
should re-bootstrap from our guards, rather than re-bootstrapping
from the preconfigured list of directory sources that ships with
Tor. Resolves ticket 6526.
- Raise the default time that a client keeps an entry guard from
"1-2 months" to "2-3 months", as suggested by Tariq Elahi's WPES
2012 paper. (We would make it even longer, but we need better client
load balancing first.) Also, make the guard lifetime controllable
via a new GuardLifetime torrc option and a GuardLifetime consensus
parameter. Start of a fix for bug 8240; bugfix on 0.1.1.11-alpha.
o Major features (bridges with pluggable transports):
- Bridges now report the pluggable transports they support to the
bridge authority, so it can pass the supported transports on to
bridgedb and/or eventually do reachability testing. Implements
ticket 3589.
- Automatically forward the TCP ports of pluggable transport
proxies using tor-fw-helper if PortForwarding is enabled. Implements
ticket 4567.
o Major features (geoip database):
- Maxmind began labelling Tor relays as being in country "A1",
which breaks by-country node selection inside Tor. Now we use a
script to replace "A1" ("Anonymous Proxy") entries in our geoip
file with real country codes. This script fixes about 90% of "A1"
entries automatically and uses manual country code assignments to
fix the remaining 10%. See src/config/README.geoip for details.
Fixes bug 6266.
- Add GeoIP database for IPv6 addresses. The new config option
is GeoIPv6File.
- Update to the October 2 2013 Maxmind GeoLite Country database.
o Major features (IPv6):
- Clients who set "ClientUseIPv6 1" may connect to entry nodes over
IPv6. Set "ClientPreferIPv6ORPort 1" to make this even more likely
to happen. Implements ticket 5535.
- All kind of relays, not just bridges, can now advertise an IPv6
OR port. Implements ticket 6362.
- Relays can now exit to IPv6 addresses: make sure that you have IPv6
connectivity, then set the IPv6Exit flag to 1. Also make sure your
exit policy reads as you would like: the address * applies to all
address families, whereas *4 is IPv4 address only, and *6 is IPv6
addresses only. On the client side, you'll need to wait for enough
exits to support IPv6, apply the "IPv6Traffic" flag to a SocksPort,
and use Socks5. Closes ticket 5547, implements proposal 117 as
revised in proposal 208.
- Bridge authorities now accept IPv6 bridge addresses and include
them in network status documents. Implements ticket 5534.
- Directory authorities vote on IPv6 OR ports. Implements ticket 6363.
o Major features (directory authorities):
- Directory authorities now prefer using measured bandwidths to
advertised ones when computing flags and thresholds. Resolves
ticket 8273.
- Directory authorities that vote measured bandwidths about more
than a threshold number of relays now treat relays with
unmeasured bandwidths as having bandwidth 0 when computing their
flags. Resolves ticket 8435.
- Directory authorities now support a new consensus method (17)
where they cap the published bandwidth of relays for which
insufficient bandwidth measurements exist. Fixes part of bug 2286.
- Directory authorities that set "DisableV2DirectoryInfo_ 1" no longer
serve any v2 directory information. Now we can test disabling the
old deprecated v2 directory format, and see whether doing so has
any effect on network load. Begins to fix bug 6783.
o Major features (build and portability):
- Switch to a nonrecursive Makefile structure. Now instead of each
Makefile.am invoking other Makefile.am's, there is a master
Makefile.am that includes the others. This change makes our build
process slightly more maintainable, and improves parallelism for
building with make -j. Original patch by Stewart Smith; various
fixes by Jim Meyering.
- Where available, we now use automake's "silent" make rules by
default, so that warnings are easier to spot. You can get the old
behavior with "make V=1". Patch by Stewart Smith for ticket 6522.
- Resume building correctly with MSVC and Makefile.nmake. This patch
resolves numerous bugs and fixes reported by ultramage, including
7305, 7308, 7309, 7310, 7312, 7313, 7315, 7316, and 7669.
o Security features:
- Switch to a completely time-invariant approach for picking nodes
weighted by bandwidth. Our old approach would run through the
part of the loop after it had made its choice slightly slower
than it ran through the part of the loop before it had made its
choice. Addresses ticket 6538.
- Disable the use of Guard nodes when in Tor2WebMode. Guard usage
by tor2web clients allows hidden services to identify tor2web
clients through their repeated selection of the same rendezvous
and introduction point circuit endpoints (their guards). Resolves
ticket 6888.
o Major bugfixes (relay denial of service):
- When we have too much memory queued in circuits (according to a new
MaxMemInCellQueues option), close the circuits that have the oldest
queued cells, on the theory that those are most responsible for
us running low on memory. This prevents us from running out of
memory as a relay if circuits fill up faster than they can be
drained. Fixes bugs 9063 and 9093; bugfix on the 54th commit of
Tor. This bug is a further fix beyond bug 6252, whose fix was
merged into 0.2.3.21-rc.
- Reject bogus create and relay cells with 0 circuit ID or 0 stream
ID: these could be used to create unexpected streams and circuits
which would count as "present" to some parts of Tor but "absent"
to others, leading to zombie circuits and streams or to a bandwidth
denial-of-service. Fixes bug 7889; bugfix on every released version
of Tor. Reported by "oftc_must_be_destroyed".
- Avoid a bug where our response to TLS renegotiation under certain
network conditions could lead to a busy-loop, with 100% CPU
consumption. Fixes bug 5650; bugfix on 0.2.0.16-alpha.
o Major bugfixes (asserts, crashes, leaks):
- Prevent the get_freelists() function from running off the end of
the list of freelists if it somehow gets an unrecognized
allocation. Fixes bug 8844; bugfix on 0.2.0.16-alpha. Reported by
eugenis.
- Avoid a memory leak where we would leak a consensus body when we
find that a consensus which we couldn't previously verify due to
missing certificates is now verifiable. Fixes bug 8719; bugfix
on 0.2.0.10-alpha.
- If we are unable to save a microdescriptor to the journal, do not
drop it from memory and then reattempt downloading it. Fixes bug
9645; bugfix on 0.2.2.6-alpha.
- Fix an assertion failure that would occur when disabling the
ORPort setting on a running Tor process while accounting was
enabled. Fixes bug 6979; bugfix on 0.2.2.18-alpha.
- Avoid an assertion failure on OpenBSD (and perhaps other BSDs)
when an exit connection with optimistic data succeeds immediately
rather than returning EINPROGRESS. Fixes bug 9017; bugfix on
0.2.3.1-alpha.
- Fix a memory leak that would occur whenever a configuration
option changed. Fixes bug 8718; bugfix on 0.2.3.3-alpha.
o Major bugfixes (relay rate limiting):
- When a TLS write is partially successful but incomplete, remember
that the flushed part has been flushed, and notice that bytes were
actually written. Reported and fixed pseudonymously. Fixes bug 7708;
bugfix on Tor 0.1.0.5-rc.
- Raise the default BandwidthRate/BandwidthBurst values from 5MB/10MB
to 1GB/1GB. The previous defaults were intended to be "basically
infinite", but it turns out they're now limiting our 100mbit+
relays and bridges. Fixes bug 6605; bugfix on 0.2.0.10-alpha (the
last time we raised it).
- No longer stop reading or writing on cpuworker connections when
our rate limiting buckets go empty. Now we should handle circuit
handshake requests more promptly. Resolves bug 9731.
o Major bugfixes (client-side privacy):
- When we mark a circuit as unusable for new circuits, have it
continue to be unusable for new circuits even if MaxCircuitDirtiness
is increased too much at the wrong time, or the system clock jumps
backwards. Fixes bug 6174; bugfix on 0.0.2pre26.
- If ClientDNSRejectInternalAddresses ("do not believe DNS queries
which have resolved to internal addresses") is set, apply that
rule to IPv6 as well. Fixes bug 8475; bugfix on 0.2.0.7-alpha.
- When an exit relay rejects a stream with reason "exit policy", but
we only know an exit policy summary (e.g. from the microdesc
consensus) for it, do not mark the relay as useless for all exiting.
Instead, mark just the circuit as unsuitable for that particular
address. Fixes part of bug 7582; bugfix on 0.2.3.2-alpha.
o Major bugfixes (stream isolation):
- Allow applications to get proper stream isolation with
IsolateSOCKSAuth. Many SOCKS5 clients that want to offer
username/password authentication also offer "no authentication". Tor
had previously preferred "no authentication", so the applications
never actually sent Tor their auth details. Now Tor selects
username/password authentication if it's offered. You can disable
this behavior on a per-SOCKSPort basis via PreferSOCKSNoAuth. Fixes
bug 8117; bugfix on 0.2.3.3-alpha.
- Follow the socks5 protocol when offering username/password
authentication. The fix for bug 8117 exposed this bug, and it
turns out real-world applications like Pidgin do care. Bugfix on
0.2.3.2-alpha; fixes bug 8879.
o Major bugfixes (client circuit building):
- Alter circuit build timeout measurement to start at the point
where we begin the CREATE/CREATE_FAST step (as opposed to circuit
initialization). This should make our timeout measurements more
uniform. Previously, we were sometimes including ORconn setup time
in our circuit build time measurements. Should resolve bug 3443.
- If the circuit build timeout logic is disabled (via the consensus,
or because we are an authority), then don't build testing circuits.
Fixes bug 9657; bugfix on 0.2.2.14-alpha.
o Major bugfixes (client-side DNS):
- Turn off the client-side DNS cache by default. Updating and using
the DNS cache is now configurable on a per-client-port
level. SOCKSPort, DNSPort, etc lines may now contain
{No,}Cache{IPv4,IPv6,}DNS lines to indicate that we shouldn't
cache these types of DNS answers when we receive them from an
exit node in response to an application request on this port, and
{No,}UseCached{IPv4,IPv6,DNS} lines to indicate that if we have
cached DNS answers of these types, we shouldn't use them. It's
potentially risky to use cached DNS answers at the client, since
doing so can indicate to one exit what answers we've gotten
for DNS lookups in the past. With IPv6, this becomes especially
problematic. Using cached DNS answers for requests on the same
circuit would present less linkability risk, since all traffic
on a circuit is already linkable, but it would also provide
little performance benefit: the exit node caches DNS replies
too. Implements a simplified version of Proposal 205. Implements
ticket 7570.
o Major bugfixes (hidden service privacy):
- Limit hidden service descriptors to at most ten introduction
points, to slow one kind of guard enumeration. Fixes bug 9002;
bugfix on 0.1.1.11-alpha.
o Major bugfixes (directory fetching):
- If the time to download the next old-style networkstatus is in
the future, do not decline to consider whether to download the
next microdescriptor networkstatus. Fixes bug 9564; bugfix on
0.2.3.14-alpha.
- We used to always request authority certificates by identity digest,
meaning we'd get the newest one even when we wanted one with a
different signing key. Then we would complain about being given
a certificate we already had, and never get the one we really
wanted. Now we use the "fp-sk/" resource as well as the "fp/"
resource to request the one we want. Fixes bug 5595; bugfix on
0.2.0.8-alpha.
o Major bugfixes (bridge reachability):
- Bridges now send AUTH_CHALLENGE cells during their v3 handshakes;
previously they did not, which prevented them from receiving
successful connections from relays for self-test or bandwidth
testing. Also, when a relay is extending a circuit to a bridge,
it needs to send a NETINFO cell, even when the bridge hasn't sent
an AUTH_CHALLENGE cell. Fixes bug 9546; bugfix on 0.2.3.6-alpha.
o Major bugfixes (control interface):
- When receiving a new configuration file via the control port's
LOADCONF command, do not treat the defaults file as absent.
Fixes bug 9122; bugfix on 0.2.3.9-alpha.
o Major bugfixes (directory authorities):
- Stop marking every relay as having been down for one hour every
time we restart a directory authority. These artificial downtimes
were messing with our Stable and Guard flag calculations. Fixes
bug 8218 (introduced by the fix for 1035). Bugfix on 0.2.2.23-alpha.
- When computing directory thresholds, ignore any rejected-as-sybil
nodes during the computation so that they can't influence Fast,
Guard, etc. (We should have done this for proposal 109.) Fixes
bug 8146.
- When marking a node as a likely sybil, reset its uptime metrics
to zero, so that it cannot time towards getting marked as Guard,
Stable, or HSDir. (We should have done this for proposal 109.) Fixes
bug 8147.
- Fix a bug in the voting algorithm that could yield incorrect results
when a non-naming authority declared too many flags. Fixes bug 9200;
bugfix on 0.2.0.3-alpha.
o Internal abstraction features:
- Introduce new channel_t abstraction between circuits and
or_connection_t to allow for implementing alternate OR-to-OR
transports. A channel_t is an abstract object which can either be a
cell-bearing channel, which is responsible for authenticating and
handshaking with the remote OR and transmitting cells to and from
it, or a listening channel, which spawns new cell-bearing channels
at the request of remote ORs. Implements part of ticket 6465.
- Make a channel_tls_t subclass of channel_t, adapting it to the
existing or_connection_t code. The V2/V3 protocol handshaking
code which formerly resided in command.c has been moved below the
channel_t abstraction layer and may be found in channeltls.c now.
Implements the rest of ticket 6465.
- Introduce new circuitmux_t storing the queue of circuits for
a channel; this encapsulates and abstracts the queue logic and
circuit selection policy, and allows the latter to be overridden
easily by switching out a policy object. The existing EWMA behavior
is now implemented as a circuitmux_policy_t. Resolves ticket 6816.
o New build requirements:
- Tor now requires OpenSSL 0.9.8 or later. OpenSSL 1.0.0 or later is
strongly recommended.
- Tor maintainers now require Automake version 1.9 or later to build
Tor from the Git repository. (Automake is not required when building
from a source distribution.)
o Minor features (protocol):
- No longer include the "opt" prefix when generating routerinfos
or v2 directories: it has been needless since Tor 0.1.2. Closes
ticket 5124.
- Reject EXTEND cells sent to nonexistent streams. According to the
spec, an EXTEND cell sent to _any_ nonzero stream ID is invalid, but
we were only checking for stream IDs that were currently in use.
Found while hunting for more instances of bug 6271. Bugfix on
0.0.2pre8, which introduced incremental circuit construction.
- Tor relays and clients now support a better CREATE/EXTEND cell
format, allowing the sender to specify multiple address, identity,
and handshake types. Implements Robert Ransom's proposal 200;
closes ticket 7199.
- Reject as invalid most directory objects containing a NUL.
Belt-and-suspender fix for bug 8037.
o Minor features (security):
- Clear keys and key-derived material left on the stack in
rendservice.c and rendclient.c. Check return value of
crypto_pk_write_private_key_to_string() in rend_service_load_keys().
These fixes should make us more forward-secure against cold-boot
attacks and the like. Fixes bug 2385.
- Use our own weak RNG when we need a weak RNG. Windows's rand() and
Irix's random() only return 15 bits; Solaris's random() returns more
bits but its RAND_MAX says it only returns 15, and so on. Motivated
by the fix for bug 7801; bugfix on 0.2.2.20-alpha.
o Minor features (control protocol):
- Add a "GETINFO signal/names" control port command. Implements
ticket 3842.
- Provide default values for all options via "GETINFO config/defaults".
Implements ticket 4971.
- Allow an optional $ before the node identity digest in the
controller command GETINFO ns/id/<identity>, for consistency with
md/id/<identity> and desc/id/<identity>. Resolves ticket 7059.
- Add CACHED keyword to ADDRMAP events in the control protocol
to indicate whether a DNS result will be cached or not. Resolves
ticket 8596.
- Generate bootstrapping status update events correctly when fetching
microdescriptors. Fixes bug 9927.
o Minor features (path selection):
- When deciding whether we have enough descriptors to build circuits,
instead of looking at raw relay counts, look at which fraction
of (bandwidth-weighted) paths we're able to build. This approach
keeps clients from building circuits if their paths are likely to
stand out statistically. The default fraction of paths needed is
taken from the consensus directory; you can override it with the
new PathsNeededToBuildCircuits option. Fixes ticket 5956.
- When any country code is listed in ExcludeNodes or ExcludeExitNodes,
and we have GeoIP information, also exclude all nodes with unknown
countries "??" and "A1". This behavior is controlled by the
new GeoIPExcludeUnknown option: you can make such nodes always
excluded with "GeoIPExcludeUnknown 1", and disable the feature
with "GeoIPExcludeUnknown 0". Setting "GeoIPExcludeUnknown auto"
gets you the default behavior. Implements feature 7706.
o Minor features (hidden services):
- Improve circuit build timeout handling for hidden services.
In particular: adjust build timeouts more accurately depending
upon the number of hop-RTTs that a particular circuit type
undergoes. Additionally, launch intro circuits in parallel
if they timeout, and take the first one to reply as valid.
- The Tor client now ignores sub-domain components of a .onion
address. This change makes HTTP "virtual" hosting
possible: http://foo.aaaaaaaaaaaaaaaa.onion/ and
http://bar.aaaaaaaaaaaaaaaa.onion/ can be two different websites
hosted on the same hidden service. Implements proposal 204.
- Enable Tor to read configuration, state, and key information from
a FIFO. Previously Tor would only read from files with a positive
stat.st_size. Code from meejah; fixes bug 6044.
o Minor features (clients):
- Teach bridge-using clients to avoid 0.2.2.x bridges when making
microdescriptor-related dir requests, and only fall back to normal
descriptors if none of their bridges can handle microdescriptors
(as opposed to the fix in ticket 4013, which caused them to fall
back to normal descriptors if *any* of their bridges preferred
them). Resolves ticket 4994.
- Tweak tor-fw-helper to accept an arbitrary amount of arbitrary
TCP ports to forward. In the past it only accepted two ports:
the ORPort and the DirPort.
o Minor features (protecting client timestamps):
- Clients no longer send timestamps in their NETINFO cells. These were
not used for anything, and they provided one small way for clients
to be distinguished from each other as they moved from network to
network or behind NAT. Implements part of proposal 222.
- Clients now round timestamps in INTRODUCE cells down to the nearest
10 minutes. If a new Support022HiddenServices option is set to 0, or
if it's set to "auto" and the feature is disabled in the consensus,
the timestamp is sent as 0 instead. Implements part of proposal 222.
- Stop sending timestamps in AUTHENTICATE cells. This is not such
a big deal from a security point of view, but it achieves no actual
good purpose, and isn't needed. Implements part of proposal 222.
- Reduce down accuracy of timestamps in hidden service descriptors.
Implements part of proposal 222.
o Minor features (bridges):
- Make bridge relays check once a minute for whether their IP
address has changed, rather than only every 15 minutes. Resolves
bugs 1913 and 1992.
- Bridge statistics now count bridge clients connecting over IPv6:
bridge statistics files now list "bridge-ip-versions" and
extra-info documents list "geoip6-db-digest". The control protocol
"CLIENTS_SEEN" and "ip-to-country" queries now support IPv6. Initial
implementation by "shkoo", addressing ticket 5055.
- Add a new torrc option "ServerTransportListenAddr" to let bridge
operators select the address where their pluggable transports will
listen for connections. Resolves ticket 7013.
- Randomize the lifetime of our SSL link certificate, so censors can't
use the static value for filtering Tor flows. Resolves ticket 8443;
related to ticket 4014 which was included in 0.2.2.33.
o Minor features (relays):
- Option OutboundBindAddress can be specified multiple times and
accepts IPv6 addresses. Resolves ticket 6876.
o Minor features (IPv6, client side):
- AutomapHostsOnResolve now supports IPv6 addresses. By default, we
prefer to hand out virtual IPv6 addresses, since there are more of
them and we can't run out. To override this behavior and make IPv4
addresses preferred, set NoPreferIPv6Automap on whatever SOCKSPort
or DNSPort you're using for resolving. Implements ticket 7571.
- AutomapHostsOnResolve responses are now randomized, to avoid
annoying situations where Tor is restarted and applications
connect to the wrong addresses.
- Never try more than 1000 times to pick a new virtual address when
AutomapHostsOnResolve is set. That's good enough so long as we
aren't close to handing out our entire virtual address space;
if you're getting there, it's best to switch to IPv6 virtual
addresses anyway.
o Minor features (IPv6, relay/authority side):
- New config option "AuthDirHasIPv6Connectivity 1" that directory
authorities should set if they have IPv6 connectivity and want to
do reachability tests for IPv6 relays. Implements feature 5974.
- A relay with an IPv6 OR port now sends that address in NETINFO
cells (in addition to its other address). Implements ticket 6364.
o Minor features (directory authorities):
- Directory authorities no long accept descriptors for any version of
Tor before 0.2.2.35, or for any 0.2.3 release before 0.2.3.10-alpha.
These versions are insecure, unsupported, or both. Implements
ticket 6789.
- When directory authorities are computing thresholds for flags,
never let the threshold for the Fast flag fall below 4096
bytes. Also, do not consider nodes with extremely low bandwidths
when deciding thresholds for various directory flags. This change
should raise our threshold for Fast relays, possibly in turn
improving overall network performance; see ticket 1854. Resolves
ticket 8145.
- Directory authorities now include inside each vote a statement of
the performance thresholds they used when assigning flags.
Implements ticket 8151.
- Add an "ignoring-advertised-bws" boolean to the flag-threshold lines
in directory authority votes to describe whether they have enough
measured bandwidths to ignore advertised (relay descriptor)
bandwidth claims. Resolves ticket 8711.
o Minor features (path bias detection):
- Path Use Bias: Perform separate accounting for successful circuit
use. Keep separate statistics on stream attempt rates versus stream
success rates for each guard. Provide configurable thresholds to
determine when to emit log messages or disable use of guards that
fail too many stream attempts. Resolves ticket 7802.
- Create three levels of Path Bias log messages, as opposed to just
two. These are configurable via consensus as well as via the torrc
options PathBiasNoticeRate, PathBiasWarnRate, PathBiasExtremeRate.
The default values are 0.70, 0.50, and 0.30 respectively.
- Separate the log message levels from the decision to drop guards,
which also is available via torrc option PathBiasDropGuards.
PathBiasDropGuards still defaults to 0 (off).
- Deprecate PathBiasDisableRate in favor of PathBiasDropGuards
in combination with PathBiasExtremeRate.
- Increase the default values for PathBiasScaleThreshold and
PathBiasCircThreshold from (200, 20) to (300, 150).
- Add in circuit usage accounting to path bias. If we try to use a
built circuit but fail for any reason, it counts as path bias.
Certain classes of circuits where the adversary gets to pick your
destination node are exempt from this accounting. Usage accounting
can be specifically disabled via consensus parameter or torrc.
- Convert all internal path bias state to double-precision floating
point, to avoid roundoff error and other issues.
- Only record path bias information for circuits that have completed
*two* hops. Assuming end-to-end tagging is the attack vector, this
makes us more resilient to ambient circuit failure without any
detection capability loss.
o Minor features (build):
- Tor now builds correctly on Bitrig, an OpenBSD fork. Patch from
dhill. Resolves ticket 6982.
- Compile on win64 using mingw64. Fixes bug 7260; patches from
"yayooo".
- Work correctly on Unix systems where EAGAIN and EWOULDBLOCK are
separate error codes; or at least, don't break for that reason.
Fixes bug 7935. Reported by "oftc_must_be_destroyed".
o Build improvements (autotools):
- Warn if building on a platform with an unsigned time_t: there
are too many places where Tor currently assumes that time_t can
hold negative values. We'd like to fix them all, but probably
some will remain.
- Do not report status verbosely from autogen.sh unless the -v flag
is specified. Fixes issue 4664. Patch from Onizuka.
- Detect and reject attempts to build Tor with threading support
when OpenSSL has been compiled without threading support.
Fixes bug 6673.
- Try to detect if we are ever building on a platform where
memset(...,0,...) does not set the value of a double to 0.0. Such
platforms are permitted by the C standard, though in practice
they're pretty rare (since IEEE 754 is nigh-ubiquitous). We don't
currently support them, but it's better to detect them and fail
than to perform erroneously.
- We no longer warn so much when generating manpages from their
asciidoc source.
- Use Ville Laurikari's implementation of AX_CHECK_SIGN() to determine
the signs of types during autoconf. This is better than our old
approach, which didn't work when cross-compiling.
o Minor features (log messages, warnings):
- Detect when we're running with a version of OpenSSL other than the
one we compiled with. This conflict has occasionally given people
hard-to-track-down errors.
- Warn users who run hidden services on a Tor client with
UseEntryGuards disabled that their hidden services will be
vulnerable to http://freehaven.net/anonbib/#hs-attack06 (the
attack which motivated Tor to support entry guards in the first
place). Resolves ticket 6889.
- Warn when we are binding low ports when hibernation is enabled;
previously we had warned when we were _advertising_ low ports with
hibernation enabled. Fixes bug 7285; bugfix on 0.2.3.9-alpha.
- Issue a warning when running with the bufferevents backend enabled.
It's still not stable, and people should know that they're likely
to hit unexpected problems. Closes ticket 9147.
o Minor features (log messages, notices):
- Refactor resolve_my_address() so it returns the method by which we
decided our public IP address (explicitly configured, resolved from
explicit hostname, guessed from interfaces, learned by gethostname).
Now we can provide more helpful log messages when a relay guesses
its IP address incorrectly (e.g. due to unexpected lines in
/etc/hosts). Resolves ticket 2267.
- Track how many "TAP" and "NTor" circuit handshake requests we get,
and how many we complete, and log it every hour to help relay
operators follow trends in network load. Addresses ticket 9658.
o Minor features (log messages, diagnostics):
- If we fail to free a microdescriptor because of bug 7164, log
the filename and line number from which we tried to free it.
- We compute the overhead from passing onionskins back and forth to
cpuworkers, and report it when dumping statistics in response to
SIGUSR1. Supports ticket 7291.
- Add another diagnostic to the heartbeat message: track and log
overhead that TLS is adding to the data we write. If this is
high, we are sending too little data to SSL_write at a time.
Diagnostic for bug 7707.
- Log packaged cell fullness as part of the heartbeat message.
Diagnosis to try to determine the extent of bug 7743.
- Add more detail to a log message about relaxed timeouts, to help
track bug 7799.
- When learning a fingerprint for a bridge, log its corresponding
transport type. Implements ticket 7896.
- Warn more aggressively when flushing microdescriptors to a
microdescriptor cache fails, in an attempt to mitigate bug 8031,
or at least make it more diagnosable.
- Improve the log message when "Bug/attack: unexpected sendme cell
from client" occurs, to help us track bug 8093.
- Improve debugging output to help track down bug 8185 ("Bug:
outgoing relay cell has n_chan==NULL. Dropping.")
o Minor features (log messages, quieter bootstrapping):
- Log fewer lines at level "notice" about our OpenSSL and Libevent
versions and capabilities when everything is going right. Resolves
part of ticket 6736.
- Omit the first heartbeat log message, because it never has anything
useful to say, and it clutters up the bootstrapping messages.
Resolves ticket 6758.
- Don't log about reloading the microdescriptor cache at startup. Our
bootstrap warnings are supposed to tell the user when there's a
problem, and our bootstrap notices say when there isn't. Resolves
ticket 6759; bugfix on 0.2.2.6-alpha.
- Don't log "I learned some more directory information" when we're
reading cached directory information. Reserve it for when new
directory information arrives in response to a fetch. Resolves
ticket 6760.
- Don't complain about bootstrapping problems while hibernating.
These complaints reflect a general code problem, but not one
with any problematic effects (no connections are actually
opened). Fixes part of bug 7302; bugfix on 0.2.3.2-alpha.
o Minor features (testing):
- In our testsuite, create temporary directories with a bit more
entropy in their name to make name collisions less likely. Fixes
bug 8638.
- Add benchmarks for DH (1024-bit multiplicative group) and ECDH
(P-256) Diffie-Hellman handshakes to src/or/bench.
- Add benchmark functions to test onion handshake performance.
o Renamed options:
- The DirServer option is now DirAuthority, for consistency with
current naming patterns. You can still use the old DirServer form.
o Minor bugfixes (protocol):
- Fix the handling of a TRUNCATE cell when it arrives while the
circuit extension is in progress. Fixes bug 7947; bugfix on 0.0.7.1.
- When a Tor client gets a "truncated" relay cell, the first byte of
its payload specifies why the circuit was truncated. We were
ignoring this 'reason' byte when tearing down the circuit, resulting
in the controller not being told why the circuit closed. Now we
pass the reason from the truncated cell to the controller. Bugfix
on 0.1.2.3-alpha; fixes bug 7039.
- Fix a misframing issue when reading the version numbers in a
VERSIONS cell. Previously we would recognize [00 01 00 02] as
'version 1, version 2, and version 0x100', when it should have
only included versions 1 and 2. Fixes bug 8059; bugfix on
0.2.0.10-alpha. Reported pseudonymously.
- Make the format and order of STREAM events for DNS lookups
consistent among the various ways to launch DNS lookups. Fixes
bug 8203; bugfix on 0.2.0.24-rc. Patch by "Desoxy".
o Minor bugfixes (syscalls and disk interaction):
- Always check the return values of functions fcntl() and
setsockopt(). We don't believe these are ever actually failing in
practice, but better safe than sorry. Also, checking these return
values should please analysis tools like Coverity. Patch from
'flupzor'. Fixes bug 8206; bugfix on all versions of Tor.
- Avoid double-closing the listener socket in our socketpair()
replacement (used on Windows) in the case where the addresses on
our opened sockets don't match what we expected. Fixes bug 9400;
bugfix on 0.0.2pre7. Found by Coverity.
- Correctly store microdescriptors and extrainfo descriptors that
include an internal NUL byte. Fixes bug 8037; bugfix on
0.2.0.1-alpha. Bug reported by "cypherpunks".
- If for some reason we fail to write a microdescriptor while
rebuilding the cache, do not let the annotations from that
microdescriptor linger in the cache file, and do not let the
microdescriptor stay recorded as present in its old location.
Fixes bug 9047; bugfix on 0.2.2.6-alpha.
- Use direct writes rather than stdio when building microdescriptor
caches, in an attempt to mitigate bug 8031, or at least make it
less common.
o Minor fixes (config options):
- Warn and fail if a server is configured not to advertise any
ORPorts at all. (We need *something* to put in our descriptor,
or we just won't work.)
- Behave correctly when the user disables LearnCircuitBuildTimeout
but doesn't tell us what they would like the timeout to be. Fixes
bug 6304; bugfix on 0.2.2.14-alpha.
- Rename the (internal-use-only) UsingTestingNetworkDefaults option
to start with a triple-underscore so the controller won't touch it.
Patch by Meejah. Fixes bug 3155. Bugfix on 0.2.2.23-alpha.
- Rename the (testing-use-only) _UseFilteringSSLBufferevents option
so it doesn't start with _. Fixes bug 3155. Bugfix on 0.2.3.1-alpha.
- When autodetecting the number of CPUs, use the number of available
CPUs in preference to the number of configured CPUs. Inform the
user if this reduces the number of available CPUs. Fixes bug 8002;
bugfix on 0.2.3.1-alpha.
- Command-line option "--version" implies "--quiet". Fixes bug 6997.
- Make it an error when you set EntryNodes but disable UseGuardNodes,
since it will (surprisingly to some users) ignore EntryNodes. Fixes
bug 8180; bugfix on 0.2.3.11-alpha.
- Avoid overflows when the user sets MaxCircuitDirtiness to a
ridiculously high value, by imposing a (ridiculously high) 30-day
maximum on MaxCircuitDirtiness.
o Minor bugfixes (control protocol):
- Stop sending a stray "(null)" in some cases for the server status
"EXTERNAL_ADDRESS" controller event. Resolves bug 8200; bugfix
on 0.1.2.6-alpha.
- The ADDRMAP command can no longer generate an ill-formed error
code on a failed MAPADDRESS. It now says "internal" rather than
an English sentence fragment with spaces in the middle. Bugfix on
Tor 0.2.0.19-alpha.
o Minor bugfixes (clients / edges):
- When we receive a RELAY_END cell with the reason DONE, or with no
reason, before receiving a RELAY_CONNECTED cell, report the SOCKS
status as "connection refused". Previously we reported these cases
as success but then immediately closed the connection. Fixes bug
7902; bugfix on 0.1.0.1-rc. Reported by "oftc_must_be_destroyed".
- If the guard we choose first doesn't answer, we would try the
second guard, but once we connected to the second guard we would
abandon it and retry the first one, slowing down bootstrapping.
The fix is to treat all our initially chosen guards as acceptable
to use. Fixes bug 9946; bugfix on 0.1.1.11-alpha.
- When choosing which stream on a formerly stalled circuit to wake
first, make better use of the platform's weak RNG. Previously,
we had been using the % ("modulo") operator to try to generate a
1/N chance of picking each stream, but this behaves badly with
many platforms' choice of weak RNG. Fixes bug 7801; bugfix on
0.2.2.20-alpha.
o Minor bugfixes (path bias detection):
- If the state file's path bias counts are invalid (presumably from a
buggy Tor prior to 0.2.4.10-alpha), make them correct. Also add
additional checks and log messages to the scaling of Path Bias
counts, in case there still are remaining issues with scaling.
Should help resolve bug 8235.
- Prevent rounding error in path bias counts when scaling
them down, and use the correct scale factor default. Also demote
some path bias related log messages down a level and make others
less scary sounding. Fixes bug 6647. Bugfix on 0.2.3.17-beta.
- Remove a source of rounding error during path bias count scaling;
don't count cannibalized circuits as used for path bias until we
actually try to use them; and fix a circuit_package_relay_cell()
warning message about n_chan==NULL. Fixes bug 7802.
- Paste the description for PathBias parameters from the man
page into or.h, so the code documents them too. Fixes bug 7982;
bugfix on 0.2.3.17-beta.
o Minor bugfixes (relays):
- Stop trying to resolve our hostname so often (e.g. every time we
think about doing a directory fetch). Now we reuse the cached
answer in some cases. Fixes bugs 1992 (bugfix on 0.2.0.20-rc)
and 2410 (bugfix on 0.1.2.2-alpha).
- When examining the list of network interfaces to find our address,
do not consider non-running or disabled network interfaces. Fixes
bug 9904; bugfix on 0.2.3.11-alpha. Patch from "hantwister".
o Minor bugfixes (blocking resistance):
- Only disable TLS session ticket support when running as a TLS
server. Now clients will blend better with regular Firefox
connections. Fixes bug 7189; bugfix on Tor 0.2.3.23-rc.
o Minor bugfixes (IPv6):
- Use square brackets around IPv6 addresses in numerous places
that needed them, including log messages, HTTPS CONNECT proxy
requests, TransportProxy statefile entries, and pluggable transport
extra-info lines. Fixes bug 7011; patch by David Fifield.
o Minor bugfixes (directory authorities):
- Reject consensus votes with more than 64 known-flags. We aren't even
close to that limit yet, and our code doesn't handle it correctly.
Fixes bug 6833; bugfix on 0.2.0.1-alpha.
- Correctly handle votes with more than 31 flags. Fixes bug 6853;
bugfix on 0.2.0.3-alpha.
o Minor bugfixes (memory leaks):
- Avoid leaking memory if we fail to compute a consensus signature
or we generate a consensus we can't parse. Bugfix on 0.2.0.5-alpha.
- Fix a memory leak when receiving headers from an HTTPS proxy. Bugfix
on 0.2.1.1-alpha; fixes bug 7816.
- Fix a memory leak during safe-cookie controller authentication.
Bugfix on 0.2.3.13-alpha; fixes bug 7816.
- Free some more still-in-use memory at exit, to make hunting for
memory leaks easier. Resolves bug 7029.
o Minor bugfixes (code correctness):
- Increase the width of the field used to remember a connection's
link protocol version to two bytes. Harmless for now, since the
only currently recognized versions are one byte long. Reported
pseudonymously. Fixes bug 8062; bugfix on 0.2.0.10-alpha.
- Fix a crash when debugging unit tests on Windows: deallocate a
shared library with FreeLibrary, not CloseHandle. Fixes bug 7306;
bugfix on 0.2.2.17-alpha. Reported by "ultramage".
- When detecting the largest possible file descriptor (in order to
close all file descriptors when launching a new program), actually
use _SC_OPEN_MAX. The old code for doing this was very, very broken.
Fixes bug 8209; bugfix on 0.2.3.1-alpha. Found by Coverity; this
is CID 743383.
- Avoid a crash if we fail to generate an extrainfo descriptor.
Fixes bug 8208; bugfix on 0.2.3.16-alpha. Found by Coverity;
this is CID 718634.
- Avoid an off-by-one error when checking buffer boundaries when
formatting the exit status of a pluggable transport helper.
This is probably not an exploitable bug, but better safe than
sorry. Fixes bug 9928; bugfix on 0.2.3.18-rc. Bug found by
Pedro Ribeiro.
- Get rid of a couple of harmless clang warnings, where we compared
enums to ints. These warnings are newly introduced in clang 3.2.
o Minor bugfixes (code cleanliness):
- Avoid use of reserved identifiers in our C code. The C standard
doesn't like us declaring anything that starts with an
underscore, so let's knock it off before we get in trouble. Fix
for bug 1031; bugfix on the first Tor commit.
- Fix round_to_power_of_2() so it doesn't invoke undefined behavior
with large values. This situation was untriggered, but nevertheless
incorrect. Fixes bug 6831; bugfix on 0.2.0.1-alpha.
- Fix an impossible buffer overrun in the AES unit tests. Fixes
bug 8845; bugfix on 0.2.0.7-alpha. Found by eugenis.
- Fix handling of rendezvous client authorization types over 8.
Fixes bug 6861; bugfix on 0.2.1.5-alpha.
- Remove a couple of extraneous semicolons that were upsetting the
cparser library. Patch by Christian Grothoff. Fixes bug 7115;
bugfix on 0.2.2.1-alpha.
- When complaining about a client port on a public address, log
which address we're complaining about. Fixes bug 4020; bugfix on
0.2.3.3-alpha. Patch by Tom Fitzhenry.
o Minor bugfixes (log messages, warnings):
- If we encounter a write failure on a SOCKS connection before we
finish our SOCKS handshake, don't warn that we closed the
connection before we could send a SOCKS reply. Fixes bug 8427;
bugfix on 0.1.0.1-rc.
- Fix a directory authority warn caused when we have a large amount
of badexit bandwidth. Fixes bug 8419; bugfix on 0.2.2.10-alpha.
- Downgrade "Failed to hand off onionskin" messages to "debug"
severity, since they're typically redundant with the "Your computer
is too slow" messages. Fixes bug 7038; bugfix on 0.2.2.16-alpha.
- Avoid spurious warnings when configuring multiple client ports of
which only some are nonlocal. Previously, we had claimed that some
were nonlocal when in fact they weren't. Fixes bug 7836; bugfix on
0.2.3.3-alpha.
o Minor bugfixes (log messages, other):
- Fix log messages and comments to avoid saying "GMT" when we mean
"UTC". Fixes bug 6113.
- When rejecting a configuration because we were unable to parse a
quoted string, log an actual error message. Fixes bug 7950; bugfix
on 0.2.0.16-alpha.
- Correctly recognize that [::1] is a loopback address. Fixes
bug 8377; bugfix on 0.2.1.3-alpha.
- Don't log inappropriate heartbeat messages when hibernating: a
hibernating node is _expected_ to drop out of the consensus,
decide it isn't bootstrapped, and so forth. Fixes bug 7302;
bugfix on 0.2.3.1-alpha.
- Eliminate several instances where we use "Nickname=ID" to refer to
nodes in logs. Use "Nickname (ID)" instead. (Elsewhere, we still use
"$ID=Nickname", which is also acceptable.) Fixes bug 7065. Bugfix
on 0.2.3.21-rc.
o Minor bugfixes (build):
- Fix some bugs in tor-fw-helper-natpmp when trying to build and
run it on Windows. More bugs likely remain. Patch from Gisle Vanem.
Fixes bug 7280; bugfix on 0.2.3.1-alpha.
o Documentation fixes:
- Make the torify manpage no longer refer to tsocks; torify hasn't
supported tsocks since 0.2.3.14-alpha.
- Make the tor manpage no longer reference tsocks.
- Fix the GeoIPExcludeUnknown documentation to refer to
ExcludeExitNodes rather than the currently nonexistent
ExcludeEntryNodes. Spotted by "hamahangi" on tor-talk.
- Resolve a typo in torrc.sample.in. Fixes bug 6819; bugfix on
0.2.3.14-alpha.
- Say "KBytes" rather than "KB" in the man page (for various values
of K), to further reduce confusion about whether Tor counts in
units of memory or fractions of units of memory. Resolves ticket 7054.
- Update tor-fw-helper.1.txt and tor-fw-helper.c to make option
names match. Fixes bug 7768.
- Fix the documentation of HeartbeatPeriod to say that the heartbeat
message is logged at notice, not at info.
- Clarify the usage and risks of setting the ContactInfo torrc line
for your relay or bridge. Resolves ticket 9854.
- Add anchors to the manpage so we can link to the html version of
the documentation for specific options. Resolves ticket 9866.
- Replace remaining references to DirServer in man page and
log entries. Resolves ticket 10124.
o Removed features:
- Stop exporting estimates of v2 and v3 directory traffic shares
in extrainfo documents. They were unneeded and sometimes inaccurate.
Also stop exporting any v2 directory request statistics. Resolves
ticket 5823.
- Drop support for detecting and warning about versions of Libevent
before 1.3e. Nothing reasonable ships with them any longer; warning
the user about them shouldn't be needed. Resolves ticket 6826.
- Now that all versions before 0.2.2.x are disallowed, we no longer
need to work around their missing features. Remove a bunch of
compatibility code.
o Removed files:
- The tor-tsocks.conf is no longer distributed or installed. We
recommend that tsocks users use torsocks instead. Resolves
ticket 8290.
- Remove some of the older contents of doc/ as obsolete; move others
to torspec.git. Fixes bug 8965.
o Code simplification:
- Avoid using character buffers when constructing most directory
objects: this approach was unwieldy and error-prone. Instead,
build smartlists of strings, and concatenate them when done.
- Rename "isin" functions to "contains", for grammar. Resolves
ticket 5285.
- Rename Tor's logging function log() to tor_log(), to avoid conflicts
with the natural logarithm function from the system libm. Resolves
ticket 7599.
- Start using OpenBSD's implementation of queue.h, so that we don't
need to hand-roll our own pointer and list structures whenever we
need them. (We can't rely on a sys/queue.h, since some operating
systems don't have them, and the ones that do have them don't all
present the same extensions.)
- Start using OpenBSD's implementation of queue.h (originally by
Niels Provos).
- Enhance our internal sscanf replacement so that we can eliminate
the last remaining uses of the system sscanf. (Though those uses
of sscanf were safe, sscanf itself is generally error prone, so
we want to eliminate when we can.) Fixes ticket 4195 and Coverity
CID 448.
- Replace all calls to snprintf() outside of src/ext with
tor_snprintf(). Also remove the #define to replace snprintf with
_snprintf on Windows; they have different semantics, and all of
our callers should be using tor_snprintf() anyway. Fixes bug 7304.
o Refactoring:
- Add a wrapper function for the common "log a message with a
rate-limit" case.
- Split the onion.c file into separate modules for the onion queue
and the different handshakes it supports.
- Move the client-side address-map/virtual-address/DNS-cache code
out of connection_edge.c into a new addressmap.c module.
- Move the entry node code from circuitbuild.c to its own file.
- Move the circuit build timeout tracking code from circuitbuild.c
to its own file.
- Source files taken from other packages now reside in src/ext;
previously they were scattered around the rest of Tor.
- Move the generic "config" code into a new file, and have "config.c"
hold only torrc- and state-related code. Resolves ticket 6823.
- Move the core of our "choose a weighted element at random" logic
into its own function, and give it unit tests. Now the logic is
testable, and a little less fragile too.
- Move ipv6_preferred from routerinfo_t to node_t. Addresses bug 4620.
- Move last_reachable and testing_since from routerinfo_t to node_t.
Implements ticket 5529.
- Add replaycache_t structure, functions and unit tests, then refactor
rend_service_introduce() to be more clear to read, improve, debug,
and test. Resolves bug 6177.
o Removed code:
- Remove some now-needless code that tried to aggressively flush
OR connections as data was added to them. Since 0.2.0.1-alpha, our
cell queue logic has saved us from the failure mode that this code
was supposed to prevent. Removing this code will limit the number
of baroque control flow paths through Tor's network logic. Reported
pseudonymously on IRC. Fixes bug 6468; bugfix on 0.2.0.1-alpha.
- Remove unused code for parsing v1 directories and "running routers"
documents. Fixes bug 6887.
- Remove the marshalling/unmarshalling code for sending requests to
cpuworkers over a socket, and instead just send structs. The
recipient will always be the same Tor binary as the sender, so
any encoding is overkill.
- Remove the testing_since field of node_t, which hasn't been used
for anything since 0.2.0.9-alpha.
- Finally remove support for malloc_good_size and malloc_usable_size.
We had hoped that these functions would let us eke a little more
memory out of our malloc implementation. Unfortunately, the only
implementations that provided these functions are also ones that
are already efficient about not overallocation: they never got us
more than 7 or so bytes per allocation. Removing them saves us a
little code complexity and a nontrivial amount of build complexity.
Changes in version 0.2.3.25 - 2012-11-19
The Tor 0.2.3 release series is dedicated to the memory of Len "rabbi"
Sassaman (1980-2011), a long-time cypherpunk, anonymity researcher,
Mixmaster maintainer, Pynchon Gate co-designer, CodeCon organizer,
programmer, and friend. Unstinting in his dedication to the cause of
freedom, he inspired and helped many of us as we began our work on
anonymity, and inspires us still. Please honor his memory by writing
software to protect people's freedoms, and by helping others to do so.
Tor 0.2.3.25, the first stable release in the 0.2.3 branch, features
significantly reduced directory overhead (via microdescriptors),
enormous crypto performance improvements for fast relays on new
enough hardware, a new v3 TLS handshake protocol that can better
resist fingerprinting, support for protocol obfuscation plugins (aka
pluggable transports), better scalability for hidden services, IPv6
support for bridges, performance improvements like allowing clients
to skip the first round-trip on the circuit ("optimistic data") and
refilling token buckets more often, a new "stream isolation" design
to isolate different applications on different circuits, and many
stability, security, and privacy fixes.
Major features (v3 directory protocol):
- Clients now use microdescriptors instead of regular descriptors
to build circuits. Microdescriptors are authority-generated
summaries of regular descriptors' contents, designed to change very
rarely (see proposal 158 for details). This feature is designed
to save bandwidth, especially for clients on slow internet
connections. Use "UseMicrodescriptors 0" to disable it.
- Caches now download, cache, and serve microdescriptors, as well
as multiple "flavors" of the consensus, including a flavor that
describes microdescriptors.
o Major features (build hardening):
- Enable gcc and ld hardening by default. Resolves ticket 5210.
o Major features (relay scaling):
- When built to use OpenSSL 1.0.1, and built for an x86 or x86_64
instruction set, take advantage of OpenSSL's AESNI, bitsliced, or
vectorized AES implementations as appropriate. These can be much,
much faster than other AES implementations.
- When using OpenSSL 1.0.0 or later, use OpenSSL's counter mode
implementation. It makes AES_CTR about 7% faster than our old one
(which was about 10% faster than the one OpenSSL used to provide).
Resolves ticket 4526.
- Use OpenSSL's EVP interface for AES encryption, so that all AES
operations can use hardware acceleration (if present). Resolves
ticket 4442.
- Unconditionally use OpenSSL's AES implementation instead of our
old built-in one. OpenSSL's AES has been better for a while, and
relatively few servers should still be on any version of OpenSSL
that doesn't have good optimized assembly AES.
o Major features (blocking resistance):
- Update TLS cipher list to match Firefox 8 and later. Resolves
ticket 4744.
- Remove support for clients falsely claiming to support standard
ciphersuites that they can actually provide. As of modern OpenSSL
versions, it's not necessary to fake any standard ciphersuite,
and doing so prevents us from using better ciphersuites in the
future, since servers can't know whether an advertised ciphersuite
is really supported or not. Some hosts -- notably, ones with very
old versions of OpenSSL or where OpenSSL has been built with ECC
disabled -- will stand out because of this change; TBB users should
not be affected. Implements the client side of proposal 198.
- Implement a new handshake protocol (v3) for authenticating Tors to
each other over TLS. It should be more resistant to fingerprinting
than previous protocols, and should require less TLS hacking for
future Tor implementations. Implements proposal 176.
- Allow variable-length padding cells, to disguise the length of
Tor's TLS records. Implements part of proposal 184.
- While we're trying to bootstrap, record how many TLS connections
fail in each state, and report which states saw the most failures
in response to any bootstrap failures. This feature may speed up
diagnosis of censorship events. Implements ticket 3116.
o Major features (pluggable transports):
- Clients and bridges can now be configured to use a separate
"transport" proxy. This approach makes the censorship arms race
easier by allowing bridges to use protocol obfuscation plugins.
Implements proposal 180 (tickets 2841 and 3472).
o Major features (DoS resistance):
- Now that Tor 0.2.0.x is completely deprecated, enable the final
part of "Proposal 110: Avoiding infinite length circuits" by
refusing all circuit-extend requests that do not use a relay_early
cell. This change helps Tor resist a class of denial-of-service
attacks by limiting the maximum circuit length.
- Tear down the circuit if we get an unexpected SENDME cell. Clients
could use this trick to make their circuits receive cells faster
than our flow control would have allowed, or to gum up the network,
or possibly to do targeted memory denial-of-service attacks on
entry nodes. Fixes bug 6252. Bugfix on the 54th commit on Tor --
from July 2002, before the release of Tor 0.0.0.
o Major features (hidden services):
- Adjust the number of introduction points that a hidden service
will try to maintain based on how long its introduction points
remain in use and how many introductions they handle. Fixes
part of bug 3825.
- Add a "tor2web mode" for clients that want to connect to hidden
services non-anonymously (and possibly more quickly). As a safety
measure to try to keep users from turning this on without knowing
what they are doing, tor2web mode must be explicitly enabled at
compile time, and a copy of Tor compiled to run in tor2web mode
cannot be used as a normal Tor client. Implements feature 2553.
o Major features (IPv6):
- Clients can now connect to private bridges over IPv6. Bridges
still need at least one IPv4 address in order to connect to
other relays. Note that we don't yet handle the case where the
user has two bridge lines for the same bridge (one IPv4, one
IPv6). Implements parts of proposal 186.
o Major features (directory authorities):
- Use a more secure consensus parameter voting algorithm. Now at
least three directory authorities or a majority of them must
vote on a given parameter before it will be included in the
consensus. Implements proposal 178.
- Remove the artificially low cutoff of 20KB to guarantee the Fast
flag. In the past few years the average relay speed has picked
up, and while the "top 7/8 of the network get the Fast flag" and
"all relays with 20KB or more of capacity get the Fast flag" rules
used to have the same result, now the top 7/8 of the network has
a capacity more like 32KB. Bugfix on 0.2.1.14-rc. Fixes bug 4489.
o Major features (performance):
- Exit nodes now accept and queue data on not-yet-connected streams.
Previously, the client wasn't allowed to send data until the
stream was connected, which slowed down all connections. This
change will enable clients to perform a "fast-start" on streams
and send data without having to wait for a confirmation that the
stream has opened. Patch from Ian Goldberg; implements the server
side of Proposal 174.
- When using an exit relay running 0.2.3.x, clients can now
"optimistically" send data before the exit relay reports that
the stream has opened. This saves a round trip when starting
connections where the client speaks first (such as web browsing).
This behavior is controlled by a consensus parameter (currently
disabled). To turn it on or off manually, use the "OptimisticData"
torrc option. Implements proposal 181; code by Ian Goldberg.
- Add a new TokenBucketRefillInterval option to refill token buckets
more frequently than once per second. This should improve network
performance, alleviate queueing problems, and make traffic less
bursty. Implements proposal 183; closes ticket 3630. Design by
Florian Tschorsch and Björn Scheuermann; implementation by
Florian Tschorsch.
- Raise the threshold of server descriptors needed (75%) and exit
server descriptors needed (50%) before we will declare ourselves
bootstrapped. This will make clients start building circuits a
little later, but makes the initially constructed circuits less
skewed and less in conflict with further directory fetches. Fixes
ticket 3196.
o Major features (relays):
- Relays now try regenerating and uploading their descriptor more
frequently if they are not listed in the consensus, or if the
version of their descriptor listed in the consensus is too
old. This fix should prevent situations where a server declines
to re-publish itself because it has done so too recently, even
though the authorities decided not to list its recent-enough
descriptor. Fix for bug 3327.
o Major features (stream isolation):
- You can now configure Tor so that streams from different
applications are isolated on different circuits, to prevent an
attacker who sees your streams as they leave an exit node from
linking your sessions to one another. To do this, choose some way
to distinguish the applications: have them connect to different
SocksPorts, or have one of them use SOCKS4 while the other uses
SOCKS5, or have them pass different authentication strings to the
SOCKS proxy. Then, use the new SocksPort syntax to configure the
degree of isolation you need. This implements Proposal 171.
- There's a new syntax for specifying multiple client ports (such as
SOCKSPort, TransPort, DNSPort, NATDPort): you can now just declare
multiple *Port entries with full addr:port syntax on each.
The old *ListenAddress format is still supported, but you can't
mix it with the new *Port syntax.
o Major features (bufferevents):
- Tor can now optionally build with the "bufferevents" buffered IO
backend provided by Libevent 2. To use this feature, make sure you
have the latest possible version of Libevent, and pass the
--enable-bufferevents flag to configure when building Tor from
source. This feature will make our networking code more flexible,
let us stack layers on each other, and let us use more efficient
zero-copy transports where available.
- Add experimental support for running on Windows with IOCP and no
kernel-space socket buffers. This feature is controlled by a new
"UserspaceIOCPBuffers" config option (off by default), which has
no effect unless Tor has been built with bufferevents enabled,
you're running on Windows, and you've set "DisableIOCP 0". In the
long run, this may help solve or mitigate bug 98.
o Major features (path selection):
- The EntryNodes option can now include country codes like {de} or IP
addresses or network masks. Previously we had disallowed these
options because we didn't have an efficient way to keep the list up
to date. Addresses ticket 1982, but see bug 2798 for an unresolved
issue here.
o Major features (port forwarding):
- Add support for automatic port mapping on the many home routers
that support NAT-PMP or UPnP. To build the support code, you'll
need to have the libnatpnp library and/or the libminiupnpc library,
and you'll need to enable the feature specifically by passing
"--enable-upnp" and/or "--enable-natpnp" to ./configure. To turn
it on, use the new PortForwarding option.
o Major features (logging):
- Add a new 'Heartbeat' log message type to periodically log a message
describing Tor's status at level Notice. This feature is meant for
operators who log at notice, and want to make sure that their Tor
server is still working. Implementation by George Kadianakis.
- Make logging resolution configurable with a new LogTimeGranularity
option, and change the default from 1 millisecond to 1 second.
Implements enhancement 1668.
o Major features (other):
- New "DisableNetwork" config option to prevent Tor from launching any
connections or accepting any connections except on a control port.
Bundles and controllers can set this option before letting Tor talk
to the rest of the network, for example to prevent any connections
to a non-bridge address. Packages like Orbot can also use this
option to instruct Tor to save power when the network is off.
- Try to use system facilities for enumerating local interface
addresses, before falling back to our old approach (which was
binding a UDP socket, and calling getsockname() on it). That
approach was scaring OS X users whose draconian firewall
software warned about binding to UDP sockets regardless of
whether packets were sent. Now we try to use getifaddrs(),
SIOCGIFCONF, or GetAdaptersAddresses(), depending on what the
system supports. Resolves ticket 1827.
- Add experimental support for a "defaults" torrc file to be parsed
before the regular torrc. Torrc options override the defaults file's
options in the same way that the command line overrides the torrc.
The SAVECONF controller command saves only those options which
differ between the current configuration and the defaults file. HUP
reloads both files. Implements task 4552.
o New directory authorities:
- Add Faravahar (run by Sina Rabbani) as the ninth v3 directory
authority. Closes ticket 5749.
o Security/privacy fixes:
- Avoid read-from-freed-memory and double-free bugs that could occur
when a DNS request fails while launching it. Fixes bug 6480;
bugfix on 0.2.0.1-alpha.
- Reject any attempt to extend to an internal address. Without
this fix, a router could be used to probe addresses on an internal
network to see whether they were accepting connections. Fixes bug
6710; bugfix on 0.0.8pre1.
- Close any connection that sends unrecognized junk before the TLS
handshake. Solves an issue noted in bug 4369.
- The advertised platform of a relay now includes only its operating
system's name (e.g., "Linux", "Darwin", "Windows 7"), and not
its service pack level (for Windows) or its CPU architecture
(for Unix). Also drop the "git-XYZ" tag in the version. Packagers
can insert an extra string in the platform line by setting the
preprocessor variable TOR_BUILD_TAG. Resolves bug 2988.
- Disable TLS session tickets. OpenSSL's implementation was giving
our TLS session keys the lifetime of our TLS context objects, when
perfect forward secrecy would want us to discard anything that
could decrypt a link connection as soon as the link connection
was closed. Fixes bug 7139; bugfix on all versions of Tor linked
against OpenSSL 1.0.0 or later. Found by Florent Daignière.
- Tor tries to wipe potentially sensitive data after using it, so
that if some subsequent security failure exposes Tor's memory,
the damage will be limited. But we had a bug where the compiler
was eliminating these wipe operations when it decided that the
memory was no longer visible to a (correctly running) program,
hence defeating our attempt at defense in depth. We fix that
by using OpenSSL's OPENSSL_cleanse() operation, which a compiler
is unlikely to optimize away. Future versions of Tor may use
a less ridiculously heavy approach for this. Fixes bug 7352.
Reported in an article by Andrey Karpov.
o Major bugfixes (crashes and asserts):
- Avoid a pair of double-free and use-after-mark bugs that can
occur with certain timings in canceled and re-received DNS
requests. Fixes bug 6472; bugfix on 0.0.7rc1.
- Fix a denial of service attack by which any directory authority
could crash all the others, or by which a single v2 directory
authority could crash everybody downloading v2 directory
information. Fixes bug 7191; bugfix on 0.2.0.10-alpha.
- Fix an assert that directory authorities could trigger on sighup
during some configuration state transitions. We now don't treat
it as a fatal error when the new descriptor we just generated in
init_keys() isn't accepted. Fixes bug 4438; bugfix on 0.2.1.9-alpha.
- Avoid segfault when starting up having run with an extremely old
version of Tor and parsing its state file. Fixes bug 6801; bugfix
on 0.2.2.23-alpha.
o Major bugfixes (clients):
- If we are unable to find any exit that supports our predicted ports,
stop calling them predicted, so that we don't loop and build
hopeless circuits indefinitely. Fixes bug 3296; bugfix on 0.0.9pre6,
which introduced predicted ports.
- Check at each new consensus whether our entry guards were picked
long enough ago that we should rotate them. Previously, we only
did this check at startup, which could lead to us holding a guard
indefinitely. Fixes bug 5380; bugfix on 0.2.1.14-rc.
- When fetching a bridge descriptor from a bridge authority,
always do so anonymously, whether we have been able to open
circuits or not. Partial fix for bug 1938; bugfix on 0.2.0.7-alpha.
This behavior makes it *safer* to use UpdateBridgesFromAuthority,
but we'll need to wait for bug 6010 before it's actually usable.
o Major bugfixes (directory voting):
- Check more thoroughly to prevent a rogue authority from
double-voting on any consensus directory parameter. Previously,
authorities would crash in this case if the total number of
votes for any parameter exceeded the number of active voters,
but would let it pass otherwise. Partially fixes bug 5786; bugfix
on 0.2.2.2-alpha.
- When computing weight parameters, behave more robustly in the
presence of a bad bwweightscale value. Previously, the authorities
would crash if they agreed on a sufficiently broken weight_scale
value; now, they use a reasonable default and carry on. Fixes the
rest of bug 5786; bugfix on 0.2.2.17-alpha.
- If authorities are unable to get a v2 consensus document from other
directory authorities, they no longer fall back to fetching
them from regular directory caches. Fixes bug 5635; bugfix on
0.2.2.26-beta, where routers stopped downloading v2 consensus
documents entirely.
o Major bugfixes (relays):
- Fix a bug handling SENDME cells on nonexistent streams that could
result in bizarre window values. Report and patch contributed
pseudonymously. Fixes part of bug 6271. This bug was introduced
before the first Tor release, in svn commit r152.
- Don't update the AccountingSoftLimitHitAt state file entry whenever
tor gets started. This prevents a wrong average bandwidth
estimate, which would cause relays to always start a new accounting
interval at the earliest possible moment. Fixes bug 2003; bugfix
on 0.2.2.7-alpha. Reported by Bryon Eldridge, who also helped
immensely in tracking this bug down.
- Fix a possible crash bug when checking for deactivated circuits
in connection_or_flush_from_first_active_circuit(). Fixes bug 6341;
bugfix on 0.2.2.7-alpha. Bug report and fix received pseudonymously.
- Set the SO_REUSEADDR socket option before we call bind() on outgoing
connections. This change should allow busy exit relays to stop
running out of available sockets as quickly. Fixes bug 4950;
bugfix on 0.2.2.26-beta.
o Major bugfixes (blocking resistance):
- Bridges no longer include their address in NETINFO cells on outgoing
OR connections, to allow them to blend in better with clients.
Removes another avenue for enumerating bridges. Reported by
"troll_un". Fixes bug 4348; bugfix on 0.2.0.10-alpha, when NETINFO
cells were introduced.
- Warn the user when HTTPProxy, but no other proxy type, is
configured. This can cause surprising behavior: it doesn't send
all of Tor's traffic over the HTTPProxy -- it sends unencrypted
directory traffic only. Resolves ticket 4663.
o Major bugfixes (hidden services):
- Improve hidden service robustness: when an attempt to connect to
a hidden service ends, be willing to refetch its hidden service
descriptors from each of the HSDir relays responsible for them
immediately. Previously, we would not consider refetching the
service's descriptors from each HSDir for 15 minutes after the last
fetch, which was inconvenient if the hidden service was not running
during the first attempt. Bugfix on 0.2.0.18-alpha; fixes bug 3335.
- Hidden services now ignore the timestamps on INTRODUCE2 cells.
They used to check that the timestamp was within 30 minutes
of their system clock, so they could cap the size of their
replay-detection cache, but that approach unnecessarily refused
service to clients with wrong clocks. Bugfix on 0.2.1.6-alpha, when
the v3 intro-point protocol (the first one which sent a timestamp
field in the INTRODUCE2 cell) was introduced; fixes bug 3460.
- When one of a hidden service's introduction points appears to be
unreachable, stop trying it. Previously, we would keep trying
to build circuits to the introduction point until we lost the
descriptor, usually because the user gave up and restarted Tor.
Fixes part of bug 3825.
o Changes to default torrc file:
- Stop listing "socksport 9050" in torrc.sample. We open a socks
port on 9050 by default anyway, so this should not change anything
in practice.
- Stop mentioning the deprecated *ListenAddress options in
torrc.sample. Fixes bug 5438.
- Document unit of bandwidth-related options in sample torrc.
Fixes bug 5621.
- Fix broken URLs in the sample torrc file, and tell readers about
the OutboundBindAddress, ExitPolicyRejectPrivate, and
PublishServerDescriptor options. Addresses bug 4652.
o Minor features (directory authorities):
- Consider new, removed or changed IPv6 OR ports a non-cosmetic
change when the authority is deciding whether to accept a newly
uploaded descriptor. Implements ticket 6423.
- Directory authorities are now a little more lenient at accepting
older router descriptors, or newer router descriptors that don't
make big changes. This should help ameliorate past and future
issues where routers think they have uploaded valid descriptors,
but the authorities don't think so. Fix for ticket 2479.
- Authority operators can now vote for all relays in a given
set of countries to be BadDir/BadExit/Invalid/Rejected.
- Provide two consensus parameters (FastFlagMinThreshold and
FastFlagMaxThreshold) to control the range of allowable bandwidths
for the Fast directory flag. These allow authorities to run
experiments on appropriate requirements for being a "Fast" node.
The AuthDirFastGuarantee config value still applies. Implements
ticket 3946.
o Minor features (bridges / bridge authorities):
- Make bridge SSL certificates a bit more stealthy by using random
serial numbers, in the same fashion as OpenSSL when generating
self-signed certificates. Implements ticket 4584.
- Tag a bridge's descriptor as "never to be sent unencrypted".
This shouldn't matter, since bridges don't open non-anonymous
connections to the bridge authority and don't allow unencrypted
directory connections from clients, but we might as well make
sure. Closes bug 5139.
- The Bridge Authority now writes statistics on how many bridge
descriptors it gave out in total, and how many unique descriptors
it gave out. It also lists how often the most and least commonly
fetched descriptors were given out, as well as the median and
25th/75th percentile. Implements tickets 4200 and 4294.
o Minor features (IPv6):
- Make the code that clients use to detect an address change be
IPv6-aware, so that it won't fill clients' logs with error
messages when trying to get the IPv4 address of an IPv6
connection. Implements ticket 5537.
- Relays now understand an IPv6 address when they get one from a
directory server. Resolves ticket 4875.
o Minor features (hidden services):
- Expire old or over-used hidden service introduction points.
Required by fix for bug 3460.
- Reduce the lifetime of elements of hidden services' Diffie-Hellman
public key replay-detection cache from 60 minutes to 5 minutes. This
replay-detection cache is now used only to detect multiple
INTRODUCE2 cells specifying the same rendezvous point, so we can
avoid launching multiple simultaneous attempts to connect to it.
- When a hidden service's introduction point times out, consider
trying it again during the next attempt to connect to the
HS. Previously, we would not try it again unless a newly fetched
descriptor contained it. Required by fixes for bugs 1297 and 3825.
o Minor features (relays):
- Relays now include a reason for regenerating their descriptors
in an HTTP header when uploading to the authorities. This will
make it easier to debug descriptor-upload issues in the future.
- Turn on directory request statistics by default and include them in
extra-info descriptors. Don't break if we have no GeoIP database.
- Replace files in stats/ rather than appending to them. Now that we
include statistics in extra-info descriptors, it makes no sense to
keep old statistics forever. Implements ticket 2930.
- Relays that set "ConnDirectionStatistics 1" write statistics on the
bidirectional use of connections to disk every 24 hours.
- Add a GeoIP file digest to the extra-info descriptor. Implements
ticket 1883.
o Minor features (new config options):
- New config option "DynamicDHGroups" (disabled by default) provides
each bridge with a unique prime DH modulus to be used during
SSL handshakes. This option attempts to help against censors
who might use the Apache DH modulus as a static identifier for
bridges. Addresses ticket 4548.
- New config option "DisableDebuggerAttachment" (on by default)
to prevent basic debugging attachment attempts by other processes.
Supports Mac OS X and Gnu/Linux. Resolves ticket 3313.
- Ordinarily, Tor does not count traffic from private addresses (like
127.0.0.1 or 10.0.0.1) when calculating rate limits or accounting.
There is now a new option, CountPrivateBandwidth, to disable this
behavior. Patch from Daniel Cagara.
o Minor features (different behavior for old config options):
- Allow MapAddress directives to specify matches against super-domains,
as in "MapAddress *.torproject.org *.torproject.org.torserver.exit".
Implements issue 933.
- Don't disable the DirPort when we cannot exceed our AccountingMax
limit during this interval because the effective bandwidthrate is
low enough. This is useful in a situation where AccountMax is only
used as an additional safeguard or to provide statistics.
- Add port 6523 (Gobby) to LongLivedPorts. Patch by intrigeri;
implements ticket 3439.
- When configuring a large set of nodes in EntryNodes, and there are
enough of them listed as Guard so that we don't need to consider
the non-guard entries, prefer the ones listed with the Guard flag.
- If you set the NumCPUs option to 0, Tor will now try to detect how
many CPUs you have. This is the new default behavior.
- The NodeFamily option -- which let you declare that you want to
consider nodes to be part of a family whether they list themselves
that way or not -- now allows IP address ranges and country codes.
o Minor features (new command-line config behavior):
- Slightly change behavior of "list" options (that is, config
options that can appear more than once) when they appear both in
torrc and on the command line. Previously, the command-line options
would be appended to the ones from torrc. Now, the command-line
options override the torrc options entirely. This new behavior
allows the user to override list options (like exit policies and
ports to listen on) from the command line, rather than simply
appending to the list.
- You can get the old (appending) command-line behavior for "list"
options by prefixing the option name with a "+".
- You can remove all the values for a "list" option from the command
line without adding any new ones by prefixing the option name
with a "/".
o Minor features (controller, new events):
- Extend the control protocol to report flags that control a circuit's
path selection in CIRC events and in replies to 'GETINFO
circuit-status'. Implements part of ticket 2411.
- Extend the control protocol to report the hidden service address
and current state of a hidden-service-related circuit in CIRC
events and in replies to 'GETINFO circuit-status'. Implements part
of ticket 2411.
- Include the creation time of a circuit in CIRC and CIRC2
control-port events and the list produced by the 'GETINFO
circuit-status' control-port command.
- Add a new CONF_CHANGED event so that controllers can be notified
of any configuration changes made by other controllers, or by the
user. Implements ticket 1692.
- Add a new SIGNAL event to the controller interface so that
controllers can be notified when Tor handles a signal. Resolves
issue 1955. Patch by John Brooks.
o Minor features (controller, new getinfo options):
- Expose our view of whether we have gone dormant to the controller,
via a new "GETINFO dormant" value. Torbutton and other controllers
can use this to avoid doing periodic requests through Tor while
it's dormant (bug 4718). Resolves ticket 5954.
- Add a new GETINFO option to get total bytes read and written. Patch
from pipe, revised by atagar. Resolves ticket 2345.
- Implement new GETINFO controller fields to provide information about
the Tor process's pid, euid, username, and resource limits.
o Minor features (controller, other):
- Allow controllers to request an event notification whenever a
circuit is cannibalized or its purpose is changed. Implements
part of ticket 3457.
- Use absolute path names when reporting the torrc filename in the
control protocol, so a controller can more easily find the torrc
file. Resolves bug 1101.
- When reporting the path to the cookie file to the controller,
give an absolute path. Resolves ticket 4881.
o Minor features (log messages):
- Add more information to a log statement that might help track down
bug 4091. If you're seeing "Bug: tor_addr_is_internal() called with a
non-IP address" messages (or any Bug messages, for that matter!),
please let us know about it.
- If EntryNodes are given, but UseEntryGuards is set to 0, warn that
EntryNodes will have no effect. Resolves issue 2571.
- Try to make the introductory warning message that Tor prints on
startup more useful for actually finding help and information.
Resolves ticket 2474.
- When the system call to create a listener socket fails, log the
error message explaining why. This may help diagnose bug 4027.
o Minor features (other):
- When we fail to initialize Libevent, retry with IOCP disabled so we
don't need to turn on multi-threading support in Libevent, which in
turn requires a working socketpair(). This is a workaround for bug
4457, which affects Libevent versions from 2.0.1-alpha through
2.0.15-stable.
- When starting as root and then changing our UID via the User
control option, and we have a ControlSocket configured, make sure
that the ControlSocket is owned by the same account that Tor will
run under. Implements ticket 3421; fix by Jérémy Bobbio.
- Accept attempts to include a password authenticator in the
handshake, as supported by SOCKS5. This handles SOCKS clients that
don't know how to omit a password when authenticating. Resolves
bug 1666.
- Check for and recover from inconsistency in the microdescriptor
cache. This will make it harder for us to accidentally free a
microdescriptor without removing it from the appropriate data
structures. Fixes issue 3135; issue noted by "wanoskarnet".
- Shorten links in the tor-exit-notice file. Patch by Christian Kujau.
o Minor bugfixes (code security):
- Prevent a null-pointer dereference when receiving a data cell
for a nonexistent stream when the circuit in question has an
empty deliver window. We don't believe this is triggerable,
since we don't currently allow deliver windows to become empty,
but the logic is tricky enough that it's better to make the code
robust. Fixes bug 5541; bugfix on 0.0.2pre14.
- Fix a (harmless) integer overflow in cell statistics reported by
some fast relays. Fixes bug 5849; bugfix on 0.2.2.1-alpha.
- Fix our implementation of crypto_random_hostname() so it can't
overflow on ridiculously large inputs. (No Tor version has ever
provided this kind of bad inputs, but let's be correct in depth.)
Fixes bug 4413; bugfix on 0.2.2.9-alpha. Fix by Stephen Palmateer.
- Add a (probably redundant) memory clear between iterations of
the router status voting loop, to prevent future coding errors
where data might leak between iterations of the loop. Resolves
ticket 6514.
o Minor bugfixes (wrapper functions):
- Abort if tor_vasprintf() fails in connection_printf_to_buf() (a
utility function used in the control-port code). This shouldn't
ever happen unless Tor is completely out of memory, but if it did
happen and Tor somehow recovered from it, Tor could have sent a log
message to a control port in the middle of a reply to a controller
command. Fixes part of bug 3428; bugfix on 0.1.2.3-alpha.
- Fix some (not actually triggerable) buffer size checks in usage of
tor_inet_ntop(). Fixes bug 4434; bugfix on Tor 0.2.0.1-alpha. Patch
by Anders Sundman.
- Fix parsing of some corner-cases with tor_inet_pton(). Fixes
bug 4515; bugfix on 0.2.0.1-alpha; fix by Anders Sundman.
- Enforce correct return behavior of tor_vsscanf() when the '%%'
pattern is used. Fixes bug 5558. Bugfix on 0.2.1.13.
- Make our replacement implementation of strtok_r() compatible with
the standard behavior of strtok_r(). Patch by nils. Fixes bug 5091;
bugfix on 0.2.2.1-alpha.
- Find more places in the code that should have been testing for
invalid sockets using the SOCKET_OK macro. Required for a fix
for bug 4533. Bugfix on 0.2.2.28-beta.
o Minor bugfixes (code correctness):
- Check return value of fputs() when writing authority certificate
file. Fixes Coverity issue 709056; bugfix on 0.2.0.1-alpha.
- When building Tor on Windows with -DUNICODE (not default), ensure
that error messages, filenames, and DNS server names are always
NUL-terminated when we convert them to a single-byte encoding.
Fixes bug 5909; bugfix on 0.2.2.16-alpha.
- Fix a memory leak when trying to launch a DNS request when the
nameservers are unconfigurable. Fixes bug 5916; bugfix on Tor
0.1.2.1-alpha.
- Correct file sizes when reading binary files on Cygwin, to avoid
a bug where Tor would fail to read its state file. Fixes bug 6844;
bugfix on 0.1.2.7-alpha.
- Make sure to set *socket_error in all error cases in
connection_connect(), so it can't produce a warning about
errno being zero from errno_to_orconn_end_reason(). Bugfix on
0.2.1.1-alpha; resolves ticket 6028.
- Initialize conn->addr to a valid state in spawn_cpuworker(). Fixes
bug 4532; found by "troll_un".
o Minor bugfixes (clients):
- Allow one-hop directory-fetching circuits the full "circuit build
timeout" period, rather than just half of it, before failing them
and marking the relay down. This fix should help reduce cases where
clients declare relays (or worse, bridges) unreachable because
the TLS handshake takes a few seconds to complete. Fixes bug 6743;
bugfix on 0.2.2.2-alpha, where we changed the timeout from a static
30 seconds.
- Ensure we don't cannibalize circuits that are longer than three hops
already, so we don't end up making circuits with 5 or more
hops. Patch contributed by wanoskarnet. Fixes bug 5231; bugfix on
0.1.0.1-rc which introduced cannibalization.
o Minor bugfixes (relays):
- Don't publish a new relay descriptor when we reload our onion key,
unless the onion key has actually changed. Fixes bug 3263 and
resolves another cause of bug 1810. Bugfix on 0.1.1.11-alpha.
- When relays refuse a "create" cell because their queue of pending
create cells is too big (typically because their cpu can't keep up
with the arrival rate), send back reason "resource limit" rather
than reason "internal", so network measurement scripts can get a
more accurate picture. Bugfix on 0.1.1.11-alpha; fixes bug 7037.
- Exit nodes don't need to fetch certificates for authorities that
they don't recognize; only directory authorities, bridges,
and caches need to do that. Fixes part of bug 2297; bugfix on
0.2.2.11-alpha.
o Minor bugfixes (directory authority / mirrors):
- Avoid O(n^2) performance characteristics when parsing a large
extrainfo cache. Fixes bug 5828; bugfix on 0.2.0.1-alpha.
- Authorities no longer include any router in their microdescriptor
consensuses for which they couldn't generate or agree on a
microdescriptor. Fixes the second piece of bug 6404; fix on
0.2.2.6-alpha.
- When checking for requested signatures on the latest consensus
before serving it to a client, make sure to check the right
consensus flavor. Bugfix on 0.2.2.6-alpha.
- Fix an edge case where TestingTorNetwork is set but the authorities
and relays all have an uptime of zero, so the private Tor network
could briefly lack support for hidden services. Fixes bug 3886;
bugfix on 0.2.2.18-alpha.
- Directory caches no longer refuse to clean out descriptors because
of missing v2 networkstatus documents, unless they're configured
to retrieve v2 networkstatus documents. Fixes bug 4838; bugfix on
0.2.2.26-beta. Patch by Daniel Bryg.
- Don't serve or accept v2 hidden service descriptors over a relay's
DirPort. It's never correct to do so, and disabling it might
make it more annoying to exploit any bugs that turn up in the
descriptor-parsing code. Fixes bug 7149.
o Minor bugfixes (hidden services, client-side):
- Assert that hidden-service-related operations are not performed
using single-hop circuits. Previously, Tor would assert that
client-side streams are not attached to single-hop circuits,
but not that other sensitive operations on the client and service
side are not performed using single-hop circuits. Fixes bug 3332;
bugfix on 0.0.6.
- Avoid undefined behavior when parsing the list of supported
rendezvous/introduction protocols in a hidden service descriptor.
Previously, Tor would have confused (as-yet-unused) protocol version
numbers greater than 32 with lower ones on many platforms. Fixes
bug 6827; bugfix on 0.2.0.10-alpha. Found by George Kadianakis.
- Don't close hidden service client circuits which have almost
finished connecting to their destination when they reach
the normal circuit-build timeout. Previously, we would close
introduction circuits which are waiting for an acknowledgement
from the introduction point, and rendezvous circuits which have
been specified in an INTRODUCE1 cell sent to a hidden service,
after the normal CBT. Now, we mark them as 'timed out', and launch
another rendezvous attempt in parallel. This behavior change can
be disabled using the new CloseHSClientCircuitsImmediatelyOnTimeout
option. Fixes part of bug 1297; bugfix on 0.2.2.2-alpha.
o Minor bugfixes (hidden services, service-side):
- Don't close hidden-service-side rendezvous circuits when they
reach the normal circuit-build timeout. This behavior change can
be disabled using the new
CloseHSServiceRendCircuitsImmediatelyOnTimeout option. Fixes the
remaining part of bug 1297; bugfix on 0.2.2.2-alpha.
- Don't launch more than 10 service-side introduction-point circuits
for a hidden service in five minutes. Previously, we would consider
launching more introduction-point circuits if at least one second
had passed without any introduction-point circuits failing. Fixes
bug 4607; bugfix on 0.0.7pre1.
o Minor bugfixes (config option behavior):
- If the user tries to set MyFamily on a bridge, refuse to
do so, and warn about the security implications. Fixes bug 4657;
bugfix on 0.2.0.3-alpha.
- The "--quiet" and "--hush" options now apply not only to Tor's
behavior before logs are configured, but also to Tor's behavior in
the absense of configured logs. Fixes bug 3550; bugfix on
0.2.0.10-alpha.
- Change the AllowDotExit rules so they should actually work.
We now enforce AllowDotExit only immediately after receiving an
address via SOCKS or DNSPort: other sources are free to provide
.exit addresses after the resolution occurs. Fixes bug 3940;
bugfix on 0.2.2.1-alpha.
- Make "LearnCircuitBuildTimeout 0" work more reliably. Specifically,
don't depend on the consensus parameters or compute adaptive
timeouts when it is disabled. Fixes bug 5049; bugfix on
0.2.2.14-alpha.
- After we pick a directory mirror, we would refuse to use it if
it's in our ExcludeExitNodes list, resulting in mysterious failures
to bootstrap for people who just wanted to avoid exiting from
certain locations. Fixes bug 5623; bugfix on 0.2.2.25-alpha.
- When told to add a bridge with the same digest as a preexisting
bridge but a different addr:port, change the addr:port as
requested. Previously we would not notice the change. Fixes half
of bug 5603; fix on 0.2.2.26-beta.
o Minor bugfixes (controller):
- Allow manual 'authenticate' commands to the controller interface
from netcat (nc) as well as telnet. We were rejecting them because
they didn't come with the expected whitespace at the end of the
command. Bugfix on 0.1.1.1-alpha; fixes bug 2893.
- Report a real bootstrap problem to the controller on router
identity mismatch. Previously we just said "foo", which probably
made a lot of sense at the time. Fixes bug 4169; bugfix on
0.2.1.1-alpha.
- When we receive a SIGHUP and the controller __ReloadTorrcOnSIGHUP
option is set to 0 (which Vidalia version 0.2.16 now does when
a SAVECONF attempt fails), perform other actions that SIGHUP
usually causes (like reopening the logs). Fixes bug 5095; bugfix
on 0.2.1.9-alpha.
- Correctly handle checking the permissions on the parent
directory of a control socket in the root directory. Bug found
by Esteban Manchado Velázquez. Fixes bug 5089; bugfix on Tor
0.2.2.26-beta.
- End AUTHCHALLENGE error messages (in the control protocol) with
a CRLF. Fixes bug 5760; bugfix on 0.2.2.36.
o Minor bugfixes (network reading/writing):
- Disable writing on marked-for-close connections when they are
blocked on bandwidth, to prevent busy-looping in Libevent. Fixes
bug 5263; bugfix on 0.0.2pre13, where we first added a special
case for flushing marked connections.
- Make sure that there are no unhandled pending TLS errors before
reading from a TLS stream. We had checks in 0.1.0.3-rc, but
lost them in 0.1.0.5-rc when we refactored read_to_buf_tls().
Bugfix on 0.1.0.5-rc; fixes bug 4528.
- Detect SSL handshake even when the initial attempt to write the
server hello fails. Fixes bug 4592; bugfix on 0.2.0.13-alpha.
- If the client fails to set a reasonable set of ciphersuites
during its v2 handshake renegotiation, allow the renegotiation to
continue nevertheless (i.e. send all the required certificates).
Fixes bug 4591; bugfix on 0.2.0.20-rc.
o Minor bugfixes (other):
- Exit nodes now correctly report EADDRINUSE and EADDRNOTAVAIL as
resource exhaustion, so that clients can adjust their load to
try other exits. Fixes bug 4710; bugfix on 0.1.0.1-rc, which
started using END_STREAM_REASON_RESOURCELIMIT.
- Don't check for whether the address we're using for outbound
connections has changed until after the outbound connection has
completed. On Windows, getsockname() doesn't succeed until the
connection is finished. Fixes bug 5374; bugfix on 0.1.1.14-alpha.
- Don't hold a Windows file handle open for every file mapping;
the file mapping handle is sufficient. Fixes bug 5951; bugfix on
0.1.2.1-alpha.
- Fix wrong TCP port range in parse_port_range(). Fixes bug 6218;
bugfix on 0.2.1.10-alpha.
- If we fail to write a microdescriptor to the disk cache, do not
continue replacing the old microdescriptor file. Fixes bug 2954;
bugfix on 0.2.2.6-alpha.
o Minor bugfixes (log messages, path selection):
- Downgrade "set buildtimeout to low value" messages to "info"
severity; they were never an actual problem, there was never
anything reasonable to do about them, and they tended to spam logs
from time to time. Fixes bug 6251; bugfix on 0.2.2.2-alpha.
- Rate-limit the "Weighted bandwidth is 0.000000" message, and add
more information to it, so that we can track it down in case it
returns again. Mitigates bug 5235.
- Check CircuitBuildTimeout and LearnCircuitBuildTimeout in
options_validate(); warn if LearnCircuitBuildTimeout is disabled and
CircuitBuildTimeout is set unreasonably low. Resolves ticket 5452.
- Issue a log message if a guard completes less than 40% of your
circuits. Threshold is configurable by torrc option
PathBiasNoticeRate and consensus parameter pb_noticepct. There is
additional, off-by-default code to disable guards which fail too
many circuits. Addresses ticket 5458.
o Minor bugfixes (log messages, client):
- Downgrade "Got a certificate, but we already have it" log messages
from warning to info, except when we're a dirauth. Fixes bug 5238;
bugfix on 0.2.1.7-alpha.
- Fix the log message describing how we work around discovering
that our version is the ill-fated OpenSSL 0.9.8l. Fixes bug
4837; bugfix on 0.2.2.9-alpha.
- When logging about a disallowed .exit name, do not also call it
an "invalid onion address". Fixes bug 3325; bugfix on 0.2.2.9-alpha.
- Fix a log message suggesting that people contact a non-existent
email address. Fixes bug 3448.
- Rephrase the log message emitted if the TestSocks check is
successful. Patch from Fabian Keil; fixes bug 4094.
- Log (at debug level) whenever a circuit's purpose is changed.
- Log SSL state transitions at log level DEBUG, log domain
HANDSHAKE. This can be useful for debugging censorship events.
Implements ticket 3264.
- We now log which torrc file we're using on startup. Implements
ticket 2444.
- Rate-limit log messages when asked to connect anonymously to
a private address. When these hit, they tended to hit fast and
often. Also, don't bother trying to connect to addresses that we
are sure will resolve to 127.0.0.1: getting 127.0.0.1 in a directory
reply makes us think we have been lied to, even when the address the
client tried to connect to was "localhost." Resolves ticket 2822.
o Minor bugfixes (log messages, non-client):
- Downgrade "eventdns rejected address" message to LOG_PROTOCOL_WARN.
Fixes bug 5932; bugfix on 0.2.2.7-alpha.
- Don't log that we have "decided to publish new relay descriptor"
unless we are actually publishing a descriptor. Fixes bug 3942;
bugfix on 0.2.2.28-beta.
- Log which authority we're missing votes from when we go to fetch
them from the other auths.
- Replace "Sending publish request" log messages with "Launching
upload", so that they no longer confusingly imply that we're
sending something to a directory we might not even be connected
to yet. Fixes bug 3311; bugfix on 0.2.0.10-alpha.
- Warn when Tor is configured to use accounting in a way that can
link a hidden service to some other hidden service or public
address. Resolves ticket 6490.
- Fix a minor formatting issue in one of tor-gencert's error messages.
Fixes bug 4574.
o Testing:
- Update to the latest version of the tinytest unit testing framework.
This includes a couple of bugfixes that can be relevant for
running forked unit tests on Windows, and removes all reserved
identifiers.
- Avoid a false positive in the util/threads unit test by increasing
the maximum timeout time. Fixes bug 6227; bugfix on 0.2.0.4-alpha.
- Make it possible to set the TestingTorNetwork configuration
option using AlternateDirAuthority and AlternateBridgeAuthority
as an alternative to setting DirServer. Addresses ticket 6377.
- Add a unit test for the environment_variable_names_equal() function.
- A wide variety of new unit tests by Esteban Manchado Velázquez.
- Numerous new unit tests for functions in util.c and address.c by
Anders Sundman.
- The long-disabled benchmark tests are now split into their own
./src/test/bench binary.
- The benchmark tests can now use more accurate timers than
gettimeofday() when such timers are available.
- Use tt_assert(), not tor_assert(), for checking for test failures.
This makes the unit tests more able to go on in the event that
one of them fails.
o Build improvements:
- Use the dead_strip option when building Tor on OS X. This reduces
binary size by almost 19% when linking openssl and libevent
statically, which we do for Tor Browser Bundle.
- Provide a better error message about possible OSX Asciidoc failure
reasons. Fixes bug 6436.
- Detect attempts to build Tor on (as yet hypothetical) versions
of Windows where sizeof(intptr_t) != sizeof(SOCKET). Partial
fix for bug 4533. Bugfix on 0.2.2.28-beta.
- On Windows, we now define the _WIN32_WINNT macros only if they
are not already defined. This lets the person building Tor decide,
if they want, to require a later version of Windows.
- Our autogen.sh script now uses autoreconf to launch autoconf,
automake, and so on. This is more robust against some of the failure
modes associated with running the autotools pieces on their own.
- Running "make version" now displays the version of Tor that
we're about to build. Idea from katmagic; resolves issue 4400.
- Make 'tor --digests' list hashes of all Tor source files. Bugfix
on 0.2.2.4-alpha; fixes bug 3427.
- New --enable-static-tor configure option for building Tor as
statically as possible. Idea, general hackery and thoughts from
Alexei Czeskis, John Gilmore, Jacob Appelbaum. Implements ticket
2702.
- Limited, experimental support for building with nmake and MSVC.
o Build requirements:
- Building Tor with bufferevent support now requires Libevent
2.0.13-stable or later. Previous versions of Libevent had bugs in
SSL-related bufferevents and related issues that would make Tor
work badly with bufferevents. Requiring 2.0.13-stable also allows
Tor with bufferevents to take advantage of Libevent APIs
introduced after 2.0.8-rc.
- Our build system requires automake 1.6 or later to create the
Makefile.in files. Previously, you could have used 1.4.
This only affects developers and people building Tor from git;
people who build Tor from the source distribution without changing
the Makefile.am files should be fine.
- Detect when we try to build on a platform that doesn't define
AF_UNSPEC to 0. We don't work there, so refuse to compile.
o Build fixes (compile/link):
- Format more doubles with %f, not %lf. Patch from grarpamp to make
Tor build correctly on older BSDs again. Fixes bug 3894; bugfix on
Tor 0.2.0.8-alpha.
- When building with --enable-static-tor on OpenBSD, do not
erroneously attempt to link -lrt. Fixes bug 5103.
- Set _WIN32_WINNT to 0x0501 consistently throughout the code, so
that IPv6 stuff will compile on MSVC, and compilation issues
will be easier to track down. Fixes bug 5861.
- Fix build and 64-bit compile warnings from --enable-openbsd-malloc.
Fixes bug 6379. Bugfix on 0.2.0.20-rc.
- Make Tor build correctly again with -DUNICODE -D_UNICODE defined.
Fixes bug 6097; bugfix on 0.2.2.16-alpha.
o Build fixes (other):
- Use the _WIN32 macro throughout our code to detect Windows.
(Previously we had used the obsolete 'WIN32' and the idiosyncratic
'MS_WINDOWS'.)
- Properly handle the case where the build-tree is not the same
as the source tree when generating src/common/common_sha1.i,
src/or/micro-revision.i, and src/or/or_sha1.i. Fixes bug 3953;
bugfix on 0.2.0.1-alpha.
- During configure, search for library containing cos function as
libm lives in libcore on some platforms (BeOS/Haiku). Linking
against libm was hard-coded before. Fixes the first part of bug
4727; bugfix on 0.2.2.2-alpha. Patch and analysis by Martin Hebnes
Pedersen.
- Prevent a false positive from the check-spaces script, by disabling
the "whitespace between function name and (" check for functions
named 'op()'.
o Packaging (RPM) changes:
- Update our default RPM spec files to work with mock and rpmbuild
on RHEL/Fedora. They have an updated set of dependencies and
conflicts, a fix for an ancient typo when creating the "_tor"
user, and better instructions. Thanks to Ondrej Mikle for the
patch series. Fixes bug 6043.
- On OpenSUSE, create the /var/run/tor directory on startup if it
is not already created. Patch from Andreas Stieger. Fixes bug 2573.
o Code refactoring (safety):
- Do not use SMARTLIST_FOREACH for any loop whose body exceeds
10 lines. Also, don't nest them. Doing so in the past has
led to hard-to-debug code. The new style is to use the
SMARTLIST_FOREACH_{BEGIN,END} pair. Addresses issue 6400.
- Use macros to indicate OpenSSL versions, so we don't need to worry
about accidental hexadecimal bit shifts.
- Use tor_sscanf() in place of scanf() in more places through the
code. This makes us a little more locale-independent, and
should help shut up code-analysis tools that can't tell
a safe sscanf string from a dangerous one.
- Convert more instances of tor_snprintf+tor_strdup into tor_asprintf.
- Use the smartlist_add_asprintf() alias more consistently.
o Code refactoring (consolidate):
- A major revision to our internal node-selecting and listing logic.
Tor already had at least two major ways to look at the question of
"which Tor servers do we know about": a list of router descriptors,
and a list of entries in the current consensus. With
microdescriptors, we're adding a third. Having so many systems
without an abstraction layer over them was hurting the codebase.
Now, we have a new "node_t" abstraction that presents a consistent
interface to a client's view of a Tor node, and holds (nearly) all
of the mutable state formerly in routerinfo_t and routerstatus_t.
- Move tor_gettimeofday_cached() into compat_libevent.c, and use
Libevent's notion of cached time when possible.
- Remove duplicate code for invoking getrlimit() from control.c.
- Use OpenSSL's built-in SSL_state_string_long() instead of our
own homebrewed ssl_state_to_string() replacement. Patch from
Emile Snyder. Fixes bug 4653.
- Change the symmetric cipher interface so that creating and
initializing a stream cipher are no longer separate functions.
o Code refactoring (separate):
- Make a new "entry connection" struct as an internal subtype of "edge
connection", to simplify the code and make exit connections smaller.
- Split connection_about_to_close() into separate functions for each
connection type.
- Rewrite the listener-selection logic so that parsing which ports
we want to listen on is now separate from binding to the ports
we want.
o Code refactoring (name changes):
- Rename a handful of old identifiers, mostly related to crypto
structures and crypto functions. By convention, our "create an
object" functions are called "type_new()", our "free an object"
functions are called "type_free()", and our types indicate that
they are types only with a final "_t". But a handful of older
types and functions broke these rules, with function names like
"type_create" or "subsystem_op_type", or with type names like
type_env_t.
- Rename Tor functions that turn strings into addresses, so that
"parse" indicates that no hostname resolution occurs, and
"lookup" indicates that hostname resolution may occur. This
should help prevent mistakes in the future. Fixes bug 3512.
- Use the name "CERTS" consistently to refer to the new cell type;
we were calling it CERT in some places and CERTS in others.
- Use a TOR_INVALID_SOCKET macro when initializing a socket to an
invalid value, rather than just -1.
- Rename the bench_{aes,dmap} functions to test_*, so that tinytest
can pick them up when the tests aren't disabled. Bugfix on
0.2.2.4-alpha which introduced tinytest.
o Code refactoring (other):
- Defensively refactor rend_mid_rendezvous() so that protocol
violations and length checks happen in the beginning. Fixes
bug 5645.
- Remove the pure attribute from all functions that used it
previously. In many cases we assigned it incorrectly, because the
functions might assert or call impure functions, and we don't have
evidence that keeping the pure attribute is worthwhile. Implements
changes suggested in ticket 4421.
- Move the replay-detection cache for the RSA-encrypted parts of
INTRODUCE2 cells to the introduction point data structures.
Previously, we would use one replay-detection cache per hidden
service. Required by fix for bug 3460.
- The helper programs tor-gencert, tor-resolve, and tor-checkkey
no longer link against Libevent: they never used it, but
our library structure used to force them to link it.
o Removed features and files:
- Remove all internal support for unpadded RSA. We never used it, and
it would be a bad idea to start.
- Remove some workaround code for OpenSSL 0.9.6 (which is no longer
supported).
- Remove some redundant #include directives throughout the code.
Patch from Andrea Gelmini.
- Remove some old code to remember statistics about which descriptors
we've served as a directory mirror. The feature wasn't used and
is outdated now that microdescriptors are around.
- Remove some old code to work around even older versions of Tor that
used forked processes to handle DNS requests. Such versions of Tor
are no longer in use as relays.
- The "torify" script no longer supports the "tsocks" socksifier
tool, since tsocks doesn't support DNS and UDP right for Tor.
Everyone should be using torsocks instead. Fixes bugs 3530 and
5180. Based on a patch by "ugh".
- Remove the torrc.bridge file: we don't use it for anything, and
it had become badly desynchronized from torrc.sample. Resolves
bug 5622.
o Documentation:
- Begin a doc/state-contents.txt file to explain the contents of
the Tor state file. Fixes bug 2987.
- Clarify the documentation for the Alternate*Authority options.
Fixes bug 6387.
- Document the --defaults-torrc option, and the new semantics for
overriding, extending, and clearing lists of options. Closes
bug 4748.
- Add missing man page documentation for consensus and microdesc
files. Resolves ticket 6732.
- Fix some typos in the manpages. Patch from A. Costa. Fixes bug 6500.
o Documentation fixes:
- Improve the manual's documentation for the NT Service command-line
options. Addresses ticket 3964.
- Clarify SessionGroup documentation slightly; resolves ticket 5437.
- Document the changes to the ORPort and DirPort options, and the
fact that {OR/Dir}ListenAddress is now unnecessary (and
therefore deprecated). Resolves ticket 5597.
- Correct a broken faq link in the INSTALL file. Fixes bug 2307.
- Clarify that hidden services are TCP only. Fixes bug 6024.
Changes in version 0.2.2.39 - 2012-09-11
Tor 0.2.2.39 fixes two more opportunities for remotely triggerable
assertions.
o Security fixes:
- Fix an assertion failure in tor_timegm() that could be triggered
by a badly formatted directory object. Bug found by fuzzing with
Radamsa. Fixes bug 6811; bugfix on 0.2.0.20-rc.
- Do not crash when comparing an address with port value 0 to an
address policy. This bug could have been used to cause a remote
assertion failure by or against directory authorities, or to
allow some applications to crash clients. Fixes bug 6690; bugfix
on 0.2.1.10-alpha.
Changes in version 0.2.2.38 - 2012-08-12
Tor 0.2.2.38 fixes a remotely triggerable crash bug, and fixes a timing
attack that could in theory leak path information.
o Security fixes:
- Avoid an uninitialized memory read when reading a vote or consensus
document that has an unrecognized flavor name. This read could
lead to a remote crash bug. Fixes bug 6530; bugfix on 0.2.2.6-alpha.
- Try to leak less information about what relays a client is
choosing to a side-channel attacker. Previously, a Tor client would
stop iterating through the list of available relays as soon as it
had chosen one, thus finishing a little earlier when it picked
a router earlier in the list. If an attacker can recover this
timing information (nontrivial but not proven to be impossible),
they could learn some coarse-grained information about which relays
a client was picking (middle nodes in particular are likelier to
be affected than exits). The timing attack might be mitigated by
other factors (see bug 6537 for some discussion), but it's best
not to take chances. Fixes bug 6537; bugfix on 0.0.8rc1.
Changes in version 0.2.2.37 - 2012-06-06
Tor 0.2.2.37 introduces a workaround for a critical renegotiation
bug in OpenSSL 1.0.1 (where 20% of the Tor network can't talk to itself
currently).
o Major bugfixes:
- Work around a bug in OpenSSL that broke renegotiation with TLS
1.1 and TLS 1.2. Without this workaround, all attempts to speak
the v2 Tor connection protocol when both sides were using OpenSSL
1.0.1 would fail. Resolves ticket 6033.
- When waiting for a client to renegotiate, don't allow it to add
any bytes to the input buffer. This fixes a potential DoS issue.
Fixes bugs 5934 and 6007; bugfix on 0.2.0.20-rc.
- Fix an edge case where if we fetch or publish a hidden service
descriptor, we might build a 4-hop circuit and then use that circuit
for exiting afterwards -- even if the new last hop doesn't obey our
ExitNodes config option. Fixes bug 5283; bugfix on 0.2.0.10-alpha.
o Minor bugfixes:
- Fix a build warning with Clang 3.1 related to our use of vasprintf.
Fixes bug 5969. Bugfix on 0.2.2.11-alpha.
o Minor features:
- Tell GCC and Clang to check for any errors in format strings passed
to the tor_v*(print|scan)f functions.
Changes in version 0.2.2.36 - 2012-05-24
Tor 0.2.2.36 updates the addresses for two of the eight directory
authorities, fixes some potential anonymity and security issues,
and fixes several crash bugs.
Tor 0.2.1.x has reached its end-of-life. Those Tor versions have many
known flaws, and nobody should be using them. You should upgrade. If
you're using a Linux or BSD and its packages are obsolete, stop using
those packages and upgrade anyway.
o Directory authority changes:
- Change IP address for maatuska (v3 directory authority).
- Change IP address for ides (v3 directory authority), and rename
it to turtles.
o Security fixes:
- When building or running with any version of OpenSSL earlier
than 0.9.8s or 1.0.0f, disable SSLv3 support. These OpenSSL
versions have a bug (CVE-2011-4576) in which their block cipher
padding includes uninitialized data, potentially leaking sensitive
information to any peer with whom they make a SSLv3 connection. Tor
does not use SSL v3 by default, but a hostile client or server
could force an SSLv3 connection in order to gain information that
they shouldn't have been able to get. The best solution here is to
upgrade to OpenSSL 0.9.8s or 1.0.0f (or later). But when building
or running with a non-upgraded OpenSSL, we disable SSLv3 entirely
to make sure that the bug can't happen.
- Never use a bridge or a controller-supplied node as an exit, even
if its exit policy allows it. Found by wanoskarnet. Fixes bug
5342. Bugfix on 0.1.1.15-rc (for controller-purpose descriptors)
and 0.2.0.3-alpha (for bridge-purpose descriptors).
- Only build circuits if we have a sufficient threshold of the total
descriptors that are marked in the consensus with the "Exit"
flag. This mitigates an attack proposed by wanoskarnet, in which
all of a client's bridges collude to restrict the exit nodes that
the client knows about. Fixes bug 5343.
- Provide controllers with a safer way to implement the cookie
authentication mechanism. With the old method, if another locally
running program could convince a controller that it was the Tor
process, then that program could trick the controller into telling
it the contents of an arbitrary 32-byte file. The new "SAFECOOKIE"
authentication method uses a challenge-response approach to prevent
this attack. Fixes bug 5185; implements proposal 193.
o Major bugfixes:
- Avoid logging uninitialized data when unable to decode a hidden
service descriptor cookie. Fixes bug 5647; bugfix on 0.2.1.5-alpha.
- Avoid a client-side assertion failure when receiving an INTRODUCE2
cell on a general purpose circuit. Fixes bug 5644; bugfix on
0.2.1.6-alpha.
- Fix builds when the path to sed, openssl, or sha1sum contains
spaces, which is pretty common on Windows. Fixes bug 5065; bugfix
on 0.2.2.1-alpha.
- Correct our replacements for the timeradd() and timersub() functions
on platforms that lack them (for example, Windows). The timersub()
function is used when expiring circuits, while timeradd() is
currently unused. Bug report and patch by Vektor. Fixes bug 4778;
bugfix on 0.2.2.24-alpha.
- Fix the SOCKET_OK test that we use to tell when socket
creation fails so that it works on Win64. Fixes part of bug 4533;
bugfix on 0.2.2.29-beta. Bug found by wanoskarnet.
o Minor bugfixes:
- Reject out-of-range times like 23:59:61 in parse_rfc1123_time().
Fixes bug 5346; bugfix on 0.0.8pre3.
- Make our number-parsing functions always treat too-large values
as an error, even when those values exceed the width of the
underlying type. Previously, if the caller provided these
functions with minima or maxima set to the extreme values of the
underlying integer type, these functions would return those
values on overflow rather than treating overflow as an error.
Fixes part of bug 5786; bugfix on 0.0.9.
- Older Linux kernels erroneously respond to strange nmap behavior
by having accept() return successfully with a zero-length
socket. When this happens, just close the connection. Previously,
we would try harder to learn the remote address: but there was
no such remote address to learn, and our method for trying to
learn it was incorrect. Fixes bugs 1240, 4745, and 4747. Bugfix
on 0.1.0.3-rc. Reported and diagnosed by "r1eo".
- Correct parsing of certain date types in parse_http_time().
Without this patch, If-Modified-Since would behave
incorrectly. Fixes bug 5346; bugfix on 0.2.0.2-alpha. Patch from
Esteban Manchado Velázques.
- Change the BridgePassword feature (part of the "bridge community"
design, which is not yet implemented) to use a time-independent
comparison. The old behavior might have allowed an adversary
to use timing to guess the BridgePassword value. Fixes bug 5543;
bugfix on 0.2.0.14-alpha.
- Detect and reject certain misformed escape sequences in
configuration values. Previously, these values would cause us
to crash if received in a torrc file or over an authenticated
control port. Bug found by Esteban Manchado Velázquez, and
independently by Robert Connolly from Matta Consulting who further
noted that it allows a post-authentication heap overflow. Patch
by Alexander Schrijver. Fixes bugs 5090 and 5402 (CVE 2012-1668);
bugfix on 0.2.0.16-alpha.
- Fix a compile warning when using the --enable-openbsd-malloc
configure option. Fixes bug 5340; bugfix on 0.2.0.20-rc.
- During configure, detect when we're building with clang version
3.0 or lower and disable the -Wnormalized=id and -Woverride-init
CFLAGS. clang doesn't support them yet.
- When sending an HTTP/1.1 proxy request, include a Host header.
Fixes bug 5593; bugfix on 0.2.2.1-alpha.
- Fix a NULL-pointer dereference on a badly formed SETCIRCUITPURPOSE
command. Found by mikeyc. Fixes bug 5796; bugfix on 0.2.2.9-alpha.
- If we hit the error case where routerlist_insert() replaces an
existing (old) server descriptor, make sure to remove that
server descriptor from the old_routers list. Fix related to bug
1776. Bugfix on 0.2.2.18-alpha.
o Minor bugfixes (documentation and log messages):
- Fix a typo in a log message in rend_service_rendezvous_has_opened().
Fixes bug 4856; bugfix on Tor 0.0.6.
- Update "ClientOnly" man page entry to explain that there isn't
really any point to messing with it. Resolves ticket 5005.
- Document the GiveGuardFlagTo_CVE_2011_2768_VulnerableRelays
directory authority option (introduced in Tor 0.2.2.34).
- Downgrade the "We're missing a certificate" message from notice
to info: people kept mistaking it for a real problem, whereas it
is seldom the problem even when we are failing to bootstrap. Fixes
bug 5067; bugfix on 0.2.0.10-alpha.
- Correctly spell "connect" in a log message on failure to create a
controlsocket. Fixes bug 4803; bugfix on 0.2.2.26-beta.
- Clarify the behavior of MaxCircuitDirtiness with hidden service
circuits. Fixes issue 5259.
o Minor features:
- Directory authorities now reject versions of Tor older than
0.2.1.30, and Tor versions between 0.2.2.1-alpha and 0.2.2.20-alpha
inclusive. These versions accounted for only a small fraction of
the Tor network, and have numerous known security issues. Resolves
issue 4788.
- Update to the May 1 2012 Maxmind GeoLite Country database.
- Feature removal:
- When sending or relaying a RELAY_EARLY cell, we used to convert
it to a RELAY cell if the connection was using the v1 link
protocol. This was a workaround for older versions of Tor, which
didn't handle RELAY_EARLY cells properly. Now that all supported
versions can handle RELAY_EARLY cells, and now that we're enforcing
the "no RELAY_EXTEND commands except in RELAY_EARLY cells" rule,
remove this workaround. Addresses bug 4786.
Changes in version 0.2.2.35 - 2011-12-16
Tor 0.2.2.35 fixes a critical heap-overflow security issue in Tor's
buffers code. Absolutely everybody should upgrade.
The bug relied on an incorrect calculation when making data continuous
in one of our IO buffers, if the first chunk of the buffer was
misaligned by just the wrong amount. The miscalculation would allow an
attacker to overflow a piece of heap-allocated memory. To mount this
attack, the attacker would need to either open a SOCKS connection to
Tor's SocksPort (usually restricted to localhost), or target a Tor
instance configured to make its connections through a SOCKS proxy
(which Tor does not do by default).
Good security practice requires that all heap-overflow bugs should be
presumed to be exploitable until proven otherwise, so we are treating
this as a potential code execution attack. Please upgrade immediately!
This bug does not affect bufferevents-based builds of Tor. Special
thanks to "Vektor" for reporting this issue to us!
Tor 0.2.2.35 also fixes several bugs in previous versions, including
crash bugs for unusual configurations, and a long-term bug that
would prevent Tor from starting on Windows machines with draconian
AV software.
With this release, we remind everyone that 0.2.0.x has reached its
formal end-of-life. Those Tor versions have many known flaws, and
nobody should be using them. You should upgrade -- ideally to the
0.2.2.x series. If you're using a Linux or BSD and its packages are
obsolete, stop using those packages and upgrade anyway.
The Tor 0.2.1.x series is also approaching its end-of-life: it will no
longer receive support after some time in early 2012.
o Major bugfixes:
- Fix a heap overflow bug that could occur when trying to pull
data into the first chunk of a buffer, when that chunk had
already had some data drained from it. Fixes CVE-2011-2778;
bugfix on 0.2.0.16-alpha. Reported by "Vektor".
- Initialize Libevent with the EVENT_BASE_FLAG_NOLOCK flag enabled, so
that it doesn't attempt to allocate a socketpair. This could cause
some problems on Windows systems with overzealous firewalls. Fix for
bug 4457; workaround for Libevent versions 2.0.1-alpha through
2.0.15-stable.
- If we mark an OR connection for close based on a cell we process,
don't process any further cells on it. We already avoid further
reads on marked-for-close connections, but now we also discard the
cells we'd already read. Fixes bug 4299; bugfix on 0.2.0.10-alpha,
which was the first version where we might mark a connection for
close based on processing a cell on it.
- Correctly sanity-check that we don't underflow on a memory
allocation (and then assert) for hidden service introduction
point decryption. Bug discovered by Dan Rosenberg. Fixes bug 4410;
bugfix on 0.2.1.5-alpha.
- Fix a memory leak when we check whether a hidden service
descriptor has any usable introduction points left. Fixes bug
4424. Bugfix on 0.2.2.25-alpha.
- Don't crash when we're running as a relay and don't have a GeoIP
file. Bugfix on 0.2.2.34; fixes bug 4340. This backports a fix
we've had in the 0.2.3.x branch already.
- When running as a client, do not print a misleading (and plain
wrong) log message that we're collecting "directory request"
statistics: clients don't collect statistics. Also don't create a
useless (because empty) stats file in the stats/ directory. Fixes
bug 4353; bugfix on 0.2.2.34.
o Minor bugfixes:
- Detect failure to initialize Libevent. This fix provides better
detection for future instances of bug 4457.
- Avoid frequent calls to the fairly expensive cull_wedged_cpuworkers
function. This was eating up hideously large amounts of time on some
busy servers. Fixes bug 4518; bugfix on 0.0.9.8.
- Resolve an integer overflow bug in smartlist_ensure_capacity().
Fixes bug 4230; bugfix on Tor 0.1.0.1-rc. Based on a patch by
Mansour Moufid.
- Don't warn about unused log_mutex in log.c when building with
--disable-threads using a recent GCC. Fixes bug 4437; bugfix on
0.1.0.6-rc which introduced --disable-threads.
- When configuring, starting, or stopping an NT service, stop
immediately after the service configuration attempt has succeeded
or failed. Fixes bug 3963; bugfix on 0.2.0.7-alpha.
- When sending a NETINFO cell, include the original address
received for the other side, not its canonical address. Found
by "troll_un"; fixes bug 4349; bugfix on 0.2.0.10-alpha.
- Fix a typo in a hibernation-related log message. Fixes bug 4331;
bugfix on 0.2.2.23-alpha; found by "tmpname0901".
- Fix a memory leak in launch_direct_bridge_descriptor_fetch() that
occurred when a client tried to fetch a descriptor for a bridge
in ExcludeNodes. Fixes bug 4383; bugfix on 0.2.2.25-alpha.
- Backport fixes for a pair of compilation warnings on Windows.
Fixes bug 4521; bugfix on 0.2.2.28-beta and on 0.2.2.29-beta.
- If we had ever tried to call tor_addr_to_str on an address of
unknown type, we would have done a strdup on an uninitialized
buffer. Now we won't. Fixes bug 4529; bugfix on 0.2.1.3-alpha.
Reported by "troll_un".
- Correctly detect and handle transient lookup failures from
tor_addr_lookup. Fixes bug 4530; bugfix on 0.2.1.5-alpha.
Reported by "troll_un".
- Fix null-pointer access that could occur if TLS allocation failed.
Fixes bug 4531; bugfix on 0.2.0.20-rc. Found by "troll_un".
- Use tor_socket_t type for listener argument to accept(). Fixes bug
4535; bugfix on 0.2.2.28-beta. Found by "troll_un".
o Minor features:
- Add two new config options for directory authorities:
AuthDirFastGuarantee sets a bandwidth threshold for guaranteeing the
Fast flag, and AuthDirGuardBWGuarantee sets a bandwidth threshold
that is always sufficient to satisfy the bandwidth requirement for
the Guard flag. Now it will be easier for researchers to simulate
Tor networks with different values. Resolves ticket 4484.
- When Tor ignores a hidden service specified in its configuration,
include the hidden service's directory in the warning message.
Previously, we would only tell the user that some hidden service
was ignored. Bugfix on 0.0.6; fixes bug 4426.
- Update to the December 6 2011 Maxmind GeoLite Country database.
o Packaging changes:
- Make it easier to automate expert package builds on Windows,
by removing an absolute path from makensis.exe command.
Changes in version 0.2.1.32 - 2011-12-16
Tor 0.2.1.32 backports important security and privacy fixes for
oldstable. This release is intended only for package maintainers and
others who cannot use the 0.2.2 stable series. All others should be
using Tor 0.2.2.x or newer.
The Tor 0.2.1.x series will reach formal end-of-life some time in
early 2012; we will stop releasing patches for it then.
o Major bugfixes (also included in 0.2.2.x):
- Correctly sanity-check that we don't underflow on a memory
allocation (and then assert) for hidden service introduction
point decryption. Bug discovered by Dan Rosenberg. Fixes bug 4410;
bugfix on 0.2.1.5-alpha.
- Fix a heap overflow bug that could occur when trying to pull
data into the first chunk of a buffer, when that chunk had
already had some data drained from it. Fixes CVE-2011-2778;
bugfix on 0.2.0.16-alpha. Reported by "Vektor".
o Minor features:
- Update to the December 6 2011 Maxmind GeoLite Country database.
Changes in version 0.2.2.34 - 2011-10-26
Tor 0.2.2.34 fixes a critical anonymity vulnerability where an attacker
can deanonymize Tor users. Everybody should upgrade.
The attack relies on four components: 1) Clients reuse their TLS cert
when talking to different relays, so relays can recognize a user by
the identity key in her cert. 2) An attacker who knows the client's
identity key can probe each guard relay to see if that identity key
is connected to that guard relay right now. 3) A variety of active
attacks in the literature (starting from "Low-Cost Traffic Analysis
of Tor" by Murdoch and Danezis in 2005) allow a malicious website to
discover the guard relays that a Tor user visiting the website is using.
4) Clients typically pick three guards at random, so the set of guards
for a given user could well be a unique fingerprint for her. This
release fixes components #1 and #2, which is enough to block the attack;
the other two remain as open research problems. Special thanks to
"frosty_un" for reporting the issue to us!
Clients should upgrade so they are no longer recognizable by the TLS
certs they present. Relays should upgrade so they no longer allow a
remote attacker to probe them to test whether unpatched clients are
currently connected to them.
This release also fixes several vulnerabilities that allow an attacker
to enumerate bridge relays. Some bridge enumeration attacks still
remain; see for example proposal 188.
o Privacy/anonymity fixes (clients):
- Clients and bridges no longer send TLS certificate chains on
outgoing OR connections. Previously, each client or bridge would
use the same cert chain for all outgoing OR connections until
its IP address changes, which allowed any relay that the client
or bridge contacted to determine which entry guards it is using.
Fixes CVE-2011-2768. Bugfix on 0.0.9pre5; found by "frosty_un".
- If a relay receives a CREATE_FAST cell on a TLS connection, it
no longer considers that connection as suitable for satisfying a
circuit EXTEND request. Now relays can protect clients from the
CVE-2011-2768 issue even if the clients haven't upgraded yet.
- Directory authorities no longer assign the Guard flag to relays
that haven't upgraded to the above "refuse EXTEND requests
to client connections" fix. Now directory authorities can
protect clients from the CVE-2011-2768 issue even if neither
the clients nor the relays have upgraded yet. There's a new
"GiveGuardFlagTo_CVE_2011_2768_VulnerableRelays" config option
to let us transition smoothly, else tomorrow there would be no
guard relays.
o Privacy/anonymity fixes (bridge enumeration):
- Bridge relays now do their directory fetches inside Tor TLS
connections, like all the other clients do, rather than connecting
directly to the DirPort like public relays do. Removes another
avenue for enumerating bridges. Fixes bug 4115; bugfix on 0.2.0.35.
- Bridges relays now build circuits for themselves in a more similar
way to how clients build them. Removes another avenue for
enumerating bridges. Fixes bug 4124; bugfix on 0.2.0.3-alpha,
when bridges were introduced.
- Bridges now refuse CREATE or CREATE_FAST cells on OR connections
that they initiated. Relays could distinguish incoming bridge
connections from client connections, creating another avenue for
enumerating bridges. Fixes CVE-2011-2769. Bugfix on 0.2.0.3-alpha.
Found by "frosty_un".
o Major bugfixes:
- Fix a crash bug when changing node restrictions while a DNS lookup
is in-progress. Fixes bug 4259; bugfix on 0.2.2.25-alpha. Bugfix
by "Tey'".
- Don't launch a useless circuit after failing to use one of a
hidden service's introduction points. Previously, we would
launch a new introduction circuit, but not set the hidden service
which that circuit was intended to connect to, so it would never
actually be used. A different piece of code would then create a
new introduction circuit correctly. Bug reported by katmagic and
found by Sebastian Hahn. Bugfix on 0.2.1.13-alpha; fixes bug 4212.
o Minor bugfixes:
- Change an integer overflow check in the OpenBSD_Malloc code so
that GCC is less likely to eliminate it as impossible. Patch
from Mansour Moufid. Fixes bug 4059.
- When a hidden service turns an extra service-side introduction
circuit into a general-purpose circuit, free the rend_data and
intro_key fields first, so we won't leak memory if the circuit
is cannibalized for use as another service-side introduction
circuit. Bugfix on 0.2.1.7-alpha; fixes bug 4251.
- Bridges now skip DNS self-tests, to act a little more stealthily.
Fixes bug 4201; bugfix on 0.2.0.3-alpha, which first introduced
bridges. Patch by "warms0x".
- Fix internal bug-checking logic that was supposed to catch
failures in digest generation so that it will fail more robustly
if we ask for a nonexistent algorithm. Found by Coverity Scan.
Bugfix on 0.2.2.1-alpha; fixes Coverity CID 479.
- Report any failure in init_keys() calls launched because our
IP address has changed. Spotted by Coverity Scan. Bugfix on
0.1.1.4-alpha; fixes CID 484.
o Minor bugfixes (log messages and documentation):
- Remove a confusing dollar sign from the example fingerprint in the
man page, and also make the example fingerprint a valid one. Fixes
bug 4309; bugfix on 0.2.1.3-alpha.
- The next version of Windows will be called Windows 8, and it has
a major version of 6, minor version of 2. Correctly identify that
version instead of calling it "Very recent version". Resolves
ticket 4153; reported by funkstar.
- Downgrade log messages about circuit timeout calibration from
"notice" to "info": they don't require or suggest any human
intervention. Patch from Tom Lowenthal. Fixes bug 4063;
bugfix on 0.2.2.14-alpha.
o Minor features:
- Turn on directory request statistics by default and include them in
extra-info descriptors. Don't break if we have no GeoIP database.
Backported from 0.2.3.1-alpha; implements ticket 3951.
- Update to the October 4 2011 Maxmind GeoLite Country database.
Changes in version 0.2.1.31 - 2011-10-26
Tor 0.2.1.31 backports important security and privacy fixes for
oldstable. This release is intended only for package maintainers and
others who cannot use the 0.2.2 stable series. All others should be
using Tor 0.2.2.x or newer.
o Security fixes (also included in 0.2.2.x):
- Replace all potentially sensitive memory comparison operations
with versions whose runtime does not depend on the data being
compared. This will help resist a class of attacks where an
adversary can use variations in timing information to learn
sensitive data. Fix for one case of bug 3122. (Safe memcmp
implementation by Robert Ransom based partially on code by DJB.)
- Fix an assert in parsing router descriptors containing IPv6
addresses. This one took down the directory authorities when
somebody tried some experimental code. Bugfix on 0.2.1.3-alpha.
o Privacy/anonymity fixes (also included in 0.2.2.x):
- Clients and bridges no longer send TLS certificate chains on
outgoing OR connections. Previously, each client or bridge would
use the same cert chain for all outgoing OR connections until
its IP address changes, which allowed any relay that the client
or bridge contacted to determine which entry guards it is using.
Fixes CVE-2011-2768. Bugfix on 0.0.9pre5; found by "frosty_un".
- If a relay receives a CREATE_FAST cell on a TLS connection, it
no longer considers that connection as suitable for satisfying a
circuit EXTEND request. Now relays can protect clients from the
CVE-2011-2768 issue even if the clients haven't upgraded yet.
- Bridges now refuse CREATE or CREATE_FAST cells on OR connections
that they initiated. Relays could distinguish incoming bridge
connections from client connections, creating another avenue for
enumerating bridges. Fixes CVE-2011-2769. Bugfix on 0.2.0.3-alpha.
Found by "frosty_un".
- When receiving a hidden service descriptor, check that it is for
the hidden service we wanted. Previously, Tor would store any
hidden service descriptors that a directory gave it, whether it
wanted them or not. This wouldn't have let an attacker impersonate
a hidden service, but it did let directories pre-seed a client
with descriptors that it didn't want. Bugfix on 0.0.6.
- Avoid linkability based on cached hidden service descriptors: forget
all hidden service descriptors cached as a client when processing a
SIGNAL NEWNYM command. Fixes bug 3000; bugfix on 0.0.6.
- Make the bridge directory authority refuse to answer directory
requests for "all" descriptors. It used to include bridge
descriptors in its answer, which was a major information leak.
Found by "piebeer". Bugfix on 0.2.0.3-alpha.
- Don't attach new streams to old rendezvous circuits after SIGNAL
NEWNYM. Previously, we would keep using an existing rendezvous
circuit if it remained open (i.e. if it were kept open by a
long-lived stream, or if a new stream were attached to it before
Tor could notice that it was old and no longer in use). Bugfix on
0.1.1.15-rc; fixes bug 3375.
o Minor bugfixes (also included in 0.2.2.x):
- When we restart our relay, we might get a successful connection
from the outside before we've started our reachability tests,
triggering a warning: "ORPort found reachable, but I have no
routerinfo yet. Failing to inform controller of success." This
bug was harmless unless Tor is running under a controller
like Vidalia, in which case the controller would never get a
REACHABILITY_SUCCEEDED status event. Bugfix on 0.1.2.6-alpha;
fixes bug 1172.
- Build correctly on OSX with zlib 1.2.4 and higher with all warnings
enabled. Fixes bug 1526.
- Remove undocumented option "-F" from tor-resolve: it hasn't done
anything since 0.2.1.16-rc.
- Avoid signed/unsigned comparisons by making SIZE_T_CEILING unsigned.
None of the cases where we did this before were wrong, but by making
this change we avoid warnings. Fixes bug 2475; bugfix on 0.2.1.28.
- Fix a rare crash bug that could occur when a client was configured
with a large number of bridges. Fixes bug 2629; bugfix on
0.2.1.2-alpha. Bugfix by trac user "shitlei".
- Correct the warning displayed when a rendezvous descriptor exceeds
the maximum size. Fixes bug 2750; bugfix on 0.2.1.5-alpha. Found by
John Brooks.
- Fix an uncommon assertion failure when running with DNSPort under
heavy load. Fixes bug 2933; bugfix on 0.2.0.1-alpha.
- When warning about missing zlib development packages during compile,
give the correct package names. Bugfix on 0.2.0.1-alpha.
- Require that introduction point keys and onion keys have public
exponent 65537. Bugfix on 0.2.0.10-alpha.
- Do not crash when our configuration file becomes unreadable, for
example due to a permissions change, between when we start up
and when a controller calls SAVECONF. Fixes bug 3135; bugfix
on 0.0.9pre6.
- Fix warnings from GCC 4.6's "-Wunused-but-set-variable" option.
Fixes bug 3208.
- Always NUL-terminate the sun_path field of a sockaddr_un before
passing it to the kernel. (Not a security issue: kernels are
smart enough to reject bad sockaddr_uns.) Found by Coverity;
CID #428. Bugfix on Tor 0.2.0.3-alpha.
- Don't stack-allocate the list of supplementary GIDs when we're
about to log them. Stack-allocating NGROUPS_MAX gid_t elements
could take up to 256K, which is way too much stack. Found by
Coverity; CID #450. Bugfix on 0.2.1.7-alpha.
o Minor bugfixes (only in 0.2.1.x):
- Resume using micro-version numbers in 0.2.1.x: our Debian packages
rely on them. Bugfix on 0.2.1.30.
- Use git revisions instead of svn revisions when generating our
micro-version numbers. Bugfix on 0.2.1.15-rc; fixes bug 2402.
o Minor features (also included in 0.2.2.x):
- Adjust the expiration time on our SSL session certificates to
better match SSL certs seen in the wild. Resolves ticket 4014.
- Allow nameservers with IPv6 address. Resolves bug 2574.
- Update to the October 4 2011 Maxmind GeoLite Country database.
Changes in version 0.2.2.33 - 2011-09-13
Tor 0.2.2.33 fixes several bugs, and includes a slight tweak to Tor's
TLS handshake that makes relays and bridges that run this new version
reachable from Iran again.
o Major bugfixes:
- Avoid an assertion failure when reloading a configuration with
TrackExitHosts changes. Found and fixed by 'laruldan'. Fixes bug
3923; bugfix on 0.2.2.25-alpha.
o Minor features (security):
- Check for replays of the public-key encrypted portion of an
INTRODUCE1 cell, in addition to the current check for replays of
the g^x value. This prevents a possible class of active attacks
by an attacker who controls both an introduction point and a
rendezvous point, and who uses the malleability of AES-CTR to
alter the encrypted g^x portion of the INTRODUCE1 cell. We think
that these attacks are infeasible (requiring the attacker to send
on the order of zettabytes of altered cells in a short interval),
but we'd rather block them off in case there are any classes of
this attack that we missed. Reported by Willem Pinckaers.
o Minor features:
- Adjust the expiration time on our SSL session certificates to
better match SSL certs seen in the wild. Resolves ticket 4014.
- Change the default required uptime for a relay to be accepted as
a HSDir (hidden service directory) from 24 hours to 25 hours.
Improves on 0.2.0.10-alpha; resolves ticket 2649.
- Add a VoteOnHidServDirectoriesV2 config option to allow directory
authorities to abstain from voting on assignment of the HSDir
consensus flag. Related to bug 2649.
- Update to the September 6 2011 Maxmind GeoLite Country database.
o Minor bugfixes (documentation and log messages):
- Correct the man page to explain that HashedControlPassword and
CookieAuthentication can both be set, in which case either method
is sufficient to authenticate to Tor. Bugfix on 0.2.0.7-alpha,
when we decided to allow these config options to both be set. Issue
raised by bug 3898.
- Demote the 'replay detected' log message emitted when a hidden
service receives the same Diffie-Hellman public key in two different
INTRODUCE2 cells to info level. A normal Tor client can cause that
log message during its normal operation. Bugfix on 0.2.1.6-alpha;
fixes part of bug 2442.
- Demote the 'INTRODUCE2 cell is too {old,new}' log message to info
level. There is nothing that a hidden service's operator can do
to fix its clients' clocks. Bugfix on 0.2.1.6-alpha; fixes part
of bug 2442.
- Clarify a log message specifying the characters permitted in
HiddenServiceAuthorizeClient client names. Previously, the log
message said that "[A-Za-z0-9+-_]" were permitted; that could have
given the impression that every ASCII character between "+" and "_"
was permitted. Now we say "[A-Za-z0-9+_-]". Bugfix on 0.2.1.5-alpha.
o Build fixes:
- Provide a substitute implementation of lround() for MSVC, which
apparently lacks it. Patch from Gisle Vanem.
- Clean up some code issues that prevented Tor from building on older
BSDs. Fixes bug 3894; reported by "grarpamp".
- Search for a platform-specific version of "ar" when cross-compiling.
Should fix builds on iOS. Resolves bug 3909, found by Marco Bonetti.
Changes in version 0.2.2.32 - 2011-08-27
The Tor 0.2.2 release series is dedicated to the memory of Andreas
Pfitzmann (1958-2010), a pioneer in anonymity and privacy research,
a founder of the PETS community, a leader in our field, a mentor,
and a friend. He left us with these words: "I had the possibility
to contribute to this world that is not as it should be. I hope I
could help in some areas to make the world a better place, and that
I could also encourage other people to be engaged in improving the
world. Please, stay engaged. This world needs you, your love, your
initiative -- now I cannot be part of that anymore."
Tor 0.2.2.32, the first stable release in the 0.2.2 branch, is finally
ready. More than two years in the making, this release features improved
client performance and hidden service reliability, better compatibility
for Android, correct behavior for bridges that listen on more than
one address, more extensible and flexible directory object handling,
better reporting of network statistics, improved code security, and
many many other features and bugfixes.
o Major features (client performance):
- When choosing which cells to relay first, relays now favor circuits
that have been quiet recently, to provide lower latency for
low-volume circuits. By default, relays enable or disable this
feature based on a setting in the consensus. They can override
this default by using the new "CircuitPriorityHalflife" config
option. Design and code by Ian Goldberg, Can Tang, and Chris
Alexander.
- Directory authorities now compute consensus weightings that instruct
clients how to weight relays flagged as Guard, Exit, Guard+Exit,
and no flag. Clients use these weightings to distribute network load
more evenly across these different relay types. The weightings are
in the consensus so we can change them globally in the future. Extra
thanks to "outofwords" for finding some nasty security bugs in
the first implementation of this feature.
o Major features (client performance, circuit build timeout):
- Tor now tracks how long it takes to build client-side circuits
over time, and adapts its timeout to local network performance.
Since a circuit that takes a long time to build will also provide
bad performance, we get significant latency improvements by
discarding the slowest 20% of circuits. Specifically, Tor creates
circuits more aggressively than usual until it has enough data
points for a good timeout estimate. Implements proposal 151.
- Circuit build timeout constants can be controlled by consensus
parameters. We set good defaults for these parameters based on
experimentation on broadband and simulated high-latency links.
- Circuit build time learning can be disabled via consensus parameter
or by the client via a LearnCircuitBuildTimeout config option. We
also automatically disable circuit build time calculation if either
AuthoritativeDirectory is set, or if we fail to write our state
file. Implements ticket 1296.
o Major features (relays use their capacity better):
- Set SO_REUSEADDR socket option on all sockets, not just
listeners. This should help busy exit nodes avoid running out of
useable ports just because all the ports have been used in the
near past. Resolves issue 2850.
- Relays now save observed peak bandwidth throughput rates to their
state file (along with total usage, which was already saved),
so that they can determine their correct estimated bandwidth on
restart. Resolves bug 1863, where Tor relays would reset their
estimated bandwidth to 0 after restarting.
- Lower the maximum weighted-fractional-uptime cutoff to 98%. This
should give us approximately 40-50% more Guard-flagged nodes,
improving the anonymity the Tor network can provide and also
decreasing the dropoff in throughput that relays experience when
they first get the Guard flag.
- Directory authorities now take changes in router IP address and
ORPort into account when determining router stability. Previously,
if a router changed its IP or ORPort, the authorities would not
treat it as having any downtime for the purposes of stability
calculation, whereas clients would experience downtime since the
change would take a while to propagate to them. Resolves issue 1035.
- New AccelName and AccelDir options add support for dynamic OpenSSL
hardware crypto acceleration engines.
o Major features (relays control their load better):
- Exit relays now try harder to block exit attempts from unknown
relays, to make it harder for people to use them as one-hop proxies
a la tortunnel. Controlled by the refuseunknownexits consensus
parameter (currently enabled), or you can override it on your
relay with the RefuseUnknownExits torrc option. Resolves bug 1751;
based on a variant of proposal 163.
- Add separate per-conn write limiting to go with the per-conn read
limiting. We added a global write limit in Tor 0.1.2.5-alpha,
but never per-conn write limits.
- New consensus params "bwconnrate" and "bwconnburst" to let us
rate-limit client connections as they enter the network. It's
controlled in the consensus so we can turn it on and off for
experiments. It's starting out off. Based on proposal 163.
o Major features (controllers):
- Export GeoIP information on bridge usage to controllers even if we
have not yet been running for 24 hours. Now Vidalia bridge operators
can get more accurate and immediate feedback about their
contributions to the network.
- Add an __OwningControllerProcess configuration option and a
TAKEOWNERSHIP control-port command. Now a Tor controller can ensure
that when it exits, Tor will shut down. Implements feature 3049.
o Major features (directory authorities):
- Directory authorities now create, vote on, and serve multiple
parallel formats of directory data as part of their voting process.
Partially implements Proposal 162: "Publish the consensus in
multiple flavors".
- Directory authorities now agree on and publish small summaries
of router information that clients can use in place of regular
server descriptors. This transition will allow Tor 0.2.3 clients
to use far less bandwidth for downloading information about the
network. Begins the implementation of Proposal 158: "Clients
download consensus + microdescriptors".
- The directory voting system is now extensible to use multiple hash
algorithms for signatures and resource selection. Newer formats
are signed with SHA256, with a possibility for moving to a better
hash algorithm in the future.
- Directory authorities can now vote on arbitary integer values as
part of the consensus process. This is designed to help set
network-wide parameters. Implements proposal 167.
o Major features and bugfixes (node selection):
- Revise and reconcile the meaning of the ExitNodes, EntryNodes,
ExcludeEntryNodes, ExcludeExitNodes, ExcludeNodes, and Strict*Nodes
options. Previously, we had been ambiguous in describing what
counted as an "exit" node, and what operations exactly "StrictNodes
0" would permit. This created confusion when people saw nodes built
through unexpected circuits, and made it hard to tell real bugs from
surprises. Now the intended behavior is:
. "Exit", in the context of ExitNodes and ExcludeExitNodes, means
a node that delivers user traffic outside the Tor network.
. "Entry", in the context of EntryNodes, means a node used as the
first hop of a multihop circuit. It doesn't include direct
connections to directory servers.
. "ExcludeNodes" applies to all nodes.
. "StrictNodes" changes the behavior of ExcludeNodes only. When
StrictNodes is set, Tor should avoid all nodes listed in
ExcludeNodes, even when it will make user requests fail. When
StrictNodes is *not* set, then Tor should follow ExcludeNodes
whenever it can, except when it must use an excluded node to
perform self-tests, connect to a hidden service, provide a
hidden service, fulfill a .exit request, upload directory
information, or fetch directory information.
Collectively, the changes to implement the behavior fix bug 1090.
- If EntryNodes, ExitNodes, ExcludeNodes, or ExcludeExitNodes
change during a config reload, mark and discard all our origin
circuits. This fix should address edge cases where we change the
config options and but then choose a circuit that we created before
the change.
- Make EntryNodes config option much more aggressive even when
StrictNodes is not set. Before it would prepend your requested
entrynodes to your list of guard nodes, but feel free to use others
after that. Now it chooses only from your EntryNodes if any of
those are available, and only falls back to others if a) they're
all down and b) StrictNodes is not set.
- Now we refresh your entry guards from EntryNodes at each consensus
fetch -- rather than just at startup and then they slowly rot as
the network changes.
- Add support for the country code "{??}" in torrc options like
ExcludeNodes, to indicate all routers of unknown country. Closes
bug 1094.
- ExcludeNodes now takes precedence over EntryNodes and ExitNodes: if
a node is listed in both, it's treated as excluded.
- ExcludeNodes now applies to directory nodes -- as a preference if
StrictNodes is 0, or an absolute requirement if StrictNodes is 1.
Don't exclude all the directory authorities and set StrictNodes to 1
unless you really want your Tor to break.
- ExcludeNodes and ExcludeExitNodes now override exit enclaving.
- ExcludeExitNodes now overrides .exit requests.
- We don't use bridges listed in ExcludeNodes.
- When StrictNodes is 1:
. We now apply ExcludeNodes to hidden service introduction points
and to rendezvous points selected by hidden service users. This
can make your hidden service less reliable: use it with caution!
. If we have used ExcludeNodes on ourself, do not try relay
reachability self-tests.
. If we have excluded all the directory authorities, we will not
even try to upload our descriptor if we're a relay.
. Do not honor .exit requests to an excluded node.
- When the set of permitted nodes changes, we now remove any mappings
introduced via TrackExitHosts to now-excluded nodes. Bugfix on
0.1.0.1-rc.
- We never cannibalize a circuit that had excluded nodes on it, even
if StrictNodes is 0. Bugfix on 0.1.0.1-rc.
- Improve log messages related to excluded nodes.
o Major features (misc):
- Numerous changes, bugfixes, and workarounds from Nathan Freitas
to help Tor build correctly for Android phones.
- The options SocksPort, ControlPort, and so on now all accept a
value "auto" that opens a socket on an OS-selected port. A
new ControlPortWriteToFile option tells Tor to write its
actual control port or ports to a chosen file. If the option
ControlPortFileGroupReadable is set, the file is created as
group-readable. Now users can run two Tor clients on the same
system without needing to manually mess with parameters. Resolves
part of ticket 3076.
- Tor now supports tunneling all of its outgoing connections over
a SOCKS proxy, using the SOCKS4Proxy and/or SOCKS5Proxy
configuration options. Code by Christopher Davis.
o Code security improvements:
- Replace all potentially sensitive memory comparison operations
with versions whose runtime does not depend on the data being
compared. This will help resist a class of attacks where an
adversary can use variations in timing information to learn
sensitive data. Fix for one case of bug 3122. (Safe memcmp
implementation by Robert Ransom based partially on code by DJB.)
- Enable Address Space Layout Randomization (ASLR) and Data Execution
Prevention (DEP) by default on Windows to make it harder for
attackers to exploit vulnerabilities. Patch from John Brooks.
- New "--enable-gcc-hardening" ./configure flag (off by default)
to turn on gcc compile time hardening options. It ensures
that signed ints have defined behavior (-fwrapv), enables
-D_FORTIFY_SOURCE=2 (requiring -O2), adds stack smashing protection
with canaries (-fstack-protector-all), turns on ASLR protection if
supported by the kernel (-fPIE, -pie), and adds additional security
related warnings. Verified to work on Mac OS X and Debian Lenny.
- New "--enable-linker-hardening" ./configure flag (off by default)
to turn on ELF specific hardening features (relro, now). This does
not work with Mac OS X or any other non-ELF binary format.
- Always search the Windows system directory for system DLLs, and
nowhere else. Bugfix on 0.1.1.23; fixes bug 1954.
- New DisableAllSwap option. If set to 1, Tor will attempt to lock all
current and future memory pages via mlockall(). On supported
platforms (modern Linux and probably BSD but not Windows or OS X),
this should effectively disable any and all attempts to page out
memory. This option requires that you start your Tor as root --
if you use DisableAllSwap, please consider using the User option
to properly reduce the privileges of your Tor.
o Major bugfixes (crashes):
- Fix crash bug on platforms where gmtime and localtime can return
NULL. Windows 7 users were running into this one. Fixes part of bug
2077. Bugfix on all versions of Tor. Found by boboper.
- Introduce minimum/maximum values that clients will believe
from the consensus. Now we'll have a better chance to avoid crashes
or worse when a consensus param has a weird value.
- Fix a rare crash bug that could occur when a client was configured
with a large number of bridges. Fixes bug 2629; bugfix on
0.2.1.2-alpha. Bugfix by trac user "shitlei".
- Do not crash when our configuration file becomes unreadable, for
example due to a permissions change, between when we start up
and when a controller calls SAVECONF. Fixes bug 3135; bugfix
on 0.0.9pre6.
- If we're in the pathological case where there's no exit bandwidth
but there is non-exit bandwidth, or no guard bandwidth but there
is non-guard bandwidth, don't crash during path selection. Bugfix
on 0.2.0.3-alpha.
- Fix a crash bug when trying to initialize the evdns module in
Libevent 2. Bugfix on 0.2.1.16-rc.
o Major bugfixes (stability):
- Fix an assert in parsing router descriptors containing IPv6
addresses. This one took down the directory authorities when
somebody tried some experimental code. Bugfix on 0.2.1.3-alpha.
- Fix an uncommon assertion failure when running with DNSPort under
heavy load. Fixes bug 2933; bugfix on 0.2.0.1-alpha.
- Treat an unset $HOME like an empty $HOME rather than triggering an
assert. Bugfix on 0.0.8pre1; fixes bug 1522.
- More gracefully handle corrupt state files, removing asserts
in favor of saving a backup and resetting state.
- Instead of giving an assertion failure on an internal mismatch
on estimated freelist size, just log a BUG warning and try later.
Mitigates but does not fix bug 1125.
- Fix an assert that got triggered when using the TestingTorNetwork
configuration option and then issuing a GETINFO config-text control
command. Fixes bug 2250; bugfix on 0.2.1.2-alpha.
- If the cached cert file is unparseable, warn but don't exit.
o Privacy fixes (relays/bridges):
- Don't list Windows capabilities in relay descriptors. We never made
use of them, and maybe it's a bad idea to publish them. Bugfix
on 0.1.1.8-alpha.
- If the Nickname configuration option isn't given, Tor would pick a
nickname based on the local hostname as the nickname for a relay.
Because nicknames are not very important in today's Tor and the
"Unnamed" nickname has been implemented, this is now problematic
behavior: It leaks information about the hostname without being
useful at all. Fixes bug 2979; bugfix on 0.1.2.2-alpha, which
introduced the Unnamed nickname. Reported by tagnaq.
- Maintain separate TLS contexts and certificates for incoming and
outgoing connections in bridge relays. Previously we would use the
same TLS contexts and certs for incoming and outgoing connections.
Bugfix on 0.2.0.3-alpha; addresses bug 988.
- Maintain separate identity keys for incoming and outgoing TLS
contexts in bridge relays. Previously we would use the same
identity keys for incoming and outgoing TLS contexts. Bugfix on
0.2.0.3-alpha; addresses the other half of bug 988.
- Make the bridge directory authority refuse to answer directory
requests for "all descriptors". It used to include bridge
descriptors in its answer, which was a major information leak.
Found by "piebeer". Bugfix on 0.2.0.3-alpha.
o Privacy fixes (clients):
- When receiving a hidden service descriptor, check that it is for
the hidden service we wanted. Previously, Tor would store any
hidden service descriptors that a directory gave it, whether it
wanted them or not. This wouldn't have let an attacker impersonate
a hidden service, but it did let directories pre-seed a client
with descriptors that it didn't want. Bugfix on 0.0.6.
- Start the process of disabling ".exit" address notation, since it
can be used for a variety of esoteric application-level attacks
on users. To reenable it, set "AllowDotExit 1" in your torrc. Fix
on 0.0.9rc5.
- Reject attempts at the client side to open connections to private
IP addresses (like 127.0.0.1, 10.0.0.1, and so on) with
a randomly chosen exit node. Attempts to do so are always
ill-defined, generally prevented by exit policies, and usually
in error. This will also help to detect loops in transparent
proxy configurations. You can disable this feature by setting
"ClientRejectInternalAddresses 0" in your torrc.
- Log a notice when we get a new control connection. Now it's easier
for security-conscious users to recognize when a local application
is knocking on their controller door. Suggested by bug 1196.
o Privacy fixes (newnym):
- Avoid linkability based on cached hidden service descriptors: forget
all hidden service descriptors cached as a client when processing a
SIGNAL NEWNYM command. Fixes bug 3000; bugfix on 0.0.6.
- On SIGHUP, do not clear out all TrackHostExits mappings, client
DNS cache entries, and virtual address mappings: that's what
NEWNYM is for. Fixes bug 1345; bugfix on 0.1.0.1-rc.
- Don't attach new streams to old rendezvous circuits after SIGNAL
NEWNYM. Previously, we would keep using an existing rendezvous
circuit if it remained open (i.e. if it were kept open by a
long-lived stream, or if a new stream were attached to it before
Tor could notice that it was old and no longer in use). Bugfix on
0.1.1.15-rc; fixes bug 3375.
o Major bugfixes (relay bandwidth accounting):
- Fix a bug that could break accounting on 64-bit systems with large
time_t values, making them hibernate for impossibly long intervals.
Fixes bug 2146. Bugfix on 0.0.9pre6; fix by boboper.
- Fix a bug in bandwidth accounting that could make us use twice
the intended bandwidth when our interval start changes due to
daylight saving time. Now we tolerate skew in stored vs computed
interval starts: if the start of the period changes by no more than
50% of the period's duration, we remember bytes that we transferred
in the old period. Fixes bug 1511; bugfix on 0.0.9pre5.
o Major bugfixes (bridges):
- Bridges now use "reject *:*" as their default exit policy. Bugfix
on 0.2.0.3-alpha. Fixes bug 1113.
- If you configure your bridge with a known identity fingerprint,
and the bridge authority is unreachable (as it is in at least
one country now), fall back to directly requesting the descriptor
from the bridge. Finishes the feature started in 0.2.0.10-alpha;
closes bug 1138.
- Fix a bug where bridge users who configure the non-canonical
address of a bridge automatically switch to its canonical
address. If a bridge listens at more than one address, it
should be able to advertise those addresses independently and
any non-blocked addresses should continue to work. Bugfix on Tor
0.2.0.3-alpha. Fixes bug 2510.
- If you configure Tor to use bridge A, and then quit and
configure Tor to use bridge B instead (or if you change Tor
to use bridge B via the controller), it would happily continue
to use bridge A if it's still reachable. While this behavior is
a feature if your goal is connectivity, in some scenarios it's a
dangerous bug. Bugfix on Tor 0.2.0.1-alpha; fixes bug 2511.
- When the controller configures a new bridge, don't wait 10 to 60
seconds before trying to fetch its descriptor. Bugfix on
0.2.0.3-alpha; fixes bug 3198 (suggested by 2355).
o Major bugfixes (directory authorities):
- Many relays have been falling out of the consensus lately because
not enough authorities know about their descriptor for them to get
a majority of votes. When we deprecated the v2 directory protocol,
we got rid of the only way that v3 authorities can hear from each
other about other descriptors. Now authorities examine every v3
vote for new descriptors, and fetch them from that authority. Bugfix
on 0.2.1.23.
- Authorities could be tricked into giving out the Exit flag to relays
that didn't allow exiting to any ports. This bug could screw
with load balancing and stats. Bugfix on 0.1.1.6-alpha; fixes bug
1238. Bug discovered by Martin Kowalczyk.
- If all authorities restart at once right before a consensus vote,
nobody will vote about "Running", and clients will get a consensus
with no usable relays. Instead, authorities refuse to build a
consensus if this happens. Bugfix on 0.2.0.10-alpha; fixes bug 1066.
o Major bugfixes (stream-level fairness):
- When receiving a circuit-level SENDME for a blocked circuit, try
to package cells fairly from all the streams that had previously
been blocked on that circuit. Previously, we had started with the
oldest stream, and allowed each stream to potentially exhaust
the circuit's package window. This gave older streams on any
given circuit priority over newer ones. Fixes bug 1937. Detected
originally by Camilo Viecco. This bug was introduced before the
first Tor release, in svn commit r152: it is the new winner of
the longest-lived bug prize.
- Fix a stream fairness bug that would cause newer streams on a given
circuit to get preference when reading bytes from the origin or
destination. Fixes bug 2210. Fix by Mashael AlSabah. This bug was
introduced before the first Tor release, in svn revision r152.
- When the exit relay got a circuit-level sendme cell, it started
reading on the exit streams, even if had 500 cells queued in the
circuit queue already, so the circuit queue just grew and grew in
some cases. We fix this by not re-enabling reading on receipt of a
sendme cell when the cell queue is blocked. Fixes bug 1653. Bugfix
on 0.2.0.1-alpha. Detected by Mashael AlSabah. Original patch by
"yetonetime".
- Newly created streams were allowed to read cells onto circuits,
even if the circuit's cell queue was blocked and waiting to drain.
This created potential unfairness, as older streams would be
blocked, but newer streams would gladly fill the queue completely.
We add code to detect this situation and prevent any stream from
getting more than one free cell. Bugfix on 0.2.0.1-alpha. Partially
fixes bug 1298.
o Major bugfixes (hidden services):
- Apply circuit timeouts to opened hidden-service-related circuits
based on the correct start time. Previously, we would apply the
circuit build timeout based on time since the circuit's creation;
it was supposed to be applied based on time since the circuit
entered its current state. Bugfix on 0.0.6; fixes part of bug 1297.
- Improve hidden service robustness: When we find that we have
extended a hidden service's introduction circuit to a relay not
listed as an introduction point in the HS descriptor we currently
have, retry with an introduction point from the current
descriptor. Previously we would just give up. Fixes bugs 1024 and
1930; bugfix on 0.2.0.10-alpha.
- Directory authorities now use data collected from their own
uptime observations when choosing whether to assign the HSDir flag
to relays, instead of trusting the uptime value the relay reports in
its descriptor. This change helps prevent an attack where a small
set of nodes with frequently-changing identity keys can blackhole
a hidden service. (Only authorities need upgrade; others will be
fine once they do.) Bugfix on 0.2.0.10-alpha; fixes bug 2709.
- Stop assigning the HSDir flag to relays that disable their
DirPort (and thus will refuse to answer directory requests). This
fix should dramatically improve the reachability of hidden services:
hidden services and hidden service clients pick six HSDir relays
to store and retrieve the hidden service descriptor, and currently
about half of the HSDir relays will refuse to work. Bugfix on
0.2.0.10-alpha; fixes part of bug 1693.
o Major bugfixes (misc):
- Clients now stop trying to use an exit node associated with a given
destination by TrackHostExits if they fail to reach that exit node.
Fixes bug 2999. Bugfix on 0.2.0.20-rc.
- Fix a regression that caused Tor to rebind its ports if it receives
SIGHUP while hibernating. Bugfix in 0.1.1.6-alpha; closes bug 919.
- Remove an extra pair of quotation marks around the error
message in control-port STATUS_GENERAL BUG events. Bugfix on
0.1.2.6-alpha; fixes bug 3732.
o Minor features (relays):
- Ensure that no empty [dirreq-](read|write)-history lines are added
to an extrainfo document. Implements ticket 2497.
- When bandwidth accounting is enabled, be more generous with how
much bandwidth we'll use up before entering "soft hibernation".
Previously, we'd refuse new connections and circuits once we'd
used up 95% of our allotment. Now, we use up 95% of our allotment,
AND make sure that we have no more than 500MB (or 3 hours of
expected traffic, whichever is lower) remaining before we enter
soft hibernation.
- Relays now log the reason for publishing a new relay descriptor,
so we have a better chance of hunting down instances of bug 1810.
Resolves ticket 3252.
- Log a little more clearly about the times at which we're no longer
accepting new connections (e.g. due to hibernating). Resolves
bug 2181.
- When AllowSingleHopExits is set, print a warning to explain to the
relay operator why most clients are avoiding her relay.
- Send END_STREAM_REASON_NOROUTE in response to EHOSTUNREACH errors.
Clients before 0.2.1.27 didn't handle NOROUTE correctly, but such
clients are already deprecated because of security bugs.
o Minor features (network statistics):
- Directory mirrors that set "DirReqStatistics 1" write statistics
about directory requests to disk every 24 hours. As compared to the
"--enable-geoip-stats" ./configure flag in 0.2.1.x, there are a few
improvements: 1) stats are written to disk exactly every 24 hours;
2) estimated shares of v2 and v3 requests are determined as mean
values, not at the end of a measurement period; 3) unresolved
requests are listed with country code '??'; 4) directories also
measure download times.
- Exit nodes that set "ExitPortStatistics 1" write statistics on the
number of exit streams and transferred bytes per port to disk every
24 hours.
- Relays that set "CellStatistics 1" write statistics on how long
cells spend in their circuit queues to disk every 24 hours.
- Entry nodes that set "EntryStatistics 1" write statistics on the
rough number and origins of connecting clients to disk every 24
hours.
- Relays that write any of the above statistics to disk and set
"ExtraInfoStatistics 1" include the past 24 hours of statistics in
their extra-info documents. Implements proposal 166.
o Minor features (GeoIP and statistics):
- Provide a log message stating which geoip file we're parsing
instead of just stating that we're parsing the geoip file.
Implements ticket 2432.
- Make sure every relay writes a state file at least every 12 hours.
Previously, a relay could go for weeks without writing its state
file, and on a crash could lose its bandwidth history, capacity
estimates, client country statistics, and so on. Addresses bug 3012.
- Relays report the number of bytes spent on answering directory
requests in extra-info descriptors similar to {read,write}-history.
Implements enhancement 1790.
- Report only the top 10 ports in exit-port stats in order not to
exceed the maximum extra-info descriptor length of 50 KB. Implements
task 2196.
- If writing the state file to disk fails, wait up to an hour before
retrying again, rather than trying again each second. Fixes bug
2346; bugfix on Tor 0.1.1.3-alpha.
- Delay geoip stats collection by bridges for 6 hours, not 2 hours,
when we switch from being a public relay to a bridge. Otherwise
there will still be clients that see the relay in their consensus,
and the stats will end up wrong. Bugfix on 0.2.1.15-rc; fixes
bug 932.
- Update to the August 2 2011 Maxmind GeoLite Country database.
o Minor features (clients):
- When expiring circuits, use microsecond timers rather than
one-second timers. This can avoid an unpleasant situation where a
circuit is launched near the end of one second and expired right
near the beginning of the next, and prevent fluctuations in circuit
timeout values.
- If we've configured EntryNodes and our network goes away and/or all
our entrynodes get marked down, optimistically retry them all when
a new socks application request appears. Fixes bug 1882.
- Always perform router selections using weighted relay bandwidth,
even if we don't need a high capacity circuit at the time. Non-fast
circuits now only differ from fast ones in that they can use relays
not marked with the Fast flag. This "feature" could turn out to
be a horrible bug; we should investigate more before it goes into
a stable release.
- When we run out of directory information such that we can't build
circuits, but then get enough that we can build circuits, log when
we actually construct a circuit, so the user has a better chance of
knowing what's going on. Fixes bug 1362.
- Log SSL state transitions at debug level during handshake, and
include SSL states in error messages. This may help debug future
SSL handshake issues.
o Minor features (directory authorities):
- When a router changes IP address or port, authorities now launch
a new reachability test for it. Implements ticket 1899.
- Directory authorities now reject relays running any versions of
Tor between 0.2.1.3-alpha and 0.2.1.18 inclusive; they have
known bugs that keep RELAY_EARLY cells from working on rendezvous
circuits. Followup to fix for bug 2081.
- Directory authorities now reject relays running any version of Tor
older than 0.2.0.26-rc. That version is the earliest that fetches
current directory information correctly. Fixes bug 2156.
- Directory authorities now do an immediate reachability check as soon
as they hear about a new relay. This change should slightly reduce
the time between setting up a relay and getting listed as running
in the consensus. It should also improve the time between setting
up a bridge and seeing use by bridge users.
- Directory authorities no longer launch a TLS connection to every
relay as they startup. Now that we have 2k+ descriptors cached,
the resulting network hiccup is becoming a burden. Besides,
authorities already avoid voting about Running for the first half
hour of their uptime.
- Directory authorities now log the source of a rejected POSTed v3
networkstatus vote, so we can track failures better.
- Backport code from 0.2.3.x that allows directory authorities to
clean their microdescriptor caches. Needed to resolve bug 2230.
o Minor features (hidden services):
- Use computed circuit-build timeouts to decide when to launch
parallel introduction circuits for hidden services. (Previously,
we would retry after 15 seconds.)
- Don't allow v0 hidden service authorities to act as clients.
Required by fix for bug 3000.
- Ignore SIGNAL NEWNYM commands on relay-only Tor instances. Required
by fix for bug 3000.
- Make hidden services work better in private Tor networks by not
requiring any uptime to join the hidden service descriptor
DHT. Implements ticket 2088.
- Log (at info level) when purging pieces of hidden-service-client
state because of SIGNAL NEWNYM.
o Minor features (controller interface):
- New "GETINFO net/listeners/(type)" controller command to return
a list of addresses and ports that are bound for listeners for a
given connection type. This is useful when the user has configured
"SocksPort auto" and the controller needs to know which port got
chosen. Resolves another part of ticket 3076.
- Have the controller interface give a more useful message than
"Internal Error" in response to failed GETINFO requests.
- Add a TIMEOUT_RATE keyword to the BUILDTIMEOUT_SET control port
event, to give information on the current rate of circuit timeouts
over our stored history.
- The 'EXTENDCIRCUIT' control port command can now be used with
a circ id of 0 and no path. This feature will cause Tor to build
a new 'fast' general purpose circuit using its own path selection
algorithms.
- Added a BUILDTIMEOUT_SET controller event to describe changes
to the circuit build timeout.
- New controller command "getinfo config-text". It returns the
contents that Tor would write if you send it a SAVECONF command,
so the controller can write the file to disk itself.
o Minor features (controller protocol):
- Add a new ControlSocketsGroupWritable configuration option: when
it is turned on, ControlSockets are group-writeable by the default
group of the current user. Patch by Jérémy Bobbio; implements
ticket 2972.
- Tor now refuses to create a ControlSocket in a directory that is
world-readable (or group-readable if ControlSocketsGroupWritable
is 0). This is necessary because some operating systems do not
enforce permissions on an AF_UNIX sockets. Permissions on the
directory holding the socket, however, seems to work everywhere.
- Warn when CookieAuthFileGroupReadable is set but CookieAuthFile is
not. This would lead to a cookie that is still not group readable.
Closes bug 1843. Suggested by katmagic.
- Future-proof the controller protocol a bit by ignoring keyword
arguments we do not recognize.
o Minor features (more useful logging):
- Revise most log messages that refer to nodes by nickname to
instead use the "$key=nickname at address" format. This should be
more useful, especially since nicknames are less and less likely
to be unique. Resolves ticket 3045.
- When an HTTPS proxy reports "403 Forbidden", we now explain
what it means rather than calling it an unexpected status code.
Closes bug 2503. Patch from Michael Yakubovich.
- Rate-limit a warning about failures to download v2 networkstatus
documents. Resolves part of bug 1352.
- Rate-limit the "your application is giving Tor only an IP address"
warning. Addresses bug 2000; bugfix on 0.0.8pre2.
- Rate-limit "Failed to hand off onionskin" warnings.
- When logging a rate-limited warning, we now mention how many messages
got suppressed since the last warning.
- Make the formerly ugly "2 unknown, 7 missing key, 0 good, 0 bad,
2 no signature, 4 required" messages about consensus signatures
easier to read, and make sure they get logged at the same severity
as the messages explaining which keys are which. Fixes bug 1290.
- Don't warn when we have a consensus that we can't verify because
of missing certificates, unless those certificates are ones
that we have been trying and failing to download. Fixes bug 1145.
o Minor features (log domains):
- Add documentation for configuring logging at different severities in
different log domains. We've had this feature since 0.2.1.1-alpha,
but for some reason it never made it into the manpage. Fixes
bug 2215.
- Make it simpler to specify "All log domains except for A and B".
Previously you needed to say "[*,~A,~B]". Now you can just say
"[~A,~B]".
- Add a "LogMessageDomains 1" option to include the domains of log
messages along with the messages. Without this, there's no way
to use log domains without reading the source or doing a lot
of guessing.
- Add a new "Handshake" log domain for activities that happen
during the TLS handshake.
o Minor features (build process):
- Make compilation with clang possible when using
"--enable-gcc-warnings" by removing two warning options that clang
hasn't implemented yet and by fixing a few warnings. Resolves
ticket 2696.
- Detect platforms that brokenly use a signed size_t, and refuse to
build there. Found and analyzed by doorss and rransom.
- Fix a bunch of compile warnings revealed by mingw with gcc 4.5.
Resolves bug 2314.
- Add support for statically linking zlib by specifying
"--enable-static-zlib", to go with our support for statically
linking openssl and libevent. Resolves bug 1358.
- Instead of adding the svn revision to the Tor version string, report
the git commit (when we're building from a git checkout).
- Rename the "log.h" header to "torlog.h" so as to conflict with fewer
system headers.
- New --digests command-line switch to output the digests of the
source files Tor was built with.
- Generate our manpage and HTML documentation using Asciidoc. This
change should make it easier to maintain the documentation, and
produce nicer HTML. The build process fails if asciidoc cannot
be found and building with asciidoc isn't disabled (via the
"--disable-asciidoc" argument to ./configure. Skipping the manpage
speeds up the build considerably.
o Minor features (options / torrc):
- Warn when the same option is provided more than once in a torrc
file, on the command line, or in a single SETCONF statement, and
the option is one that only accepts a single line. Closes bug 1384.
- Warn when the user configures two HiddenServiceDir lines that point
to the same directory. Bugfix on 0.0.6 (the version introducing
HiddenServiceDir); fixes bug 3289.
- Add new "perconnbwrate" and "perconnbwburst" consensus params to
do individual connection-level rate limiting of clients. The torrc
config options with the same names trump the consensus params, if
both are present. Replaces the old "bwconnrate" and "bwconnburst"
consensus params which were broken from 0.2.2.7-alpha through
0.2.2.14-alpha. Closes bug 1947.
- New config option "WarnUnsafeSocks 0" disables the warning that
occurs whenever Tor receives a socks handshake using a version of
the socks protocol that can only provide an IP address (rather
than a hostname). Setups that do DNS locally over Tor are fine,
and we shouldn't spam the logs in that case.
- New config option "CircuitStreamTimeout" to override our internal
timeout schedule for how many seconds until we detach a stream from
a circuit and try a new circuit. If your network is particularly
slow, you might want to set this to a number like 60.
- New options for SafeLogging to allow scrubbing only log messages
generated while acting as a relay. Specify "SafeLogging relay" if
you want to ensure that only messages known to originate from
client use of the Tor process will be logged unsafely.
- Time and memory units in the configuration file can now be set to
fractional units. For example, "2.5 GB" is now a valid value for
AccountingMax.
- Support line continuations in the torrc config file. If a line
ends with a single backslash character, the newline is ignored, and
the configuration value is treated as continuing on the next line.
Resolves bug 1929.
o Minor features (unit tests):
- Revise our unit tests to use the "tinytest" framework, so we
can run tests in their own processes, have smarter setup/teardown
code, and so on. The unit test code has moved to its own
subdirectory, and has been split into multiple modules.
- Add a unit test for cross-platform directory-listing code.
- Add some forgotten return value checks during unit tests. Found
by coverity.
- Use GetTempDir to find the proper temporary directory location on
Windows when generating temporary files for the unit tests. Patch
by Gisle Vanem.
o Minor features (misc):
- The "torify" script now uses torsocks where available.
- Make Libevent log messages get delivered to controllers later,
and not from inside the Libevent log handler. This prevents unsafe
reentrant Libevent calls while still letting the log messages
get through.
- Certain Tor clients (such as those behind check.torproject.org) may
want to fetch the consensus in an extra early manner. To enable this
a user may now set FetchDirInfoExtraEarly to 1. This also depends on
setting FetchDirInfoEarly to 1. Previous behavior will stay the same
as only certain clients who must have this information sooner should
set this option.
- Expand homedirs passed to tor-checkkey. This should silence a
coverity complaint about passing a user-supplied string into
open() without checking it.
- Make sure to disable DirPort if running as a bridge. DirPorts aren't
used on bridges, and it makes bridge scanning somewhat easier.
- Create the /var/run/tor directory on startup on OpenSUSE if it is
not already created. Patch from Andreas Stieger. Fixes bug 2573.
o Minor bugfixes (relays):
- When a relay decides that its DNS is too broken for it to serve
as an exit server, it advertised itself as a non-exit, but
continued to act as an exit. This could create accidental
partitioning opportunities for users. Instead, if a relay is
going to advertise reject *:* as its exit policy, it should
really act with exit policy "reject *:*". Fixes bug 2366.
Bugfix on Tor 0.1.2.5-alpha. Bugfix by user "postman" on trac.
- Publish a router descriptor even if generating an extra-info
descriptor fails. Previously we would not publish a router
descriptor without an extra-info descriptor; this can cause fast
exit relays collecting exit-port statistics to drop from the
consensus. Bugfix on 0.1.2.9-rc; fixes bug 2195.
- When we're trying to guess whether we know our IP address as
a relay, we would log various ways that we failed to guess
our address, but never log that we ended up guessing it
successfully. Now add a log line to help confused and anxious
relay operators. Bugfix on 0.1.2.1-alpha; fixes bug 1534.
- For bandwidth accounting, calculate our expected bandwidth rate
based on the time during which we were active and not in
soft-hibernation during the last interval. Previously, we were
also considering the time spent in soft-hibernation. If this
was a long time, we would wind up underestimating our bandwidth
by a lot, and skewing our wakeup time towards the start of the
accounting interval. Fixes bug 1789. Bugfix on 0.0.9pre5.
- Demote a confusing TLS warning that relay operators might get when
someone tries to talk to their ORPort. It is not the operator's
fault, nor can they do anything about it. Fixes bug 1364; bugfix
on 0.2.0.14-alpha.
- Change "Application request when we're believed to be offline."
notice to "Application request when we haven't used client
functionality lately.", to clarify that it's not an error. Bugfix
on 0.0.9.3; fixes bug 1222.
o Minor bugfixes (bridges):
- When a client starts or stops using bridges, never use a circuit
that was built before the configuration change. This behavior could
put at risk a user who uses bridges to ensure that her traffic
only goes to the chosen addresses. Bugfix on 0.2.0.3-alpha; fixes
bug 3200.
- Do not reset the bridge descriptor download status every time we
re-parse our configuration or get a configuration change. Fixes
bug 3019; bugfix on 0.2.0.3-alpha.
- Users couldn't configure a regular relay to be their bridge. It
didn't work because when Tor fetched the bridge descriptor, it found
that it already had it, and didn't realize that the purpose of the
descriptor had changed. Now we replace routers with a purpose other
than bridge with bridge descriptors when fetching them. Bugfix on
0.1.1.9-alpha. Fixes bug 1776.
- In the special case where you configure a public exit relay as your
bridge, Tor would be willing to use that exit relay as the last
hop in your circuit as well. Now we fail that circuit instead.
Bugfix on 0.2.0.12-alpha. Fixes bug 2403. Reported by "piebeer".
o Minor bugfixes (clients):
- We now ask the other side of a stream (the client or the exit)
for more data on that stream when the amount of queued data on
that stream dips low enough. Previously, we wouldn't ask the
other side for more data until either it sent us more data (which
it wasn't supposed to do if it had exhausted its window!) or we
had completely flushed all our queued data. This flow control fix
should improve throughput. Fixes bug 2756; bugfix on the earliest
released versions of Tor (svn commit r152).
- When a client finds that an origin circuit has run out of 16-bit
stream IDs, we now mark it as unusable for new streams. Previously,
we would try to close the entire circuit. Bugfix on 0.0.6.
- Make it explicit that we don't cannibalize one-hop circuits. This
happens in the wild, but doesn't turn out to be a problem because
we fortunately don't use those circuits. Many thanks to outofwords
for the initial analysis and to swissknife who confirmed that
two-hop circuits are actually created.
- Resolve an edge case in path weighting that could make us misweight
our relay selection. Fixes bug 1203; bugfix on 0.0.8rc1.
- Make the DNSPort option work with libevent 2.x. Don't alter the
behavior for libevent 1.x. Fixes bug 1143. Found by SwissTorExit.
o Minor bugfixes (directory authorities):
- Make directory authorities more accurate at recording when
relays that have failed several reachability tests became
unreachable, so we can provide more accuracy at assigning Stable,
Guard, HSDir, etc flags. Bugfix on 0.2.0.6-alpha. Resolves bug 2716.
- Directory authorities are now more robust to hops back in time
when calculating router stability. Previously, if a run of uptime
or downtime appeared to be negative, the calculation could give
incorrect results. Bugfix on 0.2.0.6-alpha; noticed when fixing
bug 1035.
- Directory authorities will now attempt to download consensuses
if their own efforts to make a live consensus have failed. This
change means authorities that restart will fetch a valid
consensus, and it means authorities that didn't agree with the
current consensus will still fetch and serve it if it has enough
signatures. Bugfix on 0.2.0.9-alpha; fixes bug 1300.
- Never vote for a server as "Running" if we have a descriptor for
it claiming to be hibernating, and that descriptor was published
more recently than our last contact with the server. Bugfix on
0.2.0.3-alpha; fixes bug 911.
- Directory authorities no longer change their opinion of, or vote on,
whether a router is Running, unless they have themselves been
online long enough to have some idea. Bugfix on 0.2.0.6-alpha.
Fixes bug 1023.
o Minor bugfixes (hidden services):
- Log malformed requests for rendezvous descriptors as protocol
warnings, not warnings. Also, use a more informative log message
in case someone sees it at log level warning without prior
info-level messages. Fixes bug 2748; bugfix on 0.2.0.10-alpha.
- Accept hidden service descriptors if we think we might be a hidden
service directory, regardless of what our consensus says. This
helps robustness, since clients and hidden services can sometimes
have a more up-to-date view of the network consensus than we do,
and if they think that the directory authorities list us a HSDir,
we might actually be one. Related to bug 2732; bugfix on
0.2.0.10-alpha.
- Correct the warning displayed when a rendezvous descriptor exceeds
the maximum size. Fixes bug 2750; bugfix on 0.2.1.5-alpha. Found by
John Brooks.
- Clients and hidden services now use HSDir-flagged relays for hidden
service descriptor downloads and uploads even if the relays have no
DirPort set and the client has disabled TunnelDirConns. This will
eventually allow us to give the HSDir flag to relays with no
DirPort. Fixes bug 2722; bugfix on 0.2.1.6-alpha.
- Only limit the lengths of single HS descriptors, even when multiple
HS descriptors are published to an HSDir relay in a single POST
operation. Fixes bug 2948; bugfix on 0.2.1.5-alpha. Found by hsdir.
o Minor bugfixes (controllers):
- Allow GETINFO fingerprint to return a fingerprint even when
we have not yet built a router descriptor. Fixes bug 3577;
bugfix on 0.2.0.1-alpha.
- Send a SUCCEEDED stream event to the controller when a reverse
resolve succeeded. Fixes bug 3536; bugfix on 0.0.8pre1. Issue
discovered by katmagic.
- Remove a trailing asterisk from "exit-policy/default" in the
output of the control port command "GETINFO info/names". Bugfix
on 0.1.2.5-alpha.
- Make the SIGNAL DUMP controller command work on FreeBSD. Fixes bug
2917. Bugfix on 0.1.1.1-alpha.
- When we restart our relay, we might get a successful connection
from the outside before we've started our reachability tests,
triggering a warning: "ORPort found reachable, but I have no
routerinfo yet. Failing to inform controller of success." This
bug was harmless unless Tor is running under a controller
like Vidalia, in which case the controller would never get a
REACHABILITY_SUCCEEDED status event. Bugfix on 0.1.2.6-alpha;
fixes bug 1172.
- When a controller changes TrackHostExits, remove mappings for
hosts that should no longer have their exits tracked. Bugfix on
0.1.0.1-rc.
- When a controller changes VirtualAddrNetwork, remove any mappings
for hosts that were automapped to the old network. Bugfix on
0.1.1.19-rc.
- When a controller changes one of the AutomapHosts* options, remove
any mappings for hosts that should no longer be automapped. Bugfix
on 0.2.0.1-alpha.
- Fix an off-by-one error in calculating some controller command
argument lengths. Fortunately, this mistake is harmless since
the controller code does redundant NUL termination too. Found by
boboper. Bugfix on 0.1.1.1-alpha.
- Fix a bug in the controller interface where "GETINFO ns/asdaskljkl"
would return "551 Internal error" rather than "552 Unrecognized key
ns/asdaskljkl". Bugfix on 0.1.2.3-alpha.
- Don't spam the controller with events when we have no file
descriptors available. Bugfix on 0.2.1.5-alpha. (Rate-limiting
for log messages was already solved from bug 748.)
- Emit a GUARD DROPPED controller event for a case we missed.
- Ensure DNS requests launched by "RESOLVE" commands from the
controller respect the __LeaveStreamsUnattached setconf options. The
same goes for requests launched via DNSPort or transparent
proxying. Bugfix on 0.2.0.1-alpha; fixes bug 1525.
o Minor bugfixes (config options):
- Tor used to limit HttpProxyAuthenticator values to 48 characters.
Change the limit to 512 characters by removing base64 newlines.
Fixes bug 2752. Fix by Michael Yakubovich.
- Complain if PublishServerDescriptor is given multiple arguments that
include 0 or 1. This configuration will be rejected in the future.
Bugfix on 0.2.0.1-alpha; closes bug 1107.
- Disallow BridgeRelay 1 and ORPort 0 at once in the configuration.
Bugfix on 0.2.0.13-alpha; closes bug 928.
o Minor bugfixes (log subsystem fixes):
- When unable to format an address as a string, report its value
as "???" rather than reusing the last formatted address. Bugfix
on 0.2.1.5-alpha.
- Be more consistent in our treatment of file system paths. "~" should
get expanded to the user's home directory in the Log config option.
Fixes bug 2971; bugfix on 0.2.0.1-alpha, which introduced the
feature for the -f and --DataDirectory options.
o Minor bugfixes (memory management):
- Don't stack-allocate the list of supplementary GIDs when we're
about to log them. Stack-allocating NGROUPS_MAX gid_t elements
could take up to 256K, which is way too much stack. Found by
Coverity; CID #450. Bugfix on 0.2.1.7-alpha.
- Save a couple bytes in memory allocation every time we escape
certain characters in a string. Patch from Florian Zumbiehl.
o Minor bugfixes (protocol correctness):
- When checking for 1024-bit keys, check for 1024 bits, not 128
bytes. This allows Tor to correctly discard keys of length 1017
through 1023. Bugfix on 0.0.9pre5.
- Require that introduction point keys and onion handshake keys
have a public exponent of 65537. Starts to fix bug 3207; bugfix
on 0.2.0.10-alpha.
- Handle SOCKS messages longer than 128 bytes long correctly, rather
than waiting forever for them to finish. Fixes bug 2330; bugfix
on 0.2.0.16-alpha. Found by doorss.
- Never relay a cell for a circuit we have already destroyed.
Between marking a circuit as closeable and finally closing it,
it may have been possible for a few queued cells to get relayed,
even though they would have been immediately dropped by the next
OR in the circuit. Fixes bug 1184; bugfix on 0.2.0.1-alpha.
- Never queue a cell for a circuit that's already been marked
for close.
- Fix a spec conformance issue: the network-status-version token
must be the first token in a v3 consensus or vote. Discovered by
"parakeep". Bugfix on 0.2.0.3-alpha.
- A networkstatus vote must contain exactly one signature. Spec
conformance issue. Bugfix on 0.2.0.3-alpha.
- When asked about a DNS record type we don't support via a
client DNSPort, reply with NOTIMPL rather than an empty
reply. Patch by intrigeri. Fixes bug 3369; bugfix on 2.0.1-alpha.
- Make more fields in the controller protocol case-insensitive, since
control-spec.txt said they were.
o Minor bugfixes (log messages):
- Fix a log message that said "bits" while displaying a value in
bytes. Found by wanoskarnet. Fixes bug 3318; bugfix on
0.2.0.1-alpha.
- Downgrade "no current certificates known for authority" message from
Notice to Info. Fixes bug 2899; bugfix on 0.2.0.10-alpha.
- Correctly describe errors that occur when generating a TLS object.
Previously we would attribute them to a failure while generating a
TLS context. Patch by Robert Ransom. Bugfix on 0.1.0.4-rc; fixes
bug 1994.
- Fix an instance where a Tor directory mirror might accidentally
log the IP address of a misbehaving Tor client. Bugfix on
0.1.0.1-rc.
- Stop logging at severity 'warn' when some other Tor client tries
to establish a circuit with us using weak DH keys. It's a protocol
violation, but that doesn't mean ordinary users need to hear about
it. Fixes the bug part of bug 1114. Bugfix on 0.1.0.13.
- If your relay can't keep up with the number of incoming create
cells, it would log one warning per failure into your logs. Limit
warnings to 1 per minute. Bugfix on 0.0.2pre10; fixes bug 1042.
o Minor bugfixes (build fixes):
- Fix warnings from GCC 4.6's "-Wunused-but-set-variable" option.
- When warning about missing zlib development packages during compile,
give the correct package names. Bugfix on 0.2.0.1-alpha.
- Fix warnings that newer versions of autoconf produce during
./autogen.sh. These warnings appear to be harmless in our case,
but they were extremely verbose. Fixes bug 2020.
- Squash a compile warning on OpenBSD. Reported by Tas; fixes
bug 1848.
o Minor bugfixes (portability):
- Write several files in text mode, on OSes that distinguish text
mode from binary mode (namely, Windows). These files are:
'buffer-stats', 'dirreq-stats', and 'entry-stats' on relays
that collect those statistics; 'client_keys' and 'hostname' for
hidden services that use authentication; and (in the tor-gencert
utility) newly generated identity and signing keys. Previously,
we wouldn't specify text mode or binary mode, leading to an
assertion failure. Fixes bug 3607. Bugfix on 0.2.1.1-alpha (when
the DirRecordUsageByCountry option which would have triggered
the assertion failure was added), although this assertion failure
would have occurred in tor-gencert on Windows in 0.2.0.1-alpha.
- Selectively disable deprecation warnings on OS X because Lion
started deprecating the shipped copy of openssl. Fixes bug 3643.
- Use a wide type to hold sockets when built for 64-bit Windows.
Fixes bug 3270.
- Fix an issue that prevented static linking of libevent on
some platforms (notably Linux). Fixes bug 2698; bugfix on 0.2.1.23,
where we introduced the "--with-static-libevent" configure option.
- Fix a bug with our locking implementation on Windows that couldn't
correctly detect when a file was already locked. Fixes bug 2504,
bugfix on 0.2.1.6-alpha.
- Build correctly on OSX with zlib 1.2.4 and higher with all warnings
enabled.
- Fix IPv6-related connect() failures on some platforms (BSD, OS X).
Bugfix on 0.2.0.3-alpha; fixes first part of bug 2660. Patch by
"piebeer".
o Minor bugfixes (code correctness):
- Always NUL-terminate the sun_path field of a sockaddr_un before
passing it to the kernel. (Not a security issue: kernels are
smart enough to reject bad sockaddr_uns.) Found by Coverity;
CID #428. Bugfix on Tor 0.2.0.3-alpha.
- Make connection_printf_to_buf()'s behavior sane. Its callers
expect it to emit a CRLF iff the format string ends with CRLF;
it actually emitted a CRLF iff (a) the format string ended with
CRLF or (b) the resulting string was over 1023 characters long or
(c) the format string did not end with CRLF *and* the resulting
string was 1021 characters long or longer. Bugfix on 0.1.1.9-alpha;
fixes part of bug 3407.
- Make send_control_event_impl()'s behavior sane. Its callers
expect it to always emit a CRLF at the end of the string; it
might have emitted extra control characters as well. Bugfix on
0.1.1.9-alpha; fixes another part of bug 3407.
- Make crypto_rand_int() check the value of its input correctly.
Previously, it accepted values up to UINT_MAX, but could return a
negative number if given a value above INT_MAX+1. Found by George
Kadianakis. Fixes bug 3306; bugfix on 0.2.2pre14.
- Fix a potential null-pointer dereference while computing a
consensus. Bugfix on tor-0.2.0.3-alpha, found with the help of
clang's analyzer.
- If we fail to compute the identity digest of a v3 legacy keypair,
warn, and don't use a buffer-full of junk instead. Bugfix on
0.2.1.1-alpha; fixes bug 3106.
- Resolve an untriggerable issue in smartlist_string_num_isin(),
where if the function had ever in the future been used to check
for the presence of a too-large number, it would have given an
incorrect result. (Fortunately, we only used it for 16-bit
values.) Fixes bug 3175; bugfix on 0.1.0.1-rc.
- Be more careful about reporting the correct error from a failed
connect() system call. Under some circumstances, it was possible to
look at an incorrect value for errno when sending the end reason.
Bugfix on 0.1.0.1-rc.
- Correctly handle an "impossible" overflow cases in connection byte
counting, where we write or read more than 4GB on an edge connection
in a single second. Bugfix on 0.1.2.8-beta.
- Avoid a double mark-for-free warning when failing to attach a
transparent proxy connection. Bugfix on 0.1.2.1-alpha. Fixes
bug 2279.
- Correctly detect failure to allocate an OpenSSL BIO. Fixes bug 2378;
found by "cypherpunks". This bug was introduced before the first
Tor release, in svn commit r110.
- Fix a bug in bandwidth history state parsing that could have been
triggered if a future version of Tor ever changed the timing
granularity at which bandwidth history is measured. Bugfix on
Tor 0.1.1.11-alpha.
- Add assertions to check for overflow in arguments to
base32_encode() and base32_decode(); fix a signed-unsigned
comparison there too. These bugs are not actually reachable in Tor,
but it's good to prevent future errors too. Found by doorss.
- Avoid a bogus overlapped memcpy in tor_addr_copy(). Reported by
"memcpyfail".
- Set target port in get_interface_address6() correctly. Bugfix
on 0.1.1.4-alpha and 0.2.0.3-alpha; fixes second part of bug 2660.
- Fix an impossible-to-actually-trigger buffer overflow in relay
descriptor generation. Bugfix on 0.1.0.15.
- Fix numerous small code-flaws found by Coverity Scan Rung 3.
o Minor bugfixes (code improvements):
- After we free an internal connection structure, overwrite it
with a different memory value than we use for overwriting a freed
internal circuit structure. Should help with debugging. Suggested
by bug 1055.
- If OpenSSL fails to make a duplicate of a private or public key, log
an error message and try to exit cleanly. May help with debugging
if bug 1209 ever remanifests.
- Some options used different conventions for uppercasing of acronyms
when comparing manpage and source. Fix those in favor of the
manpage, as it makes sense to capitalize acronyms.
- Take a first step towards making or.h smaller by splitting out
function definitions for all source files in src/or/. Leave
structures and defines in or.h for now.
- Remove a few dead assignments during router parsing. Found by
coverity.
- Don't use 1-bit wide signed bit fields. Found by coverity.
- Avoid signed/unsigned comparisons by making SIZE_T_CEILING unsigned.
None of the cases where we did this before were wrong, but by making
this change we avoid warnings. Fixes bug 2475; bugfix on 0.2.1.28.
- The memarea code now uses a sentinel value at the end of each area
to make sure nothing writes beyond the end of an area. This might
help debug some conceivable causes of bug 930.
- Always treat failure to allocate an RSA key as an unrecoverable
allocation error.
- Add some more defensive programming for architectures that can't
handle unaligned integer accesses. We don't know of any actual bugs
right now, but that's the best time to fix them. Fixes bug 1943.
o Minor bugfixes (misc):
- Fix a rare bug in rend_fn unit tests: we would fail a test when
a randomly generated port is 0. Diagnosed by Matt Edman. Bugfix
on 0.2.0.10-alpha; fixes bug 1808.
- Where available, use Libevent 2.0's periodic timers so that our
once-per-second cleanup code gets called even more closely to
once per second than it would otherwise. Fixes bug 943.
- Ignore OutboundBindAddress when connecting to localhost.
Connections to localhost need to come _from_ localhost, or else
local servers (like DNS and outgoing HTTP/SOCKS proxies) will often
refuse to listen.
- Update our OpenSSL 0.9.8l fix so that it works with OpenSSL 0.9.8m
too.
- If any of the v3 certs we download are unparseable, we should
actually notice the failure so we don't retry indefinitely. Bugfix
on 0.2.0.x; reported by "rotator".
- When Tor fails to parse a descriptor of any kind, dump it to disk.
Might help diagnosing bug 1051.
- Make our 'torify' script more portable; if we have only one of
'torsocks' or 'tsocks' installed, don't complain to the user;
and explain our warning about tsocks better.
- Fix some urls in the exit notice file and make it XHTML1.1 strict
compliant. Based on a patch from Christian Kujau.
o Documentation changes:
- Modernize the doxygen configuration file slightly. Fixes bug 2707.
- Resolve all doxygen warnings except those for missing documentation.
Fixes bug 2705.
- Add doxygen documentation for more functions, fields, and types.
- Convert the HACKING file to asciidoc, and add a few new sections
to it, explaining how we use Git, how we make changelogs, and
what should go in a patch.
- Document the default socks host and port (127.0.0.1:9050) for
tor-resolve.
- Removed some unnecessary files from the source distribution. The
AUTHORS file has now been merged into the people page on the
website. The roadmaps and design doc can now be found in the
projects directory in svn.
o Deprecated and removed features (config):
- Remove the torrc.complete file. It hasn't been kept up to date
and users will have better luck checking out the manpage.
- Remove the HSAuthorityRecordStats option that version 0 hidden
service authorities could use to track statistics of overall v0
hidden service usage.
- Remove the obsolete "NoPublish" option; it has been flagged
as obsolete and has produced a warning since 0.1.1.18-rc.
- Caches no longer download and serve v2 networkstatus documents
unless FetchV2Networkstatus flag is set: these documents haven't
haven't been used by clients or relays since 0.2.0.x. Resolves
bug 3022.
o Deprecated and removed features (controller):
- The controller no longer accepts the old obsolete "addr-mappings/"
or "unregistered-servers-" GETINFO values.
- The EXTENDED_EVENTS and VERBOSE_NAMES controller features are now
always on; using them is necessary for correct forward-compatible
controllers.
o Deprecated and removed features (misc):
- Hidden services no longer publish version 0 descriptors, and clients
do not request or use version 0 descriptors. However, the old hidden
service authorities still accept and serve version 0 descriptors
when contacted by older hidden services/clients.
- Remove undocumented option "-F" from tor-resolve: it hasn't done
anything since 0.2.1.16-rc.
- Remove everything related to building the expert bundle for OS X.
It has confused many users, doesn't work right on OS X 10.6,
and is hard to get rid of once installed. Resolves bug 1274.
- Remove support for .noconnect style addresses. Nobody was using
them, and they provided another avenue for detecting Tor users
via application-level web tricks.
- When we fixed bug 1038 we had to put in a restriction not to send
RELAY_EARLY cells on rend circuits. This was necessary as long
as relays using Tor 0.2.1.3-alpha through 0.2.1.18-alpha were
active. Now remove this obsolete check. Resolves bug 2081.
- Remove workaround code to handle directory responses from servers
that had bug 539 (they would send HTTP status 503 responses _and_
send a body too). Since only server versions before
0.2.0.16-alpha/0.1.2.19 were affected, there is no longer reason to
keep the workaround in place.
- Remove the old 'fuzzy time' logic. It was supposed to be used for
handling calculations where we have a known amount of clock skew and
an allowed amount of unknown skew. But we only used it in three
places, and we never adjusted the known/unknown skew values. This is
still something we might want to do someday, but if we do, we'll
want to do it differently.
- Remove the "--enable-iphone" option to ./configure. According to
reports from Marco Bonetti, Tor builds fine without any special
tweaking on recent iPhone SDK versions.
Changes in version 0.2.1.30 - 2011-02-23
Tor 0.2.1.30 fixes a variety of less critical bugs. The main other
change is a slight tweak to Tor's TLS handshake that makes relays
and bridges that run this new version reachable from Iran again.
We don't expect this tweak will win the arms race long-term, but it
buys us time until we roll out a better solution.
o Major bugfixes:
- Stop sending a CLOCK_SKEW controller status event whenever
we fetch directory information from a relay that has a wrong clock.
Instead, only inform the controller when it's a trusted authority
that claims our clock is wrong. Bugfix on 0.1.2.6-alpha; fixes
the rest of bug 1074.
- Fix a bounds-checking error that could allow an attacker to
remotely crash a directory authority. Bugfix on 0.2.1.5-alpha.
Found by "piebeer".
- If relays set RelayBandwidthBurst but not RelayBandwidthRate,
Tor would ignore their RelayBandwidthBurst setting,
potentially using more bandwidth than expected. Bugfix on
0.2.0.1-alpha. Reported by Paul Wouters. Fixes bug 2470.
- Ignore and warn if the user mistakenly sets "PublishServerDescriptor
hidserv" in her torrc. The 'hidserv' argument never controlled
publication of hidden service descriptors. Bugfix on 0.2.0.1-alpha.
o Minor features:
- Adjust our TLS Diffie-Hellman parameters to match those used by
Apache's mod_ssl.
- Update to the February 1 2011 Maxmind GeoLite Country database.
o Minor bugfixes:
- Check for and reject overly long directory certificates and
directory tokens before they have a chance to hit any assertions.
Bugfix on 0.2.1.28. Found by "doorss".
- Bring the logic that gathers routerinfos and assesses the
acceptability of circuits into line. This prevents a Tor OP from
getting locked in a cycle of choosing its local OR as an exit for a
path (due to a .exit request) and then rejecting the circuit because
its OR is not listed yet. It also prevents Tor clients from using an
OR running in the same instance as an exit (due to a .exit request)
if the OR does not meet the same requirements expected of an OR
running elsewhere. Fixes bug 1859; bugfix on 0.1.0.1-rc.
o Packaging changes:
- Stop shipping the Tor specs files and development proposal documents
in the tarball. They are now in a separate git repository at
git://git.torproject.org/torspec.git
- Do not include Git version tags as though they are SVN tags when
generating a tarball from inside a repository that has switched
between branches. Bugfix on 0.2.1.15-rc; fixes bug 2402.
Changes in version 0.2.1.29 - 2011-01-15
Tor 0.2.1.29 continues our recent code security audit work. The main
fix resolves a remote heap overflow vulnerability that can allow remote
code execution. Other fixes address a variety of assert and crash bugs,
most of which we think are hard to exploit remotely.
o Major bugfixes (security):
- Fix a heap overflow bug where an adversary could cause heap
corruption. This bug probably allows remote code execution
attacks. Reported by "debuger". Fixes CVE-2011-0427. Bugfix on
0.1.2.10-rc.
- Prevent a denial-of-service attack by disallowing any
zlib-compressed data whose compression factor is implausibly
high. Fixes part of bug 2324; reported by "doorss".
- Zero out a few more keys in memory before freeing them. Fixes
bug 2384 and part of bug 2385. These key instances found by
"cypherpunks", based on Andrew Case's report about being able
to find sensitive data in Tor's memory space if you have enough
permissions. Bugfix on 0.0.2pre9.
o Major bugfixes (crashes):
- Prevent calls to Libevent from inside Libevent log handlers.
This had potential to cause a nasty set of crashes, especially
if running Libevent with debug logging enabled, and running
Tor with a controller watching for low-severity log messages.
Bugfix on 0.1.0.2-rc. Fixes bug 2190.
- Add a check for SIZE_T_MAX to tor_realloc() to try to avoid
underflow errors there too. Fixes the other part of bug 2324.
- Fix a bug where we would assert if we ever had a
cached-descriptors.new file (or another file read directly into
memory) of exactly SIZE_T_CEILING bytes. Fixes bug 2326; bugfix
on 0.2.1.25. Found by doorss.
- Fix some potential asserts and parsing issues with grossly
malformed router caches. Fixes bug 2352; bugfix on Tor 0.2.1.27.
Found by doorss.
o Minor bugfixes (other):
- Fix a bug with handling misformed replies to reverse DNS lookup
requests in DNSPort. Bugfix on Tor 0.2.0.1-alpha. Related to a
bug reported by doorss.
- Fix compilation on mingw when a pthreads compatibility library
has been installed. (We don't want to use it, so we shouldn't
be including pthread.h.) Fixes bug 2313; bugfix on 0.1.0.1-rc.
- Fix a bug where we would declare that we had run out of virtual
addresses when the address space was only half-exhausted. Bugfix
on 0.1.2.1-alpha.
- Correctly handle the case where AutomapHostsOnResolve is set but
no virtual addresses are available. Fixes bug 2328; bugfix on
0.1.2.1-alpha. Bug found by doorss.
- Correctly handle wrapping around when we run out of virtual
address space. Found by cypherpunks; bugfix on 0.2.0.5-alpha.
o Minor features:
- Update to the January 1 2011 Maxmind GeoLite Country database.
- Introduce output size checks on all of our decryption functions.
o Build changes:
- Tor does not build packages correctly with Automake 1.6 and earlier;
added a check to Makefile.am to make sure that we're building with
Automake 1.7 or later.
- The 0.2.1.28 tarball was missing src/common/OpenBSD_malloc_Linux.c
because we built it with a too-old version of automake. Thus that
release broke ./configure --enable-openbsd-malloc, which is popular
among really fast exit relays on Linux.
Changes in version 0.2.1.28 - 2010-12-17
Tor 0.2.1.28 does some code cleanup to reduce the risk of remotely
exploitable bugs. We also took this opportunity to change the IP address
for one of our directory authorities, and to update the geoip database
we ship.
o Major bugfixes:
- Fix a remotely exploitable bug that could be used to crash instances
of Tor remotely by overflowing on the heap. Remote-code execution
hasn't been confirmed, but can't be ruled out. Everyone should
upgrade. Bugfix on the 0.1.1 series and later.
o Directory authority changes:
- Change IP address and ports for gabelmoo (v3 directory authority).
o Minor features:
- Update to the December 1 2010 Maxmind GeoLite Country database.
Changes in version 0.2.1.27 - 2010-11-23
Yet another OpenSSL security patch broke its compatibility with Tor:
Tor 0.2.1.27 makes relays work with openssl 0.9.8p and 1.0.0.b. We
also took this opportunity to fix several crash bugs, integrate a new
directory authority, and update the bundled GeoIP database.
o Major bugfixes:
- Resolve an incompatibility with OpenSSL 0.9.8p and OpenSSL 1.0.0b:
No longer set the tlsext_host_name extension on server SSL objects;
but continue to set it on client SSL objects. Our goal in setting
it was to imitate a browser, not a vhosting server. Fixes bug 2204;
bugfix on 0.2.1.1-alpha.
- Do not log messages to the controller while shrinking buffer
freelists. Doing so would sometimes make the controller connection
try to allocate a buffer chunk, which would mess up the internals
of the freelist and cause an assertion failure. Fixes bug 1125;
fixed by Robert Ransom. Bugfix on 0.2.0.16-alpha.
- Learn our external IP address when we're a relay or bridge, even if
we set PublishServerDescriptor to 0. Bugfix on 0.2.0.3-alpha,
where we introduced bridge relays that don't need to publish to
be useful. Fixes bug 2050.
- Do even more to reject (and not just ignore) annotations on
router descriptors received anywhere but from the cache. Previously
we would ignore such annotations at first, but cache them to disk
anyway. Bugfix on 0.2.0.8-alpha. Found by piebeer.
- When you're using bridges and your network goes away and your
bridges get marked as down, recover when you attempt a new socks
connection (if the network is back), rather than waiting up to an
hour to try fetching new descriptors for your bridges. Bugfix on
0.2.0.3-alpha; fixes bug 1981.
o Major features:
- Move to the November 2010 Maxmind GeoLite country db (rather
than the June 2009 ip-to-country GeoIP db) for our statistics that
count how many users relays are seeing from each country. Now we'll
have more accurate data, especially for many African countries.
o New directory authorities:
- Set up maatuska (run by Linus Nordberg) as the eighth v3 directory
authority.
o Minor bugfixes:
- Fix an assertion failure that could occur in directory caches or
bridge users when using a very short voting interval on a testing
network. Diagnosed by Robert Hogan. Fixes bug 1141; bugfix on
0.2.0.8-alpha.
- Enforce multiplicity rules when parsing annotations. Bugfix on
0.2.0.8-alpha. Found by piebeer.
- Allow handshaking OR connections to take a full KeepalivePeriod
seconds to handshake. Previously, we would close them after
IDLE_OR_CONN_TIMEOUT (180) seconds, the same timeout as if they
were open. Bugfix on 0.2.1.26; fixes bug 1840. Thanks to mingw-san
for analysis help.
- When building with --enable-gcc-warnings on OpenBSD, disable
warnings in system headers. This makes --enable-gcc-warnings
pass on OpenBSD 4.8.
o Minor features:
- Exit nodes didn't recognize EHOSTUNREACH as a plausible error code,
and so sent back END_STREAM_REASON_MISC. Clients now recognize a new
stream ending reason for this case: END_STREAM_REASON_NOROUTE.
Servers can start sending this code when enough clients recognize
it. Bugfix on 0.1.0.1-rc; fixes part of bug 1793.
- Build correctly on mingw with more recent versions of OpenSSL 0.9.8.
Patch from mingw-san.
o Removed files:
- Remove the old debian/ directory from the main Tor distribution.
The official Tor-for-debian git repository lives at the URL
https://git.torproject.org/debian/tor.git
- Stop shipping the old doc/website/ directory in the tarball. We
changed the website format in late 2010, and what we shipped in
0.2.1.26 really wasn't that useful anyway.
Changes in version 0.2.1.26 - 2010-05-02
Tor 0.2.1.26 addresses the recent connection and memory overload
problems we've been seeing on relays, especially relays with their
DirPort open. If your relay has been crashing, or you turned it off
because it used too many resources, give this release a try.
This release also fixes yet another instance of broken OpenSSL libraries
that was causing some relays to drop out of the consensus.
o Major bugfixes:
- Teach relays to defend themselves from connection overload. Relays
now close idle circuits early if it looks like they were intended
for directory fetches. Relays are also more aggressive about closing
TLS connections that have no circuits on them. Such circuits are
unlikely to be re-used, and tens of thousands of them were piling
up at the fast relays, causing the relays to run out of sockets
and memory. Bugfix on 0.2.0.22-rc (where clients started tunneling
their directory fetches over TLS).
- Fix SSL renegotiation behavior on OpenSSL versions like on Centos
that claim to be earlier than 0.9.8m, but which have in reality
backported huge swaths of 0.9.8m or 0.9.8n renegotiation
behavior. Possible fix for some cases of bug 1346.
- Directory mirrors were fetching relay descriptors only from v2
directory authorities, rather than v3 authorities like they should.
Only 2 v2 authorities remain (compared to 7 v3 authorities), leading
to a serious bottleneck. Bugfix on 0.2.0.9-alpha. Fixes bug 1324.
o Minor bugfixes:
- Finally get rid of the deprecated and now harmful notion of "clique
mode", where directory authorities maintain TLS connections to
every other relay.
o Testsuite fixes:
- In the util/threads test, no longer free the test_mutex before all
worker threads have finished. Bugfix on 0.2.1.6-alpha.
- The master thread could starve the worker threads quite badly on
certain systems, causing them to run only partially in the allowed
window. This resulted in test failures. Now the master thread sleeps
occasionally for a few microseconds while the two worker-threads
compete for the mutex. Bugfix on 0.2.0.1-alpha.
Changes in version 0.2.1.25 - 2010-03-16
Tor 0.2.1.25 fixes a regression introduced in 0.2.1.23 that could
prevent relays from guessing their IP address correctly. It also fixes
several minor potential security bugs.
o Major bugfixes:
- Fix a regression from our patch for bug 1244 that caused relays
to guess their IP address incorrectly if they didn't set Address
in their torrc and/or their address fails to resolve. Bugfix on
0.2.1.23; fixes bug 1269.
- When freeing a session key, zero it out completely. We only zeroed
the first ptrsize bytes. Bugfix on 0.0.2pre8. Discovered and
patched by ekir. Fixes bug 1254.
o Minor bugfixes:
- Fix a dereference-then-NULL-check sequence when publishing
descriptors. Bugfix on 0.2.1.5-alpha. Discovered by ekir; fixes
bug 1255.
- Fix another dereference-then-NULL-check sequence. Bugfix on
0.2.1.14-rc. Discovered by ekir; fixes bug 1256.
- Make sure we treat potentially not NUL-terminated strings correctly.
Bugfix on 0.1.1.13-alpha. Discovered by rieo; fixes bug 1257.
Changes in version 0.2.1.24 - 2010-02-21
Tor 0.2.1.24 makes Tor work again on the latest OS X -- this time
for sure!
o Minor bugfixes:
- Work correctly out-of-the-box with even more vendor-patched versions
of OpenSSL. In particular, make it so Debian and OS X don't need
customized patches to run/build.
Changes in version 0.2.1.23 - 2010-02-13
Tor 0.2.1.23 fixes a huge client-side performance bug, makes Tor work
again on the latest OS X, and updates the location of a directory
authority.
o Major bugfixes (performance):
- We were selecting our guards uniformly at random, and then weighting
which of our guards we'd use uniformly at random. This imbalance
meant that Tor clients were severely limited on throughput (and
probably latency too) by the first hop in their circuit. Now we
select guards weighted by currently advertised bandwidth. We also
automatically discard guards picked using the old algorithm. Fixes
bug 1217; bugfix on 0.2.1.3-alpha. Found by Mike Perry.
o Major bugfixes:
- Make Tor work again on the latest OS X: when deciding whether to
use strange flags to turn TLS renegotiation on, detect the OpenSSL
version at run-time, not compile time. We need to do this because
Apple doesn't update its dev-tools headers when it updates its
libraries in a security patch.
- Fix a potential buffer overflow in lookup_last_hid_serv_request()
that could happen on 32-bit platforms with 64-bit time_t. Also fix
a memory leak when requesting a hidden service descriptor we've
requested before. Fixes bug 1242, bugfix on 0.2.0.18-alpha. Found
by aakova.
o Minor bugfixes:
- Refactor resolve_my_address() to not use gethostbyname() anymore.
Fixes bug 1244; bugfix on 0.0.2pre25. Reported by Mike Mestnik.
o Minor features:
- Avoid a mad rush at the beginning of each month when each client
rotates half of its guards. Instead we spread the rotation out
throughout the month, but we still avoid leaving a precise timestamp
in the state file about when we first picked the guard. Improves
over the behavior introduced in 0.1.2.17.
Changes in version 0.2.1.22 - 2010-01-19
Tor 0.2.1.22 fixes a critical privacy problem in bridge directory
authorities -- it would tell you its whole history of bridge descriptors
if you make the right directory request. This stable update also
rotates two of the seven v3 directory authority keys and locations.
o Directory authority changes:
- Rotate keys (both v3 identity and relay identity) for moria1
and gabelmoo.
o Major bugfixes:
- Stop bridge directory authorities from answering dbg-stability.txt
directory queries, which would let people fetch a list of all
bridge identities they track. Bugfix on 0.2.1.6-alpha.
Changes in version 0.2.1.21 - 2009-12-21
Tor 0.2.1.21 fixes an incompatibility with the most recent OpenSSL
library. If you use Tor on Linux / Unix and you're getting SSL
renegotiation errors, upgrading should help. We also recommend an
upgrade if you're an exit relay.
o Major bugfixes:
- Work around a security feature in OpenSSL 0.9.8l that prevents our
handshake from working unless we explicitly tell OpenSSL that we
are using SSL renegotiation safely. We are, of course, but OpenSSL
0.9.8l won't work unless we say we are.
- Avoid crashing if the client is trying to upload many bytes and the
circuit gets torn down at the same time, or if the flip side
happens on the exit relay. Bugfix on 0.2.0.1-alpha; fixes bug 1150.
o Minor bugfixes:
- Do not refuse to learn about authority certs and v2 networkstatus
documents that are older than the latest consensus. This bug might
have degraded client bootstrapping. Bugfix on 0.2.0.10-alpha.
Spotted and fixed by xmux.
- Fix a couple of very-hard-to-trigger memory leaks, and one hard-to-
trigger platform-specific option misparsing case found by Coverity
Scan.
- Fix a compilation warning on Fedora 12 by removing an impossible-to-
trigger assert. Fixes bug 1173.
Changes in version 0.2.1.20 - 2009-10-15
Tor 0.2.1.20 fixes a crash bug when you're accessing many hidden
services at once, prepares for more performance improvements, and
fixes a bunch of smaller bugs.
The Windows and OS X bundles also include a more recent Vidalia,
and switch from Privoxy to Polipo.
The OS X installers are now drag and drop. It's best to un-install
Tor/Vidalia and then install this new bundle, rather than upgrade. If
you want to upgrade, you'll need to update the paths for Tor and Polipo
in the Vidalia Settings window.
o Major bugfixes:
- Send circuit or stream sendme cells when our window has decreased
by 100 cells, not when it has decreased by 101 cells. Bug uncovered
by Karsten when testing the "reduce circuit window" performance
patch. Bugfix on the 54th commit on Tor -- from July 2002,
before the release of Tor 0.0.0. This is the new winner of the
oldest-bug prize.
- Fix a remotely triggerable memory leak when a consensus document
contains more than one signature from the same voter. Bugfix on
0.2.0.3-alpha.
- Avoid segfault in rare cases when finishing an introduction circuit
as a client and finding out that we don't have an introduction key
for it. Fixes bug 1073. Reported by Aaron Swartz.
o Major features:
- Tor now reads the "circwindow" parameter out of the consensus,
and uses that value for its circuit package window rather than the
default of 1000 cells. Begins the implementation of proposal 168.
o New directory authorities:
- Set up urras (run by Jacob Appelbaum) as the seventh v3 directory
authority.
- Move moria1 and tonga to alternate IP addresses.
o Minor bugfixes:
- Fix a signed/unsigned compile warning in 0.2.1.19.
- Fix possible segmentation fault on directory authorities. Bugfix on
0.2.1.14-rc.
- Fix an extremely rare infinite recursion bug that could occur if
we tried to log a message after shutting down the log subsystem.
Found by Matt Edman. Bugfix on 0.2.0.16-alpha.
- Fix an obscure bug where hidden services on 64-bit big-endian
systems might mis-read the timestamp in v3 introduce cells, and
refuse to connect back to the client. Discovered by "rotor".
Bugfix on 0.2.1.6-alpha.
- We were triggering a CLOCK_SKEW controller status event whenever
we connect via the v2 connection protocol to any relay that has
a wrong clock. Instead, we should only inform the controller when
it's a trusted authority that claims our clock is wrong. Bugfix
on 0.2.0.20-rc; starts to fix bug 1074. Reported by SwissTorExit.
- We were telling the controller about CHECKING_REACHABILITY and
REACHABILITY_FAILED status events whenever we launch a testing
circuit or notice that one has failed. Instead, only tell the
controller when we want to inform the user of overall success or
overall failure. Bugfix on 0.1.2.6-alpha. Fixes bug 1075. Reported
by SwissTorExit.
- Don't warn when we're using a circuit that ends with a node
excluded in ExcludeExitNodes, but the circuit is not used to access
the outside world. This should help fix bug 1090. Bugfix on
0.2.1.6-alpha.
- Work around a small memory leak in some versions of OpenSSL that
stopped the memory used by the hostname TLS extension from being
freed.
o Minor features:
- Add a "getinfo status/accepted-server-descriptor" controller
command, which is the recommended way for controllers to learn
whether our server descriptor has been successfully received by at
least on directory authority. Un-recommend good-server-descriptor
getinfo and status events until we have a better design for them.
Changes in version 0.2.1.19 - 2009-07-28
Tor 0.2.1.19 fixes a major bug with accessing and providing hidden
services.
o Major bugfixes:
- Make accessing hidden services on 0.2.1.x work right again.
Bugfix on 0.2.1.3-alpha; workaround for bug 1038. Diagnosis and
part of patch provided by "optimist".
o Minor features:
- When a relay/bridge is writing out its identity key fingerprint to
the "fingerprint" file and to its logs, write it without spaces. Now
it will look like the fingerprints in our bridges documentation,
and confuse fewer users.
o Minor bugfixes:
- Relays no longer publish a new server descriptor if they change
their MaxAdvertisedBandwidth config option but it doesn't end up
changing their advertised bandwidth numbers. Bugfix on 0.2.0.28-rc;
fixes bug 1026. Patch from Sebastian.
- Avoid leaking memory every time we get a create cell but we have
so many already queued that we refuse it. Bugfix on 0.2.0.19-alpha;
fixes bug 1034. Reported by BarkerJr.
Changes in version 0.2.1.18 - 2009-07-24
Tor 0.2.1.18 lays the foundations for performance improvements,
adds status events to help users diagnose bootstrap problems, adds
optional authentication/authorization for hidden services, fixes a
variety of potential anonymity problems, and includes a huge pile of
other features and bug fixes.
o Major features (clients):
- Start sending "bootstrap phase" status events to the controller,
so it can keep the user informed of progress fetching directory
information and establishing circuits. Also inform the controller
if we think we're stuck at a particular bootstrap phase. Implements
proposal 137.
- Clients replace entry guards that were chosen more than a few months
ago. This change should significantly improve client performance,
especially once more people upgrade, since relays that have been
a guard for a long time are currently overloaded.
- Network status consensus documents and votes now contain bandwidth
information for each relay. Clients use the bandwidth values
in the consensus, rather than the bandwidth values in each
relay descriptor. This approach opens the door to more accurate
bandwidth estimates once the directory authorities start doing
active measurements. Implements part of proposal 141.
o Major features (relays):
- Disable and refactor some debugging checks that forced a linear scan
over the whole server-side DNS cache. These accounted for over 50%
of CPU time on a relatively busy exit node's gprof profile. Also,
disable some debugging checks that appeared in exit node profile
data. Found by Jacob.
- New DirPortFrontPage option that takes an html file and publishes
it as "/" on the DirPort. Now relay operators can provide a
disclaimer without needing to set up a separate webserver. There's
a sample disclaimer in contrib/tor-exit-notice.html.
o Major features (hidden services):
- Make it possible to build hidden services that only certain clients
are allowed to connect to. This is enforced at several points,
so that unauthorized clients are unable to send INTRODUCE cells
to the service, or even (depending on the type of authentication)
to learn introduction points. This feature raises the bar for
certain kinds of active attacks against hidden services. Design
and code by Karsten Loesing. Implements proposal 121.
- Relays now store and serve v2 hidden service descriptors by default,
i.e., the new default value for HidServDirectoryV2 is 1. This is
the last step in proposal 114, which aims to make hidden service
lookups more reliable.
o Major features (path selection):
- ExitNodes and Exclude*Nodes config options now allow you to restrict
by country code ("{US}") or IP address or address pattern
("255.128.0.0/16"). Patch from Robert Hogan. It still needs some
refinement to decide what config options should take priority if
you ask to both use a particular node and exclude it.
o Major features (misc):
- When building a consensus, do not include routers that are down.
This cuts down 30% to 40% on consensus size. Implements proposal
138.
- New TestingTorNetwork config option to allow adjustment of
previously constant values that could slow bootstrapping. Implements
proposal 135. Patch from Karsten.
- Convert many internal address representations to optionally hold
IPv6 addresses. Generate and accept IPv6 addresses in many protocol
elements. Make resolver code handle nameservers located at IPv6
addresses.
- More work on making our TLS handshake blend in: modify the list
of ciphers advertised by OpenSSL in client mode to even more
closely resemble a common web browser. We cheat a little so that
we can advertise ciphers that the locally installed OpenSSL doesn't
know about.
- Use the TLS1 hostname extension to more closely resemble browser
behavior.
o Security fixes (anonymity/entropy):
- Never use a connection with a mismatched address to extend a
circuit, unless that connection is canonical. A canonical
connection is one whose address is authenticated by the router's
identity key, either in a NETINFO cell or in a router descriptor.
- Implement most of proposal 110: The first K cells to be sent
along a circuit are marked as special "early" cells; only K "early"
cells will be allowed. Once this code is universal, we can block
certain kinds of denial-of-service attack by requiring that EXTEND
commands must be sent using an "early" cell.
- Resume using OpenSSL's RAND_poll() for better (and more portable)
cross-platform entropy collection again. We used to use it, then
stopped using it because of a bug that could crash systems that
called RAND_poll when they had a lot of fds open. It looks like the
bug got fixed in late 2006. Our new behavior is to call RAND_poll()
at startup, and to call RAND_poll() when we reseed later only if
we have a non-buggy OpenSSL version.
- When the client is choosing entry guards, now it selects at most
one guard from a given relay family. Otherwise we could end up with
all of our entry points into the network run by the same operator.
Suggested by Camilo Viecco. Fix on 0.1.1.11-alpha.
- Do not use or believe expired v3 authority certificates. Patch
from Karsten. Bugfix in 0.2.0.x. Fixes bug 851.
- Drop begin cells to a hidden service if they come from the middle
of a circuit. Patch from lark.
- When we erroneously receive two EXTEND cells for the same circuit
ID on the same connection, drop the second. Patch from lark.
- Authorities now vote for the Stable flag for any router whose
weighted MTBF is at least 5 days, regardless of the mean MTBF.
- Clients now never report any stream end reason except 'MISC'.
Implements proposal 148.
o Major bugfixes (crashes):
- Parse dates and IPv4 addresses in a locale- and libc-independent
manner, to avoid platform-dependent behavior on malformed input.
- Fix a crash that occurs on exit nodes when a nameserver request
timed out. Bugfix on 0.1.2.1-alpha; our CLEAR debugging code had
been suppressing the bug since 0.1.2.10-alpha. Partial fix for
bug 929.
- Do not assume that a stack-allocated character array will be
64-bit aligned on platforms that demand that uint64_t access is
aligned. Possible fix for bug 604.
- Resolve a very rare crash bug that could occur when the user forced
a nameserver reconfiguration during the middle of a nameserver
probe. Fixes bug 526. Bugfix on 0.1.2.1-alpha.
- Avoid a "0 divided by 0" calculation when calculating router uptime
at directory authorities. Bugfix on 0.2.0.8-alpha.
- Fix an assertion bug in parsing policy-related options; possible fix
for bug 811.
- Rate-limit too-many-sockets messages: when they happen, they happen
a lot and end up filling up the disk. Resolves bug 748.
- Fix a race condition that could cause crashes or memory corruption
when running as a server with a controller listening for log
messages.
- Avoid crashing when we have a policy specified in a DirPolicy or
SocksPolicy or ReachableAddresses option with ports set on it,
and we re-load the policy. May fix bug 996.
- Fix an assertion failure on 64-bit platforms when we allocated
memory right up to the end of a memarea, then realigned the memory
one step beyond the end. Fixes a possible cause of bug 930.
- Protect the count of open sockets with a mutex, so we can't
corrupt it when two threads are closing or opening sockets at once.
Fix for bug 939. Bugfix on 0.2.0.1-alpha.
o Major bugfixes (clients):
- Discard router descriptors as we load them if they are more than
five days old. Otherwise if Tor is off for a long time and then
starts with cached descriptors, it will try to use the onion keys
in those obsolete descriptors when building circuits. Fixes bug 887.
- When we choose to abandon a new entry guard because we think our
older ones might be better, close any circuits pending on that
new entry guard connection. This fix should make us recover much
faster when our network is down and then comes back. Bugfix on
0.1.2.8-beta; found by lodger.
- When Tor clients restart after 1-5 days, they discard all their
cached descriptors as too old, but they still use the cached
consensus document. This approach is good for robustness, but
bad for performance: since they don't know any bandwidths, they
end up choosing at random rather than weighting their choice by
speed. Fixed by the above feature of putting bandwidths in the
consensus.
o Major bugfixes (relays):
- Relays were falling out of the networkstatus consensus for
part of a day if they changed their local config but the
authorities discarded their new descriptor as "not sufficiently
different". Now directory authorities accept a descriptor as changed
if BandwidthRate or BandwidthBurst changed. Partial fix for bug 962;
patch by Sebastian.
- Ensure that two circuits can never exist on the same connection
with the same circuit ID, even if one is marked for close. This
is conceivably a bugfix for bug 779; fixes a bug on 0.1.0.4-rc.
- Directory authorities were neglecting to mark relays down in their
internal histories if the relays fall off the routerlist without
ever being found unreachable. So there were relays in the histories
that haven't been seen for eight months, and are listed as being
up for eight months. This wreaked havoc on the "median wfu" and
"median mtbf" calculations, in turn making Guard and Stable flags
wrong, hurting network performance. Fixes bugs 696 and 969. Bugfix
on 0.2.0.6-alpha.
o Major bugfixes (hidden services):
- When establishing a hidden service, introduction points that
originate from cannibalized circuits were completely ignored
and not included in rendezvous service descriptors. This might
have been another reason for delay in making a hidden service
available. Bugfix from long ago (0.0.9.x?)
o Major bugfixes (memory and resource management):
- Fixed some memory leaks -- some quite frequent, some almost
impossible to trigger -- based on results from Coverity.
- Speed up parsing and cut down on memory fragmentation by using
stack-style allocations for parsing directory objects. Previously,
this accounted for over 40% of allocations from within Tor's code
on a typical directory cache.
- Use a Bloom filter rather than a digest-based set to track which
descriptors we need to keep around when we're cleaning out old
router descriptors. This speeds up the computation significantly,
and may reduce fragmentation.
o New/changed config options:
- Now NodeFamily and MyFamily config options allow spaces in
identity fingerprints, so it's easier to paste them in.
Suggested by Lucky Green.
- Allow ports 465 and 587 in the default exit policy again. We had
rejected them in 0.1.0.15, because back in 2005 they were commonly
misconfigured and ended up as spam targets. We hear they are better
locked down these days.
- Make TrackHostExit mappings expire a while after their last use, not
after their creation. Patch from Robert Hogan.
- Add an ExcludeExitNodes option so users can list a set of nodes
that should be be excluded from the exit node position, but
allowed elsewhere. Implements proposal 151.
- New --hush command-line option similar to --quiet. While --quiet
disables all logging to the console on startup, --hush limits the
output to messages of warning and error severity.
- New configure/torrc options (--enable-geoip-stats,
DirRecordUsageByCountry) to record how many IPs we've served
directory info to in each country code, how many status documents
total we've sent to each country code, and what share of the total
directory requests we should expect to see.
- Make outbound DNS packets respect the OutboundBindAddress setting.
Fixes the bug part of bug 798. Bugfix on 0.1.2.2-alpha.
- Allow separate log levels to be configured for different logging
domains. For example, this allows one to log all notices, warnings,
or errors, plus all memory management messages of level debug or
higher, with: Log [MM] debug-err [*] notice-err file /var/log/tor.
- Update to the "June 3 2009" ip-to-country file.
o Minor features (relays):
- Raise the minimum rate limiting to be a relay from 20000 bytes
to 20480 bytes (aka 20KB/s), to match our documentation. Also
update directory authorities so they always assign the Fast flag
to relays with 20KB/s of capacity. Now people running relays won't
suddenly find themselves not seeing any use, if the network gets
faster on average.
- If we're a relay and we change our IP address, be more verbose
about the reason that made us change. Should help track down
further bugs for relays on dynamic IP addresses.
- Exit servers can now answer resolve requests for ip6.arpa addresses.
- Implement most of Proposal 152: allow specialized servers to permit
single-hop circuits, and clients to use those servers to build
single-hop circuits when using a specialized controller. Patch
from Josh Albrecht. Resolves feature request 768.
- When relays do their initial bandwidth measurement, don't limit
to just our entry guards for the test circuits. Otherwise we tend
to have multiple test circuits going through a single entry guard,
which makes our bandwidth test less accurate. Fixes part of bug 654;
patch contributed by Josh Albrecht.
o Minor features (directory authorities):
- Try not to open more than one descriptor-downloading connection
to an authority at once. This should reduce load on directory
authorities. Fixes bug 366.
- Add cross-certification to newly generated certificates, so that
a signing key is enough information to look up a certificate. Start
serving certificates by <identity digest, signing key digest>
pairs. Implements proposal 157.
- When a directory authority downloads a descriptor that it then
immediately rejects, do not retry downloading it right away. Should
save some bandwidth on authorities. Fix for bug 888. Patch by
Sebastian Hahn.
- Directory authorities now serve a /tor/dbg-stability.txt URL to
help debug WFU and MTBF calculations.
- In directory authorities' approved-routers files, allow
fingerprints with or without space.
o Minor features (directory mirrors):
- When a download gets us zero good descriptors, do not notify
Tor that new directory information has arrived.
- Servers support a new URL scheme for consensus downloads that
allows the client to specify which authorities are trusted.
The server then only sends the consensus if the client will trust
it. Otherwise a 404 error is sent back. Clients use this
new scheme when the server supports it (meaning it's running
0.2.1.1-alpha or later). Implements proposal 134.
o Minor features (bridges):
- If the bridge config line doesn't specify a port, assume 443.
This makes bridge lines a bit smaller and easier for users to
understand.
- If we're using bridges and our network goes away, be more willing
to forgive our bridges and try again when we get an application
request.
o Minor features (hidden services):
- When the client launches an introduction circuit, retry with a
new circuit after 30 seconds rather than 60 seconds.
- Launch a second client-side introduction circuit in parallel
after a delay of 15 seconds (based on work by Christian Wilms).
- Hidden services start out building five intro circuits rather
than three, and when the first three finish they publish a service
descriptor using those. Now we publish our service descriptor much
faster after restart.
- Drop the requirement to have an open dir port for storing and
serving v2 hidden service descriptors.
o Minor features (build and packaging):
- On Linux, use the prctl call to re-enable core dumps when the User
option is set.
- Try to make sure that the version of Libevent we're running with
is binary-compatible with the one we built with. May address bug
897 and others.
- Add a new --enable-local-appdata configuration switch to change
the default location of the datadir on win32 from APPDATA to
LOCAL_APPDATA. In the future, we should migrate to LOCAL_APPDATA
entirely. Patch from coderman.
- Build correctly against versions of OpenSSL 0.9.8 or later that
are built without support for deprecated functions.
- On platforms with a maximum syslog string length, truncate syslog
messages to that length ourselves, rather than relying on the
system to do it for us.
- Automatically detect MacOSX versions earlier than 10.4.0, and
disable kqueue from inside Tor when running with these versions.
We previously did this from the startup script, but that was no
help to people who didn't use the startup script. Resolves bug 863.
- Build correctly when configured to build outside the main source
path. Patch from Michael Gold.
- Disable GCC's strict alias optimization by default, to avoid the
likelihood of its introducing subtle bugs whenever our code violates
the letter of C99's alias rules.
- Change the contrib/tor.logrotate script so it makes the new
logs as "_tor:_tor" rather than the default, which is generally
"root:wheel". Fixes bug 676, reported by Serge Koksharov.
- Change our header file guard macros to be less likely to conflict
with system headers. Adam Langley noticed that we were conflicting
with log.h on Android.
- Add a couple of extra warnings to --enable-gcc-warnings for GCC 4.3,
and stop using a warning that had become unfixably verbose under
GCC 4.3.
- Use a lockfile to make sure that two Tor processes are not
simultaneously running with the same datadir.
- Allow OpenSSL to use dynamic locks if it wants.
- Add LIBS=-lrt to Makefile.am so the Tor RPMs use a static libevent.
o Minor features (controllers):
- When generating circuit events with verbose nicknames for
controllers, try harder to look up nicknames for routers on a
circuit. (Previously, we would look in the router descriptors we had
for nicknames, but not in the consensus.) Partial fix for bug 941.
- New controller event NEWCONSENSUS that lists the networkstatus
lines for every recommended relay. Now controllers like Torflow
can keep up-to-date on which relays they should be using.
- New controller event "clients_seen" to report a geoip-based summary
of which countries we've seen clients from recently. Now controllers
like Vidalia can show bridge operators that they're actually making
a difference.
- Add a 'getinfo status/clients-seen' controller command, in case
controllers want to hear clients_seen events but connect late.
- New CONSENSUS_ARRIVED event to note when a new consensus has
been fetched and validated.
- Add an internal-use-only __ReloadTorrcOnSIGHUP option for
controllers to prevent SIGHUP from reloading the configuration.
Fixes bug 856.
- Return circuit purposes in response to GETINFO circuit-status.
Fixes bug 858.
- Serve the latest v3 networkstatus consensus via the control
port. Use "getinfo dir/status-vote/current/consensus" to fetch it.
- Add a "GETINFO /status/bootstrap-phase" controller option, so the
controller can query our current bootstrap state in case it attaches
partway through and wants to catch up.
- Provide circuit purposes along with circuit events to the controller.
o Minor features (tools):
- Do not have tor-resolve automatically refuse all .onion addresses;
if AutomapHostsOnResolve is set in your torrc, this will work fine.
- Add a -p option to tor-resolve for specifying the SOCKS port: some
people find host:port too confusing.
- Print the SOCKS5 error message string as well as the error code
when a tor-resolve request fails. Patch from Jacob.
o Minor bugfixes (memory and resource management):
- Clients no longer cache certificates for authorities they do not
recognize. Bugfix on 0.2.0.9-alpha.
- Do not use C's stdio library for writing to log files. This will
improve logging performance by a minute amount, and will stop
leaking fds when our disk is full. Fixes bug 861.
- Stop erroneous use of O_APPEND in cases where we did not in fact
want to re-seek to the end of a file before every last write().
- Fix a small alignment and memory-wasting bug on buffer chunks.
Spotted by rovv.
- Add a malloc_good_size implementation to OpenBSD_malloc_linux.c,
to avoid unused RAM in buffer chunks and memory pools.
- Reduce the default smartlist size from 32 to 16; it turns out that
most smartlists hold around 8-12 elements tops.
- Make dumpstats() log the fullness and size of openssl-internal
buffers.
- If the user has applied the experimental SSL_MODE_RELEASE_BUFFERS
patch to their OpenSSL, turn it on to save memory on servers. This
patch will (with any luck) get included in a mainline distribution
before too long.
- Fix a memory leak when v3 directory authorities load their keys
and cert from disk. Bugfix on 0.2.0.1-alpha.
- Stop using malloc_usable_size() to use more area than we had
actually allocated: it was safe, but made valgrind really unhappy.
- Make the assert_circuit_ok() function work correctly on circuits that
have already been marked for close.
- Fix uninitialized size field for memory area allocation: may improve
memory performance during directory parsing.
o Minor bugfixes (clients):
- Stop reloading the router list from disk for no reason when we
run out of reachable directory mirrors. Once upon a time reloading
it would set the 'is_running' flag back to 1 for them. It hasn't
done that for a long time.
- When we had picked an exit node for a connection, but marked it as
"optional", and it turned out we had no onion key for the exit,
stop wanting that exit and try again. This situation may not
be possible now, but will probably become feasible with proposal
158. Spotted by rovv. Fixes another case of bug 752.
- Fix a bug in address parsing that was preventing bridges or hidden
service targets from being at IPv6 addresses.
- Do not remove routers as too old if we do not have any consensus
document. Bugfix on 0.2.0.7-alpha.
- When an exit relay resolves a stream address to a local IP address,
do not just keep retrying that same exit relay over and
over. Instead, just close the stream. Addresses bug 872. Bugfix
on 0.2.0.32. Patch from rovv.
- Made Tor a little less aggressive about deleting expired
certificates. Partial fix for bug 854.
- Treat duplicate certificate fetches as failures, so that we do
not try to re-fetch an expired certificate over and over and over.
- Do not say we're fetching a certificate when we'll in fact skip it
because of a pending download.
- If we have correct permissions on $datadir, we complain to stdout
and fail to start. But dangerous permissions on
$datadir/cached-status/ would cause us to open a log and complain
there. Now complain to stdout and fail to start in both cases. Fixes
bug 820, reported by seeess.
o Minor bugfixes (bridges):
- When we made bridge authorities stop serving bridge descriptors over
unencrypted links, we also broke DirPort reachability testing for
bridges. So bridges with a non-zero DirPort were printing spurious
warns to their logs. Bugfix on 0.2.0.16-alpha. Fixes bug 709.
- Don't allow a bridge to publish its router descriptor to a
non-bridge directory authority. Fixes part of bug 932.
- When we change to or from being a bridge, reset our counts of
client usage by country. Fixes bug 932.
o Minor bugfixes (relays):
- Log correct error messages for DNS-related network errors on
Windows.
- Actually return -1 in the error case for read_bandwidth_usage().
Harmless bug, since we currently don't care about the return value
anywhere. Bugfix on 0.2.0.9-alpha.
- Provide a more useful log message if bug 977 (related to buffer
freelists) ever reappears, and do not crash right away.
- We were already rejecting relay begin cells with destination port
of 0. Now also reject extend cells with destination port or address
of 0. Suggested by lark.
- When we can't transmit a DNS request due to a network error, retry
it after a while, and eventually transmit a failing response to
the RESOLVED cell. Bugfix on 0.1.2.5-alpha.
- Solve a bug that kept hardware crypto acceleration from getting
enabled when accounting was turned on. Fixes bug 907. Bugfix on
0.0.9pre6.
- When a canonical connection appears later in our internal list
than a noncanonical one for a given OR ID, always use the
canonical one. Bugfix on 0.2.0.12-alpha. Fixes bug 805.
Spotted by rovv.
- Avoid some nasty corner cases in the logic for marking connections
as too old or obsolete or noncanonical for circuits. Partial
bugfix on bug 891.
- Fix another interesting corner-case of bug 891 spotted by rovv:
Previously, if two hosts had different amounts of clock drift, and
one of them created a new connection with just the wrong timing,
the other might decide to deprecate the new connection erroneously.
Bugfix on 0.1.1.13-alpha.
- If one win32 nameserver fails to get added, continue adding the
rest, and don't automatically fail.
- Fix a bug where an unreachable relay would establish enough
reachability testing circuits to do a bandwidth test -- if
we already have a connection to the middle hop of the testing
circuit, then it could establish the last hop by using the existing
connection. Bugfix on 0.1.2.2-alpha, exposed when we made testing
circuits no longer use entry guards in 0.2.1.3-alpha.
o Minor bugfixes (directory authorities):
- Limit uploaded directory documents to be 16M rather than 500K.
The directory authorities were refusing v3 consensus votes from
other authorities, since the votes are now 504K. Fixes bug 959;
bugfix on 0.0.2pre17 (where we raised it from 50K to 500K ;).
- Directory authorities should never send a 503 "busy" response to
requests for votes or keys. Bugfix on 0.2.0.8-alpha; exposed by
bug 959.
- Fix code so authorities _actually_ send back X-Descriptor-Not-New
headers. Bugfix on 0.2.0.10-alpha.
o Minor bugfixes (hidden services):
- When we can't find an intro key for a v2 hidden service descriptor,
fall back to the v0 hidden service descriptor and log a bug message.
Workaround for bug 1024.
- In very rare situations new hidden service descriptors were
published earlier than 30 seconds after the last change to the
service. (We currently think that a hidden service descriptor
that's been stable for 30 seconds is worth publishing.)
- If a hidden service sends us an END cell, do not consider
retrying the connection; just close it. Patch from rovv.
- If we are not using BEGIN_DIR cells, don't attempt to contact hidden
service directories if they have no advertised dir port. Bugfix
on 0.2.0.10-alpha.
o Minor bugfixes (tools):
- In the torify(1) manpage, mention that tsocks will leak your
DNS requests.
o Minor bugfixes (controllers):
- If the controller claimed responsibility for a stream, but that
stream never finished making its connection, it would live
forever in circuit_wait state. Now we close it after SocksTimeout
seconds. Bugfix on 0.1.2.7-alpha; reported by Mike Perry.
- Make DNS resolved controller events into "CLOSED", not
"FAILED". Bugfix on 0.1.2.5-alpha. Fix by Robert Hogan. Resolves
bug 807.
- The control port would close the connection before flushing long
replies, such as the network consensus, if a QUIT command was issued
before the reply had completed. Now, the control port flushes all
pending replies before closing the connection. Also fix a spurious
warning when a QUIT command is issued after a malformed or rejected
AUTHENTICATE command, but before the connection was closed. Patch
by Marcus Griep. Fixes bugs 1015 and 1016.
- Fix a bug that made stream bandwidth get misreported to the
controller.
o Deprecated and removed features:
- The old "tor --version --version" command, which would print out
the subversion "Id" of most of the source files, is now removed. It
turned out to be less useful than we'd expected, and harder to
maintain.
- RedirectExits has been removed. It was deprecated since
0.2.0.3-alpha.
- Finally remove deprecated "EXTENDED_FORMAT" controller feature. It
has been called EXTENDED_EVENTS since 0.1.2.4-alpha.
- Cell pools are now always enabled; --disable-cell-pools is ignored.
- Directory mirrors no longer fetch the v1 directory or
running-routers files. They are obsolete, and nobody asks for them
anymore. This is the first step to making v1 authorities obsolete.
- Take out the TestVia config option, since it was a workaround for
a bug that was fixed in Tor 0.1.1.21.
- Mark RendNodes, RendExcludeNodes, HiddenServiceNodes, and
HiddenServiceExcludeNodes as obsolete: they never worked properly,
and nobody seems to be using them. Fixes bug 754. Bugfix on
0.1.0.1-rc. Patch from Christian Wilms.
- Remove all backward-compatibility code for relays running
versions of Tor so old that they no longer work at all on the
Tor network.
o Code simplifications and refactoring:
- Tool-assisted documentation cleanup. Nearly every function or
static variable in Tor should have its own documentation now.
- Rename the confusing or_is_obsolete field to the more appropriate
is_bad_for_new_circs, and move it to or_connection_t where it
belongs.
- Move edge-only flags from connection_t to edge_connection_t: not
only is this better coding, but on machines of plausible alignment,
it should save 4-8 bytes per connection_t. "Every little bit helps."
- Rename ServerDNSAllowBrokenResolvConf to ServerDNSAllowBrokenConfig
for consistency; keep old option working for backward compatibility.
- Simplify the code for finding connections to use for a circuit.
- Revise the connection_new functions so that a more typesafe variant
exists. This will work better with Coverity, and let us find any
actual mistakes we're making here.
- Refactor unit testing logic so that dmalloc can be used sensibly
with unit tests to check for memory leaks.
- Move all hidden-service related fields from connection and circuit
structure to substructures: this way they won't eat so much memory.
- Squeeze 2-5% out of client performance (according to oprofile) by
improving the implementation of some policy-manipulation functions.
- Change the implementation of ExcludeNodes and ExcludeExitNodes to
be more efficient. Formerly it was quadratic in the number of
servers; now it should be linear. Fixes bug 509.
- Save 16-22 bytes per open circuit by moving the n_addr, n_port,
and n_conn_id_digest fields into a separate structure that's
only needed when the circuit has not yet attached to an n_conn.
- Optimize out calls to time(NULL) that occur for every IO operation,
or for every cell. On systems like Windows where time() is a
slow syscall, this fix will be slightly helpful.
Changes in version 0.2.0.35 - 2009-06-24
o Security fix:
- Avoid crashing in the presence of certain malformed descriptors.
Found by lark, and by automated fuzzing.
- Fix an edge case where a malicious exit relay could convince a
controller that the client's DNS question resolves to an internal IP
address. Bug found and fixed by "optimist"; bugfix on 0.1.2.8-beta.
o Major bugfixes:
- Finally fix the bug where dynamic-IP relays disappear when their
IP address changes: directory mirrors were mistakenly telling
them their old address if they asked via begin_dir, so they
never got an accurate answer about their new address, so they
just vanished after a day. For belt-and-suspenders, relays that
don't set Address in their config now avoid using begin_dir for
all direct connections. Should fix bugs 827, 883, and 900.
- Fix a timing-dependent, allocator-dependent, DNS-related crash bug
that would occur on some exit nodes when DNS failures and timeouts
occurred in certain patterns. Fix for bug 957.
o Minor bugfixes:
- When starting with a cache over a few days old, do not leak
memory for the obsolete router descriptors in it. Bugfix on
0.2.0.33; fixes bug 672.
- Hidden service clients didn't use a cached service descriptor that
was older than 15 minutes, but wouldn't fetch a new one either,
because there was already one in the cache. Now, fetch a v2
descriptor unless the same descriptor was added to the cache within
the last 15 minutes. Fixes bug 997; reported by Marcus Griep.
Changes in version 0.2.0.34 - 2009-02-08
Tor 0.2.0.34 features several more security-related fixes. You should
upgrade, especially if you run an exit relay (remote crash) or a
directory authority (remote infinite loop), or you're on an older
(pre-XP) or not-recently-patched Windows (remote exploit).
This release marks end-of-life for Tor 0.1.2.x. Those Tor versions
have many known flaws, and nobody should be using them. You should
upgrade. If you're using a Linux or BSD and its packages are obsolete,
stop using those packages and upgrade anyway.
o Security fixes:
- Fix an infinite-loop bug on handling corrupt votes under certain
circumstances. Bugfix on 0.2.0.8-alpha.
- Fix a temporary DoS vulnerability that could be performed by
a directory mirror. Bugfix on 0.2.0.9-alpha; reported by lark.
- Avoid a potential crash on exit nodes when processing malformed
input. Remote DoS opportunity. Bugfix on 0.2.0.33.
- Do not accept incomplete ipv4 addresses (like 192.168.0) as valid.
Spec conformance issue. Bugfix on Tor 0.0.2pre27.
o Minor bugfixes:
- Fix compilation on systems where time_t is a 64-bit integer.
Patch from Matthias Drochner.
- Don't consider expiring already-closed client connections. Fixes
bug 893. Bugfix on 0.0.2pre20.
Changes in version 0.2.0.33 - 2009-01-21
Tor 0.2.0.33 fixes a variety of bugs that were making relays less
useful to users. It also finally fixes a bug where a relay or client
that's been off for many days would take a long time to bootstrap.
This update also fixes an important security-related bug reported by
Ilja van Sprundel. You should upgrade. (We'll send out more details
about the bug once people have had some time to upgrade.)
o Security fixes:
- Fix a heap-corruption bug that may be remotely triggerable on
some platforms. Reported by Ilja van Sprundel.
o Major bugfixes:
- When a stream at an exit relay is in state "resolving" or
"connecting" and it receives an "end" relay cell, the exit relay
would silently ignore the end cell and not close the stream. If
the client never closes the circuit, then the exit relay never
closes the TCP connection. Bug introduced in Tor 0.1.2.1-alpha;
reported by "wood".
- When sending CREATED cells back for a given circuit, use a 64-bit
connection ID to find the right connection, rather than an addr:port
combination. Now that we can have multiple OR connections between
the same ORs, it is no longer possible to use addr:port to uniquely
identify a connection.
- Bridge relays that had DirPort set to 0 would stop fetching
descriptors shortly after startup, and then briefly resume
after a new bandwidth test and/or after publishing a new bridge
descriptor. Bridge users that try to bootstrap from them would
get a recent networkstatus but would get descriptors from up to
18 hours earlier, meaning most of the descriptors were obsolete
already. Reported by Tas; bugfix on 0.2.0.13-alpha.
- Prevent bridge relays from serving their 'extrainfo' document
to anybody who asks, now that extrainfo docs include potentially
sensitive aggregated client geoip summaries. Bugfix on
0.2.0.13-alpha.
- If the cached networkstatus consensus is more than five days old,
discard it rather than trying to use it. In theory it could be
useful because it lists alternate directory mirrors, but in practice
it just means we spend many minutes trying directory mirrors that
are long gone from the network. Also discard router descriptors as
we load them if they are more than five days old, since the onion
key is probably wrong by now. Bugfix on 0.2.0.x. Fixes bug 887.
o Minor bugfixes:
- Do not mark smartlist_bsearch_idx() function as ATTR_PURE. This bug
could make gcc generate non-functional binary search code. Bugfix
on 0.2.0.10-alpha.
- Build correctly on platforms without socklen_t.
- Compile without warnings on solaris.
- Avoid potential crash on internal error during signature collection.
Fixes bug 864. Patch from rovv.
- Correct handling of possible malformed authority signing key
certificates with internal signature types. Fixes bug 880.
Bugfix on 0.2.0.3-alpha.
- Fix a hard-to-trigger resource leak when logging credential status.
CID 349.
- When we can't initialize DNS because the network is down, do not
automatically stop Tor from starting. Instead, we retry failed
dns_init() every 10 minutes, and change the exit policy to reject
*:* until one succeeds. Fixes bug 691.
- Use 64 bits instead of 32 bits for connection identifiers used with
the controller protocol, to greatly reduce risk of identifier reuse.
- When we're choosing an exit node for a circuit, and we have
no pending streams, choose a good general exit rather than one that
supports "all the pending streams". Bugfix on 0.1.1.x. Fix by rovv.
- Fix another case of assuming, when a specific exit is requested,
that we know more than the user about what hosts it allows.
Fixes one case of bug 752. Patch from rovv.
- Clip the MaxCircuitDirtiness config option to a minimum of 10
seconds. Warn the user if lower values are given in the
configuration. Bugfix on 0.1.0.1-rc. Patch by Sebastian.
- Clip the CircuitBuildTimeout to a minimum of 30 seconds. Warn the
user if lower values are given in the configuration. Bugfix on
0.1.1.17-rc. Patch by Sebastian.
- Fix a memory leak when we decline to add a v2 rendezvous descriptor to
the cache because we already had a v0 descriptor with the same ID.
Bugfix on 0.2.0.18-alpha.
- Fix a race condition when freeing keys shared between main thread
and CPU workers that could result in a memory leak. Bugfix on
0.1.0.1-rc. Fixes bug 889.
- Send a valid END cell back when a client tries to connect to a
nonexistent hidden service port. Bugfix on 0.1.2.15. Fixes bug
840. Patch from rovv.
- Check which hops rendezvous stream cells are associated with to
prevent possible guess-the-streamid injection attacks from
intermediate hops. Fixes another case of bug 446. Based on patch
from rovv.
- If a broken client asks a non-exit router to connect somewhere,
do not even do the DNS lookup before rejecting the connection.
Fixes another case of bug 619. Patch from rovv.
- When a relay gets a create cell it can't decrypt (e.g. because it's
using the wrong onion key), we were dropping it and letting the
client time out. Now actually answer with a destroy cell. Fixes
bug 904. Bugfix on 0.0.2pre8.
o Minor bugfixes (hidden services):
- Do not throw away existing introduction points on SIGHUP. Bugfix on
0.0.6pre1. Patch by Karsten. Fixes bug 874.
o Minor features:
- Report the case where all signatures in a detached set are rejected
differently than the case where there is an error handling the
detached set.
- When we realize that another process has modified our cached
descriptors, print out a more useful error message rather than
triggering an assertion. Fixes bug 885. Patch from Karsten.
- Implement the 0x20 hack to better resist DNS poisoning: set the
case on outgoing DNS requests randomly, and reject responses that do
not match the case correctly. This logic can be disabled with the
ServerDNSRamdomizeCase setting, if you are using one of the 0.3%
of servers that do not reliably preserve case in replies. See
"Increased DNS Forgery Resistance through 0x20-Bit Encoding"
for more info.
- Check DNS replies for more matching fields to better resist DNS
poisoning.
- Never use OpenSSL compression: it wastes RAM and CPU trying to
compress cells, which are basically all encrypted, compressed, or
both.
Changes in version 0.2.0.32 - 2008-11-20
Tor 0.2.0.32 fixes a major security problem in Debian and Ubuntu
packages (and maybe other packages) noticed by Theo de Raadt, fixes
a smaller security flaw that might allow an attacker to access local
services, further improves hidden service performance, and fixes a
variety of other issues.
o Security fixes:
- The "User" and "Group" config options did not clear the
supplementary group entries for the Tor process. The "User" option
is now more robust, and we now set the groups to the specified
user's primary group. The "Group" option is now ignored. For more
detailed logging on credential switching, set CREDENTIAL_LOG_LEVEL
in common/compat.c to LOG_NOTICE or higher. Patch by Jacob Appelbaum
and Steven Murdoch. Bugfix on 0.0.2pre14. Fixes bug 848 and 857.
- The "ClientDNSRejectInternalAddresses" config option wasn't being
consistently obeyed: if an exit relay refuses a stream because its
exit policy doesn't allow it, we would remember what IP address
the relay said the destination address resolves to, even if it's
an internal IP address. Bugfix on 0.2.0.7-alpha; patch by rovv.
o Major bugfixes:
- Fix a DOS opportunity during the voting signature collection process
at directory authorities. Spotted by rovv. Bugfix on 0.2.0.x.
o Major bugfixes (hidden services):
- When fetching v0 and v2 rendezvous service descriptors in parallel,
we were failing the whole hidden service request when the v0
descriptor fetch fails, even if the v2 fetch is still pending and
might succeed. Similarly, if the last v2 fetch fails, we were
failing the whole hidden service request even if a v0 fetch is
still pending. Fixes bug 814. Bugfix on 0.2.0.10-alpha.
- When extending a circuit to a hidden service directory to upload a
rendezvous descriptor using a BEGIN_DIR cell, almost 1/6 of all
requests failed, because the router descriptor has not been
downloaded yet. In these cases, do not attempt to upload the
rendezvous descriptor, but wait until the router descriptor is
downloaded and retry. Likewise, do not attempt to fetch a rendezvous
descriptor from a hidden service directory for which the router
descriptor has not yet been downloaded. Fixes bug 767. Bugfix
on 0.2.0.10-alpha.
o Minor bugfixes:
- Fix several infrequent memory leaks spotted by Coverity.
- When testing for libevent functions, set the LDFLAGS variable
correctly. Found by Riastradh.
- Avoid a bug where the FastFirstHopPK 0 option would keep Tor from
bootstrapping with tunneled directory connections. Bugfix on
0.1.2.5-alpha. Fixes bug 797. Found by Erwin Lam.
- When asked to connect to A.B.exit:80, if we don't know the IP for A
and we know that server B rejects most-but-not all connections to
port 80, we would previously reject the connection. Now, we assume
the user knows what they were asking for. Fixes bug 752. Bugfix
on 0.0.9rc5. Diagnosed by BarkerJr.
- If we overrun our per-second write limits a little, count this as
having used up our write allocation for the second, and choke
outgoing directory writes. Previously, we had only counted this when
we had met our limits precisely. Fixes bug 824. Patch from by rovv.
Bugfix on 0.2.0.x (??).
- Remove the old v2 directory authority 'lefkada' from the default
list. It has been gone for many months.
- Stop doing unaligned memory access that generated bus errors on
sparc64. Bugfix on 0.2.0.10-alpha. Fixes bug 862.
- Make USR2 log-level switch take effect immediately. Bugfix on
0.1.2.8-beta.
o Minor bugfixes (controller):
- Make DNS resolved events into "CLOSED", not "FAILED". Bugfix on
0.1.2.5-alpha. Fix by Robert Hogan. Resolves bug 807.
Changes in version 0.2.0.31 - 2008-09-03
Tor 0.2.0.31 addresses two potential anonymity issues, starts to fix
a big bug we're seeing where in rare cases traffic from one Tor stream
gets mixed into another stream, and fixes a variety of smaller issues.
o Major bugfixes:
- Make sure that two circuits can never exist on the same connection
with the same circuit ID, even if one is marked for close. This
is conceivably a bugfix for bug 779. Bugfix on 0.1.0.4-rc.
- Relays now reject risky extend cells: if the extend cell includes
a digest of all zeroes, or asks to extend back to the relay that
sent the extend cell, tear down the circuit. Ideas suggested
by rovv.
- If not enough of our entry guards are available so we add a new
one, we might use the new one even if it overlapped with the
current circuit's exit relay (or its family). Anonymity bugfix
pointed out by rovv.
o Minor bugfixes:
- Recover 3-7 bytes that were wasted per memory chunk. Fixes bug
794; bug spotted by rovv. Bugfix on 0.2.0.1-alpha.
- Correctly detect the presence of the linux/netfilter_ipv4.h header
when building against recent kernels. Bugfix on 0.1.2.1-alpha.
- Pick size of default geoip filename string correctly on windows.
Fixes bug 806. Bugfix on 0.2.0.30.
- Make the autoconf script accept the obsolete --with-ssl-dir
option as an alias for the actually-working --with-openssl-dir
option. Fix the help documentation to recommend --with-openssl-dir.
Based on a patch by "Dave". Bugfix on 0.2.0.1-alpha.
- When using the TransPort option on OpenBSD, and using the User
option to change UID and drop privileges, make sure to open
/dev/pf before dropping privileges. Fixes bug 782. Patch from
Christopher Davis. Bugfix on 0.1.2.1-alpha.
- Try to attach connections immediately upon receiving a RENDEZVOUS2
or RENDEZVOUS_ESTABLISHED cell. This can save a second or two
on the client side when connecting to a hidden service. Bugfix
on 0.0.6pre1. Found and fixed by Christian Wilms; resolves bug 743.
- When closing an application-side connection because its circuit is
getting torn down, generate the stream event correctly. Bugfix on
0.1.2.x. Anonymous patch.
Changes in version 0.2.0.30 - 2008-07-15
This new stable release switches to a more efficient directory
distribution design, adds features to make connections to the Tor
network harder to block, allows Tor to act as a DNS proxy, adds separate
rate limiting for relayed traffic to make it easier for clients to
become relays, fixes a variety of potential anonymity problems, and
includes the usual huge pile of other features and bug fixes.
o New v3 directory design:
- Tor now uses a new way to learn about and distribute information
about the network: the directory authorities vote on a common
network status document rather than each publishing their own
opinion. Now clients and caches download only one networkstatus
document to bootstrap, rather than downloading one for each
authority. Clients only download router descriptors listed in
the consensus. Implements proposal 101; see doc/spec/dir-spec.txt
for details.
- Set up moria1, tor26, and dizum as v3 directory authorities
in addition to being v2 authorities. Also add three new ones:
ides (run by Mike Perry), gabelmoo (run by Karsten Loesing), and
dannenberg (run by CCC).
- Switch to multi-level keys for directory authorities: now their
long-term identity key can be kept offline, and they periodically
generate a new signing key. Clients fetch the "key certificates"
to keep up to date on the right keys. Add a standalone tool
"tor-gencert" to generate key certificates. Implements proposal 103.
- Add a new V3AuthUseLegacyKey config option to make it easier for
v3 authorities to change their identity keys if another bug like
Debian's OpenSSL RNG flaw appears.
- Authorities and caches fetch the v2 networkstatus documents
less often, now that v3 is recommended.
o Make Tor connections stand out less on the wire:
- Use an improved TLS handshake designed by Steven Murdoch in proposal
124, as revised in proposal 130. The new handshake is meant to
be harder for censors to fingerprint, and it adds the ability
to detect certain kinds of man-in-the-middle traffic analysis
attacks. The new handshake format includes version negotiation for
OR connections as described in proposal 105, which will allow us
to improve Tor's link protocol more safely in the future.
- Enable encrypted directory connections by default for non-relays,
so censor tools that block Tor directory connections based on their
plaintext patterns will no longer work. This means Tor works in
certain censored countries by default again.
- Stop including recognizeable strings in the commonname part of
Tor's x509 certificates.
o Implement bridge relays:
- Bridge relays (or "bridges" for short) are Tor relays that aren't
listed in the main Tor directory. Since there is no complete public
list of them, even an ISP that is filtering connections to all the
known Tor relays probably won't be able to block all the bridges.
See doc/design-paper/blocking.pdf and proposal 125 for details.
- New config option BridgeRelay that specifies you want to be a
bridge relay rather than a normal relay. When BridgeRelay is set
to 1, then a) you cache dir info even if your DirPort ins't on,
and b) the default for PublishServerDescriptor is now "bridge"
rather than "v2,v3".
- New config option "UseBridges 1" for clients that want to use bridge
relays instead of ordinary entry guards. Clients then specify
bridge relays by adding "Bridge" lines to their config file. Users
can learn about a bridge relay either manually through word of
mouth, or by one of our rate-limited mechanisms for giving out
bridge addresses without letting an attacker easily enumerate them
all. See https://www.torproject.org/bridges for details.
- Bridge relays behave like clients with respect to time intervals
for downloading new v3 consensus documents -- otherwise they
stand out. Bridge users now wait until the end of the interval,
so their bridge relay will be sure to have a new consensus document.
o Implement bridge directory authorities:
- Bridge authorities are like normal directory authorities, except
they don't serve a list of known bridges. Therefore users that know
a bridge's fingerprint can fetch a relay descriptor for that bridge,
including fetching updates e.g. if the bridge changes IP address,
yet an attacker can't just fetch a list of all the bridges.
- Set up Tonga as the default bridge directory authority.
- Bridge authorities refuse to serve bridge descriptors or other
bridge information over unencrypted connections (that is, when
responding to direct DirPort requests rather than begin_dir cells.)
- Bridge directory authorities do reachability testing on the
bridges they know. They provide router status summaries to the
controller via "getinfo ns/purpose/bridge", and also dump summaries
to a file periodically, so we can keep internal stats about which
bridges are functioning.
- If bridge users set the UpdateBridgesFromAuthority config option,
but the digest they ask for is a 404 on the bridge authority,
they fall back to contacting the bridge directly.
- Bridges always use begin_dir to publish their server descriptor to
the bridge authority using an anonymous encrypted tunnel.
- Early work on a "bridge community" design: if bridge authorities set
the BridgePassword config option, they will serve a snapshot of
known bridge routerstatuses from their DirPort to anybody who
knows that password. Unset by default.
- Tor now includes an IP-to-country GeoIP file, so bridge relays can
report sanitized aggregated summaries in their extra-info documents
privately to the bridge authority, listing which countries are
able to reach them. We hope this mechanism will let us learn when
certain countries start trying to block bridges.
- Bridge authorities write bridge descriptors to disk, so they can
reload them after a reboot. They can also export the descriptors
to other programs, so we can distribute them to blocked users via
the BridgeDB interface, e.g. via https://bridges.torproject.org/
and bridges@torproject.org.
o Tor can be a DNS proxy:
- The new client-side DNS proxy feature replaces the need for
dns-proxy-tor: Just set "DNSPort 9999", and Tor will now listen
for DNS requests on port 9999, use the Tor network to resolve them
anonymously, and send the reply back like a regular DNS server.
The code still only implements a subset of DNS.
- Add a new AutomapHostsOnResolve option: when it is enabled, any
resolve request for hosts matching a given pattern causes Tor to
generate an internal virtual address mapping for that host. This
allows DNSPort to work sensibly with hidden service users. By
default, .exit and .onion addresses are remapped; the list of
patterns can be reconfigured with AutomapHostsSuffixes.
- Add an "-F" option to tor-resolve to force a resolve for a .onion
address. Thanks to the AutomapHostsOnResolve option, this is no
longer a completely silly thing to do.
o Major features (relay usability):
- New config options RelayBandwidthRate and RelayBandwidthBurst:
a separate set of token buckets for relayed traffic. Right now
relayed traffic is defined as answers to directory requests, and
OR connections that don't have any local circuits on them. See
proposal 111 for details.
- Create listener connections before we setuid to the configured
User and Group. Now non-Windows users can choose port values
under 1024, start Tor as root, and have Tor bind those ports
before it changes to another UID. (Windows users could already
pick these ports.)
- Added a new ConstrainedSockets config option to set SO_SNDBUF and
SO_RCVBUF on TCP sockets. Hopefully useful for Tor servers running
on "vserver" accounts. Patch from coderman.
o Major features (directory authorities):
- Directory authorities track weighted fractional uptime and weighted
mean-time-between failures for relays. WFU is suitable for deciding
whether a node is "usually up", while MTBF is suitable for deciding
whether a node is "likely to stay up." We need both, because
"usually up" is a good requirement for guards, while "likely to
stay up" is a good requirement for long-lived connections.
- Directory authorities use a new formula for selecting which relays
to advertise as Guards: they must be in the top 7/8 in terms of
how long we have known about them, and above the median of those
nodes in terms of weighted fractional uptime.
- Directory authorities use a new formula for selecting which relays
to advertise as Stable: when we have 4 or more days of data, use
median measured MTBF rather than median declared uptime. Implements
proposal 108.
- Directory authorities accept and serve "extra info" documents for
routers. Routers now publish their bandwidth-history lines in the
extra-info docs rather than the main descriptor. This step saves
60% (!) on compressed router descriptor downloads. Servers upload
extra-info docs to any authority that accepts them; directory
authorities now allow multiple router descriptors and/or extra
info documents to be uploaded in a single go. Authorities, and
caches that have been configured to download extra-info documents,
download them as needed. Implements proposal 104.
- Authorities now list relays who have the same nickname as
a different named relay, but list them with a new flag:
"Unnamed". Now we can make use of relays that happen to pick the
same nickname as a server that registered two years ago and then
disappeared. Implements proposal 122.
- Store routers in a file called cached-descriptors instead of in
cached-routers. Initialize cached-descriptors from cached-routers
if the old format is around. The new format allows us to store
annotations along with descriptors, to record the time we received
each descriptor, its source, and its purpose: currently one of
general, controller, or bridge.
o Major features (other):
- New config options WarnPlaintextPorts and RejectPlaintextPorts so
Tor can warn and/or refuse connections to ports commonly used with
vulnerable-plaintext protocols. Currently we warn on ports 23,
109, 110, and 143, but we don't reject any. Based on proposal 129
by Kevin Bauer and Damon McCoy.
- Integrate Karsten Loesing's Google Summer of Code project to publish
hidden service descriptors on a set of redundant relays that are a
function of the hidden service address. Now we don't have to rely
on three central hidden service authorities for publishing and
fetching every hidden service descriptor. Implements proposal 114.
- Allow tunnelled directory connections to ask for an encrypted
"begin_dir" connection or an anonymized "uses a full Tor circuit"
connection independently. Now we can make anonymized begin_dir
connections for (e.g.) more secure hidden service posting and
fetching.
o Major bugfixes (crashes and assert failures):
- Stop imposing an arbitrary maximum on the number of file descriptors
used for busy servers. Bug reported by Olaf Selke; patch from
Sebastian Hahn.
- Avoid possible failures when generating a directory with routers
with over-long versions strings, or too many flags set.
- Fix a rare assert error when we're closing one of our threads:
use a mutex to protect the list of logs, so we never write to the
list as it's being freed. Fixes the very rare bug 575, which is
kind of the revenge of bug 222.
- Avoid segfault in the case where a badly behaved v2 versioning
directory sends a signed networkstatus with missing client-versions.
- When we hit an EOF on a log (probably because we're shutting down),
don't try to remove the log from the list: just mark it as
unusable. (Bulletproofs against bug 222.)
o Major bugfixes (code security fixes):
- Detect size overflow in zlib code. Reported by Justin Ferguson and
Dan Kaminsky.
- Rewrite directory tokenization code to never run off the end of
a string. Fixes bug 455. Patch from croup.
- Be more paranoid about overwriting sensitive memory on free(),
as a defensive programming tactic to ensure forward secrecy.
o Major bugfixes (anonymity fixes):
- Reject requests for reverse-dns lookup of names that are in
a private address space. Patch from lodger.
- Never report that we've used more bandwidth than we're willing to
relay: it leaks how much non-relay traffic we're using. Resolves
bug 516.
- As a client, do not believe any server that tells us that an
address maps to an internal address space.
- Warn about unsafe ControlPort configurations.
- Directory authorities now call routers Fast if their bandwidth is
at least 100KB/s, and consider their bandwidth adequate to be a
Guard if it is at least 250KB/s, no matter the medians. This fix
complements proposal 107.
- Directory authorities now never mark more than 2 servers per IP as
Valid and Running (or 5 on addresses shared by authorities).
Implements proposal 109, by Kevin Bauer and Damon McCoy.
- If we're a relay, avoid picking ourselves as an introduction point,
a rendezvous point, or as the final hop for internal circuits. Bug
reported by taranis and lodger.
- Exit relays that are used as a client can now reach themselves
using the .exit notation, rather than just launching an infinite
pile of circuits. Fixes bug 641. Reported by Sebastian Hahn.
- Fix a bug where, when we were choosing the 'end stream reason' to
put in our relay end cell that we send to the exit relay, Tor
clients on Windows were sometimes sending the wrong 'reason'. The
anonymity problem is that exit relays may be able to guess whether
the client is running Windows, thus helping partition the anonymity
set. Down the road we should stop sending reasons to exit relays,
or otherwise prevent future versions of this bug.
- Only update guard status (usable / not usable) once we have
enough directory information. This was causing us to discard all our
guards on startup if we hadn't been running for a few weeks. Fixes
bug 448.
- When our directory information has been expired for a while, stop
being willing to build circuits using it. Fixes bug 401.
o Major bugfixes (peace of mind for relay operators)
- Non-exit relays no longer answer "resolve" relay cells, so they
can't be induced to do arbitrary DNS requests. (Tor clients already
avoid using non-exit relays for resolve cells, but now servers
enforce this too.) Fixes bug 619. Patch from lodger.
- When we setconf ClientOnly to 1, close any current OR and Dir
listeners. Reported by mwenge.
o Major bugfixes (other):
- If we only ever used Tor for hidden service lookups or posts, we
would stop building circuits and start refusing connections after
24 hours, since we falsely believed that Tor was dormant. Reported
by nwf.
- Add a new __HashedControlSessionPassword option for controllers
to use for one-off session password hashes that shouldn't get
saved to disk by SAVECONF --- Vidalia users were accumulating a
pile of HashedControlPassword lines in their torrc files, one for
each time they had restarted Tor and then clicked Save. Make Tor
automatically convert "HashedControlPassword" to this new option but
only when it's given on the command line. Partial fix for bug 586.
- Patch from "Andrew S. Lists" to catch when we contact a directory
mirror at IP address X and he says we look like we're coming from
IP address X. Otherwise this would screw up our address detection.
- Reject uploaded descriptors and extrainfo documents if they're
huge. Otherwise we'll cache them all over the network and it'll
clog everything up. Suggested by Aljosha Judmayer.
- When a hidden service was trying to establish an introduction point,
and Tor *did* manage to reuse one of the preemptively built
circuits, it didn't correctly remember which one it used,
so it asked for another one soon after, until there were no
more preemptive circuits, at which point it launched one from
scratch. Bugfix on 0.0.9.x.
o Rate limiting and load balancing improvements:
- When we add data to a write buffer in response to the data on that
write buffer getting low because of a flush, do not consider the
newly added data as a candidate for immediate flushing, but rather
make it wait until the next round of writing. Otherwise, we flush
and refill recursively, and a single greedy TLS connection can
eat all of our bandwidth.
- When counting the number of bytes written on a TLS connection,
look at the BIO actually used for writing to the network, not
at the BIO used (sometimes) to buffer data for the network.
Looking at different BIOs could result in write counts on the
order of ULONG_MAX. Fixes bug 614.
- If we change our MaxAdvertisedBandwidth and then reload torrc,
Tor won't realize it should publish a new relay descriptor. Fixes
bug 688, reported by mfr.
- Avoid using too little bandwidth when our clock skips a few seconds.
- Choose which bridge to use proportional to its advertised bandwidth,
rather than uniformly at random. This should speed up Tor for
bridge users. Also do this for people who set StrictEntryNodes.
o Bootstrapping faster and building circuits more intelligently:
- Fix bug 660 that was preventing us from knowing that we should
preemptively build circuits to handle expected directory requests.
- When we're checking if we have enough dir info for each relay
to begin establishing circuits, make sure that we actually have
the descriptor listed in the consensus, not just any descriptor.
- Correctly notify one-hop connections when a circuit build has
failed. Possible fix for bug 669. Found by lodger.
- Clients now hold circuitless TLS connections open for 1.5 times
MaxCircuitDirtiness (15 minutes), since it is likely that they'll
rebuild a new circuit over them within that timeframe. Previously,
they held them open only for KeepalivePeriod (5 minutes).
o Performance improvements (memory):
- Add OpenBSD malloc code from "phk" as an optional malloc
replacement on Linux: some glibc libraries do very poorly with
Tor's memory allocation patterns. Pass --enable-openbsd-malloc to
./configure to get the replacement malloc code.
- Switch our old ring buffer implementation for one more like that
used by free Unix kernels. The wasted space in a buffer with 1mb
of data will now be more like 8k than 1mb. The new implementation
also avoids realloc();realloc(); patterns that can contribute to
memory fragmentation.
- Change the way that Tor buffers data that it is waiting to write.
Instead of queueing data cells in an enormous ring buffer for each
client->OR or OR->OR connection, we now queue cells on a separate
queue for each circuit. This lets us use less slack memory, and
will eventually let us be smarter about prioritizing different kinds
of traffic.
- Reference-count and share copies of address policy entries; only 5%
of them were actually distinct.
- Tune parameters for cell pool allocation to minimize amount of
RAM overhead used.
- Keep unused 4k and 16k buffers on free lists, rather than wasting 8k
for every single inactive connection_t. Free items from the
4k/16k-buffer free lists when they haven't been used for a while.
- Make memory debugging information describe more about history
of cell allocation, so we can help reduce our memory use.
- Be even more aggressive about releasing RAM from small
empty buffers. Thanks to our free-list code, this shouldn't be too
performance-intensive.
- Log malloc statistics from mallinfo() on platforms where it exists.
- Use memory pools to allocate cells with better speed and memory
efficiency, especially on platforms where malloc() is inefficient.
- Add a --with-tcmalloc option to the configure script to link
against tcmalloc (if present). Does not yet search for non-system
include paths.
o Performance improvements (socket management):
- Count the number of open sockets separately from the number of
active connection_t objects. This will let us avoid underusing
our allocated connection limit.
- We no longer use socket pairs to link an edge connection to an
anonymous directory connection or a DirPort test connection.
Instead, we track the link internally and transfer the data
in-process. This saves two sockets per "linked" connection (at the
client and at the server), and avoids the nasty Windows socketpair()
workaround.
- We were leaking a file descriptor if Tor started with a zero-length
cached-descriptors file. Patch by "freddy77".
o Performance improvements (CPU use):
- Never walk through the list of logs if we know that no log target
is interested in a given message.
- Call routerlist_remove_old_routers() much less often. This should
speed startup, especially on directory caches.
- Base64 decoding was actually showing up on our profile when parsing
the initial descriptor file; switch to an in-process all-at-once
implementation that's about 3.5x times faster than calling out to
OpenSSL.
- Use a slightly simpler string hashing algorithm (copying Python's
instead of Java's) and optimize our digest hashing algorithm to take
advantage of 64-bit platforms and to remove some possibly-costly
voodoo.
- When implementing AES counter mode, update only the portions of the
counter buffer that need to change, and don't keep separate
network-order and host-order counters on big-endian hosts (where
they are the same).
- Add an in-place version of aes_crypt() so that we can avoid doing a
needless memcpy() call on each cell payload.
- Use Critical Sections rather than Mutexes for synchronizing threads
on win32; Mutexes are heavier-weight, and designed for synchronizing
between processes.
o Performance improvements (bandwidth use):
- Don't try to launch new descriptor downloads quite so often when we
already have enough directory information to build circuits.
- Version 1 directories are no longer generated in full. Instead,
authorities generate and serve "stub" v1 directories that list
no servers. This will stop Tor versions 0.1.0.x and earlier from
working, but (for security reasons) nobody should be running those
versions anyway.
- Avoid going directly to the directory authorities even if you're a
relay, if you haven't found yourself reachable yet or if you've
decided not to advertise your dirport yet. Addresses bug 556.
- If we've gone 12 hours since our last bandwidth check, and we
estimate we have less than 50KB bandwidth capacity but we could
handle more, do another bandwidth test.
- Support "If-Modified-Since" when answering HTTP requests for
directories, running-routers documents, and v2 and v3 networkstatus
documents. (There's no need to support it for router descriptors,
since those are downloaded by descriptor digest.)
- Stop fetching directory info so aggressively if your DirPort is
on but your ORPort is off; stop fetching v2 dir info entirely.
You can override these choices with the new FetchDirInfoEarly
config option.
o Changed config option behavior (features):
- Configuration files now accept C-style strings as values. This
helps encode characters not allowed in the current configuration
file format, such as newline or #. Addresses bug 557.
- Add hidden services and DNSPorts to the list of things that make
Tor accept that it has running ports. Change starting Tor with no
ports from a fatal error to a warning; we might change it back if
this turns out to confuse anybody. Fixes bug 579.
- Make PublishServerDescriptor default to 1, so the default doesn't
have to change as we invent new directory protocol versions.
- Allow people to say PreferTunnelledDirConns rather than
PreferTunneledDirConns, for those alternate-spellers out there.
- Raise the default BandwidthRate/BandwidthBurst to 5MB/10MB, to
accommodate the growing number of servers that use the default
and are reaching it.
- Make it possible to enable HashedControlPassword and
CookieAuthentication at the same time.
- When a TrackHostExits-chosen exit fails too many times in a row,
stop using it. Fixes bug 437.
o Changed config option behavior (bugfixes):
- Do not read the configuration file when we've only been told to
generate a password hash. Fixes bug 643. Bugfix on 0.0.9pre5. Fix
based on patch from Sebastian Hahn.
- Actually validate the options passed to AuthDirReject,
AuthDirInvalid, AuthDirBadDir, and AuthDirBadExit.
- Make "ClientOnly 1" config option disable directory ports too.
- Don't stop fetching descriptors when FetchUselessDescriptors is
set, even if we stop asking for circuits. Bug reported by tup
and ioerror.
- Servers used to decline to publish their DirPort if their
BandwidthRate or MaxAdvertisedBandwidth were below a threshold. Now
they look only at BandwidthRate and RelayBandwidthRate.
- Treat "2gb" when given in torrc for a bandwidth as meaning 2gb,
minus 1 byte: the actual maximum declared bandwidth.
- Make "TrackHostExits ." actually work. Bugfix on 0.1.0.x.
- Make the NodeFamilies config option work. (Reported by
lodger -- it has never actually worked, even though we added it
in Oct 2004.)
- If Tor is invoked from something that isn't a shell (e.g. Vidalia),
now we expand "-f ~/.tor/torrc" correctly. Suggested by Matt Edman.
o New config options:
- New configuration options AuthDirMaxServersPerAddr and
AuthDirMaxServersperAuthAddr to override default maximum number
of servers allowed on a single IP address. This is important for
running a test network on a single host.
- Three new config options (AlternateDirAuthority,
AlternateBridgeAuthority, and AlternateHSAuthority) that let the
user selectively replace the default directory authorities by type,
rather than the all-or-nothing replacement that DirServer offers.
- New config options AuthDirBadDir and AuthDirListBadDirs for
authorities to mark certain relays as "bad directories" in the
networkstatus documents. Also supports the "!baddir" directive in
the approved-routers file.
- New config option V2AuthoritativeDirectory that all v2 directory
authorities must set. This lets v3 authorities choose not to serve
v2 directory information.
o Minor features (other):
- When we're not serving v2 directory information, there is no reason
to actually keep any around. Remove the obsolete files and directory
on startup if they are very old and we aren't going to serve them.
- When we negotiate a v2 link-layer connection (not yet implemented),
accept RELAY_EARLY cells and turn them into RELAY cells if we've
negotiated a v1 connection for their next step. Initial steps for
proposal 110.
- When we have no consensus, check FallbackNetworkstatusFile (defaults
to $PREFIX/share/tor/fallback-consensus) for a consensus. This way
we can start out knowing some directory caches. We don't ship with
a fallback consensus by default though, because it was making
bootstrapping take too long while we tried many down relays.
- Authorities send back an X-Descriptor-Not-New header in response to
an accepted-but-discarded descriptor upload. Partially implements
fix for bug 535.
- If we find a cached-routers file that's been sitting around for more
than 28 days unmodified, then most likely it's a leftover from
when we upgraded to 0.2.0.8-alpha. Remove it. It has no good
routers anyway.
- When we (as a cache) download a descriptor because it was listed
in a consensus, remember when the consensus was supposed to expire,
and don't expire the descriptor until then.
- Optionally (if built with -DEXPORTMALLINFO) export the output
of mallinfo via http, as tor/mallinfo.txt. Only accessible
from localhost.
- Tag every guard node in our state file with the version that
we believe added it, or with our own version if we add it. This way,
if a user temporarily runs an old version of Tor and then switches
back to a new one, she doesn't automatically lose her guards.
- When somebody requests a list of statuses or servers, and we have
none of those, return a 404 rather than an empty 200.
- Merge in some (as-yet-unused) IPv6 address manipulation code. (Patch
from croup.)
- Add an HSAuthorityRecordStats option that hidden service authorities
can use to track statistics of overall hidden service usage without
logging information that would be as useful to an attacker.
- Allow multiple HiddenServicePort directives with the same virtual
port; when they occur, the user is sent round-robin to one
of the target ports chosen at random. Partially fixes bug 393 by
adding limited ad-hoc round-robining.
- Revamp file-writing logic so we don't need to have the entire
contents of a file in memory at once before we write to disk. Tor,
meet stdio.
o Minor bugfixes (other):
- Alter the code that tries to recover from unhandled write
errors, to not try to flush onto a socket that's given us
unhandled errors.
- Directory mirrors no longer include a guess at the client's IP
address if the connection appears to be coming from the same /24
network; it was producing too many wrong guesses.
- If we're trying to flush the last bytes on a connection (for
example, when answering a directory request), reset the
time-to-give-up timeout every time we manage to write something
on the socket.
- Reject router descriptors with out-of-range bandwidthcapacity or
bandwidthburst values.
- If we can't expand our list of entry guards (e.g. because we're
using bridges or we have StrictEntryNodes set), don't mark relays
down when they fail a directory request. Otherwise we're too quick
to mark all our entry points down.
- Authorities no longer send back "400 you're unreachable please fix
it" errors to Tor servers that aren't online all the time. We're
supposed to tolerate these servers now.
- Let directory authorities startup even when they can't generate
a descriptor immediately, e.g. because they don't know their
address.
- Correctly enforce that elements of directory objects do not appear
more often than they are allowed to appear.
- Stop allowing hibernating servers to be "stable" or "fast".
- On Windows, we were preventing other processes from reading
cached-routers while Tor was running. (Reported by janbar)
- Check return values from pthread_mutex functions.
- When opening /dev/null in finish_daemonize(), do not pass the
O_CREAT flag. Fortify was complaining, and correctly so. Fixes
bug 742; fix from Michael Scherer. Bugfix on 0.0.2pre19.
o Controller features:
- The GETCONF command now escapes and quotes configuration values
that don't otherwise fit into the torrc file.
- The SETCONF command now handles quoted values correctly.
- Add "GETINFO/desc-annotations/id/<OR digest>" so controllers can
ask about source, timestamp of arrival, purpose, etc. We need
something like this to help Vidalia not do GeoIP lookups on bridge
addresses.
- Allow multiple HashedControlPassword config lines, to support
multiple controller passwords.
- Accept LF instead of CRLF on controller, since some software has a
hard time generating real Internet newlines.
- Add GETINFO values for the server status events
"REACHABILITY_SUCCEEDED" and "GOOD_SERVER_DESCRIPTOR". Patch from
Robert Hogan.
- There is now an ugly, temporary "desc/all-recent-extrainfo-hack"
GETINFO for Torstat to use until it can switch to using extrainfos.
- New config option CookieAuthFile to choose a new location for the
cookie authentication file, and config option
CookieAuthFileGroupReadable to make it group-readable.
- Add a SOURCE_ADDR field to STREAM NEW events so that controllers can
match requests to applications. Patch from Robert Hogan.
- Add a RESOLVE command to launch hostname lookups. Original patch
from Robert Hogan.
- Add GETINFO status/enough-dir-info to let controllers tell whether
Tor has downloaded sufficient directory information. Patch from Tup.
- You can now use the ControlSocket option to tell Tor to listen for
controller connections on Unix domain sockets on systems that
support them. Patch from Peter Palfrader.
- New "GETINFO address-mappings/*" command to get address mappings
with expiry information. "addr-mappings/*" is now deprecated.
Patch from Tup.
- Add a new config option __DisablePredictedCircuits designed for
use by the controller, when we don't want Tor to build any circuits
preemptively.
- Let the controller specify HOP=%d as an argument to ATTACHSTREAM,
so we can exit from the middle of the circuit.
- Implement "getinfo status/circuit-established".
- Implement "getinfo status/version/..." so a controller can tell
whether the current version is recommended, and whether any versions
are good, and how many authorities agree. Patch from "shibz".
- Controllers should now specify cache=no or cache=yes when using
the +POSTDESCRIPTOR command.
- Add a "PURPOSE=" argument to "STREAM NEW" events, as suggested by
Robert Hogan. Fixes the first part of bug 681.
- When reporting clock skew, and we know that the clock is _at least
as skewed_ as some value, but we don't know the actual value,
report the value as a "minimum skew."
o Controller bugfixes:
- Generate "STATUS_SERVER" events rather than misspelled
"STATUS_SEVER" events. Caught by mwenge.
- Reject controller commands over 1MB in length, so rogue
processes can't run us out of memory.
- Change the behavior of "getinfo status/good-server-descriptor"
so it doesn't return failure when any authority disappears.
- Send NAMESERVER_STATUS messages for a single failed nameserver
correctly.
- When the DANGEROUS_VERSION controller status event told us we're
running an obsolete version, it used the string "OLD" to describe
it. Yet the "getinfo" interface used the string "OBSOLETE". Now use
"OBSOLETE" in both cases.
- Respond to INT and TERM SIGNAL commands before we execute the
signal, in case the signal shuts us down. We had a patch in
0.1.2.1-alpha that tried to do this by queueing the response on
the connection's buffer before shutting down, but that really
isn't the same thing at all. Bug located by Matt Edman.
- Provide DNS expiry times in GMT, not in local time. For backward
compatibility, ADDRMAP events only provide GMT expiry in an extended
field. "GETINFO address-mappings" always does the right thing.
- Use CRLF line endings properly in NS events.
- Make 'getinfo fingerprint' return a 551 error if we're not a
server, so we match what the control spec claims we do. Reported
by daejees.
- Fix a typo in an error message when extendcircuit fails that
caused us to not follow the \r\n-based delimiter protocol. Reported
by daejees.
- When tunneling an encrypted directory connection, and its first
circuit fails, do not leave it unattached and ask the controller
to deal. Fixes the second part of bug 681.
- Treat some 403 responses from directory servers as INFO rather than
WARN-severity events.
o Portability / building / compiling:
- When building with --enable-gcc-warnings, check for whether Apple's
warning "-Wshorten-64-to-32" is available.
- Support compilation to target iPhone; patch from cjacker huang.
To build for iPhone, pass the --enable-iphone option to configure.
- Port Tor to build and run correctly on Windows CE systems, using
the wcecompat library. Contributed by Valerio Lupi.
- Detect non-ASCII platforms (if any still exist) and refuse to
build there: some of our code assumes that 'A' is 65 and so on.
- Clear up some MIPSPro compiler warnings.
- Make autoconf search for libevent, openssl, and zlib consistently.
- Update deprecated macros in configure.in.
- When warning about missing headers, tell the user to let us
know if the compile succeeds anyway, so we can downgrade the
warning.
- Include the current subversion revision as part of the version
string: either fetch it directly if we're in an SVN checkout, do
some magic to guess it if we're in an SVK checkout, or use
the last-detected version if we're building from a .tar.gz.
Use this version consistently in log messages.
- Correctly report platform name on Windows 95 OSR2 and Windows 98 SE.
- Read resolv.conf files correctly on platforms where read() returns
partial results on small file reads.
- Build without verbose warnings even on gcc 4.2 and 4.3.
- On Windows, correctly detect errors when listing the contents of
a directory. Fix from lodger.
- Run 'make test' as part of 'make dist', so we stop releasing so
many development snapshots that fail their unit tests.
- Add support to detect Libevent versions in the 1.4.x series
on mingw.
- Add command-line arguments to unit-test executable so that we can
invoke any chosen test from the command line rather than having
to run the whole test suite at once; and so that we can turn on
logging for the unit tests.
- Do not automatically run configure from autogen.sh. This
non-standard behavior tended to annoy people who have built other
programs.
- Fix a macro/CPP interaction that was confusing some compilers:
some GCCs don't like #if/#endif pairs inside macro arguments.
Fixes bug 707.
- Fix macro collision between OpenSSL 0.9.8h and Windows headers.
Fixes bug 704; fix from Steven Murdoch.
- Correctly detect transparent proxy support on Linux hosts that
require in.h to be included before netfilter_ipv4.h. Patch
from coderman.
o Logging improvements:
- When we haven't had any application requests lately, don't bother
logging that we have expired a bunch of descriptors.
- When attempting to open a logfile fails, tell us why.
- Only log guard node status when guard node status has changed.
- Downgrade the 3 most common "INFO" messages to "DEBUG". This will
make "INFO" 75% less verbose.
- When SafeLogging is disabled, log addresses along with all TLS
errors.
- Report TLS "zero return" case as a "clean close" and "IO error"
as a "close". Stop calling closes "unexpected closes": existing
Tors don't use SSL_close(), so having a connection close without
the TLS shutdown handshake is hardly unexpected.
- When we receive a consensus from the future, warn about skew.
- Make "not enough dir info yet" warnings describe *why* Tor feels
it doesn't have enough directory info yet.
- On the USR1 signal, when dmalloc is in use, log the top 10 memory
consumers. (We already do this on HUP.)
- Give more descriptive well-formedness errors for out-of-range
hidden service descriptor/protocol versions.
- Stop recommending that every server operator send mail to tor-ops.
Resolves bug 597. Bugfix on 0.1.2.x.
- Improve skew reporting: try to give the user a better log message
about how skewed they are, and how much this matters.
- New --quiet command-line option to suppress the default console log.
Good in combination with --hash-password.
- Don't complain that "your server has not managed to confirm that its
ports are reachable" if we haven't been able to build any circuits
yet.
- Detect the reason for failing to mmap a descriptor file we just
wrote, and give a more useful log message. Fixes bug 533.
- Always prepend "Bug: " to any log message about a bug.
- When dumping memory usage, list bytes used in buffer memory
free-lists.
- When running with dmalloc, dump more stats on hup and on exit.
- Put a platform string (e.g. "Linux i686") in the startup log
message, so when people paste just their logs, we know if it's
OpenBSD or Windows or what.
- When logging memory usage, break down memory used in buffers by
buffer type.
- When we are reporting the DirServer line we just parsed, we were
logging the second stanza of the key fingerprint, not the first.
- Even though Windows is equally happy with / and \ as path separators,
try to use \ consistently on Windows and / consistently on Unix: it
makes the log messages nicer.
- On OSX, stop warning the user that kqueue support in libevent is
"experimental", since it seems to have worked fine for ages.
o Contributed scripts and tools:
- Update linux-tor-prio.sh script to allow QoS based on the uid of
the Tor process. Patch from Marco Bonetti with tweaks from Mike
Perry.
- Include the "tor-ctrl.sh" bash script by Stefan Behte to provide
Unix users an easy way to script their Tor process (e.g. by
adjusting bandwidth based on the time of the day).
- In the exitlist script, only consider the most recently published
server descriptor for each server. Also, when the user requests
a list of servers that _reject_ connections to a given address,
explicitly exclude the IPs that also have servers that accept
connections to that address. Resolves bug 405.
- Include a new contrib/tor-exit-notice.html file that exit relay
operators can put on their website to help reduce abuse queries.
o Newly deprecated features:
- The status/version/num-versioning and status/version/num-concurring
GETINFO controller options are no longer useful in the v3 directory
protocol: treat them as deprecated, and warn when they're used.
- The RedirectExits config option is now deprecated.
o Removed features:
- Drop the old code to choke directory connections when the
corresponding OR connections got full: thanks to the cell queue
feature, OR conns don't get full any more.
- Remove the old "dns worker" server DNS code: it hasn't been default
since 0.1.2.2-alpha, and all the servers are using the new
eventdns code.
- Remove the code to generate the oldest (v1) directory format.
- Remove support for the old bw_accounting file: we've been storing
bandwidth accounting information in the state file since
0.1.2.5-alpha. This may result in bandwidth accounting errors
if you try to upgrade from 0.1.1.x or earlier, or if you try to
downgrade to 0.1.1.x or earlier.
- Drop support for OpenSSL version 0.9.6. Just about nobody was using
it, it had no AES, and it hasn't seen any security patches since
2004.
- Stop overloading the circuit_t.onionskin field for both "onionskin
from a CREATE cell that we are waiting for a cpuworker to be
assigned" and "onionskin from an EXTEND cell that we are going to
send to an OR as soon as we are connected". Might help with bug 600.
- Remove the tor_strpartition() function: its logic was confused,
and it was only used for one thing that could be implemented far
more easily.
- Remove the contrib scripts ExerciseServer.py, PathDemo.py,
and TorControl.py, as they use the old v0 controller protocol,
and are obsoleted by TorFlow anyway.
- Drop support for v1 rendezvous descriptors, since we never used
them anyway, and the code has probably rotted by now. Based on
patch from Karsten Loesing.
- Stop allowing address masks that do not correspond to bit prefixes.
We have warned about these for a really long time; now it's time
to reject them. (Patch from croup.)
- Remove an optimization in the AES counter-mode code that assumed
that the counter never exceeded 2^68. When the counter can be set
arbitrarily as an IV (as it is by Karsten's new hidden services
code), this assumption no longer holds.
- Disable the SETROUTERPURPOSE controller command: it is now
obsolete.
Changes in version 0.1.2.19 - 2008-01-17
Tor 0.1.2.19 fixes a huge memory leak on exit relays, makes the default
exit policy a little bit more conservative so it's safer to run an
exit relay on a home system, and fixes a variety of smaller issues.
o Security fixes:
- Exit policies now reject connections that are addressed to a
relay's public (external) IP address too, unless
ExitPolicyRejectPrivate is turned off. We do this because too
many relays are running nearby to services that trust them based
on network address.
o Major bugfixes:
- When the clock jumps forward a lot, do not allow the bandwidth
buckets to become negative. Fixes bug 544.
- Fix a memory leak on exit relays; we were leaking a cached_resolve_t
on every successful resolve. Reported by Mike Perry.
- Purge old entries from the "rephist" database and the hidden
service descriptor database even when DirPort is zero.
- Stop thinking that 0.1.2.x directory servers can handle "begin_dir"
requests. Should ease bugs 406 and 419 where 0.1.2.x relays are
crashing or mis-answering these requests.
- When we decide to send a 503 response to a request for servers, do
not then also send the server descriptors: this defeats the whole
purpose. Fixes bug 539.
o Minor bugfixes:
- Changing the ExitPolicyRejectPrivate setting should cause us to
rebuild our server descriptor.
- Fix handling of hex nicknames when answering controller requests for
networkstatus by name, or when deciding whether to warn about
unknown routers in a config option. (Patch from mwenge.)
- Fix a couple of hard-to-trigger autoconf problems that could result
in really weird results on platforms whose sys/types.h files define
nonstandard integer types.
- Don't try to create the datadir when running --verify-config or
--hash-password. Resolves bug 540.
- If we were having problems getting a particular descriptor from the
directory caches, and then we learned about a new descriptor for
that router, we weren't resetting our failure count. Reported
by lodger.
- Although we fixed bug 539 (where servers would send HTTP status 503
responses _and_ send a body too), there are still servers out there
that haven't upgraded. Therefore, make clients parse such bodies
when they receive them.
- Run correctly on systems where rlim_t is larger than unsigned long.
This includes some 64-bit systems.
- Run correctly on platforms (like some versions of OS X 10.5) where
the real limit for number of open files is OPEN_FILES, not rlim_max
from getrlimit(RLIMIT_NOFILES).
- Avoid a spurious free on base64 failure.
- Avoid segfaults on certain complex invocations of
router_get_by_hexdigest().
- Fix rare bug on REDIRECTSTREAM control command when called with no
port set: it could erroneously report an error when none had
happened.
Changes in version 0.1.2.18 - 2007-10-28
Tor 0.1.2.18 fixes many problems including crash bugs, problems with
hidden service introduction that were causing huge delays, and a big
bug that was causing some servers to disappear from the network status
lists for a few hours each day.
o Major bugfixes (crashes):
- If a connection is shut down abruptly because of something that
happened inside connection_flushed_some(), do not call
connection_finished_flushing(). Should fix bug 451:
"connection_stop_writing: Assertion conn->write_event failed"
Bugfix on 0.1.2.7-alpha.
- Fix possible segfaults in functions called from
rend_process_relay_cell().
o Major bugfixes (hidden services):
- Hidden services were choosing introduction points uniquely by
hexdigest, but when constructing the hidden service descriptor
they merely wrote the (potentially ambiguous) nickname.
- Clients now use the v2 intro format for hidden service
connections: they specify their chosen rendezvous point by identity
digest rather than by (potentially ambiguous) nickname. These
changes could speed up hidden service connections dramatically.
o Major bugfixes (other):
- Stop publishing a new server descriptor just because we get a
HUP signal. This led (in a roundabout way) to some servers getting
dropped from the networkstatus lists for a few hours each day.
- When looking for a circuit to cannibalize, consider family as well
as identity. Fixes bug 438. Bugfix on 0.1.0.x (which introduced
circuit cannibalization).
- When a router wasn't listed in a new networkstatus, we were leaving
the flags for that router alone -- meaning it remained Named,
Running, etc -- even though absence from the networkstatus means
that it shouldn't be considered to exist at all anymore. Now we
clear all the flags for routers that fall out of the networkstatus
consensus. Fixes bug 529.
o Minor bugfixes:
- Don't try to access (or alter) the state file when running
--list-fingerprint or --verify-config or --hash-password. Resolves
bug 499.
- When generating information telling us how to extend to a given
router, do not try to include the nickname if it is
absent. Resolves bug 467.
- Fix a user-triggerable segfault in expand_filename(). (There isn't
a way to trigger this remotely.)
- When sending a status event to the controller telling it that an
OR address is reachable, set the port correctly. (Previously we
were reporting the dir port.)
- Fix a minor memory leak whenever a controller sends the PROTOCOLINFO
command. Bugfix on 0.1.2.17.
- When loading bandwidth history, do not believe any information in
the future. Fixes bug 434.
- When loading entry guard information, do not believe any information
in the future.
- When we have our clock set far in the future and generate an
onion key, then re-set our clock to be correct, we should not stop
the onion key from getting rotated.
- On some platforms, accept() can return a broken address. Detect
this more quietly, and deal accordingly. Fixes bug 483.
- It's not actually an error to find a non-pending entry in the DNS
cache when canceling a pending resolve. Don't log unless stuff
is fishy. Resolves bug 463.
- Don't reset trusted dir server list when we set a configuration
option. Patch from Robert Hogan.
Changes in version 0.1.2.17 - 2007-08-30
Tor 0.1.2.17 features a new Vidalia version in the Windows and OS
X bundles. Vidalia 0.0.14 makes authentication required for the
ControlPort in the default configuration, which addresses important
security risks. Everybody who uses Vidalia (or another controller)
should upgrade.
In addition, this Tor update fixes major load balancing problems with
path selection, which should speed things up a lot once many people
have upgraded.
o Major bugfixes (security):
- We removed support for the old (v0) control protocol. It has been
deprecated since Tor 0.1.1.1-alpha, and keeping it secure has
become more of a headache than it's worth.
o Major bugfixes (load balancing):
- When choosing nodes for non-guard positions, weight guards
proportionally less, since they already have enough load. Patch
from Mike Perry.
- Raise the "max believable bandwidth" from 1.5MB/s to 10MB/s. This
will allow fast Tor servers to get more attention.
- When we're upgrading from an old Tor version, forget our current
guards and pick new ones according to the new weightings. These
three load balancing patches could raise effective network capacity
by a factor of four. Thanks to Mike Perry for measurements.
o Major bugfixes (stream expiration):
- Expire not-yet-successful application streams in all cases if
they've been around longer than SocksTimeout. Right now there are
some cases where the stream will live forever, demanding a new
circuit every 15 seconds. Fixes bug 454; reported by lodger.
o Minor features (controller):
- Add a PROTOCOLINFO controller command. Like AUTHENTICATE, it
is valid before any authentication has been received. It tells
a controller what kind of authentication is expected, and what
protocol is spoken. Implements proposal 119.
o Minor bugfixes (performance):
- Save on most routerlist_assert_ok() calls in routerlist.c, thus
greatly speeding up loading cached-routers from disk on startup.
- Disable sentinel-based debugging for buffer code: we squashed all
the bugs that this was supposed to detect a long time ago, and now
its only effect is to change our buffer sizes from nice powers of
two (which platform mallocs tend to like) to values slightly over
powers of two (which make some platform mallocs sad).
o Minor bugfixes (misc):
- If exit bandwidth ever exceeds one third of total bandwidth, then
use the correct formula to weight exit nodes when choosing paths.
Based on patch from Mike Perry.
- Choose perfectly fairly among routers when choosing by bandwidth and
weighting by fraction of bandwidth provided by exits. Previously, we
would choose with only approximate fairness, and correct ourselves
if we ran off the end of the list.
- If we require CookieAuthentication but we fail to write the
cookie file, we would warn but not exit, and end up in a state
where no controller could authenticate. Now we exit.
- If we require CookieAuthentication, stop generating a new cookie
every time we change any piece of our config.
- Refuse to start with certain directory authority keys, and
encourage people using them to stop.
- Terminate multi-line control events properly. Original patch
from tup.
- Fix a minor memory leak when we fail to find enough suitable
servers to choose a circuit.
- Stop leaking part of the descriptor when we run into a particularly
unparseable piece of it.
Changes in version 0.1.2.16 - 2007-08-01
Tor 0.1.2.16 fixes a critical security vulnerability that allows a
remote attacker in certain situations to rewrite the user's torrc
configuration file. This can completely compromise anonymity of users
in most configurations, including those running the Vidalia bundles,
TorK, etc. Or worse.
o Major security fixes:
- Close immediately after missing authentication on control port;
do not allow multiple authentication attempts.
Changes in version 0.1.2.15 - 2007-07-17
Tor 0.1.2.15 fixes several crash bugs, fixes some anonymity-related
problems, fixes compilation on BSD, and fixes a variety of other
bugs. Everybody should upgrade.
o Major bugfixes (compilation):
- Fix compile on FreeBSD/NetBSD/OpenBSD. Oops.
o Major bugfixes (crashes):
- Try even harder not to dereference the first character after
an mmap(). Reported by lodger.
- Fix a crash bug in directory authorities when we re-number the
routerlist while inserting a new router.
- When the cached-routers file is an even multiple of the page size,
don't run off the end and crash. (Fixes bug 455; based on idea
from croup.)
- Fix eventdns.c behavior on Solaris: It is critical to include
orconfig.h _before_ sys/types.h, so that we can get the expected
definition of _FILE_OFFSET_BITS.
o Major bugfixes (security):
- Fix a possible buffer overrun when using BSD natd support. Bug
found by croup.
- When sending destroy cells from a circuit's origin, don't include
the reason for tearing down the circuit. The spec says we didn't,
and now we actually don't. Reported by lodger.
- Keep streamids from different exits on a circuit separate. This
bug may have allowed other routers on a given circuit to inject
cells into streams. Reported by lodger; fixes bug 446.
- If there's a never-before-connected-to guard node in our list,
never choose any guards past it. This way we don't expand our
guard list unless we need to.
o Minor bugfixes (guard nodes):
- Weight guard selection by bandwidth, so that low-bandwidth nodes
don't get overused as guards.
o Minor bugfixes (directory):
- Correctly count the number of authorities that recommend each
version. Previously, we were under-counting by 1.
- Fix a potential crash bug when we load many server descriptors at
once and some of them make others of them obsolete. Fixes bug 458.
o Minor bugfixes (hidden services):
- Stop tearing down the whole circuit when the user asks for a
connection to a port that the hidden service didn't configure.
Resolves bug 444.
o Minor bugfixes (misc):
- On Windows, we were preventing other processes from reading
cached-routers while Tor was running. Reported by janbar.
- Fix a possible (but very unlikely) bug in picking routers by
bandwidth. Add a log message to confirm that it is in fact
unlikely. Patch from lodger.
- Backport a couple of memory leak fixes.
- Backport miscellaneous cosmetic bugfixes.
Changes in version 0.1.2.14 - 2007-05-25
Tor 0.1.2.14 changes the addresses of two directory authorities (this
change especially affects those who serve or use hidden services),
and fixes several other crash- and security-related bugs.
o Directory authority changes:
- Two directory authorities (moria1 and moria2) just moved to new
IP addresses. This change will particularly affect those who serve
or use hidden services.
o Major bugfixes (crashes):
- If a directory server runs out of space in the connection table
as it's processing a begin_dir request, it will free the exit stream
but leave it attached to the circuit, leading to unpredictable
behavior. (Reported by seeess, fixes bug 425.)
- Fix a bug in dirserv_remove_invalid() that would cause authorities
to corrupt memory under some really unlikely scenarios.
- Tighten router parsing rules. (Bugs reported by Benedikt Boss.)
- Avoid segfaults when reading from mmaped descriptor file. (Reported
by lodger.)
o Major bugfixes (security):
- When choosing an entry guard for a circuit, avoid using guards
that are in the same family as the chosen exit -- not just guards
that are exactly the chosen exit. (Reported by lodger.)
o Major bugfixes (resource management):
- If a directory authority is down, skip it when deciding where to get
networkstatus objects or descriptors. Otherwise we keep asking
every 10 seconds forever. Fixes bug 384.
- Count it as a failure if we fetch a valid network-status but we
don't want to keep it. Otherwise we'll keep fetching it and keep
not wanting to keep it. Fixes part of bug 422.
- If all of our dirservers have given us bad or no networkstatuses
lately, then stop hammering them once per minute even when we
think they're failed. Fixes another part of bug 422.
o Minor bugfixes:
- Actually set the purpose correctly for descriptors inserted with
purpose=controller.
- When we have k non-v2 authorities in our DirServer config,
we ignored the last k authorities in the list when updating our
network-statuses.
- Correctly back-off from requesting router descriptors that we are
having a hard time downloading.
- Read resolv.conf files correctly on platforms where read() returns
partial results on small file reads.
- Don't rebuild the entire router store every time we get 32K of
routers: rebuild it when the journal gets very large, or when
the gaps in the store get very large.
o Minor features:
- When routers publish SVN revisions in their router descriptors,
authorities now include those versions correctly in networkstatus
documents.
- Warn when using a version of libevent before 1.3b to run a server on
OSX or BSD: these versions interact badly with userspace threads.
Changes in version 0.1.2.13 - 2007-04-24
This release features some major anonymity fixes, such as safer path
selection; better client performance; faster bootstrapping, better
address detection, and better DNS support for servers; write limiting as
well as read limiting to make servers easier to run; and a huge pile of
other features and bug fixes. The bundles also ship with Vidalia 0.0.11.
Tor 0.1.2.13 is released in memory of Rob Levin (1955-2006), aka lilo
of the Freenode IRC network, remembering his patience and vision for
free speech on the Internet.
o Major features, client performance:
- Weight directory requests by advertised bandwidth. Now we can
let servers enable write limiting but still allow most clients to
succeed at their directory requests. (We still ignore weights when
choosing a directory authority; I hope this is a feature.)
- Stop overloading exit nodes -- avoid choosing them for entry or
middle hops when the total bandwidth available from non-exit nodes
is much higher than the total bandwidth available from exit nodes.
- Rather than waiting a fixed amount of time between retrying
application connections, we wait only 10 seconds for the first,
10 seconds for the second, and 15 seconds for each retry after
that. Hopefully this will improve the expected user experience.
- Sometimes we didn't bother sending a RELAY_END cell when an attempt
to open a stream fails; now we do in more cases. This should
make clients able to find a good exit faster in some cases, since
unhandleable requests will now get an error rather than timing out.
o Major features, client functionality:
- Implement BEGIN_DIR cells, so we can connect to a directory
server via TLS to do encrypted directory requests rather than
plaintext. Enable via the TunnelDirConns and PreferTunneledDirConns
config options if you like. For now, this feature only works if
you already have a descriptor for the destination dirserver.
- Add support for transparent application connections: this basically
bundles the functionality of trans-proxy-tor into the Tor
mainline. Now hosts with compliant pf/netfilter implementations
can redirect TCP connections straight to Tor without diverting
through SOCKS. (Based on patch from tup.)
- Add support for using natd; this allows FreeBSDs earlier than
5.1.2 to have ipfw send connections through Tor without using
SOCKS. (Patch from Zajcev Evgeny with tweaks from tup.)
o Major features, servers:
- Setting up a dyndns name for your server is now optional: servers
with no hostname or IP address will learn their IP address by
asking the directory authorities. This code only kicks in when you
would normally have exited with a "no address" error. Nothing's
authenticated, so use with care.
- Directory servers now spool server descriptors, v1 directories,
and v2 networkstatus objects to buffers as needed rather than en
masse. They also mmap the cached-routers files. These steps save
lots of memory.
- Stop requiring clients to have well-formed certificates, and stop
checking nicknames in certificates. (Clients have certificates so
that they can look like Tor servers, but in the future we might want
to allow them to look like regular TLS clients instead. Nicknames
in certificates serve no purpose other than making our protocol
easier to recognize on the wire.) Implements proposal 106.
o Improvements on DNS support:
- Add "eventdns" asynchronous dns library originally based on code
from Adam Langley. Now we can discard the old rickety dnsworker
concept, and support a wider variety of DNS functions. Allows
multithreaded builds on NetBSD and OpenBSD again.
- Add server-side support for "reverse" DNS lookups (using PTR
records so clients can determine the canonical hostname for a given
IPv4 address). Only supported by servers using eventdns; servers
now announce in their descriptors if they don't support eventdns.
- Workaround for name servers (like Earthlink's) that hijack failing
DNS requests and replace the no-such-server answer with a "helpful"
redirect to an advertising-driven search portal. Also work around
DNS hijackers who "helpfully" decline to hijack known-invalid
RFC2606 addresses. Config option "ServerDNSDetectHijacking 0"
lets you turn it off.
- Servers now check for the case when common DNS requests are going to
wildcarded addresses (i.e. all getting the same answer), and change
their exit policy to reject *:* if it's happening.
- When asked to resolve a hostname, don't use non-exit servers unless
requested to do so. This allows servers with broken DNS to be
useful to the network.
- Start passing "ipv4" hints to getaddrinfo(), so servers don't do
useless IPv6 DNS resolves.
- Specify and implement client-side SOCKS5 interface for reverse DNS
lookups (see doc/socks-extensions.txt). Also cache them.
- When we change nameservers or IP addresses, reset and re-launch
our tests for DNS hijacking.
o Improvements on reachability testing:
- Servers send out a burst of long-range padding cells once they've
established that they're reachable. Spread them over 4 circuits,
so hopefully a few will be fast. This exercises bandwidth and
bootstraps them into the directory more quickly.
- When we find our DirPort to be reachable, publish a new descriptor
so we'll tell the world (reported by pnx).
- Directory authorities now only decide that routers are reachable
if their identity keys are as expected.
- Do DirPort reachability tests less often, since a single test
chews through many circuits before giving up.
- Avoid some false positives during reachability testing: don't try
to test via a server that's on the same /24 network as us.
- Start publishing one minute or so after we find our ORPort
to be reachable. This will help reduce the number of descriptors
we have for ourselves floating around, since it's quite likely
other things (e.g. DirPort) will change during that minute too.
- Routers no longer try to rebuild long-term connections to directory
authorities, and directory authorities no longer try to rebuild
long-term connections to all servers. We still don't hang up
connections in these two cases though -- we need to look at it
more carefully to avoid flapping, and we likely need to wait til
0.1.1.x is obsolete.
o Improvements on rate limiting:
- Enable write limiting as well as read limiting. Now we sacrifice
capacity if we're pushing out lots of directory traffic, rather
than overrunning the user's intended bandwidth limits.
- Include TLS overhead when counting bandwidth usage; previously, we
would count only the bytes sent over TLS, but not the bytes used
to send them.
- Servers decline directory requests much more aggressively when
they're low on bandwidth. Otherwise they end up queueing more and
more directory responses, which can't be good for latency.
- But never refuse directory requests from local addresses.
- Be willing to read or write on local connections (e.g. controller
connections) even when the global rate limiting buckets are empty.
- Flush local controller connection buffers periodically as we're
writing to them, so we avoid queueing 4+ megabytes of data before
trying to flush.
- Revise and clean up the torrc.sample that we ship with; add
a section for BandwidthRate and BandwidthBurst.
o Major features, NT services:
- Install as NT_AUTHORITY\LocalService rather than as SYSTEM; add a
command-line flag so that admins can override the default by saying
"tor --service install --user "SomeUser"". This will not affect
existing installed services. Also, warn the user that the service
will look for its configuration file in the service user's
%appdata% directory. (We can't do the "hardwire the user's appdata
directory" trick any more, since we may not have read access to that
directory.)
- Support running the Tor service with a torrc not in the same
directory as tor.exe and default to using the torrc located in
the %appdata%\Tor\ of the user who installed the service. Patch
from Matt Edman.
- Add an --ignore-missing-torrc command-line option so that we can
get the "use sensible defaults if the configuration file doesn't
exist" behavior even when specifying a torrc location on the
command line.
- When stopping an NT service, wait up to 10 sec for it to actually
stop. (Patch from Matt Edman; resolves bug 295.)
o Directory authority improvements:
- Stop letting hibernating or obsolete servers affect uptime and
bandwidth cutoffs.
- Stop listing hibernating servers in the v1 directory.
- Authorities no longer recommend exits as guards if this would shift
too much load to the exit nodes.
- Authorities now specify server versions in networkstatus. This adds
about 2% to the size of compressed networkstatus docs, and allows
clients to tell which servers support BEGIN_DIR and which don't.
The implementation is forward-compatible with a proposed future
protocol version scheme not tied to Tor versions.
- DirServer configuration lines now have an orport= option so
clients can open encrypted tunnels to the authorities without
having downloaded their descriptors yet. Enabled for moria1,
moria2, tor26, and lefkada now in the default configuration.
- Add a BadDirectory flag to network status docs so that authorities
can (eventually) tell clients about caches they believe to be
broken. Not used yet.
- Allow authorities to list nodes as bad exits in their
approved-routers file by fingerprint or by address. If most
authorities set a BadExit flag for a server, clients don't think
of it as a general-purpose exit. Clients only consider authorities
that advertise themselves as listing bad exits.
- Patch from Steve Hildrey: Generate network status correctly on
non-versioning dirservers.
- Have directory authorities allow larger amounts of drift in uptime
without replacing the server descriptor: previously, a server that
restarted every 30 minutes could have 48 "interesting" descriptors
per day.
- Reserve the nickname "Unnamed" for routers that can't pick
a hostname: any router can call itself Unnamed; directory
authorities will never allocate Unnamed to any particular router;
clients won't believe that any router is the canonical Unnamed.
o Directory mirrors and clients:
- Discard any v1 directory info that's over 1 month old (for
directories) or over 1 week old (for running-routers lists).
- Clients track responses with status 503 from dirservers. After a
dirserver has given us a 503, we try not to use it until an hour has
gone by, or until we have no dirservers that haven't given us a 503.
- When we get a 503 from a directory, and we're not a server, we no
longer count the failure against the total number of failures
allowed for the object we're trying to download.
- Prepare for servers to publish descriptors less often: never
discard a descriptor simply for being too old until either it is
recommended by no authorities, or until we get a better one for
the same router. Make caches consider retaining old recommended
routers for even longer.
- Directory servers now provide 'Pragma: no-cache' and 'Expires'
headers for content, so that we can work better in the presence of
caching HTTP proxies.
- Stop fetching descriptors if you're not a dir mirror and you
haven't tried to establish any circuits lately. (This currently
causes some dangerous behavior, because when you start up again
you'll use your ancient server descriptors.)
o Major fixes, crashes:
- Stop crashing when the controller asks us to resetconf more than
one config option at once. (Vidalia 0.0.11 does this.)
- Fix a longstanding obscure crash bug that could occur when we run
out of DNS worker processes, if we're not using eventdns. (Resolves
bug 390.)
- Fix an assert that could trigger if a controller quickly set then
cleared EntryNodes. (Bug found by Udo van den Heuvel.)
- Avoid crash when telling controller about stream-status and a
stream is detached.
- Avoid sending junk to controllers or segfaulting when a controller
uses EVENT_NEW_DESC with verbose nicknames.
- Stop triggering asserts if the controller tries to extend hidden
service circuits (reported by mwenge).
- If we start a server with ClientOnly 1, then set ClientOnly to 0
and hup, stop triggering an assert based on an empty onion_key.
- Mask out all signals in sub-threads; only the libevent signal
handler should be processing them. This should prevent some crashes
on some machines using pthreads. (Patch from coderman.)
- Disable kqueue on OS X 10.3 and earlier, to fix bug 371.
o Major fixes, anonymity/security:
- Automatically avoid picking more than one node from the same
/16 network when constructing a circuit. Add an
"EnforceDistinctSubnets" option to let people disable it if they
want to operate private test networks on a single subnet.
- When generating bandwidth history, round down to the nearest
1k. When storing accounting data, round up to the nearest 1k.
- When we're running as a server, remember when we last rotated onion
keys, so that we will rotate keys once they're a week old even if
we never stay up for a week ourselves.
- If a client asked for a server by name, and there's a named server
in our network-status but we don't have its descriptor yet, we
could return an unnamed server instead.
- Reject (most) attempts to use Tor circuits with length one. (If
many people start using Tor as a one-hop proxy, exit nodes become
a more attractive target for compromise.)
- Just because your DirPort is open doesn't mean people should be
able to remotely teach you about hidden service descriptors. Now
only accept rendezvous posts if you've got HSAuthoritativeDir set.
- Fix a potential race condition in the rpm installer. Found by
Stefan Nordhausen.
- Do not log IPs with TLS failures for incoming TLS
connections. (Fixes bug 382.)
o Major fixes, other:
- If our system clock jumps back in time, don't publish a negative
uptime in the descriptor.
- When we start during an accounting interval before it's time to wake
up, remember to wake up at the correct time. (May fix bug 342.)
- Previously, we would cache up to 16 old networkstatus documents
indefinitely, if they came from nontrusted authorities. Now we
discard them if they are more than 10 days old.
- When we have a state file we cannot parse, tell the user and
move it aside. Now we avoid situations where the user starts
Tor in 1904, Tor writes a state file with that timestamp in it,
the user fixes her clock, and Tor refuses to start.
- Publish a new descriptor after we hup/reload. This is important
if our config has changed such that we'll want to start advertising
our DirPort now, etc.
- If we are using an exit enclave and we can't connect, e.g. because
its webserver is misconfigured to not listen on localhost, then
back off and try connecting from somewhere else before we fail.
o New config options or behaviors:
- When EntryNodes are configured, rebuild the guard list to contain,
in order: the EntryNodes that were guards before; the rest of the
EntryNodes; the nodes that were guards before.
- Do not warn when individual nodes in the configuration's EntryNodes,
ExitNodes, etc are down: warn only when all possible nodes
are down. (Fixes bug 348.)
- Put a lower-bound on MaxAdvertisedBandwidth.
- Start using the state file to store bandwidth accounting data:
the bw_accounting file is now obsolete. We'll keep generating it
for a while for people who are still using 0.1.2.4-alpha.
- Try to batch changes to the state file so that we do as few
disk writes as possible while still storing important things in
a timely fashion.
- The state file and the bw_accounting file get saved less often when
the AvoidDiskWrites config option is set.
- Make PIDFile work on Windows.
- Add internal descriptions for a bunch of configuration options:
accessible via controller interface and in comments in saved
options files.
- Reject *:563 (NNTPS) in the default exit policy. We already reject
NNTP by default, so this seems like a sensible addition.
- Clients now reject hostnames with invalid characters. This should
avoid some inadvertent info leaks. Add an option
AllowNonRFC953Hostnames to disable this behavior, in case somebody
is running a private network with hosts called @, !, and #.
- Check for addresses with invalid characters at the exit as well,
and warn less verbosely when they fail. You can override this by
setting ServerDNSAllowNonRFC953Addresses to 1.
- Remove some options that have been deprecated since at least
0.1.0.x: AccountingMaxKB, LogFile, DebugLogFile, LogLevel, and
SysLog. Use AccountingMax instead of AccountingMaxKB, and use Log
to set log options. Mark PathlenCoinWeight as obsolete.
- Stop accepting certain malformed ports in configured exit policies.
- When the user uses bad syntax in the Log config line, stop
suggesting other bad syntax as a replacement.
- Add new config option "ResolvConf" to let the server operator
choose an alternate resolve.conf file when using eventdns.
- If one of our entry guards is on the ExcludeNodes list, or the
directory authorities don't think it's a good guard, treat it as
if it were unlisted: stop using it as a guard, and throw it off
the guards list if it stays that way for a long time.
- Allow directory authorities to be marked separately as authorities
for the v1 directory protocol, the v2 directory protocol, and
as hidden service directories, to make it easier to retire old
authorities. V1 authorities should set "HSAuthoritativeDir 1"
to continue being hidden service authorities too.
- Remove 8888 as a LongLivedPort, and add 6697 (IRCS).
- Make TrackExitHosts case-insensitive, and fix the behavior of
".suffix" TrackExitHosts items to avoid matching in the middle of
an address.
- New DirPort behavior: if you have your dirport set, you download
descriptors aggressively like a directory mirror, whether or not
your ORPort is set.
o Docs:
- Create a new file ReleaseNotes which was the old ChangeLog. The
new ChangeLog file now includes the notes for all development
versions too.
- Add a new address-spec.txt document to describe our special-case
addresses: .exit, .onion, and .noconnnect.
- Fork the v1 directory protocol into its own spec document,
and mark dir-spec.txt as the currently correct (v2) spec.
o Packaging, porting, and contrib
- "tor --verify-config" now exits with -1(255) or 0 depending on
whether the config options are bad or good.
- The Debian package now uses --verify-config when (re)starting,
to distinguish configuration errors from other errors.
- Adapt a patch from goodell to let the contrib/exitlist script
take arguments rather than require direct editing.
- Prevent the contrib/exitlist script from printing the same
result more than once.
- Add support to tor-resolve tool for reverse lookups and SOCKS5.
- In the hidden service example in torrc.sample, stop recommending
esoteric and discouraged hidden service options.
- Patch from Michael Mohr to contrib/cross.sh, so it checks more
values before failing, and always enables eventdns.
- Try to detect Windows correctly when cross-compiling.
- Libevent-1.2 exports, but does not define in its headers, strlcpy.
Try to fix this in configure.in by checking for most functions
before we check for libevent.
- Update RPMs to require libevent 1.2.
- Experimentally re-enable kqueue on OSX when using libevent 1.1b
or later. Log when we are doing this, so we can diagnose it when
it fails. (Also, recommend libevent 1.1b for kqueue and
win32 methods; deprecate libevent 1.0b harder; make libevent
recommendation system saner.)
- Build with recent (1.3+) libevents on platforms that do not
define the nonstandard types "u_int8_t" and friends.
- Remove architecture from OS X builds. The official builds are
now universal binaries.
- Run correctly on OS X platforms with case-sensitive filesystems.
- Correctly set maximum connection limit on Cygwin. (This time
for sure!)
- Start compiling on MinGW on Windows (patches from Mike Chiussi
and many others).
- Start compiling on MSVC6 on Windows (patches from Frediano Ziglio).
- Finally fix the openssl warnings from newer gccs that believe that
ignoring a return value is okay, but casting a return value and
then ignoring it is a sign of madness.
- On architectures where sizeof(int)>4, still clamp declarable
bandwidth to INT32_MAX.
o Minor features, controller:
- Warn the user when an application uses the obsolete binary v0
control protocol. We're planning to remove support for it during
the next development series, so it's good to give people some
advance warning.
- Add STREAM_BW events to report per-entry-stream bandwidth
use. (Patch from Robert Hogan.)
- Rate-limit SIGNEWNYM signals in response to controllers that
impolitely generate them for every single stream. (Patch from
mwenge; closes bug 394.)
- Add a REMAP status to stream events to note that a stream's
address has changed because of a cached address or a MapAddress
directive.
- Make REMAP stream events have a SOURCE (cache or exit), and
make them generated in every case where we get a successful
connected or resolved cell.
- Track reasons for OR connection failure; make these reasons
available via the controller interface. (Patch from Mike Perry.)
- Add a SOCKS_BAD_HOSTNAME client status event so controllers
can learn when clients are sending malformed hostnames to Tor.
- Specify and implement some of the controller status events.
- Have GETINFO dir/status/* work on hosts with DirPort disabled.
- Reimplement GETINFO so that info/names stays in sync with the
actual keys.
- Implement "GETINFO fingerprint".
- Implement "SETEVENTS GUARD" so controllers can get updates on
entry guard status as it changes.
- Make all connections to addresses of the form ".noconnect"
immediately get closed. This lets application/controller combos
successfully test whether they're talking to the same Tor by
watching for STREAM events.
- Add a REASON field to CIRC events; for backward compatibility, this
field is sent only to controllers that have enabled the extended
event format. Also, add additional reason codes to explain why
a given circuit has been destroyed or truncated. (Patches from
Mike Perry)
- Add a REMOTE_REASON field to extended CIRC events to tell the
controller why a remote OR told us to close a circuit.
- Stream events also now have REASON and REMOTE_REASON fields,
working much like those for circuit events.
- There's now a GETINFO ns/... field so that controllers can ask Tor
about the current status of a router.
- A new event type "NS" to inform a controller when our opinion of
a router's status has changed.
- Add a GETINFO events/names and GETINFO features/names so controllers
can tell which events and features are supported.
- A new CLEARDNSCACHE signal to allow controllers to clear the
client-side DNS cache without expiring circuits.
- Fix CIRC controller events so that controllers can learn the
identity digests of non-Named servers used in circuit paths.
- Let controllers ask for more useful identifiers for servers. Instead
of learning identity digests for un-Named servers and nicknames
for Named servers, the new identifiers include digest, nickname,
and indication of Named status. Off by default; see control-spec.txt
for more information.
- Add a "getinfo address" controller command so it can display Tor's
best guess to the user.
- New controller event to alert the controller when our server
descriptor has changed.
- Give more meaningful errors on controller authentication failure.
- Export the default exit policy via the control port, so controllers
don't need to guess what it is / will be later.
o Minor bugfixes, controller:
- When creating a circuit via the controller, send a 'launched'
event when we're done, so we follow the spec better.
- Correct the control spec to match how the code actually responds
to 'getinfo addr-mappings/*'. Reported by daejees.
- The control spec described a GUARDS event, but the code
implemented a GUARD event. Standardize on GUARD, but let people
ask for GUARDS too. Reported by daejees.
- Give the controller END_STREAM_REASON_DESTROY events _before_ we
clear the corresponding on_circuit variable, and remember later
that we don't need to send a redundant CLOSED event. (Resolves part
3 of bug 367.)
- Report events where a resolve succeeded or where we got a socks
protocol error correctly, rather than calling both of them
"INTERNAL".
- Change reported stream target addresses to IP consistently when
we finally get the IP from an exit node.
- Send log messages to the controller even if they happen to be very
long.
- Flush ERR-level controller status events just like we currently
flush ERR-level log events, so that a Tor shutdown doesn't prevent
the controller from learning about current events.
- Report the circuit number correctly in STREAM CLOSED events. Bug
reported by Mike Perry.
- Do not report bizarre values for results of accounting GETINFOs
when the last second's write or read exceeds the allotted bandwidth.
- Report "unrecognized key" rather than an empty string when the
controller tries to fetch a networkstatus that doesn't exist.
- When the controller does a "GETINFO network-status", tell it
about even those routers whose descriptors are very old, and use
long nicknames where appropriate.
- Fix handling of verbose nicknames with ORCONN controller events:
make them show up exactly when requested, rather than exactly when
not requested.
- Controller signals now work on non-Unix platforms that don't define
SIGUSR1 and SIGUSR2 the way we expect.
- Respond to SIGNAL command before we execute the signal, in case
the signal shuts us down. Suggested by Karsten Loesing.
- Handle reporting OR_CONN_EVENT_NEW events to the controller.
o Minor features, code performance:
- Major performance improvement on inserting descriptors: change
algorithm from O(n^2) to O(n).
- Do not rotate onion key immediately after setting it for the first
time.
- Call router_have_min_dir_info half as often. (This is showing up in
some profiles, but not others.)
- When using GCC, make log_debug never get called at all, and its
arguments never get evaluated, when no debug logs are configured.
(This is showing up in some profiles, but not others.)
- Statistics dumped by -USR2 now include a breakdown of public key
operations, for profiling.
- Make the common memory allocation path faster on machines where
malloc(0) returns a pointer.
- Split circuit_t into origin_circuit_t and or_circuit_t, and
split connection_t into edge, or, dir, control, and base structs.
These will save quite a bit of memory on busy servers, and they'll
also help us track down bugs in the code and bugs in the spec.
- Use OpenSSL's AES implementation on platforms where it's faster.
This could save us as much as 10% CPU usage.
o Minor features, descriptors and descriptor handling:
- Avoid duplicate entries on MyFamily line in server descriptor.
- When Tor receives a router descriptor that it asked for, but
no longer wants (because it has received fresh networkstatuses
in the meantime), do not warn the user. Cache the descriptor if
we're a cache; drop it if we aren't.
- Servers no longer ever list themselves in their "family" line,
even if configured to do so. This makes it easier to configure
family lists conveniently.
o Minor fixes, confusing/misleading log messages:
- Display correct results when reporting which versions are
recommended, and how recommended they are. (Resolves bug 383.)
- Inform the server operator when we decide not to advertise a
DirPort due to AccountingMax enabled or a low BandwidthRate.
- Only include function names in log messages for info/debug messages.
For notice/warn/err, the content of the message should be clear on
its own, and printing the function name only confuses users.
- Remove even more protocol-related warnings from Tor server logs,
such as bad TLS handshakes and malformed begin cells.
- Fix bug 314: Tor clients issued "unsafe socks" warnings even
when the IP address is mapped through MapAddress to a hostname.
- Fix misleading log messages: an entry guard that is "unlisted",
as well as not known to be "down" (because we've never heard
of it), is not therefore "up".
o Minor fixes, old/obsolete behavior:
- Start assuming we can use a create_fast cell if we don't know
what version a router is running.
- We no longer look for identity and onion keys in "identity.key" and
"onion.key" -- these were replaced by secret_id_key and
secret_onion_key in 0.0.8pre1.
- We no longer require unrecognized directory entries to be
preceded by "opt".
- Drop compatibility with obsolete Tors that permit create cells
to have the wrong circ_id_type.
- Remove code to special-case "-cvs" ending, since it has not
actually mattered since 0.0.9.
- Don't re-write the fingerprint file every restart, unless it has
changed.
o Minor fixes, misc client-side behavior:
- Always remove expired routers and networkstatus docs before checking
whether we have enough information to build circuits. (Fixes
bug 373.)
- When computing clock skew from directory HTTP headers, consider what
time it was when we finished asking for the directory, not what
time it is now.
- Make our socks5 handling more robust to broken socks clients:
throw out everything waiting on the buffer in between socks
handshake phases, since they can't possibly (so the theory
goes) have predicted what we plan to respond to them.
- Expire socks connections if they spend too long waiting for the
handshake to finish. Previously we would let them sit around for
days, if the connecting application didn't close them either.
- And if the socks handshake hasn't started, don't send a
"DNS resolve socks failed" handshake reply; just close it.
- If the user asks to use invalid exit nodes, be willing to use
unstable ones.
- Track unreachable entry guards correctly: don't conflate
'unreachable by us right now' with 'listed as down by the directory
authorities'. With the old code, if a guard was unreachable by us
but listed as running, it would clog our guard list forever.
- Behave correctly in case we ever have a network with more than
2GB/s total advertised capacity.
- Claim a commonname of Tor, rather than TOR, in TLS handshakes.
- Fix a memory leak when we ask for "all" networkstatuses and we
get one we don't recognize.
Changes in version 0.1.1.26 - 2006-12-14
o Security bugfixes:
- Stop sending the HttpProxyAuthenticator string to directory
servers when directory connections are tunnelled through Tor.
- Clients no longer store bandwidth history in the state file.
- Do not log introduction points for hidden services if SafeLogging
is set.
o Minor bugfixes:
- Fix an assert failure when a directory authority sets
AuthDirRejectUnlisted and then receives a descriptor from an
unlisted router (reported by seeess).
Changes in version 0.1.1.25 - 2006-11-04
o Major bugfixes:
- When a client asks us to resolve (rather than connect to)
an address, and we have a cached answer, give them the cached
answer. Previously, we would give them no answer at all.
- We were building exactly the wrong circuits when we predict
hidden service requirements, meaning Tor would have to build all
its circuits on demand.
- If none of our live entry guards have a high uptime, but we
require a guard with a high uptime, try adding a new guard before
we give up on the requirement. This patch should make long-lived
connections more stable on average.
- When testing reachability of our DirPort, don't launch new
tests when there's already one in progress -- unreachable
servers were stacking up dozens of testing streams.
o Security bugfixes:
- When the user sends a NEWNYM signal, clear the client-side DNS
cache too. Otherwise we continue to act on previous information.
o Minor bugfixes:
- Avoid a memory corruption bug when creating a hash table for
the first time.
- Avoid possibility of controller-triggered crash when misusing
certain commands from a v0 controller on platforms that do not
handle printf("%s",NULL) gracefully.
- Avoid infinite loop on unexpected controller input.
- Don't log spurious warnings when we see a circuit close reason we
don't recognize; it's probably just from a newer version of Tor.
- Add Vidalia to the OS X uninstaller script, so when we uninstall
Tor/Privoxy we also uninstall Vidalia.
Changes in version 0.1.1.24 - 2006-09-29
o Major bugfixes:
- Allow really slow clients to not hang up five minutes into their
directory downloads (suggested by Adam J. Richter).
- Fix major performance regression from 0.1.0.x: instead of checking
whether we have enough directory information every time we want to
do something, only check when the directory information has changed.
This should improve client CPU usage by 25-50%.
- Don't crash if, after a server has been running for a while,
it can't resolve its hostname.
- When a client asks us to resolve (not connect to) an address,
and we have a cached answer, give them the cached answer.
Previously, we would give them no answer at all.
o Minor bugfixes:
- Allow Tor to start when RunAsDaemon is set but no logs are set.
- Don't crash when the controller receives a third argument to an
"extendcircuit" request.
- Controller protocol fixes: fix encoding in "getinfo addr-mappings"
response; fix error code when "getinfo dir/status/" fails.
- Fix configure.in to not produce broken configure files with
more recent versions of autoconf. Thanks to Clint for his auto*
voodoo.
- Fix security bug on NetBSD that could allow someone to force
uninitialized RAM to be sent to a server's DNS resolver. This
only affects NetBSD and other platforms that do not bounds-check
tolower().
- Warn user when using libevent 1.1a or earlier with win32 or kqueue
methods: these are known to be buggy.
- If we're a directory mirror and we ask for "all" network status
documents, we would discard status documents from authorities
we don't recognize.
Changes in version 0.1.1.23 - 2006-07-30
o Major bugfixes:
- Fast Tor servers, especially exit nodes, were triggering asserts
due to a bug in handling the list of pending DNS resolves. Some
bugs still remain here; we're hunting them.
- Entry guards could crash clients by sending unexpected input.
- More fixes on reachability testing: if you find yourself reachable,
then don't ever make any client requests (so you stop predicting
circuits), then hup or have your clock jump, then later your IP
changes, you won't think circuits are working, so you won't try to
test reachability, so you won't publish.
o Minor bugfixes:
- Avoid a crash if the controller does a resetconf firewallports
and then a setconf fascistfirewall=1.
- Avoid an integer underflow when the dir authority decides whether
a router is stable: we might wrongly label it stable, and compute
a slightly wrong median stability, when a descriptor is published
later than now.
- Fix a place where we might trigger an assert if we can't build our
own server descriptor yet.
Changes in version 0.1.1.22 - 2006-07-05
o Major bugfixes:
- Fix a big bug that was causing servers to not find themselves
reachable if they changed IP addresses. Since only 0.1.1.22+
servers can do reachability testing correctly, now we automatically
make sure to test via one of these.
- Fix to allow clients and mirrors to learn directory info from
descriptor downloads that get cut off partway through.
- Directory authorities had a bug in deciding if a newly published
descriptor was novel enough to make everybody want a copy -- a few
servers seem to be publishing new descriptors many times a minute.
o Minor bugfixes:
- Fix a rare bug that was causing some servers to complain about
"closing wedged cpuworkers" and skip some circuit create requests.
- Make the Exit flag in directory status documents actually work.
Changes in version 0.1.1.21 - 2006-06-10
o Crash and assert fixes from 0.1.1.20:
- Fix a rare crash on Tor servers that have enabled hibernation.
- Fix a seg fault on startup for Tor networks that use only one
directory authority.
- Fix an assert from a race condition that occurs on Tor servers
while exiting, where various threads are trying to log that they're
exiting, and delete the logs, at the same time.
- Make our unit tests pass again on certain obscure platforms.
o Other fixes:
- Add support for building SUSE RPM packages.
- Speed up initial bootstrapping for clients: if we are making our
first ever connection to any entry guard, then don't mark it down
right after that.
- When only one Tor server in the network is labelled as a guard,
and we've already picked him, we would cycle endlessly picking him
again, being unhappy about it, etc. Now we specifically exclude
current guards when picking a new guard.
- Servers send create cells more reliably after the TLS connection
is established: we were sometimes forgetting to send half of them
when we had more than one pending.
- If we get a create cell that asks us to extend somewhere, but the
Tor server there doesn't match the expected digest, we now send
a destroy cell back, rather than silently doing nothing.
- Make options->RedirectExit work again.
- Make cookie authentication for the controller work again.
- Stop being picky about unusual characters in the arguments to
mapaddress. It's none of our business.
- Add a new config option "TestVia" that lets you specify preferred
middle hops to use for test circuits. Perhaps this will let me
debug the reachability problems better.
o Log / documentation fixes:
- If we're a server and some peer has a broken TLS certificate, don't
log about it unless ProtocolWarnings is set, i.e., we want to hear
about protocol violations by others.
- Fix spelling of VirtualAddrNetwork in man page.
- Add a better explanation at the top of the autogenerated torrc file
about what happened to our old torrc.
Changes in version 0.1.1.20 - 2006-05-23
o Crash and assert fixes from 0.1.0.17:
- Fix assert bug in close_logs() on exit: when we close and delete
logs, remove them all from the global "logfiles" list.
- Fix an assert error when we're out of space in the connection_list
and we try to post a hidden service descriptor (reported by Peter
Palfrader).
- Fix a rare assert error when we've tried all intro points for
a hidden service and we try fetching the service descriptor again:
"Assertion conn->state != AP_CONN_STATE_RENDDESC_WAIT failed".
- Setconf SocksListenAddress kills Tor if it fails to bind. Now back
out and refuse the setconf if it would fail.
- If you specify a relative torrc path and you set RunAsDaemon in
your torrc, then it chdir()'s to the new directory. If you then
HUP, it tries to load the new torrc location, fails, and exits.
The fix: no longer allow a relative path to torrc when using -f.
- Check for integer overflows in more places, when adding elements
to smartlists. This could possibly prevent a buffer overflow
on malicious huge inputs.
o Security fixes, major:
- When we're printing strings from the network, don't try to print
non-printable characters. Now we're safer against shell escape
sequence exploits, and also against attacks to fool users into
misreading their logs.
- Implement entry guards: automatically choose a handful of entry
nodes and stick with them for all circuits. Only pick new guards
when the ones you have are unsuitable, and if the old guards
become suitable again, switch back. This will increase security
dramatically against certain end-point attacks. The EntryNodes
config option now provides some hints about which entry guards you
want to use most; and StrictEntryNodes means to only use those.
Fixes CVE-2006-0414.
- Implement exit enclaves: if we know an IP address for the
destination, and there's a running Tor server at that address
which allows exit to the destination, then extend the circuit to
that exit first. This provides end-to-end encryption and end-to-end
authentication. Also, if the user wants a .exit address or enclave,
use 4 hops rather than 3, and cannibalize a general circ for it
if you can.
- Obey our firewall options more faithfully:
. If we can't get to a dirserver directly, try going via Tor.
. Don't ever try to connect (as a client) to a place our
firewall options forbid.
. If we specify a proxy and also firewall options, obey the
firewall options even when we're using the proxy: some proxies
can only proxy to certain destinations.
- Make clients regenerate their keys when their IP address changes.
- For the OS X package's modified privoxy config file, comment
out the "logfile" line so we don't log everything passed
through privoxy.
- Our TLS handshakes were generating a single public/private
keypair for the TLS context, rather than making a new one for
each new connection. Oops. (But we were still rotating them
periodically, so it's not so bad.)
- When we were cannibalizing a circuit with a particular exit
node in mind, we weren't checking to see if that exit node was
already present earlier in the circuit. Now we are.
- Require server descriptors to list IPv4 addresses -- hostnames
are no longer allowed. This also fixes potential vulnerabilities
to servers providing hostnames as their address and then
preferentially resolving them so they can partition users.
- Our logic to decide if the OR we connected to was the right guy
was brittle and maybe open to a mitm for invalid routers.
o Security fixes, minor:
- Adjust tor-spec.txt to parameterize cell and key lengths. Now
Ian Goldberg can prove things about our handshake protocol more
easily.
- Make directory authorities generate a separate "guard" flag to
mean "would make a good entry guard". Clients now honor the
is_guard flag rather than looking at is_fast or is_stable.
- Try to list MyFamily elements by key, not by nickname, and warn
if we've not heard of a server.
- Start using RAND_bytes rather than RAND_pseudo_bytes from
OpenSSL. Also, reseed our entropy every hour, not just at
startup. And add entropy in 512-bit chunks, not 160-bit chunks.
- Refuse server descriptors where the fingerprint line doesn't match
the included identity key. Tor doesn't care, but other apps (and
humans) might actually be trusting the fingerprint line.
- We used to kill the circuit when we receive a relay command we
don't recognize. Now we just drop that cell.
- Fix a bug found by Lasse Overlier: when we were making internal
circuits (intended to be cannibalized later for rendezvous and
introduction circuits), we were picking them so that they had
useful exit nodes. There was no need for this, and it actually
aids some statistical attacks.
- Start treating internal circuits and exit circuits separately.
It's important to keep them separate because internal circuits
have their last hops picked like middle hops, rather than like
exit hops. So exiting on them will break the user's expectations.
- Fix a possible way to DoS dirservers.
- When the client asked for a rendezvous port that the hidden
service didn't want to provide, we were sending an IP address
back along with the end cell. Fortunately, it was zero. But stop
that anyway.
o Packaging improvements:
- Implement --with-libevent-dir option to ./configure. Improve
search techniques to find libevent, and use those for openssl too.
- Fix a couple of bugs in OpenSSL detection. Deal better when
there are multiple SSLs installed with different versions.
- Avoid warnings about machine/limits.h on Debian GNU/kFreeBSD.
- On non-gcc compilers (e.g. Solaris's cc), use "-g -O" instead of
"-Wall -g -O2".
- Make unit tests (and other invocations that aren't the real Tor)
run without launching listeners, creating subdirectories, and so on.
- The OS X installer was adding a symlink for tor_resolve but
the binary was called tor-resolve (reported by Thomas Hardly).
- Now we can target arch and OS in rpm builds (contributed by
Phobos). Also make the resulting dist-rpm filename match the
target arch.
- Apply Matt Ghali's --with-syslog-facility patch to ./configure
if you log to syslog and want something other than LOG_DAEMON.
- Fix the torify (tsocks) config file to not use Tor for localhost
connections.
- Start shipping socks-extensions.txt, tor-doc-unix.html,
tor-doc-server.html, and stylesheet.css in the tarball.
- Stop shipping tor-doc.html, INSTALL, and README in the tarball.
They are useless now.
- Add Peter Palfrader's contributed check-tor script. It lets you
easily check whether a given server (referenced by nickname)
is reachable by you.
- Add BSD-style contributed startup script "rc.subr" from Peter
Thoenen.
o Directory improvements -- new directory protocol:
- See tor/doc/dir-spec.txt for all the juicy details. Key points:
- Authorities and caches publish individual descriptors (by
digest, by fingerprint, by "all", and by "tell me yours").
- Clients don't download or use the old directory anymore. Now they
download network-statuses from the directory authorities, and
fetch individual server descriptors as needed from mirrors.
- Clients don't download descriptors of non-running servers.
- Download descriptors by digest, not by fingerprint. Caches try to
download all listed digests from authorities; clients try to
download "best" digests from caches. This avoids partitioning
and isolating attacks better.
- Only upload a new server descriptor when options change, 18
hours have passed, uptime is reset, or bandwidth changes a lot.
- Directory authorities silently throw away new descriptors that
haven't changed much if the timestamps are similar. We do this to
tolerate older Tor servers that upload a new descriptor every 15
minutes. (It seemed like a good idea at the time.)
- Clients choose directory servers from the network status lists,
not from their internal list of router descriptors. Now they can
go to caches directly rather than needing to go to authorities
to bootstrap the first set of descriptors.
- When picking a random directory, prefer non-authorities if any
are known.
- Add a new flag to network-status indicating whether the server
can answer v2 directory requests too.
- Directory mirrors now cache up to 16 unrecognized network-status
docs, so new directory authorities will be cached too.
- Stop parsing, storing, or using running-routers output (but
mirrors still cache and serve it).
- Clients consider a threshold of "versioning" directory authorities
before deciding whether to warn the user that he's obsolete.
- Authorities publish separate sorted lists of recommended versions
for clients and for servers.
- Change DirServers config line to note which dirs are v1 authorities.
- Put nicknames on the DirServer line, so we can refer to them
without requiring all our users to memorize their IP addresses.
- Remove option when getting directory cache to see whether they
support running-routers; they all do now. Replace it with one
to see whether caches support v2 stuff.
- Stop listing down or invalid nodes in the v1 directory. This
reduces its bulk by about 1/3, and reduces load on mirrors.
- Mirrors no longer cache the v1 directory as often.
- If we as a directory mirror don't know of any v1 directory
authorities, then don't try to cache any v1 directories.
o Other directory improvements:
- Add lefkada.eecs.harvard.edu and tor.dizum.com as fourth and
fifth authoritative directory servers.
- Directory authorities no longer require an open connection from
a server to consider him "reachable". We need this change because
when we add new directory authorities, old servers won't know not
to hang up on them.
- Dir authorities now do their own external reachability testing
of each server, and only list as running the ones they found to
be reachable. We also send back warnings to the server's logs if
it uploads a descriptor that we already believe is unreachable.
- Spread the directory authorities' reachability testing over the
entire testing interval, so we don't try to do 500 TLS's at once
every 20 minutes.
- Make the "stable" router flag in network-status be the median of
the uptimes of running valid servers, and make clients pay
attention to the network-status flags. Thus the cutoff adapts
to the stability of the network as a whole, making IRC, IM, etc
connections more reliable.
- Make the v2 dir's "Fast" flag based on relative capacity, just
like "Stable" is based on median uptime. Name everything in the
top 7/8 Fast, and only the top 1/2 gets to be a Guard.
- Retry directory requests if we fail to get an answer we like
from a given dirserver (we were retrying before, but only if
we fail to connect).
- Return a robots.txt on our dirport to discourage google indexing.
o Controller protocol improvements:
- Revised controller protocol (version 1) that uses ascii rather
than binary: tor/doc/control-spec.txt. Add supporting libraries
in python and java and c# so you can use the controller from your
applications without caring how our protocol works.
- Allow the DEBUG controller event to work again. Mark certain log
entries as "don't tell this to controllers", so we avoid cycles.
- New controller function "getinfo accounting", to ask how
many bytes we've used in this time period.
- Add a "resetconf" command so you can set config options like
AllowUnverifiedNodes and LongLivedPorts to "". Also, if you give
a config option in the torrc with no value, then it clears it
entirely (rather than setting it to its default).
- Add a "getinfo config-file" to tell us where torrc is. Also
expose guard nodes, config options/names.
- Add a "quit" command (when when using the controller manually).
- Add a new signal "newnym" to "change pseudonyms" -- that is, to
stop using any currently-dirty circuits for new streams, so we
don't link new actions to old actions. This also occurs on HUP
or "signal reload".
- If we would close a stream early (e.g. it asks for a .exit that
we know would refuse it) but the LeaveStreamsUnattached config
option is set by the controller, then don't close it.
- Add a new controller event type "authdir_newdescs" that allows
controllers to get all server descriptors that were uploaded to
a router in its role as directory authority.
- New controller option "getinfo desc/all-recent" to fetch the
latest server descriptor for every router that Tor knows about.
- Fix the controller's "attachstream 0" command to treat conn like
it just connected, doing address remapping, handling .exit and
.onion idioms, and so on. Now we're more uniform in making sure
that the controller hears about new and closing connections.
- Permit transitioning from ORPort==0 to ORPort!=0, and back, from
the controller. Also, rotate dns and cpu workers if the controller
changes options that will affect them; and initialize the dns
worker cache tree whether or not we start out as a server.
- Add a new circuit purpose 'controller' to let the controller ask
for a circuit that Tor won't try to use. Extend the "extendcircuit"
controller command to let you specify the purpose if you're starting
a new circuit. Add a new "setcircuitpurpose" controller command to
let you change a circuit's purpose after it's been created.
- Let the controller ask for "getinfo dir/server/foo" so it can ask
directly rather than connecting to the dir port. "getinfo
dir/status/foo" also works, but currently only if your DirPort
is enabled.
- Let the controller tell us about certain router descriptors
that it doesn't want Tor to use in circuits. Implement
"setrouterpurpose" and modify "+postdescriptor" to do this.
- If the controller's *setconf commands fail, collect an error
message in a string and hand it back to the controller -- don't
just tell them to go read their logs.
o Scalability, resource management, and performance:
- Fix a major load balance bug: we were round-robin reading in 16 KB
chunks, and servers with bandwidthrate of 20 KB, while downloading
a 600 KB directory, would starve their other connections. Now we
try to be a bit more fair.
- Be more conservative about whether to advertise our DirPort.
The main change is to not advertise if we're running at capacity
and either a) we could hibernate ever or b) our capacity is low
and we're using a default DirPort.
- We weren't cannibalizing circuits correctly for
CIRCUIT_PURPOSE_C_ESTABLISH_REND and
CIRCUIT_PURPOSE_S_ESTABLISH_INTRO, so we were being forced to
build those from scratch. This should make hidden services faster.
- Predict required circuits better, with an eye toward making hidden
services faster on the service end.
- Compress exit policies even more: look for duplicate lines and
remove them.
- Generate 18.0.0.0/8 address policy format in descs when we can;
warn when the mask is not reducible to a bit-prefix.
- There used to be two ways to specify your listening ports in a
server descriptor: on the "router" line and with a separate "ports"
line. Remove support for the "ports" line.
- Reduce memory requirements in our structs by changing the order
of fields. Replace balanced trees with hash tables. Inline
bottleneck smartlist functions. Add a "Map from digest to void*"
abstraction so we can do less hex encoding/decoding, and use it
in router_get_by_digest(). Many other CPU and memory improvements.
- Allow tor_gzip_uncompress to extract as much as possible from
truncated compressed data. Try to extract as many
descriptors as possible from truncated http responses (when
purpose is DIR_PURPOSE_FETCH_ROUTERDESC).
- Make circ->onionskin a pointer, not a static array. moria2 was using
125000 circuit_t's after it had been up for a few weeks, which
translates to 20+ megs of wasted space.
- The private half of our EDH handshake keys are now chosen out
of 320 bits, not 1024 bits. (Suggested by Ian Goldberg.)
- Stop doing the complex voodoo overkill checking for insecure
Diffie-Hellman keys. Just check if it's in [2,p-2] and be happy.
- Do round-robin writes for TLS of at most 16 kB per write. This
might be more fair on loaded Tor servers.
- Do not use unaligned memory access on alpha, mips, or mipsel.
It *works*, but is very slow, so we treat them as if it doesn't.
o Other bugfixes and improvements:
- Start storing useful information to $DATADIR/state, so we can
remember things across invocations of Tor. Retain unrecognized
lines so we can be forward-compatible, and write a TorVersion line
so we can be backward-compatible.
- If ORPort is set, Address is not explicitly set, and our hostname
resolves to a private IP address, try to use an interface address
if it has a public address. Now Windows machines that think of
themselves as localhost can guess their address.
- Regenerate our local descriptor if it's dirty and we try to use
it locally (e.g. if it changes during reachability detection).
This was causing some Tor servers to keep publishing the same
initial descriptor forever.
- Tor servers with dynamic IP addresses were needing to wait 18
hours before they could start doing reachability testing using
the new IP address and ports. This is because they were using
the internal descriptor to learn what to test, yet they were only
rebuilding the descriptor once they decided they were reachable.
- It turns out we couldn't bootstrap a network since we added
reachability detection in 0.1.0.1-rc. Good thing the Tor network
has never gone down. Add an AssumeReachable config option to let
servers and authorities bootstrap. When we're trying to build a
high-uptime or high-bandwidth circuit but there aren't enough
suitable servers, try being less picky rather than simply failing.
- Newly bootstrapped Tor networks couldn't establish hidden service
circuits until they had nodes with high uptime. Be more tolerant.
- Really busy servers were keeping enough circuits open on stable
connections that they were wrapping around the circuit_id
space. (It's only two bytes.) This exposed a bug where we would
feel free to reuse a circuit_id even if it still exists but has
been marked for close. Try to fix this bug. Some bug remains.
- When we fail to bind or listen on an incoming or outgoing
socket, we now close it before refusing, rather than just
leaking it. (Thanks to Peter Palfrader for finding.)
- Fix a file descriptor leak in start_daemon().
- On Windows, you can't always reopen a port right after you've
closed it. So change retry_listeners() to only close and re-open
ports that have changed.
- Workaround a problem with some http proxies that refuse GET
requests that specify "Content-Length: 0". Reported by Adrian.
- Recover better from TCP connections to Tor servers that are
broken but don't tell you (it happens!); and rotate TLS
connections once a week.
- Fix a scary-looking but apparently harmless bug where circuits
would sometimes start out in state CIRCUIT_STATE_OR_WAIT at
servers, and never switch to state CIRCUIT_STATE_OPEN.
- Check for even more Windows version flags when writing the platform
string in server descriptors, and note any we don't recognize.
- Add reasons to DESTROY and RELAY_TRUNCATED cells, so clients can
get a better idea of why their circuits failed. Not used yet.
- Add TTLs to RESOLVED, CONNECTED, and END_REASON_EXITPOLICY cells.
We don't use them yet, but maybe one day our DNS resolver will be
able to discover them.
- Let people type "tor --install" as well as "tor -install" when they
want to make it an NT service.
- Looks like we were never delivering deflated (i.e. compressed)
running-routers lists, even when asked. Oops.
- We were leaking some memory every time the client changed IPs.
- Clean up more of the OpenSSL memory when exiting, so we can detect
memory leaks better.
- Never call free() on tor_malloc()d memory. This will help us
use dmalloc to detect memory leaks.
- Some Tor servers process billions of cells per day. These
statistics are now uint64_t's.
- Check [X-]Forwarded-For headers in HTTP requests when generating
log messages. This lets people run dirservers (and caches) behind
Apache but still know which IP addresses are causing warnings.
- Fix minor integer overflow in calculating when we expect to use up
our bandwidth allocation before hibernating.
- Lower the minimum required number of file descriptors to 1000,
so we can have some overhead for Valgrind on Linux, where the
default ulimit -n is 1024.
- Stop writing the "router.desc" file, ever. Nothing uses it anymore,
and its existence is confusing some users.
o Config option fixes:
- Add a new config option ExitPolicyRejectPrivate which defaults
to on. Now all exit policies will begin with rejecting private
addresses, unless the server operator explicitly turns it off.
- Bump the default bandwidthrate to 3 MB, and burst to 6 MB.
- Add new ReachableORAddresses and ReachableDirAddresses options
that understand address policies. FascistFirewall is now a synonym
for "ReachableORAddresses *:443", "ReachableDirAddresses *:80".
- Start calling it FooListenAddress rather than FooBindAddress,
since few of our users know what it means to bind an address
or port.
- If the user gave Tor an odd number of command-line arguments,
we were silently ignoring the last one. Now we complain and fail.
This wins the oldest-bug prize -- this bug has been present since
November 2002, as released in Tor 0.0.0.
- If you write "HiddenServicePort 6667 127.0.0.1 6668" in your
torrc rather than "HiddenServicePort 6667 127.0.0.1:6668",
it would silently ignore the 6668.
- If we get a linelist or linelist_s config option from the torrc,
e.g. ExitPolicy, and it has no value, warn and skip rather than
silently resetting it to its default.
- Setconf was appending items to linelists, not clearing them.
- Add MyFamily to torrc.sample in the server section, so operators
will be more likely to learn that it exists.
- Make ContactInfo mandatory for authoritative directory servers.
- MaxConn has been obsolete for a while now. Document the ConnLimit
config option, which is a *minimum* number of file descriptors
that must be available else Tor refuses to start.
- Get rid of IgnoreVersion undocumented config option, and make us
only warn, never exit, when we're running an obsolete version.
- Make MonthlyAccountingStart config option truly obsolete now.
- Correct the man page entry on TrackHostExitsExpire.
- Let directory authorities start even if they don't specify an
Address config option.
- Change "AllowUnverifiedNodes" to "AllowInvalidNodes", to
reflect the updated flags in our v2 dir protocol.
o Config option features:
- Add a new config option FastFirstHopPK (on by default) so clients
do a trivial crypto handshake for their first hop, since TLS has
already taken care of confidentiality and authentication.
- Let the user set ControlListenAddress in the torrc. This can be
dangerous, but there are some cases (like a secured LAN) where it
makes sense.
- New config options to help controllers: FetchServerDescriptors
and FetchHidServDescriptors for whether to fetch server
info and hidserv info or let the controller do it, and
PublishServerDescriptor and PublishHidServDescriptors.
- Also let the controller set the __AllDirActionsPrivate config
option if you want all directory fetches/publishes to happen via
Tor (it assumes your controller bootstraps your circuits).
- Add "HardwareAccel" config option: support for crypto hardware
accelerators via OpenSSL. Off by default, until we find somebody
smart who can test it for us. (It appears to produce seg faults
in at least some cases.)
- New config option "AuthDirRejectUnlisted" for directory authorities
as a panic button: if we get flooded with unusable servers we can
revert to only listing servers in the approved-routers file.
- Directory authorities can now reject/invalidate by key and IP,
with the config options "AuthDirInvalid" and "AuthDirReject", or
by marking a fingerprint as "!reject" or "!invalid" (as its
nickname) in the approved-routers file. This is useful since
currently we automatically list servers as running and usable
even if we know they're jerks.
- Add a new config option TestSocks so people can see whether their
applications are using socks4, socks4a, socks5-with-ip, or
socks5-with-fqdn. This way they don't have to keep mucking
with tcpdump and wondering if something got cached somewhere.
- Add "private:*" as an alias in configuration for policies. Now
you can simplify your exit policy rather than needing to list
every single internal or nonroutable network space.
- Accept "private:*" in routerdesc exit policies; not generated yet
because older Tors do not understand it.
- Add configuration option "V1AuthoritativeDirectory 1" which
moria1, moria2, and tor26 have set.
- Implement an option, VirtualAddrMask, to set which addresses
get handed out in response to mapaddress requests. This works
around a bug in tsocks where 127.0.0.0/8 is never socksified.
- Add a new config option FetchUselessDescriptors, off by default,
for when you plan to run "exitlist" on your client and you want
to know about even the non-running descriptors.
- SocksTimeout: How long do we let a socks connection wait
unattached before we fail it?
- CircuitBuildTimeout: Cull non-open circuits that were born
at least this many seconds ago.
- CircuitIdleTimeout: Cull open clean circuits that were born
at least this many seconds ago.
- New config option SafeSocks to reject all application connections
using unsafe socks protocols. Defaults to off.
o Improved and clearer log messages:
- Reduce clutter in server logs. We're going to try to make
them actually usable now. New config option ProtocolWarnings that
lets you hear about how _other Tors_ are breaking the protocol. Off
by default.
- Divide log messages into logging domains. Once we put some sort
of interface on this, it will let people looking at more verbose
log levels specify the topics they want to hear more about.
- Log server fingerprint on startup, so new server operators don't
have to go hunting around their filesystem for it.
- Provide dire warnings to any users who set DirServer manually;
move it out of torrc.sample and into torrc.complete.
- Make the log message less scary when all the dirservers are
temporarily unreachable.
- When tor_socketpair() fails in Windows, give a reasonable
Windows-style errno back.
- Improve tor_gettimeofday() granularity on windows.
- We were printing the number of idle dns workers incorrectly when
culling them.
- Handle duplicate lines in approved-routers files without warning.
- We were whining about using socks4 or socks5-with-local-lookup
even when it's an IP address in the "virtual" range we designed
exactly for this case.
- Check for named servers when looking them up by nickname;
warn when we're calling a non-named server by its nickname;
don't warn twice about the same name.
- Downgrade the dirserver log messages when whining about
unreachability.
- Correct "your server is reachable" log entries to indicate that
it was self-testing that told us so.
- If we're trying to be a Tor server and running Windows 95/98/ME
as a server, explain that we'll likely crash.
- Provide a more useful warn message when our onion queue gets full:
the CPU is too slow or the exit policy is too liberal.
- Don't warn when we receive a 503 from a dirserver/cache -- this
will pave the way for them being able to refuse if they're busy.
- When we fail to bind a listener, try to provide a more useful
log message: e.g., "Is Tor already running?"
- Only start testing reachability once we've established a
circuit. This will make startup on dir authorities less noisy.
- Don't try to upload hidden service descriptors until we have
established a circuit.
- Tor didn't warn when it failed to open a log file.
- Warn when listening on a public address for socks. We suspect a
lot of people are setting themselves up as open socks proxies,
and they have no idea that jerks on the Internet are using them,
since they simply proxy the traffic into the Tor network.
- Give a useful message when people run Tor as the wrong user,
rather than telling them to start chowning random directories.
- Fix a harmless bug that was causing Tor servers to log
"Got an end because of misc error, but we're not an AP. Closing."
- Fix wrong log message when you add a "HiddenServiceNodes" config
line without any HiddenServiceDir line (reported by Chris Thomas).
- Directory authorities now stop whining so loudly about bad
descriptors that they fetch from other dirservers. So when there's
a log complaint, it's for sure from a freshly uploaded descriptor.
- When logging via syslog, include the pid whenever we provide
a log entry. Suggested by Todd Fries.
- When we're shutting down and we do something like try to post a
server descriptor or rendezvous descriptor, don't complain that
we seem to be unreachable. Of course we are, we're shutting down.
- Change log line for unreachability to explicitly suggest /etc/hosts
as the culprit. Also make it clearer what IP address and ports we're
testing for reachability.
- Put quotes around user-supplied strings when logging so users are
more likely to realize if they add bad characters (like quotes)
to the torrc.
- NT service patch from Matt Edman to improve error messages on Win32.
Changes in version 0.1.0.17 - 2006-02-17
o Crash bugfixes on 0.1.0.x:
- When servers with a non-zero DirPort came out of hibernation,
sometimes they would trigger an assert.
o Other important bugfixes:
- On platforms that don't have getrlimit (like Windows), we were
artificially constraining ourselves to a max of 1024
connections. Now just assume that we can handle as many as 15000
connections. Hopefully this won't cause other problems.
o Backported features:
- When we're a server, a client asks for an old-style directory,
and our write bucket is empty, don't give it to him. This way
small servers can continue to serve the directory *sometimes*,
without getting overloaded.
- Whenever you get a 503 in response to a directory fetch, try
once more. This will become important once servers start sending
503's whenever they feel busy.
- Fetch a new directory every 120 minutes, not every 40 minutes.
Now that we have hundreds of thousands of users running the old
directory algorithm, it's starting to hurt a lot.
- Bump up the period for forcing a hidden service descriptor upload
from 20 minutes to 1 hour.
Changes in version 0.1.0.16 - 2006-01-02
o Crash bugfixes on 0.1.0.x:
- On Windows, build with a libevent patch from "I-M Weasel" to avoid
corrupting the heap, losing FDs, or crashing when we need to resize
the fd_sets. (This affects the Win32 binaries, not Tor's sources.)
- It turns out sparc64 platforms crash on unaligned memory access
too -- so detect and avoid this.
- Handle truncated compressed data correctly (by detecting it and
giving an error).
- Fix possible-but-unlikely free(NULL) in control.c.
- When we were closing connections, there was a rare case that
stomped on memory, triggering seg faults and asserts.
- Avoid potential infinite recursion when building a descriptor. (We
don't know that it ever happened, but better to fix it anyway.)
- We were neglecting to unlink marked circuits from soon-to-close OR
connections, which caused some rare scribbling on freed memory.
- Fix a memory stomping race bug when closing the joining point of two
rendezvous circuits.
- Fix an assert in time parsing found by Steven Murdoch.
o Other bugfixes on 0.1.0.x:
- When we're doing reachability testing, provide more useful log
messages so the operator knows what to expect.
- Do not check whether DirPort is reachable when we are suppressing
advertising it because of hibernation.
- When building with -static or on Solaris, we sometimes needed -ldl.
- One of the dirservers (tor26) changed its IP address.
- When we're deciding whether a stream has enough circuits around
that can handle it, count the freshly dirty ones and not the ones
that are so dirty they won't be able to handle it.
- When we're expiring old circuits, we had a logic error that caused
us to close new rendezvous circuits rather than old ones.
- Give a more helpful log message when you try to change ORPort via
the controller: you should upgrade Tor if you want that to work.
- We were failing to parse Tor versions that start with "Tor ".
- Tolerate faulty streams better: when a stream fails for reason
exitpolicy, stop assuming that the router is lying about his exit
policy. When a stream fails for reason misc, allow it to retry just
as if it was resolvefailed. When a stream has failed three times,
reset its failure count so we can try again and get all three tries.
Changes in version 0.1.0.15 - 2005-09-23
o Bugfixes on 0.1.0.x:
- Reject ports 465 and 587 (spam targets) in default exit policy.
- Don't crash when we don't have any spare file descriptors and we
try to spawn a dns or cpu worker.
- Get rid of IgnoreVersion undocumented config option, and make us
only warn, never exit, when we're running an obsolete version.
- Don't try to print a null string when your server finds itself to
be unreachable and the Address config option is empty.
- Make the numbers in read-history and write-history into uint64s,
so they don't overflow and publish negatives in the descriptor.
- Fix a minor memory leak in smartlist_string_remove().
- We were only allowing ourselves to upload a server descriptor at
most every 20 minutes, even if it changed earlier than that.
- Clean up log entries that pointed to old URLs.
Changes in version 0.1.0.14 - 2005-08-08
o Bugfixes on 0.1.0.x:
- Fix the other half of the bug with crypto handshakes
(CVE-2005-2643).
- Fix an assert trigger if you send a 'signal term' via the
controller when it's listening for 'event info' messages.
Changes in version 0.1.0.13 - 2005-08-04
o Bugfixes on 0.1.0.x:
- Fix a critical bug in the security of our crypto handshakes.
- Fix a size_t underflow in smartlist_join_strings2() that made
it do bad things when you hand it an empty smartlist.
- Fix Windows installer to ship Tor license (thanks to Aphex for
pointing out this oversight) and put a link to the doc directory
in the start menu.
- Explicitly set no-unaligned-access for sparc: it turns out the
new gcc's let you compile broken code, but that doesn't make it
not-broken.
Changes in version 0.1.0.12 - 2005-07-18
o New directory servers:
- tor26 has changed IP address.
o Bugfixes on 0.1.0.x:
- Fix a possible double-free in tor_gzip_uncompress().
- When --disable-threads is set, do not search for or link against
pthreads libraries.
- Don't trigger an assert if an authoritative directory server
claims its dirport is 0.
- Fix bug with removing Tor as an NT service: some people were
getting "The service did not return an error." Thanks to Matt
Edman for the fix.
Changes in version 0.1.0.11 - 2005-06-30
o Bugfixes on 0.1.0.x:
- Fix major security bug: servers were disregarding their
exit policies if clients behaved unexpectedly.
- Make OS X init script check for missing argument, so we don't
confuse users who invoke it incorrectly.
- Fix a seg fault in "tor --hash-password foo".
- The MAPADDRESS control command was broken.
Changes in version 0.1.0.10 - 2005-06-14
o Fixes on Win32:
- Make NT services work and start on startup on Win32 (based on
patch by Matt Edman). See the FAQ entry for details.
- Make 'platform' string in descriptor more accurate for Win32
servers, so it's not just "unknown platform".
- REUSEADDR on normal platforms means you can rebind to the port
right after somebody else has let it go. But REUSEADDR on Win32
means you can bind to the port _even when somebody else already
has it bound_! So, don't do that on Win32.
- Clean up the log messages when starting on Win32 with no config
file.
- Allow seeding the RNG on Win32 even when you're not running as
Administrator. If seeding the RNG on Win32 fails, quit.
o Assert / crash bugs:
- Refuse relay cells that claim to have a length larger than the
maximum allowed. This prevents a potential attack that could read
arbitrary memory (e.g. keys) from an exit server's process
(CVE-2005-2050).
- If unofficial Tor clients connect and send weird TLS certs, our
Tor server triggers an assert. Stop asserting, and start handling
TLS errors better in other situations too.
- Fix a race condition that can trigger an assert when we have a
pending create cell and an OR connection attempt fails.
o Resource leaks:
- Use pthreads for worker processes rather than forking. This was
forced because when we forked, we ended up wasting a lot of
duplicate ram over time.
- Also switch to foo_r versions of some library calls to allow
reentry and threadsafeness.
- Implement --disable-threads configure option. Disable threads on
netbsd and openbsd by default, because they have no reentrant
resolver functions (!), and on solaris since it has other
threading issues.
- Fix possible bug on threading platforms (e.g. win32) which was
leaking a file descriptor whenever a cpuworker or dnsworker died.
- Fix a minor memory leak when somebody establishes an introduction
point at your Tor server.
- Fix possible memory leak in tor_lookup_hostname(). (Thanks to
Adam Langley.)
- Add ./configure --with-dmalloc option, to track memory leaks.
- And try to free all memory on closing, so we can detect what
we're leaking.
o Protocol correctness:
- When we've connected to an OR and handshaked but didn't like
the result, we were closing the conn without sending destroy
cells back for pending circuits. Now send those destroys.
- Start sending 'truncated' cells back rather than destroy cells
if the circuit closes in front of you. This means we won't have
to abandon partially built circuits.
- Handle changed router status correctly when dirserver reloads
fingerprint file. We used to be dropping all unverified descriptors
right then. The bug was hidden because we would immediately
fetch a directory from another dirserver, which would include the
descriptors we just dropped.
- Revise tor-spec to add more/better stream end reasons.
- Revise all calls to connection_edge_end to avoid sending 'misc',
and to take errno into account where possible.
- Client now retries when streams end early for 'hibernating' or
'resource limit' reasons, rather than failing them.
- Try to be more zealous about calling connection_edge_end when
things go bad with edge conns in connection.c.
o Robustness improvements:
- Better handling for heterogeneous / unreliable nodes:
- Annotate circuits with whether they aim to contain high uptime
nodes and/or high capacity nodes. When building circuits, choose
appropriate nodes.
- This means that every single node in an intro rend circuit,
not just the last one, will have a minimum uptime.
- New config option LongLivedPorts to indicate application streams
that will want high uptime circuits.
- Servers reset uptime when a dir fetch entirely fails. This
hopefully reflects stability of the server's network connectivity.
- If somebody starts his tor server in Jan 2004 and then fixes his
clock, don't make his published uptime be a year.
- Reset published uptime when we wake up from hibernation.
- Introduce a notion of 'internal' circs, which are chosen without
regard to the exit policy of the last hop. Intro and rendezvous
circs must be internal circs, to avoid leaking information. Resolve
and connect streams can use internal circs if they want.
- New circuit pooling algorithm: keep track of what destination ports
we've used recently (start out assuming we'll want to use 80), and
make sure to have enough circs around to satisfy these ports. Also
make sure to have 2 internal circs around if we've required internal
circs lately (and with high uptime if we've seen that lately too).
- Turn addr_policy_compare from a tristate to a quadstate; this should
help address our "Ah, you allow 1.2.3.4:80. You are a good choice
for google.com" problem.
- When a client asks us for a dir mirror and we don't have one,
launch an attempt to get a fresh one.
- First cut at support for "create-fast" cells. Clients can use
these when extending to their first hop, since the TLS already
provides forward secrecy and authentication. Not enabled on
clients yet.
o Reachability testing.
- Your Tor server will automatically try to see if its ORPort and
DirPort are reachable from the outside, and it won't upload its
descriptor until it decides at least ORPort is reachable (when
DirPort is not yet found reachable, publish it as zero).
- When building testing circs for ORPort testing, use only
high-bandwidth nodes, so fewer circuits fail.
- Notice when our IP changes, and reset stats/uptime/reachability.
- Authdirservers don't do ORPort reachability detection, since
they're in clique mode, so it will be rare to find a server not
already connected to them.
- Authdirservers now automatically approve nodes running 0.1.0.2-rc
or later.
o Dirserver fixes:
- Now we allow two unverified servers with the same nickname
but different keys. But if a nickname is verified, only that
nickname+key are allowed.
- If you're an authdirserver connecting to an address:port,
and it's not the OR you were expecting, forget about that
descriptor. If he *was* the one you were expecting, then forget
about all other descriptors for that address:port.
- Allow servers to publish descriptors from 12 hours in the future.
Corollary: only whine about clock skew from the dirserver if
he's a trusted dirserver (since now even verified servers could
have quite wrong clocks).
- Require servers that use the default dirservers to have public IP
addresses. We have too many servers that are configured with private
IPs and their admins never notice the log entries complaining that
their descriptors are being rejected.
o Efficiency improvements:
- Use libevent. Now we can use faster async cores (like epoll, kpoll,
and /dev/poll), and hopefully work better on Windows too.
- Apple's OS X 10.4.0 ships with a broken kqueue API, and using
kqueue on 10.3.9 causes kernel panics. Don't use kqueue on OS X.
- Find libevent even if it's hiding in /usr/local/ and your
CFLAGS and LDFLAGS don't tell you to look there.
- Be able to link with libevent as a shared library (the default
after 1.0d), even if it's hiding in /usr/local/lib and even
if you haven't added /usr/local/lib to your /etc/ld.so.conf,
assuming you're running gcc. Otherwise fail and give a useful
error message.
- Switch to a new buffer management algorithm, which tries to avoid
reallocing and copying quite as much. In first tests it looks like
it uses *more* memory on average, but less cpu.
- Switch our internal buffers implementation to use a ring buffer,
to hopefully improve performance for fast servers a lot.
- Reenable the part of the code that tries to flush as soon as an
OR outbuf has a full TLS record available. Perhaps this will make
OR outbufs not grow as huge except in rare cases, thus saving lots
of CPU time plus memory.
- Improve performance for dirservers: stop re-parsing the whole
directory every time you regenerate it.
- Keep a big splay tree of (circid,orconn)->circuit mappings to make
it much faster to look up a circuit for each relay cell.
- Remove most calls to assert_all_pending_dns_resolves_ok(),
since they're eating our cpu on exit nodes.
- Stop wasting time doing a case insensitive comparison for every
dns name every time we do any lookup. Canonicalize the names to
lowercase when you first see them.
o Hidden services:
- Handle unavailable hidden services better. Handle slow or busy
hidden services better.
- Cannibalize GENERAL circs to be C_REND, C_INTRO, S_INTRO, and S_REND
circ as necessary, if there are any completed ones lying around
when we try to launch one.
- Make hidden services try to establish a rendezvous for 30 seconds
after fetching the descriptor, rather than for n (where n=3)
attempts to build a circuit.
- Adjust maximum skew and age for rendezvous descriptors: let skew
be 48 hours rather than 90 minutes.
- Reject malformed .onion addresses rather then passing them on as
normal web requests.
o Controller:
- More Tor controller support. See
http://tor.eff.org/doc/control-spec.txt for all the new features,
including signals to emulate unix signals from any platform;
redirectstream; extendcircuit; mapaddress; getinfo; postdescriptor;
closestream; closecircuit; etc.
- Encode hashed controller passwords in hex instead of base64,
to make it easier to write controllers.
- Revise control spec and implementation to allow all log messages to
be sent to controller with their severities intact (suggested by
Matt Edman). Disable debug-level logs while delivering a debug-level
log to the controller, to prevent loop. Update TorControl to handle
new log event types.
o New config options/defaults:
- Begin scrubbing sensitive strings from logs by default. Turn off
the config option SafeLogging if you need to do debugging.
- New exit policy: accept most low-numbered ports, rather than
rejecting most low-numbered ports.
- Put a note in the torrc about abuse potential with the default
exit policy.
- Add support for CONNECTing through https proxies, with "HttpsProxy"
config option.
- Add HttpProxyAuthenticator and HttpsProxyAuthenticator support
based on patch from Adam Langley (basic auth only).
- Bump the default BandwidthRate from 1 MB to 2 MB, to accommodate
the fast servers that have been joining lately. (Clients are now
willing to load balance over up to 2 MB of advertised bandwidth
capacity too.)
- New config option MaxAdvertisedBandwidth which lets you advertise
a low bandwidthrate (to not attract as many circuits) while still
allowing a higher bandwidthrate in reality.
- Require BandwidthRate to be at least 20kB/s for servers.
- Add a NoPublish config option, so you can be a server (e.g. for
testing running Tor servers in other Tor networks) without
publishing your descriptor to the primary dirservers.
- Add a new AddressMap config directive to rewrite incoming socks
addresses. This lets you, for example, declare an implicit
required exit node for certain sites.
- Add a new TrackHostExits config directive to trigger addressmaps
for certain incoming socks addresses -- for sites that break when
your exit keeps changing (based on patch from Mike Perry).
- Split NewCircuitPeriod option into NewCircuitPeriod (30 secs),
which describes how often we retry making new circuits if current
ones are dirty, and MaxCircuitDirtiness (10 mins), which describes
how long we're willing to make use of an already-dirty circuit.
- Change compiled-in SHUTDOWN_WAIT_LENGTH from a fixed 30 secs to
a config option "ShutdownWaitLength" (when using kill -INT on
servers).
- Fix an edge case in parsing config options: if they say "--"
on the commandline, it's not a config option (thanks weasel).
- New config option DirAllowPrivateAddresses for authdirservers.
Now by default they refuse router descriptors that have non-IP or
private-IP addresses.
- Change DirFetchPeriod/StatusFetchPeriod to have a special "Be
smart" default value: low for servers and high for clients.
- Some people were putting "Address " in their torrc, and they had
a buggy resolver that resolved " " to 0.0.0.0. Oops.
- If DataDir is ~/.tor, and that expands to /.tor, then default to
LOCALSTATEDIR/tor instead.
- Implement --verify-config command-line option to check if your torrc
is valid without actually launching Tor.
o Logging improvements:
- When dirservers refuse a server descriptor, we now log its
contactinfo, platform, and the poster's IP address.
- Only warn once per nickname from add_nickname_list_to_smartlist()
per failure, so an entrynode or exitnode choice that's down won't
yell so much.
- When we're connecting to an OR and he's got a different nickname/key
than we were expecting, only complain loudly if we're an OP or a
dirserver. Complaining loudly to the OR admins just confuses them.
- Whine at you if you're a server and you don't set your contactinfo.
- Warn when exit policy implicitly allows local addresses.
- Give a better warning when some other server advertises an
ORPort that is actually an apache running ssl.
- If we get an incredibly skewed timestamp from a dirserver mirror
that isn't a verified OR, don't warn -- it's probably him that's
wrong.
- When a dirserver causes you to give a warn, mention which dirserver
it was.
- Initialize libevent later in the startup process, so the logs are
already established by the time we start logging libevent warns.
- Use correct errno on win32 if libevent fails.
- Check and warn about known-bad/slow libevent versions.
- Stop warning about sigpipes in the logs. We're going to
pretend that getting these occassionally is normal and fine.
o New contrib scripts:
- New experimental script tor/contrib/exitlist: a simple python
script to parse directories and find Tor nodes that exit to listed
addresses/ports.
- New experimental script tor/contrib/ExerciseServer.py (needs more
work) that uses the controller interface to build circuits and
fetch pages over them. This will help us bootstrap servers that
have lots of capacity but haven't noticed it yet.
- New experimental script tor/contrib/PathDemo.py (needs more work)
that uses the controller interface to let you choose whole paths
via addresses like
"<hostname>.<path,separated by dots>.<length of path>.path"
- New contributed script "privoxy-tor-toggle" to toggle whether
Privoxy uses Tor. Seems to be configured for Debian by default.
- Have torctl.in/tor.sh.in check for location of su binary (needed
on FreeBSD)
o Misc bugfixes:
- chdir() to your datadirectory at the *end* of the daemonize process,
not the beginning. This was a problem because the first time you
run tor, if your datadir isn't there, and you have runasdaemon set
to 1, it will try to chdir to it before it tries to create it. Oops.
- Fix several double-mark-for-close bugs, e.g. where we were finding
a conn for a cell even if that conn is already marked for close.
- Stop most cases of hanging up on a socks connection without sending
the socks reject.
- Fix a bug in the RPM package: set home directory for _tor to
something more reasonable when first installing.
- Stop putting nodename in the Platform string in server descriptors.
It doesn't actually help, and it is confusing/upsetting some people.
- When using preferred entry or exit nodes, ignore whether the
circuit wants uptime or capacity. They asked for the nodes, they
get the nodes.
- Tie MAX_DIR_SIZE to MAX_BUF_SIZE, so now directory sizes won't get
artificially capped at 500kB.
- Cache local dns resolves correctly even when they're .exit
addresses.
- If we're hibernating and we get a SIGINT, exit immediately.
- tor-resolve requests were ignoring .exit if there was a working circuit
they could use instead.
- Pay more attention to the ClientOnly config option.
- Resolve OS X installer bugs: stop claiming to be 0.0.9.2 in certain
installer screens; and don't put stuff into StartupItems unless
the user asks you to.
o Misc features:
- Rewrite address "serifos.exit" to "externalIP.serifos.exit"
rather than just rejecting it.
- If our clock jumps forward by 100 seconds or more, assume something
has gone wrong with our network and abandon all not-yet-used circs.
- When an application is using socks5, give him the whole variety of
potential socks5 responses (connect refused, host unreachable, etc),
rather than just "success" or "failure".
- A more sane version numbering system. See
http://tor.eff.org/cvs/tor/doc/version-spec.txt for details.
- Change version parsing logic: a version is "obsolete" if it is not
recommended and (1) there is a newer recommended version in the
same series, or (2) there are no recommended versions in the same
series, but there are some recommended versions in a newer series.
A version is "new" if it is newer than any recommended version in
the same series.
- Report HTTP reasons to client when getting a response from directory
servers -- so you can actually know what went wrong.
- Reject odd-looking addresses at the client (e.g. addresses that
contain a colon), rather than having the server drop them because
they're malformed.
- Stop publishing socksport in the directory, since it's not
actually meant to be public. For compatibility, publish a 0 there
for now.
- Since we ship our own Privoxy on OS X, tweak it so it doesn't write
cookies to disk and doesn't log each web request to disk. (Thanks
to Brett Carrington for pointing this out.)
- Add OSX uninstall instructions. An actual uninstall script will
come later.
- Add "opt hibernating 1" to server descriptor to make it clearer
whether the server is hibernating.
Changes in version 0.0.9.10 - 2005-06-16
o Bugfixes on 0.0.9.x (backported from 0.1.0.10):
- Refuse relay cells that claim to have a length larger than the
maximum allowed. This prevents a potential attack that could read
arbitrary memory (e.g. keys) from an exit server's process
(CVE-2005-2050).
Changes in version 0.0.9.9 - 2005-04-23
o Bugfixes on 0.0.9.x:
- If unofficial Tor clients connect and send weird TLS certs, our
Tor server triggers an assert. This release contains a minimal
backport from the broader fix that we put into 0.1.0.4-rc.
Changes in version 0.0.9.8 - 2005-04-07
o Bugfixes on 0.0.9.x:
- We have a bug that I haven't found yet. Sometimes, very rarely,
cpuworkers get stuck in the 'busy' state, even though the cpuworker
thinks of itself as idle. This meant that no new circuits ever got
established. Here's a workaround to kill any cpuworker that's been
busy for more than 100 seconds.
Changes in version 0.0.9.7 - 2005-04-01
o Bugfixes on 0.0.9.x:
- Fix another race crash bug (thanks to Glenn Fink for reporting).
- Compare identity to identity, not to nickname, when extending to
a router not already in the directory. This was preventing us from
extending to unknown routers. Oops.
- Make sure to create OS X Tor user in <500 range, so we aren't
creating actual system users.
- Note where connection-that-hasn't-sent-end was marked, and fix
a few really loud instances of this harmless bug (it's fixed more
in 0.1.0.x).
Changes in version 0.0.9.6 - 2005-03-24
o Bugfixes on 0.0.9.x (crashes and asserts):
- Add new end stream reasons to maintainance branch. Fix bug where
reason (8) could trigger an assert. Prevent bug from recurring.
- Apparently win32 stat wants paths to not end with a slash.
- Fix assert triggers in assert_cpath_layer_ok(), where we were
blowing away the circuit that conn->cpath_layer points to, then
checking to see if the circ is well-formed. Backport check to make
sure we dont use the cpath on a closed connection.
- Prevent circuit_resume_edge_reading_helper() from trying to package
inbufs for marked-for-close streams.
- Don't crash on hup if your options->address has become unresolvable.
- Some systems (like OS X) sometimes accept() a connection and tell
you the remote host is 0.0.0.0:0. If this happens, due to some
other mis-features, we get confused; so refuse the conn for now.
o Bugfixes on 0.0.9.x (other):
- Fix harmless but scary "Unrecognized content encoding" warn message.
- Add new stream error reason: TORPROTOCOL reason means "you are not
speaking a version of Tor I understand; say bye-bye to your stream."
- Be willing to cache directories from up to ROUTER_MAX_AGE seconds
into the future, now that we are more tolerant of skew. This
resolves a bug where a Tor server would refuse to cache a directory
because all the directories it gets are too far in the future;
yet the Tor server never logs any complaints about clock skew.
- Mac packaging magic: make man pages useable, and do not overwrite
existing torrc files.
- Make OS X log happily to /var/log/tor/tor.log
Changes in version 0.0.9.5 - 2005-02-22
o Bugfixes on 0.0.9.x:
- Fix an assert race at exit nodes when resolve requests fail.
- Stop picking unverified dir mirrors--it only leads to misery.
- Patch from Matt Edman to make NT services work better. Service
support is still not compiled into the executable by default.
- Patch from Dmitri Bely so the Tor service runs better under
the win32 SYSTEM account.
- Make tor-resolve actually work (?) on Win32.
- Fix a sign bug when getrlimit claims to have 4+ billion
file descriptors available.
- Stop refusing to start when bandwidthburst == bandwidthrate.
- When create cells have been on the onion queue more than five
seconds, just send back a destroy and take them off the list.
Changes in version 0.0.9.4 - 2005-02-03
o Bugfixes on 0.0.9:
- Fix an assert bug that took down most of our servers: when
a server claims to have 1 GB of bandwidthburst, don't
freak out.
- Don't crash as badly if we have spawned the max allowed number
of dnsworkers, or we're out of file descriptors.
- Block more file-sharing ports in the default exit policy.
- MaxConn is now automatically set to the hard limit of max
file descriptors we're allowed (ulimit -n), minus a few for
logs, etc.
- Give a clearer message when servers need to raise their
ulimit -n when they start running out of file descriptors.
- SGI Compatibility patches from Jan Schaumann.
- Tolerate a corrupt cached directory better.
- When a dirserver hasn't approved your server, list which one.
- Go into soft hibernation after 95% of the bandwidth is used,
not 99%. This is especially important for daily hibernators who
have a small accounting max. Hopefully it will result in fewer
cut connections when the hard hibernation starts.
- Load-balance better when using servers that claim more than
800kB/s of capacity.
- Make NT services work (experimental, only used if compiled in).
Changes in version 0.0.9.3 - 2005-01-21
o Bugfixes on 0.0.9:
- Backport the cpu use fixes from main branch, so busy servers won't
need as much processor time.
- Work better when we go offline and then come back, or when we
run Tor at boot before the network is up. We do this by
optimistically trying to fetch a new directory whenever an
application request comes in and we think we're offline -- the
human is hopefully a good measure of when the network is back.
- Backport some minimal hidserv bugfixes: keep rend circuits open as
long as you keep using them; actually publish hidserv descriptors
shortly after they change, rather than waiting 20-40 minutes.
- Enable Mac startup script by default.
- Fix duplicate dns_cancel_pending_resolve reported by Giorgos Pallas.
- When you update AllowUnverifiedNodes or FirewallPorts via the
controller's setconf feature, we were always appending, never
resetting.
- When you update HiddenServiceDir via setconf, it was screwing up
the order of reading the lines, making it fail.
- Do not rewrite a cached directory back to the cache; otherwise we
will think it is recent and not fetch a newer one on startup.
- Workaround for webservers that lie about Content-Encoding: Tor
now tries to autodetect compressed directories and compression
itself. This lets us Proxypass dir fetches through apache.
Changes in version 0.0.9.2 - 2005-01-04
o Bugfixes on 0.0.9 (crashes and asserts):
- Fix an assert on startup when the disk is full and you're logging
to a file.
- If you do socks4 with an IP of 0.0.0.x but *don't* provide a socks4a
style address, then we'd crash.
- Fix an assert trigger when the running-routers string we get from
a dirserver is broken.
- Make worker threads start and run on win32. Now win32 servers
may work better.
- Bandaid (not actually fix, but now it doesn't crash) an assert
where the dns worker dies mysteriously and the main Tor process
doesn't remember anything about the address it was resolving.
o Bugfixes on 0.0.9 (Win32):
- Workaround for brain-damaged __FILE__ handling on MSVC: keep Nick's
name out of the warning/assert messages.
- Fix a superficial "unhandled error on read" bug on win32.
- The win32 installer no longer requires a click-through for our
license, since our Free Software license grants rights but does not
take any away.
- Win32: When connecting to a dirserver fails, try another one
immediately. (This was already working for non-win32 Tors.)
- Stop trying to parse $HOME on win32 when hunting for default
DataDirectory.
- Make tor-resolve.c work on win32 by calling network_init().
o Bugfixes on 0.0.9 (other):
- Make 0.0.9.x build on Solaris again.
- Due to a fencepost error, we were blowing away the \n when reporting
confvalue items in the controller. So asking for multiple config
values at once couldn't work.
- When listing circuits that are pending on an opening OR connection,
if we're an OR we were listing circuits that *end* at us as
being pending on every listener, dns/cpu worker, etc. Stop that.
- Dirservers were failing to create 'running-routers' or 'directory'
strings if we had more than some threshold of routers. Fix them so
they can handle any number of routers.
- Fix a superficial "Duplicate mark for close" bug.
- Stop checking for clock skew for OR connections, even for servers.
- Fix a fencepost error that was chopping off the last letter of any
nickname that is the maximum allowed nickname length.
- Update URLs in log messages so they point to the new website.
- Fix a potential problem in mangling server private keys while
writing to disk (not triggered yet, as far as we know).
- Include the licenses for other free software we include in Tor,
now that we're shipping binary distributions more regularly.
Changes in version 0.0.9.1 - 2004-12-15
o Bugfixes on 0.0.9:
- Make hibernation actually work.
- Make HashedControlPassword config option work.
- When we're reporting event circuit status to a controller,
don't use the stream status code.
Changes in version 0.0.9 - 2004-12-12
o Bugfixes on 0.0.8.1 (Crashes and asserts):
- Catch and ignore SIGXFSZ signals when log files exceed 2GB; our
write() call will fail and we handle it there.
- When we run out of disk space, or other log writing error, don't
crash. Just stop logging to that log and continue.
- Fix isspace() and friends so they still make Solaris happy
but also so they don't trigger asserts on win32.
- Fix assert failure on malformed socks4a requests.
- Fix an assert bug where a hidden service provider would fail if
the first hop of his rendezvous circuit was down.
- Better handling of size_t vs int, so we're more robust on 64
bit platforms.
o Bugfixes on 0.0.8.1 (Win32):
- Make windows sockets actually non-blocking (oops), and handle
win32 socket errors better.
- Fix parse_iso_time on platforms without strptime (eg win32).
- win32: when being multithreaded, leave parent fdarray open.
- Better handling of winsock includes on non-MSV win32 compilers.
- Change our file IO stuff (especially wrt OpenSSL) so win32 is
happier.
- Make unit tests work on win32.
o Bugfixes on 0.0.8.1 (Path selection and streams):
- Calculate timeout for waiting for a connected cell from the time
we sent the begin cell, not from the time the stream started. If
it took a long time to establish the circuit, we would time out
right after sending the begin cell.
- Fix router_compare_addr_to_addr_policy: it was not treating a port
of * as always matching, so we were picking reject *:* nodes as
exit nodes too. Oops.
- When read() failed on a stream, we would close it without sending
back an end. So 'connection refused' would simply be ignored and
the user would get no response.
- Stop a sigpipe: when an 'end' cell races with eof from the app,
we shouldn't hold-open-until-flush if the eof arrived first.
- Let resolve conns retry/expire also, rather than sticking around
forever.
- Fix more dns related bugs: send back resolve_failed and end cells
more reliably when the resolve fails, rather than closing the
circuit and then trying to send the cell. Also attach dummy resolve
connections to a circuit *before* calling dns_resolve(), to fix
a bug where cached answers would never be sent in RESOLVED cells.
o Bugfixes on 0.0.8.1 (Circuits):
- Finally fix a bug that's been plaguing us for a year:
With high load, circuit package window was reaching 0. Whenever
we got a circuit-level sendme, we were reading a lot on each
socket, but only writing out a bit. So we would eventually reach
eof. This would be noticed and acted on even when there were still
bytes sitting in the inbuf.
- Use identity comparison, not nickname comparison, to choose which
half of circuit-ID-space each side gets to use. This is needed
because sometimes we think of a router as a nickname, and sometimes
as a hex ID, and we can't predict what the other side will do.
o Bugfixes on 0.0.8.1 (Other):
- Fix a whole slew of memory leaks.
- Disallow NDEBUG. We don't ever want anybody to turn off debug.
- If we are using select, make sure we stay within FD_SETSIZE.
- When poll() is interrupted, we shouldn't believe the revents values.
- Add a FAST_SMARTLIST define to optionally inline smartlist_get
and smartlist_len, which are two major profiling offenders.
- If do_hup fails, actually notice.
- Flush the log file descriptor after we print "Tor opening log file",
so we don't see those messages days later.
- Hidden service operators now correctly handle version 1 style
INTRODUCE1 cells (nobody generates them still, so not a critical
bug).
- Handle more errnos from accept() without closing the listener.
Some OpenBSD machines were closing their listeners because
they ran out of file descriptors.
- Some people had wrapped their tor client/server in a script
that would restart it whenever it died. This did not play well
with our "shut down if your version is obsolete" code. Now people
don't fetch a new directory if their local cached version is
recent enough.
- Make our autogen.sh work on ksh as well as bash.
- Better torrc example lines for dirbindaddress and orbindaddress.
- Improved bounds checking on parsed ints (e.g. config options and
the ones we find in directories.)
- Stop using separate defaults for no-config-file and
empty-config-file. Now you have to explicitly turn off SocksPort,
if you don't want it open.
- We were starting to daemonize before we opened our logs, so if
there were any problems opening logs, we would complain to stderr,
which wouldn't work, and then mysteriously exit.
- If a verified OR connects to us before he's uploaded his descriptor,
or we verify him and hup but he still has the original TLS
connection, then conn->nickname is still set like he's unverified.
o Code security improvements, inspired by Ilja:
- tor_snprintf wrapper over snprintf with consistent (though not C99)
overflow behavior.
- Replace sprintf with tor_snprintf. (I think they were all safe, but
hey.)
- Replace strcpy/strncpy with strlcpy in more places.
- Avoid strcat; use tor_snprintf or strlcat instead.
o Features (circuits and streams):
- New circuit building strategy: keep a list of ports that we've
used in the past 6 hours, and always try to have 2 circuits open
or on the way that will handle each such port. Seed us with port
80 so web users won't complain that Tor is "slow to start up".
- Make kill -USR1 dump more useful stats about circuits.
- When warning about retrying or giving up, print the address, so
the user knows which one it's talking about.
- If you haven't used a clean circuit in an hour, throw it away,
just to be on the safe side. (This means after 6 hours a totally
unused Tor client will have no circuits open.)
- Support "foo.nickname.exit" addresses, to let Alice request the
address "foo" as viewed by exit node "nickname". Based on a patch
from Geoff Goodell.
- If your requested entry or exit node has advertised bandwidth 0,
pick it anyway.
- Be more greedy about filling up relay cells -- we try reading again
once we've processed the stuff we read, in case enough has arrived
to fill the last cell completely.
- Refuse application socks connections to port 0.
- Use only 0.0.9pre1 and later servers for resolve cells.
o Features (bandwidth):
- Hibernation: New config option "AccountingMax" lets you
set how many bytes per month (in each direction) you want to
allow your server to consume. Rather than spreading those
bytes out evenly over the month, we instead hibernate for some
of the month and pop up at a deterministic time, work until
the bytes are consumed, then hibernate again. Config option
"MonthlyAccountingStart" lets you specify which day of the month
your billing cycle starts on.
- Implement weekly/monthly/daily accounting: now you specify your
hibernation properties by
AccountingMax N bytes|KB|MB|GB|TB
AccountingStart day|week|month [day] HH:MM
Defaults to "month 1 0:00".
- Let bandwidth and interval config options be specified as 5 bytes,
kb, kilobytes, etc; and as seconds, minutes, hours, days, weeks.
o Features (directories):
- New "router-status" line in directory, to better bind each verified
nickname to its identity key.
- Clients can ask dirservers for /dir.z to get a compressed version
of the directory. Only works for servers running 0.0.9, of course.
- Make clients cache directories and use them to seed their router
lists at startup. This means clients have a datadir again.
- Respond to content-encoding headers by trying to uncompress as
appropriate.
- Clients and servers now fetch running-routers; cache
running-routers; compress running-routers; serve compressed
running-routers.z
- Make moria2 advertise a dirport of 80, so people behind firewalls
will be able to get a directory.
- Http proxy support
- Dirservers translate requests for http://%s:%d/x to /x
- You can specify "HttpProxy %s[:%d]" and all dir fetches will
be routed through this host.
- Clients ask for /tor/x rather than /x for new enough dirservers.
This way we can one day coexist peacefully with apache.
- Clients specify a "Host: %s%d" http header, to be compatible
with more proxies, and so running squid on an exit node can work.
- Protect dirservers from overzealous descriptor uploading -- wait
10 seconds after directory gets dirty, before regenerating.
o Features (packages and install):
- Add NSI installer contributed by J Doe.
- Apply NT service patch from Osamu Fujino. Still needs more work.
- Commit VC6 and VC7 workspace/project files.
- Commit a tor.spec for making RPM files, with help from jbash.
- Add contrib/torctl.in contributed by Glenn Fink.
- Make expand_filename handle ~ and ~username.
- Use autoconf to enable largefile support where necessary. Use
ftello where available, since ftell can fail at 2GB.
- Ship src/win32/ in the tarball, so people can use it to build.
- Make old win32 fall back to CWD if SHGetSpecialFolderLocation
is broken.
o Features (ui controller):
- Control interface: a separate program can now talk to your
client/server over a socket, and get/set config options, receive
notifications of circuits and streams starting/finishing/dying,
bandwidth used, etc. The next step is to get some GUIs working.
Let us know if you want to help out. See doc/control-spec.txt .
- Ship a contrib/tor-control.py as an example script to interact
with the control port.
- "tor --hash-password zzyxz" will output a salted password for
use in authenticating to the control interface.
- Implement the control-spec's SAVECONF command, to write your
configuration to torrc.
- Get cookie authentication for the controller closer to working.
- When set_conf changes our server descriptor, upload a new copy.
But don't upload it too often if there are frequent changes.
o Features (config and command-line):
- Deprecate unofficial config option abbreviations, and abbreviations
not on the command line.
- Configuration infrastructure support for warning on obsolete
options.
- Give a slightly more useful output for "tor -h".
- Break DirFetchPostPeriod into:
- DirFetchPeriod for fetching full directory,
- StatusFetchPeriod for fetching running-routers,
- DirPostPeriod for posting server descriptor,
- RendPostPeriod for posting hidden service descriptors.
- New log format in config:
"Log minsev[-maxsev] stdout|stderr|syslog" or
"Log minsev[-maxsev] file /var/foo"
- DirPolicy config option, to let people reject incoming addresses
from their dirserver.
- "tor --list-fingerprint" will list your identity key fingerprint
and then exit.
- Make tor --version --version dump the cvs Id of every file.
- New 'MyFamily nick1,...' config option for a server to
specify other servers that shouldn't be used in the same circuit
with it. Only believed if nick1 also specifies us.
- New 'NodeFamily nick1,nick2,...' config option for a client to
specify nodes that it doesn't want to use in the same circuit.
- New 'Redirectexit pattern address:port' config option for a
server to redirect exit connections, e.g. to a local squid.
- Add "pass" target for RedirectExit, to make it easier to break
out of a sequence of RedirectExit rules.
- Make the dirservers file obsolete.
- Include a dir-signing-key token in directories to tell the
parsing entity which key is being used to sign.
- Remove the built-in bulky default dirservers string.
- New config option "Dirserver %s:%d [fingerprint]", which can be
repeated as many times as needed. If no dirservers specified,
default to moria1,moria2,tor26.
- Make 'Routerfile' config option obsolete.
- Discourage people from setting their dirfetchpostperiod more often
than once per minute.
o Features (other):
- kill -USR2 now moves all logs to loglevel debug (kill -HUP to
get back to normal.)
- Accept *:706 (silc) in default exit policy.
- Implement new versioning format for post 0.1.
- Distinguish between TOR_TLS_CLOSE and TOR_TLS_ERROR, so we can
log more informatively.
- Check clock skew for verified servers, but allow unverified
servers and clients to have any clock skew.
- Make sure the hidden service descriptors are at a random offset
from each other, to hinder linkability.
- Clients now generate a TLS cert too, in preparation for having
them act more like real nodes.
- Add a pure-C tor-resolve implementation.
- Use getrlimit and friends to ensure we can reach MaxConn (currently
1024) file descriptors.
- Raise the max dns workers from 50 to 100.
Changes in version 0.0.8.1 - 2004-10-13
o Bugfixes:
- Fix a seg fault that can be triggered remotely for Tor
clients/servers with an open dirport.
- Fix a rare assert trigger, where routerinfos for entries in
our cpath would expire while we're building the path.
- Fix a bug in OutboundBindAddress so it (hopefully) works.
- Fix a rare seg fault for people running hidden services on
intermittent connections.
- Fix a bug in parsing opt keywords with objects.
- Fix a stale pointer assert bug when a stream detaches and
reattaches.
- Fix a string format vulnerability (probably not exploitable)
in reporting stats locally.
- Fix an assert trigger: sometimes launching circuits can fail
immediately, e.g. because too many circuits have failed recently.
- Fix a compile warning on 64 bit platforms.
Changes in version 0.0.8 - 2004-08-25
o Bugfixes:
- Made our unit tests compile again on OpenBSD 3.5, and tor
itself compile again on OpenBSD on a sparc64.
- We were neglecting milliseconds when logging on win32, so
everything appeared to happen at the beginning of each second.
- Check directory signature _before_ you decide whether you're
you're running an obsolete version and should exit.
- Check directory signature _before_ you parse the running-routers
list to decide who's running.
- Check return value of fclose while writing to disk, so we don't
end up with broken files when servers run out of disk space.
- Port it to SunOS 5.9 / Athena
- Fix two bugs in saving onion keys to disk when rotating, so
hopefully we'll get fewer people using old onion keys.
- Remove our mostly unused -- and broken -- hex_encode()
function. Use base16_encode() instead. (Thanks to Timo Lindfors
for pointing out this bug.)
- Only pick and establish intro points after we've gotten a
directory.
- Fix assert triggers: if the other side returns an address 0.0.0.0,
don't put it into the client dns cache.
- If a begin failed due to exit policy, but we believe the IP
address should have been allowed, switch that router to exitpolicy
reject *:* until we get our next directory.
o Protocol changes:
- 'Extend' relay cell payloads now include the digest of the
intended next hop's identity key. Now we can verify that we're
extending to the right router, and also extend to routers we
hadn't heard of before.
o Features:
- Tor nodes can now act as relays (with an advertised ORPort)
without being manually verified by the dirserver operators.
- Uploaded descriptors of unverified routers are now accepted
by the dirservers, and included in the directory.
- Verified routers are listed by nickname in the running-routers
list; unverified routers are listed as "$<fingerprint>".
- We now use hash-of-identity-key in most places rather than
nickname or addr:port, for improved security/flexibility.
- AllowUnverifiedNodes config option to let circuits choose no-name
routers in entry,middle,exit,introduction,rendezvous positions.
Allow middle and rendezvous positions by default.
- When picking unverified routers, skip those with low uptime and/or
low bandwidth, depending on what properties you care about.
- ClientOnly option for nodes that never want to become servers.
- Directory caching.
- "AuthoritativeDir 1" option for the official dirservers.
- Now other nodes (clients and servers) will cache the latest
directory they've pulled down.
- They can enable their DirPort to serve it to others.
- Clients will pull down a directory from any node with an open
DirPort, and check the signature/timestamp correctly.
- Authoritative dirservers now fetch directories from other
authdirservers, to stay better synced.
- Running-routers list tells who's down also, along with noting
if they're verified (listed by nickname) or unverified (listed
by hash-of-key).
- Allow dirservers to serve running-router list separately.
This isn't used yet.
- You can now fetch $DIRURL/running-routers to get just the
running-routers line, not the whole descriptor list. (But
clients don't use this yet.)
- Clients choose nodes proportional to advertised bandwidth.
- Clients avoid using nodes with low uptime as introduction points.
- Handle servers with dynamic IP addresses: don't just replace
options->Address with the resolved one at startup, and
detect our address right before we make a routerinfo each time.
- 'FascistFirewall' option to pick dirservers and ORs on specific
ports; plus 'FirewallPorts' config option to tell FascistFirewall
which ports are open. (Defaults to 80,443)
- Try other dirservers immediately if the one you try is down. This
should tolerate down dirservers better now.
- ORs connect-on-demand to other ORs
- If you get an extend cell to an OR you're not connected to,
connect, handshake, and forward the create cell.
- The authoritative dirservers stay connected to everybody,
and everybody stays connected to 0.0.7 servers, but otherwise
clients/servers expire unused connections after 5 minutes.
- When servers get a sigint, they delay 30 seconds (refusing new
connections) then exit. A second sigint causes immediate exit.
- File and name management:
- Look for .torrc if no CONFDIR "torrc" is found.
- If no datadir is defined, then choose, make, and secure ~/.tor
as datadir.
- If torrc not found, exitpolicy reject *:*.
- Expands ~/ in filenames to $HOME/ (but doesn't yet expand ~arma).
- If no nickname is defined, derive default from hostname.
- Rename secret key files, e.g. identity.key -> secret_id_key,
to discourage people from mailing their identity key to tor-ops.
- Refuse to build a circuit before the directory has arrived --
it won't work anyway, since you won't know the right onion keys
to use.
- Parse tor version numbers so we can do an is-newer-than check
rather than an is-in-the-list check.
- New socks command 'resolve', to let us shim gethostbyname()
locally.
- A 'tor_resolve' script to access the socks resolve functionality.
- A new socks-extensions.txt doc file to describe our
interpretation and extensions to the socks protocols.
- Add a ContactInfo option, which gets published in descriptor.
- Write tor version at the top of each log file
- New docs in the tarball:
- tor-doc.html.
- Document that you should proxy your SSL traffic too.
- Log a warning if the user uses an unsafe socks variant, so people
are more likely to learn about privoxy or socat.
- Log a warning if you're running an unverified server, to let you
know you might want to get it verified.
- Change the default exit policy to reject the default edonkey,
kazaa, gnutella ports.
- Add replace_file() to util.[ch] to handle win32's rename().
- Publish OR uptime in descriptor (and thus in directory) too.
- Remember used bandwidth (both in and out), and publish 15-minute
snapshots for the past day into our descriptor.
- Be more aggressive about trying to make circuits when the network
has changed (e.g. when you unsuspend your laptop).
- Check for time skew on http headers; report date in response to
"GET /".
- If the entrynode config line has only one node, don't pick it as
an exitnode.
- Add strict{entry|exit}nodes config options. If set to 1, then
we refuse to build circuits that don't include the specified entry
or exit nodes.
- OutboundBindAddress config option, to bind to a specific
IP address for outgoing connect()s.
- End truncated log entries (e.g. directories) with "[truncated]".
Changes in version 0.0.7.3 - 2004-08-12
o Stop dnsworkers from triggering an assert failure when you
ask them to resolve the host "".
Changes in version 0.0.7.2 - 2004-07-07
o A better fix for the 0.0.0.0 problem, that will hopefully
eliminate the remaining related assertion failures.
Changes in version 0.0.7.1 - 2004-07-04
o When an address resolves to 0.0.0.0, treat it as a failed resolve,
since internally we use 0.0.0.0 to signify "not yet resolved".
Changes in version 0.0.7 - 2004-06-07
o Fixes for crashes and other obnoxious bugs:
- Fix an epipe bug: sometimes when directory connections failed
to connect, we would give them a chance to flush before closing
them.
- When we detached from a circuit because of resolvefailed, we
would immediately try the same circuit twice more, and then
give up on the resolve thinking we'd tried three different
exit nodes.
- Limit the number of intro circuits we'll attempt to build for a
hidden service per 15-minute period.
- Check recommended-software string *early*, before actually parsing
the directory. Thus we can detect an obsolete version and exit,
even if the new directory format doesn't parse.
o Fixes for security bugs:
- Remember which nodes are dirservers when you startup, and if a
random OR enables his dirport, don't automatically assume he's
a trusted dirserver.
o Other bugfixes:
- Directory connections were asking the wrong poll socket to
start writing, and not asking themselves to start writing.
- When we detached from a circuit because we sent a begin but
didn't get a connected, we would use it again the first time;
but after that we would correctly switch to a different one.
- Stop warning when the first onion decrypt attempt fails; they
will sometimes legitimately fail now that we rotate keys.
- Override unaligned-access-ok check when $host_cpu is ia64 or
arm. Apparently they allow it but the kernel whines.
- Dirservers try to reconnect periodically too, in case connections
have failed.
- Fix some memory leaks in directory servers.
- Allow backslash in Win32 filenames.
- Made Tor build complain-free on FreeBSD, hopefully without
breaking other BSD builds. We'll see.
- Check directory signatures based on name of signer, not on whom
we got the directory from. This will let us cache directories more
easily.
- Rotate dnsworkers and cpuworkers on SIGHUP, so they get new config
settings too.
o Features:
- Doxygen markup on all functions and global variables.
- Make directory functions update routerlist, not replace it. So
now directory disagreements are not so critical a problem.
- Remove the upper limit on number of descriptors in a dirserver's
directory (not that we were anywhere close).
- Allow multiple logfiles at different severity ranges.
- Allow *BindAddress to specify ":port" rather than setting *Port
separately. Allow multiple instances of each BindAddress config
option, so you can bind to multiple interfaces if you want.
- Allow multiple exit policy lines, which are processed in order.
Now we don't need that huge line with all the commas in it.
- Enable accept/reject policies on SOCKS connections, so you can bind
to 0.0.0.0 but still control who can use your OP.
- Updated the man page to reflect these features.
Changes in version 0.0.6.2 - 2004-05-16
o Our integrity-checking digest was checking only the most recent cell,
not the previous cells like we'd thought.
Thanks to Stefan Mark for finding the flaw!
Changes in version 0.0.6.1 - 2004-05-06
o Fix two bugs in our AES counter-mode implementation (this affected
onion-level stream encryption, but not TLS-level). It turns
out we were doing something much more akin to a 16-character
polyalphabetic cipher. Oops.
Thanks to Stefan Mark for finding the flaw!
o Retire moria3 as a directory server, and add tor26 as a directory
server.
Changes in version 0.0.6 - 2004-05-02
o Features:
- Hidden services and rendezvous points are implemented. Go to
http://6sxoyfb3h2nvok2d.onion/ for an index of currently available
hidden services. (This only works via a socks4a proxy such as
Privoxy, and currently it's quite slow.)
- We now rotate link (tls context) keys and onion keys.
- CREATE cells now include oaep padding, so you can tell
if you decrypted them correctly.
- Retry stream correctly when we fail to connect because of
exit-policy-reject (should try another) or can't-resolve-address.
- When we hup a dirserver and we've *removed* a server from the
approved-routers list, now we remove that server from the
in-memory directories too.
- Add bandwidthburst to server descriptor.
- Directories now say which dirserver signed them.
- Use a tor_assert macro that logs failed assertions too.
- Since we don't support truncateds much, don't bother sending them;
just close the circ.
- Fetch randomness from /dev/urandom better (not via fopen/fread)
- Better debugging for tls errors
- Set Content-Type on the directory and hidserv descriptor.
- Remove IVs from cipher code, since AES-ctr has none.
o Bugfixes:
- Fix an assert trigger for exit nodes that's been plaguing us since
the days of 0.0.2prexx (thanks weasel!)
- Fix a bug where we were closing tls connections intermittently.
It turns out openssl keeps its errors around -- so if an error
happens, and you don't ask about it, and then another openssl
operation happens and succeeds, and you ask if there was an error,
it tells you about the first error.
- Fix a bug that's been lurking since 27 may 03 (!)
When passing back a destroy cell, we would use the wrong circ id.
- Don't crash if a conn that sent a begin has suddenly lost its circuit.
- Some versions of openssl have an SSL_pending function that erroneously
returns bytes when there is a non-application record pending.
- Win32 fixes. Tor now compiles on win32 with no warnings/errors.
o We were using an array of length zero in a few places.
o Win32's gethostbyname can't resolve an IP to an IP.
o Win32's close can't close a socket.
o Handle windows socket errors correctly.
o Portability:
- check for <sys/limits.h> so we build on FreeBSD again, and
<machine/limits.h> for NetBSD.
Changes in version 0.0.5 - 2004-03-30
o Install torrc as torrc.sample -- we no longer clobber your
torrc. (Woo!)
o Fix mangled-state bug in directory fetching (was causing sigpipes).
o Only build circuits after we've fetched the directory: clients were
using only the directory servers before they'd fetched a directory.
This also means longer startup time; so it goes.
o Fix an assert trigger where an OP would fail to handshake, and we'd
expect it to have a nickname.
o Work around a tsocks bug: do a socks reject when AP connection dies
early, else tsocks goes into an infinite loop.
o Hold socks connection open until reply is flushed (if possible)
o Make exit nodes resolve IPs to IPs immediately, rather than asking
the dns farm to do it.
o Fix c99 aliasing warnings in rephist.c
o Don't include server descriptors that are older than 24 hours in the
directory.
o Give socks 'reject' replies their whole 15s to attempt to flush,
rather than seeing the 60s timeout and assuming the flush had failed.
o Clean automake droppings from the cvs repository
o Add in a 'notice' log level for things the operator should hear
but that aren't warnings
Changes in version 0.0.4 - 2004-03-26
o When connecting to a dirserver or OR and the network is down,
we would crash.
Changes in version 0.0.3 - 2004-03-26
o Warn and fail if server chose a nickname with illegal characters
o Port to Solaris and Sparc:
- include missing header fcntl.h
- have autoconf find -lsocket -lnsl automatically
- deal with hardware word alignment
- make uname() work (solaris has a different return convention)
- switch from using signal() to sigaction()
o Preliminary work on reputation system:
- Keep statistics on success/fail of connect attempts; they're published
by kill -USR1 currently.
- Add a RunTesting option to try to learn link state by creating test
circuits, even when SocksPort is off.
- Remove unused open circuits when there are too many.
Changes in version 0.0.2 - 2004-03-19
- Include strlcpy and strlcat for safer string ops
- define INADDR_NONE so we compile (but still not run) on solaris
Changes in version 0.0.2pre27 - 2004-03-14
o Bugfixes:
- Allow internal tor networks (we were rejecting internal IPs,
now we allow them if they're set explicitly).
- And fix a few endian issues.
Changes in version 0.0.2pre26 - 2004-03-14
o New features:
- If a stream times out after 15s without a connected cell, don't
try that circuit again: try a new one.
- Retry streams at most 4 times. Then give up.
- When a dirserver gets a descriptor from an unknown router, it
logs its fingerprint (so the dirserver operator can choose to
accept it even without mail from the server operator).
- Inform unapproved servers when we reject their descriptors.
- Make tor build on Windows again. It works as a client, who knows
about as a server.
- Clearer instructions in the torrc for how to set up a server.
- Be more efficient about reading fd's when our global token bucket
(used for rate limiting) becomes empty.
o Bugfixes:
- Stop asserting that computers always go forward in time. It's
simply not true.
- When we sent a cell (e.g. destroy) and then marked an OR connection
expired, we might close it before finishing a flush if the other
side isn't reading right then.
- Don't allow dirservers to start if they haven't defined
RecommendedVersions
- We were caching transient dns failures. Oops.
- Prevent servers from publishing an internal IP as their address.
- Address a strcat vulnerability in circuit.c
Changes in version 0.0.2pre25 - 2004-03-04
o New features:
- Put the OR's IP in its router descriptor, not its fqdn. That way
we'll stop being stalled by gethostbyname for nodes with flaky dns,
e.g. poblano.
o Bugfixes:
- If the user typed in an address that didn't resolve, the server
crashed.
Changes in version 0.0.2pre24 - 2004-03-03
o Bugfixes:
- Fix an assertion failure in dns.c, where we were trying to dequeue
a pending dns resolve even if it wasn't pending
- Fix a spurious socks5 warning about still trying to write after the
connection is finished.
- Hold certain marked_for_close connections open until they're finished
flushing, rather than losing bytes by closing them too early.
- Correctly report the reason for ending a stream
- Remove some duplicate calls to connection_mark_for_close
- Put switch_id and start_daemon earlier in the boot sequence, so it
will actually try to chdir() to options.DataDirectory
- Make 'make test' exit(1) if a test fails; fix some unit tests
- Make tor fail when you use a config option it doesn't know about,
rather than warn and continue.
- Make --version work
- Bugfixes on the rpm spec file and tor.sh, so it's more up to date
Changes in version 0.0.2pre23 - 2004-02-29
o New features:
- Print a statement when the first circ is finished, so the user
knows it's working.
- If a relay cell is unrecognized at the end of the circuit,
send back a destroy. (So attacks to mutate cells are more
clearly thwarted.)
- New config option 'excludenodes' to avoid certain nodes for circuits.
- When it daemonizes, it chdir's to the DataDirectory rather than "/",
so you can collect coredumps there.
o Bugfixes:
- Fix a bug in tls flushing where sometimes data got wedged and
didn't flush until more data got sent. Hopefully this bug was
a big factor in the random delays we were seeing.
- Make 'connected' cells include the resolved IP, so the client
dns cache actually gets populated.
- Disallow changing from ORPort=0 to ORPort>0 on hup.
- When we time-out on a stream and detach from the circuit, send an
end cell down it first.
- Only warn about an unknown router (in exitnodes, entrynodes,
excludenodes) after we've fetched a directory.
Changes in version 0.0.2pre22 - 2004-02-26
o New features:
- Servers publish less revealing uname information in descriptors.
- More memory tracking and assertions, to crash more usefully when
errors happen.
- If the default torrc isn't there, just use some default defaults.
Plus provide an internal dirservers file if they don't have one.
- When the user tries to use Tor as an http proxy, give them an http
501 failure explaining that we're a socks proxy.
- Dump a new router.desc on hup, to help confused people who change
their exit policies and then wonder why router.desc doesn't reflect
it.
- Clean up the generic tor.sh init script that we ship with.
o Bugfixes:
- If the exit stream is pending on the resolve, and a destroy arrives,
then the stream wasn't getting removed from the pending list. I
think this was the one causing recent server crashes.
- Use a more robust poll on OSX 10.3, since their poll is flaky.
- When it couldn't resolve any dirservers, it was useless from then on.
Now it reloads the RouterFile (or default dirservers) if it has no
dirservers.
- Move the 'tor' binary back to /usr/local/bin/ -- it turns out
many users don't even *have* a /usr/local/sbin/.
Changes in version 0.0.2pre21 - 2004-02-18
o New features:
- There's a ChangeLog file that actually reflects the changelog.
- There's a 'torify' wrapper script, with an accompanying
tor-tsocks.conf, that simplifies the process of using tsocks for
tor. It even has a man page.
- The tor binary gets installed to sbin rather than bin now.
- Retry streams where the connected cell hasn't arrived in 15 seconds
- Clean up exit policy handling -- get the default out of the torrc,
so we can update it without forcing each server operator to fix
his/her torrc.
- Allow imaps and pop3s in default exit policy
o Bugfixes:
- Prevent picking middleman nodes as the last node in the circuit
Changes in version 0.0.2pre20 - 2004-01-30
o New features:
- We now have a deb package, and it's in debian unstable. Go to
it, apt-getters. :)
- I've split the TotalBandwidth option into BandwidthRate (how many
bytes per second you want to allow, long-term) and
BandwidthBurst (how many bytes you will allow at once before the cap
kicks in). This better token bucket approach lets you, say, set
BandwidthRate to 10KB/s and BandwidthBurst to 10MB, allowing good
performance while not exceeding your monthly bandwidth quota.
- Push out a tls record's worth of data once you've got it, rather
than waiting until you've read everything waiting to be read. This
may improve performance by pipelining better. We'll see.
- Add an AP_CONN_STATE_CONNECTING state, to allow streams to detach
from failed circuits (if they haven't been connected yet) and attach
to new ones.
- Expire old streams that haven't managed to connect. Some day we'll
have them reattach to new circuits instead.
o Bugfixes:
- Fix several memory leaks that were causing servers to become bloated
after a while.
- Fix a few very rare assert triggers. A few more remain.
- Setuid to User _before_ complaining about running as root.
Changes in version 0.0.2pre19 - 2004-01-07
o Bugfixes:
- Fix deadlock condition in dns farm. We were telling a child to die by
closing the parent's file descriptor to him. But newer children were
inheriting the open file descriptor from the parent, and since they
weren't closing it, the socket never closed, so the child never read
eof, so he never knew to exit. Similarly, dns workers were holding
open other sockets, leading to all sorts of chaos.
- New cleaner daemon() code for forking and backgrounding.
- If you log to a file, it now prints an entry at the top of the
logfile so you know it's working.
- The onionskin challenge length was 30 bytes longer than necessary.
- Started to patch up the spec so it's not quite so out of date.
Changes in version 0.0.2pre18 - 2004-01-02
o Bugfixes:
- Fix endian issues with the 'integrity' field in the relay header.
- Fix a potential bug where connections in state
AP_CONN_STATE_CIRCUIT_WAIT might unexpectedly ask to write.
Changes in version 0.0.2pre17 - 2003-12-30
o Bugfixes:
- Made --debuglogfile (or any second log file, actually) work.
- Resolved an edge case in get_unique_circ_id_by_conn where a smart
adversary could force us into an infinite loop.
o Features:
- Each onionskin handshake now includes a hash of the computed key,
to prove the server's identity and help perfect forward secrecy.
- Changed cell size from 256 to 512 bytes (working toward compatibility
with MorphMix).
- Changed cell length to 2 bytes, and moved it to the relay header.
- Implemented end-to-end integrity checking for the payloads of
relay cells.
- Separated streamid from 'recognized' (otherwise circuits will get
messed up when we try to have streams exit from the middle). We
use the integrity-checking to confirm that a cell is addressed to
this hop.
- Randomize the initial circid and streamid values, so an adversary who
breaks into a node can't learn how many circuits or streams have
been made so far.
Changes in version 0.0.2pre16 - 2003-12-14
o Bugfixes:
- Fixed a bug that made HUP trigger an assert
- Fixed a bug where a circuit that immediately failed wasn't being
counted as a failed circuit in counting retries.
o Features:
- Now we close the circuit when we get a truncated cell: otherwise we're
open to an anonymity attack where a bad node in the path truncates
the circuit and then we open streams at him.
- Add port ranges to exit policies
- Add a conservative default exit policy
- Warn if you're running tor as root
- on HUP, retry OR connections and close/rebind listeners
- options.EntryNodes: try these nodes first when picking the first node
- options.ExitNodes: if your best choices happen to include any of
your preferred exit nodes, you choose among just those preferred
exit nodes.
- options.ExcludedNodes: nodes that are never picked in path building
Changes in version 0.0.2pre15 - 2003-12-03
o Robustness and bugfixes:
- Sometimes clients would cache incorrect DNS resolves, which would
really screw things up.
- An OP that goes offline would slowly leak all its sockets and stop
working.
- A wide variety of bugfixes in exit node selection, exit policy
handling, and processing pending streams when a new circuit is
established.
- Pick nodes for a path only from those the directory says are up
- Choose randomly from all running dirservers, not always the first one
- Increase allowed http header size for directory fetch.
- Stop writing to stderr (if we're daemonized it will be closed).
- Enable -g always, so cores will be more useful to me.
- Switch "-lcrypto -lssl" to "-lssl -lcrypto" for broken distributions.
o Documentation:
- Wrote a man page. It lists commonly used options.
o Configuration:
- Change default loglevel to warn.
- Make PidFile default to null rather than littering in your CWD.
- OnionRouter config option is now obsolete. Instead it just checks
ORPort>0.
- Moved to a single unified torrc file for both clients and servers.
Changes in version 0.0.2pre14 - 2003-11-29
o Robustness and bugfixes:
- Force the admin to make the DataDirectory himself
- to get ownership/permissions right
- so clients no longer make a DataDirectory and then never use it
- fix bug where a client who was offline for 45 minutes would never
pull down a directory again
- fix (or at least hide really well) the dns assert bug that was
causing server crashes
- warnings and improved robustness wrt clockskew for certs
- use the native daemon(3) to daemonize, when available
- exit if bind() fails
- exit if neither socksport nor orport is defined
- include our own tor_timegm (Win32 doesn't have its own)
- bugfix for win32 with lots of connections
- fix minor bias in PRNG
- make dirserver more robust to corrupt cached directory
o Documentation:
- Wrote the design document (woo)
o Circuit building and exit policies:
- Circuits no longer try to use nodes that the directory has told them
are down.
- Exit policies now support bitmasks (18.0.0.0/255.0.0.0) and
bitcounts (18.0.0.0/8).
- Make AP connections standby for a circuit if no suitable circuit
exists, rather than failing
- Circuits choose exit node based on addr/port, exit policies, and
which AP connections are standing by
- Bump min pathlen from 2 to 3
- Relay end cells have a payload to describe why the stream ended.
- If the stream failed because of exit policy, try again with a new
circuit.
- Clients have a dns cache to remember resolved addresses.
- Notice more quickly when we have no working circuits
o Configuration:
- APPort is now called SocksPort
- SocksBindAddress, ORBindAddress, DirBindAddress let you configure
where to bind
- RecommendedVersions is now a config variable rather than
hardcoded (for dirservers)
- Reloads config on HUP
- Usage info on -h or --help
- If you set User and Group config vars, it'll setu/gid to them.
Changes in version 0.0.2pre13 - 2003-10-19
o General stability:
- SSL_write no longer fails when it returns WANTWRITE and the number
of bytes in the buf has changed by the next SSL_write call.
- Fix segfault fetching directory when network is down
- Fix a variety of minor memory leaks
- Dirservers reload the fingerprints file on HUP, so I don't have
to take down the network when I approve a new router
- Default server config file has explicit Address line to specify fqdn
o Buffers:
- Buffers grow and shrink as needed (Cut process size from 20M to 2M)
- Make listener connections not ever alloc bufs
o Autoconf improvements:
- don't clobber an external CFLAGS in ./configure
- Make install now works
- create var/lib/tor on make install
- autocreate a tor.sh initscript to help distribs
- autocreate the torrc and sample-server-torrc with correct paths
o Log files and Daemonizing now work:
- If --DebugLogFile is specified, log to it at -l debug
- If --LogFile is specified, use it instead of commandline
- If --RunAsDaemon is set, tor forks and backgrounds on startup
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