The defense counts the circuit failure rate for each guard for the past N
circuits. Failure is defined as the ability to complete a first hop, but not
finish completing the circuit all the way to the exit.
If the failure rate exceeds a certain amount, a notice is emitted.
If it exceeds a greater amount, a warn is emitted and the guard is disabled.
These values are governed by consensus parameters which we intend to tune as
we perform experiments and statistical simulations.
From what I can tell, this configuration is usually a mistake, and
leads people to think that all their traffic is getting proxied when
in fact practically none of it is. Resolves the issue behind "bug"
4663.
The function is not guaranteed to NUL-terminate its output. It
*is*, however, guaranteed not to generate more than two bytes per
multibyte character (plus terminating nul), so the general approach
I'm taking is to try to allocate enough space, AND to manually add a
NUL at the end of each buffer just in case I screwed up the "enough
space" thing.
Fixes bug 5909.
This feature can make Tor relays less identifiable by their use of the
mod_ssl DH group, but at the cost of some usability (#4721) and bridge
tracing (#6087) regressions.
We should try to turn this on by default again if we find that the
mod_ssl group is uncommon and/or we move to a different DH group size
(see #6088). Before we can do so, we need a fix for bugs #6087 and
Resolves ticket #5598 for now.
These stats are currently discarded, but we might as well
hard-disable them on bridges, to be clean.
Fix for bug 5824; bugfix on 0.2.1.17-rc.
Patch originally by Karsten Loesing.
Also, try to resolve some doxygen issues. First, define a magic
"This is doxygen!" macro so that we take the correct branch in
various #if/#else/#endifs in order to get the right documentation.
Second, add in a few grouping @{ and @} entries in order to get some
variables and fields to get grouped together.
Roger explains at
http://archives.seul.org/tor/talk/Nov-2011/msg00209.html :
"If you list your bridge as part of your family in the relay
descriptor, then everybody can learn your bridge fingerprint, and
they can look up your bridge's descriptor (and thus location) at
the bridge directory authority."
Now, we can't stop relays from listing bridges, but we can warn when
we notice a bridge listing anybody, which might help some.
This fixes bug 4657; it's a fix on 0.2.0.3-alpha, where bridges were
first introduced.
Previously, we skipped everything that got invoked from
options_init_from_torrc. But some of the stuff in
options_act_reversible and options_act is actually important, like
reopening the logs.
Now, a SIGHUP always makes the effects of an options_set() happen,
even though the options haven't changed.
Fix for bug 5095; bugfix on 0.2.1.9-alpha, which introduced
__ReloadTorrcOnSIGHUP.
Instead, allow packagers to put a 'TOR_BUILD_TAG' field in the
server descriptor to indicate a platform-specific value, if they
need to. (According to weasel, this was his use for the git- tag
previously.)
This is part of 2988
* Document fmt_addr_impl() and friends.
* Parenthesize macro arguments.
* Rename get_first_listener_addrport_for_pt() to
get_first_listener_addrport_string().
* Handle port_cfg_t with no_listen.
* Handle failure of router_get_active_listener_port_by_type().
* Add an XXX to router_get_active_listener_port_by_type().
This is just refactoring work here. The old logic was kind of
convoluted, especially after the bug 5572 fix. We don't actually need to
distinguish so many cases here. Dropping detection of the
"!old_options || !old_options->DynamicDHGroups" case is fine because
that's the same that we'd do for clients.
Also add a changes file for bug 5572.
This fixes a side-channel attack on the (fortunately unused!)
BridgePassword option for bridge authorities. Fix for bug 5543;
bugfix on 0.2.0.14-alpha.
Introduce get_first_listener_addrport_for_pt() which returns a string
containing the addrport of the first listener we could find. Use it to
form the TOR_PT_ORPORT managed proxy protocol line.
This commit is completely mechanical; I used this perl script to make it:
#!/usr/bin/perl -w -i.bak -p
if (/^\s*\#/) {
s/MS_WINDOWS/_WIN32/g;
s/\bWIN32\b/_WIN32/g;
}
These were found by looking for tor_snprintf() instances that were
preceeded closely by tor_malloc(), though I probably converted some
more snprintfs as well.
(In every case, make sure that the length variable (if any) is
removed, renamed, or lowered, so that anything else that might have
assumed a longer buffer doesn't exist.)
These were found by looking for tor_snprintf() instances that were
followed closely by tor_strdup(), though I probably converted some
other snprintfs as well.
(To ensure correctness, in every case, make sure that the temporary
variable is deleted, renamed, or lowered in scope, so we can't have
any bugs related to accidentally relying on the no-longer-filled
variable.)
The Tor2webMode torrc option is still required to run a Tor client in
'tor2web mode', but now it can't be turned on at runtime in a normal build
of Tor. (And a tor2web build of Tor can't be used as a normal Tor client,
so we don't have to worry as much about someone distributing packages with
this particular pistol accessible to normal users.)
It might be nice to support this someday, but for now it would fail
with an infinite remap cycle. (If I say "remap * *.foo.exit",
then example.com ->
example.com.foo.exit ->
example.com.foo.exit.foo.exit ->
example.com.foo.exit.foo.exit.foo.exit -> ...)
In this new representation for wildcarded addresses, there are no
longer any 'magic addresses': rather, "a.b c.d", "*.a.b c.d" and
"*.a.b *.c.d" are all represented by a mapping from "a.b" to "c.d". we
now distinguish them by setting bits in the addressmap_entry_t
structure, where src_wildcard is set if the source address had a
wildcard, and dst_wildcard is set if the target address had a
wildcard.
This lets the case where "*.a.b *.c.d" or "*.a.b c.d" remap the
address "a.b" get handled trivially, and lets us simplify and improve
the addressmap_match_superdomains implementation: we can now have it
run in O(parts of address) rather than O(entries in addressmap).
1. Only allow '*.' in MapAddress expressions. Ignore '*ample.com' and '.example.com'.
This has resulted in a slight refactoring of config_register_addressmaps.
2. Add some more detail to the man page entry for AddressMap.
3. Fix initialization of a pointer to NULL rather than 0.
4. Update the unit tests to cater for the changes in 1 and test more explicitly for
recursive mapping.
1. Implement the following mapping rules:
MapAddress a.b.c d.e.f # This is what we have now
MapAddress .a.b.c d.e.f # Replaces any address ending with .a.b.c with d.e.f
MapAddress .a.b.c .d.e.f # Replaces the .a.b.c at the end of any addr with .d.e.f
(Note that 'a.b.c .d.e.f' is invalid, and will be rejected.)
2. Add tests for the new rules.
3. Allow proper wildcard annotation, i.e. '*.d.e' '.d.e' will still work.
4. Update addressmap_entry_t with an is_wildcard member.
This code handles the new ORPort options, and incidentally makes all
remaining port types use the new port configuration systems.
There are some rough edges! It doesn't do well in the case where your
Address says one thing but you say to Advertise another ORPort. It
doesn't handle AllAddrs. It doesn't actually advertise anything besides
the first listed advertised IPv4 ORPort and DirPort. It doesn't do
port forwarding to them either.
It's not tested either, it needs more documentation, and it probably
forgets to put the milk back in the refrigerator.
Some controllers want this so they can mess with Tor's configuration
for a while via the control port before actually letting Tor out of
the house.
We do this with a new DisableNetwork option, that prevents Tor from
making any outbound connections or binding any non-control
listeners. Additionally, it shuts down the same functionality as
shuts down when we are hibernating, plus the code that launches
directory downloads.
To make sure I didn't miss anything, I added a clause straight to
connection_connect, so that we won't even try to open an outbound
socket when the network is disabled. In my testing, I made this an
assert, but since I probably missed something, I've turned it into a
BUG warning for testing.
This will mainly help distributors by giving a way to set system or package
defaults that a user can override, and that a later package can replace.
No promises about the particular future location or semantics for this:
we will probably want to tweak it some before 0.2.3.x-rc
The file is searched for in CONFDIR/torrc-defaults , which can be
overridden with the "--defaults-torrc" option on the command line.
This starts an effort to refactor torrc handling code to make it easier
to live with. It makes it possible to override exit policies from the
command line, and possible to override (rather than append to) socksport
lists from the command line.
It'll be necessary to make a "base" torrc implementation work at all.
Instead of only writing the dynamic DH prime modulus to a file, write
the whole DH parameters set for forward compatibility. At the moment
we only accept '2' as the group generator.
The DH parameters gets stored in base64-ed DER format to the
'dynamic_dh_params' file.
We used to do init_keys() if DynamicDHGroups changed after a HUP, so
that the dynamic DH modulus was stored on the disk. Since we are now
doing dynamic DH modulus storing in crypto.c, we can simply initialize
the TLS context and be good with it.
Introduce a new function router_initialize_tls_context() which
initializes the TLS context and use it appropriately.
