This macro defers to __attribute__((fallthrough)) on GCC (and
clang). Previously we had been using GCC's magic /* fallthrough */
comments, but clang very sensibly doesn't accept those.
Since not all compiler recognize it, we only define it when our
configure script detects that it works.
Part of a fix for 34078.
Do not try to stuff "HS_DESC_DECODE_GENERIC_ERROR" (-1) into a
socks5_reply_status_t (enum). It doesn't actually make sense, and
isn't one of our documented extensions.
(This can only happen on a nonfatal assertion that we haven't seen,
so it probably isn't happening in practice.)
Fixes another case of bug 34077; bugfix on 0.4.3.1-alpha.
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>
