The client auth protocol allows attacker-controlled x25519 private keys being
passed around, which allows an attacker to potentially trigger the all-zeroes
assert for client_auth_sk in hs_descriptor.c:decrypt_descriptor_cookie().
We fixed that by making sure that an all-zeroes client auth key will not be
used.
There are no guidelines for validating x25519 private keys, and the assert was
there as a sanity check for code flow issues (we don't want to enter that
function with an unitialized key if client auth is being used). To avoid such
crashes in the future, we also changed the assert to a BUG-and-err.
This change broke torsocks that by default is expecting an IPv4 for hostname
resolution because it can't ask tor for a specific IP version with the SOCKS5
extension.
PreferIPv6 made it that sometimes the IPv6 could be returned to torsocks that
was expecting an IPv4.
Torsocks is probably a very unique case because the runtime flow is that it
hijacks DNS resolution (ex: getaddrinfo()), gets an IP and then sends it back
for the connect() to happen.
The libc has DNS resolution functions that allows the caller to request a
specific INET family but torsocks can't tell tor to resolve the hostname only
to an IPv4 or IPv6 and thus by default fallsback to IPv4.
Reverting this change into 0.4.3.x series but we'll keep it in the 0.4.4.x
series in the hope that we add this SOCKS5 extension to tor for DNS resolution
and then change torsocks to use that.
Fixes#33804
Signed-off-by: David Goulet <dgoulet@torproject.org>
Avoid conflicts between the fake sockets in tor's unit tests, and real
file descriptors. Resolves issues running unit tests with GitHub
Actions, where the process that embeds or launches the tests has
already opened a large number of file descriptors.
Fixes bug 33782; bugfix on 0.2.8.1-alpha.
Found and fixed by Putta Khunchalee.
Previously we just ignored this option, which would leave it unset,
and cause an assertion failure later on when running with the User
option.
Fixes bug 33668; bugfix on 0.4.3.1-alpha.
Copy required DLLs to test and app, before running tor's tests.
This ensures that tor.exe and test*.exe use the correct version of each
DLL. This fix is not required, but we hope it will avoid DLL search
issues in future.
Closes bug 33673; bugfix on 0.3.4.2-alpha.
For example, "TOR_SKIP_TESTCASES=crypto/.. ./src/test/test" will run
the tests and suppress all the "crypto/" tests. You could get the
same effect by running "./src/test/test :crypto/..", but that can be
harder to arrange from CI.
Part of a fix/workaround for 33643.
Given that ed25519 public key validity checks are usually not needed
and (so far) they are only necessary for onion addesses in the Tor
protocol, we decided to fix this specific bug instance without
modifying the rest of the codebase (see below for other fix
approaches).
In our minimal fix we check that the pubkey in
hs_service_add_ephemeral() is valid and error out otherwise.
This function does a nonfatal assertion to make sure that a machine
is not registered twice, but Tobias Pulls found a case where it
happens. Instead, make the function exit early so that it doesn't
cause a remotely triggered memory leak.
Fixes bug 33619; bugfix on 0.4.0.1-alpha. This is also tracked as
TROVE-2020-004.
Nick Mathewson
teor
George Kadianakis
David Goulet