Users can't run an anonymous client and non-anonymous single
onion service at the same time. We need to know whether we have
any client ports or sockets open to do this check.
When determining whether a client port (SOCKS, Trans, NATD, DNS)
is set, count unix sockets when counting client listeners. This
has no user-visible behaviour change, because these options are
set once and never read in the current tor codebase.
Don't count sockets when setting ControlPort_set, that's what
ControlSocket is for. (This will be reviewed in #19665.)
Don't count sockets when counting server listeners, because the code
that uses these options expects to count externally-visible ports.
(And it would change the behaviour of Tor.)
Copying the integer 42 in a char buffer has a different representation
depending on the endianess of the system thus that unit test was failing on
big endian system.
This commit introduces a python script, like the one we have for SRV, that
computes a COMMIT/REVEAL from scratch so we can use it as a test vector for
our encoding unit tests.
With this, we use a random value of bytes instead of a number fixing the
endianess issue and making the whole test case more solid with an external
tool that builds the COMMIT and REVEAL according to the spec.
Fixes#19977
Signed-off-by: David Goulet <dgoulet@torproject.org>
OnionTrafficOnly is equivalent to NoDNSRequest, NoIPv4Traffic,
and NoIPv6Traffic.
Add unit tests for parsing and checking option validity.
Add documentation for each flag to the man page.
Add changes file for all of #18693.
Parsing only: the flags do not change client behaviour (yet!)
Rely on onion_populate_cpath to check that we're only using
TAP for the rare hidden service cases.
Check and log if handshakes only support TAP when they should support
ntor.
This bug had existed since 0.2.4.7-alpha, but now that we have
FallbackDirs by default, it actually matters.
Fixes bug 19947; bugfix on 0.2.4.7-alpha or maybe 0.2.8.1-alpha.
Rubiate wrote the patch; teor wrote the changes file.
OpenBSD removes this function, and now that Tor requires Libevent 2,
we should also support the OpenBSD Libevent 2.
Fixes bug 19904; bugfix on 0.2.5.4-alpha.
* Raise limit: 16k isn't all that high.
* Don't log when limit exceded; log later on.
* Say "over" when we log more than we say we log.
* Add target version to changes file
If we know a node's version, and it can't do ntor, consider it not running.
If we have a node's descriptor, and it doesn't have a valid ntor key,
consider it not running.
Refactor these checks so they're consistent between authorities and clients.
Before, they checked for version 0.2.4.18-rc or later, but this
would not catch relays without version lines, or buggy or malicious
relays missing an ntor key.
If we did not find a non-private IPaddress by iterating over interfaces,
we would try to get one via
get_interface_address6_via_udp_socket_hack(). This opens a datagram
socket with IPPROTO_UDP. Previously all our datagram sockets (via
libevent) used IPPROTO_IP, so we did not have that in the sandboxing
whitelist. Add (SOCK_DGRAM, IPPROTO_UDP) sockets to the sandboxing
whitelist. Fixes bug 19660.
The test-network-all target assumes the test-driver script lives in the
current working directory. This assumption breaks out-of-tree builds
because it actually lives in the source directory.
Automake 1.12 introduces `LOG_DRIVER` which defines the location of the
test driver script. Because Tor still supports Automake 1.11 we use the
default value of this variable directly. The default value uses the
configured shell for calling the test driver script and explicitly
prefixes the source directory.
This fixes#19608, allowing IPv6-only clients to use
microdescriptors, while preserving the ability of bridge clients
to have some IPv4 bridges and some IPv6 bridges.
Fix on c281c036 in 0.2.8.2-alpha.
We introduded a shadowed variable, thereby causing a log message to
be wrong. Fixes 19578. I believe the bug was introduced by
54d7d31cba in 0.2.2.29-beta.
asciidoc adds a timestamp at the end of a generated HTML file.
This timestamp is based on the date of the file but it can change
depending on the TZ environment variable.
Our sandboxing code would not allow us to write to stats/hidserv-stats,
causing tor to abort while trying to write stats. This was previously
masked by bug#19556.
When sandboxing is enabled, we could not write any stats to disk.
check_or_create_data_subdir("stats"), which prepares the private stats
directory, calls check_private_dir(), which also opens and not just stats() the
directory. Therefore, we need to also allow open() for the stats dir in our
sandboxing setup.
From 0.2.7.2-alpha onwards, Exits would reject all the IP addresses
they knew about in their exit policy. But this may have disclosed
addresses that were otherwise unlisted.
Now, only advertised addresses are rejected by default by
ExitPolicyRejectPrivate. All known addresses are only rejected when
ExitPolicyRejectLocalInterfaces is explicitly set to 1.
If we manually remove fallbacks in C by adding '/*' and '*/' on separate
lines, stem still parses them as being present, because it only looks at
the start of a line.
Add a comment to this effect in the generated source code.
zlib 1.2 came out in 2003; earlier versions should be dead by now.
Our workaround code was only preventing us from using the gzip
encoding (if we decide to do so), and having some dead code linger
around in torgzip.c
The Autoconf macro AC_USE_SYSTEM_EXTENSIONS defines preprocessor macros
which turn on extensions to C and POSIX. The macro also makes it easier
for developers to use the extensions without needing (or forgetting) to
define them manually.
The macro can be safely used because it was introduced in Autoconf 2.60
and Tor requires Autoconf 2.63 and above.
When deleting an ephemeral HS, we were only iterating on circuit with an
OPEN state. However, it could be possible that an intro point circuit didn't
reached the open state yet.
This commit makes it that we close the circuit regardless of its state
except if it was already marked for close.
Fixes#18604
Signed-off-by: David Goulet <dgoulet@torproject.org>
The FetchHidServDescriptors check was placed before the descriptor cache
lookup which made the option not working because it was never using the
cache in the first place.
Fixes#18704
Patched-by: twim
Signef-off-by: David Goulet <dgoulet@torproject.org>
This is a fairly easy way for us to get our test coverage up on
compat_threads.c and workqueue.c -- I already implemented these
tests, so we might as well enable them.
Previously, we used !directory_fetches_from_authorities() to predict
that we would tunnel connections. But the rules have changed
somewhat over the course of 0.2.8
There was a > that should have been an ==, and a missing !. These
together prevented us from issuing a warning in the case that a
nickname matched an Unnamed node only.
Fixes bug 19203; bugfix on 0.2.3.1-alpha.
Remove support for "GET /tor/bytes.txt" DirPort request, and
"GETINFO dir-usage" controller request, which were only available
via a compile-time option in Tor anyway.
Feature was added in 0.2.2.1-alpha. Resolves ticket 19035.
If OpenSSL fails to generate an RSA key, do not retain a dangling
pointer to the previous (uninitialized) key value. The impact here
should be limited to a difficult-to-trigger crash, if OpenSSL is
running an engine that makes key generation failures possible, or if
OpenSSL runs out of memory. Fixes bug 19152; bugfix on
0.2.1.10-alpha. Found by Yuan Jochen Kang, Suman Jana, and Baishakhi
Ray.
This is potentially scary stuff, so let me walk through my analysis.
I think this is a bug, and a backport candidate, but not remotely
triggerable in any useful way.
Observation 1a:
Looking over the OpenSSL code here, the only way we can really fail in
the non-engine case is if malloc() fails. But if malloc() is failing,
then tor_malloc() calls should be tor_asserting -- the only way that an
attacker could do an exploit here would be to figure out some way to
make malloc() fail when openssl does it, but work whenever Tor does it.
(Also ordinary malloc() doesn't fail on platforms like Linux that
overcommit.)
Observation 1b:
Although engines are _allowed_ to fail in extra ways, I can't find much
evidence online that they actually _do_ fail in practice. More evidence
would be nice, though.
Observation 2:
We don't call crypto_pk_generate*() all that often, and we don't do it
in response to external inputs. The only way to get it to happen
remotely would be by causing a hidden service to build new introduction
points.
Observation 3a:
So, let's assume that both of the above observations are wrong, and the
attacker can make us generate a crypto_pk_env_t with a dangling pointer
in its 'key' field, and not immediately crash.
This dangling pointer will point to what used to be an RSA structure,
with the fields all set to NULL. Actually using this RSA structure,
before the memory is reused for anything else, will cause a crash.
In nearly every function where we call crypto_pk_generate*(), we quickly
use the RSA key pointer -- either to sign something, or to encode the
key, or to free the key. The only exception is when we generate an
intro key in rend_consider_services_intro_points(). In that case, we
don't actually use the key until the intro circuit is opened -- at which
point we encode it, and use it to sign an introduction request.
So in order to exploit this bug to do anything besides crash Tor, the
attacker needs to make sure that by the time the introduction circuit
completes, either:
* the e, d, and n BNs look valid, and at least one of the other BNs is
still NULL.
OR
* all 8 of the BNs must look valid.
To look like a valid BN, *they* all need to have their 'top' index plus
their 'd' pointer indicate an addressable region in memory.
So actually getting useful data of of this, rather than a crash, is
going to be pretty damn hard. You'd have to force an introduction point
to be created (or wait for one to be created), and force that particular
crypto_pk_generate*() to fail, and then arrange for the memory that the
RSA points to to in turn point to 3...8 valid BNs, all by the time the
introduction circuit completes.
Naturally, the signature won't check as valid [*], so the intro point
will reject the ESTABLISH_INTRO cell. So you need to _be_ the
introduction point, or you don't actually see this information.
[*] Okay, so if you could somehow make the 'rsa' pointer point to a
different valid RSA key, then you'd get a valid signature of an
ESTABLISH_INTRO cell using a key that was supposed to be used for
something else ... but nothing else looks like that, so you can't use
that signature elsewhere.
Observation 3b:
Your best bet as an attacker would be to make the dangling RSA pointer
actually contain a fake method, with a fake RSA_private_encrypt
function that actually pointed to code you wanted to execute. You'd
still need to transit 3 or 4 pointers deep though in order to make that
work.
Conclusion:
By 1, you probably can't trigger this without Tor crashing from OOM.
By 2, you probably can't trigger this reliably.
By 3, even if I'm wrong about 1 and 2, you have to jump through a pretty
big array of hoops in order to get any kind of data leak or code
execution.
So I'm calling it a bug, but not a security hole. Still worth
patching.
Fortunately, the arithmetic cannot actually overflow, so long as we
*always* check for the size of potentially hostile input before
copying it. I think we do, though. We do check each line against
MAX_LINE_LENGTH, and each object name or object against
MAX_UNPARSED_OBJECT_SIZE, both of which are 128k. So to get this
overflow, we need to have our memarea allocated way way too high up
in RAM, which most allocators won't actually do.
Bugfix on 0.2.1.1-alpha, where memarea was introduced.
Found by Guido Vranken.
Previously, if the header was present, we'd proceed even if the
function wasn't there.
Easy fix for bug 19161. A better fix would involve trying harder to
find libscrypt_scrypt.
We use a pretty specific pair of autoconf tests here to make sure
that we only add this code when:
a) a 64-bit signed multiply fails to link,
AND
b) the same 64-bit signed multiply DOES link correctly when
__mulodi4 is defined.
Closes ticket 19079.
The routerinfo we pass to routerinfo_incompatible_with_extrainfo is
the latest routerinfo for the relay. The signed_descriptor_t, on
the other hand, is the signed_descriptor_t that corresponds to the
extrainfo. That means we should be checking the digest256 match
with that signed_descriptor_t, not with the routerinfo.
Fixes bug 17150 (and 19017); bugfix on 0.2.7.2-alpha.
When parsing detached signature, we make sure that we use the length of the
digest algorithm instead of an hardcoded DIGEST256_LEN in order to avoid
comparing bytes out of bound with a smaller digest length such as SHA1.
Fixes#19066
Signed-off-by: David Goulet <dgoulet@torproject.org>
Previously we'd only check whether the hardening options succeeded
at the compile step. Now we'll try to link with them too, and tell
the user in advance if something seems likely to go wrong.
Closes ticket 18895.
We know there are overflows in curve25519-donna-c32, so we'll have
to have that one be fwrapv.
Only apply the asan, ubsan, and trapv options to the code that does
not need to run in constant time. Those options introduce branches
to the code they instrument.
(These introduced branches should never actually be taken, so it
might _still_ be constant time after all, but branch predictors are
complicated enough that I'm not really confident here. Let's aim for
safety.)
Closes 17983.
Make directory authorities write the v3-status-votes file out
to disk earlier in the consensus process, so we have the votes
even if we abort the consensus process later on.
Resolves ticket 19036.
In dirserv_compute_performance_thresholds, we allocate arrays based
on the length of 'routers', a list of routerinfo_t, but loop over
the nodelist. The 'routers' list may be shorter when relays were
filtered by routers_make_ed_keys_unique, leading to an out-of-bounds
write on directory authorities.
This bug was originally introduced in 26e89742, but it doesn't look
possible to trigger until routers_make_ed_keys_unique was introduced
in 13a31e72.
Fixes bug 19032; bugfix on tor 0.2.8.2-alpha.
