This issue was reported by Jann Horn part of Google's Project Zero.
Jann's one-sentence summary: entry/middle relays can spoof RELAY_END cells on
half-closed streams, which can lead to stream confusion between OP and
exit.
Fixes#40389
Previously, we would detect errors from a missing RNG
implementation, but not failures from the RNG code itself.
Fortunately, it appears those failures do not happen in practice
when Tor is using OpenSSL's default RNG implementation. Fixes bug
40390; bugfix on 0.2.8.1-alpha. This issue is also tracked as
TROVE-2021-004. Reported by Jann Horn at Google's Project Zero.
As of GCC 11.1.1, the compiler warns us about code like this:
if (a)
b;
c;
and that's a good thing: we wouldn't want to "goto fail". But we
had an instance if this in circuituse.c, which was making our
compilation sad.
Fixes bug 40380; bugfix on 0.3.0.1-alpha.
We were looking for the first instance of "directory-signature "
when instead the correct behavior is to look for the first instance
of "directory-signature " at the start of a line.
Unfortunately, this can be exploited as to crash authorities while
they're voting.
Fixes#40316; bugfix on 0.2.2.4-alpha. This is TROVE-2021-002,
also tracked as CVE-2021-28090.
It can be called with strings that should have been
length-delimited, but which in fact are not. This can cause a
CPU-DoS bug or, in a worse case, a crash.
Since this function isn't essential, the best solution for older
Tors is to just turn it off.
Fixes bug 40286; bugfix on 0.2.2.1-alpha when dump_desc() was
introduced.
The TORPROTOCOL reason causes the client to close the circuit which is not
what we want because other valid streams might be on it.
Instead, CONNECTION_REFUSED will leave it open but will not allow more streams
to be attached to it. The client then open a new circuit to the destination.
Closes#40270
Signed-off-by: David Goulet <dgoulet@torproject.org>
This is to minimize false positive and thus deny reentry to Exit connections
that were in reality not re-entering. Helps with overall UX.
Signed-off-by: David Goulet <dgoulet@torproject.org>
Obey the "allow-network-reentry" consensus parameters in order to decide to
allow it or not at the Exit.
Closes#40268
Signed-off-by: David Goulet <dgoulet@torproject.org>
Exit relays now reject exit attempts to known relay addresses + ORPort and
also to authorities on the ORPort and DirPort.
Closes#2667
Signed-off-by: David Goulet <dgoulet@torproject.org>
In order to deny re-entry in the network, we now keep a bloomfilter of relay
ORPort + address and authorities ORPort + address and DirPort + address
combinations.
So when an Exit stream is handled, we deny anything connecting back into the
network on the ORPorts for relays and on the ORPort+DirPort for the
authorities.
Related to #2667
Signed-off-by: David Goulet <dgoulet@torproject.org>
Generates the compile_commands.json file using the "bear" application so the
ccls server can be more efficient with our code base.
Closes#40227
Signed-off-by: David Goulet <dgoulet@torproject.org>
George Kadianakis
David Goulet
Nick Mathewson
Roger Dingledine
Alex Xu (Hello71)