Allow clients and relays to send dual-stack and IPv6-only EXTEND2 cells.
Parse dual-stack and IPv6-only EXTEND2 cells on relays.
Relays do not make connections or extend circuits via IPv6: that's the
next step.
Closes ticket 33901.
Log IPv6 addresses on connections where this relay is the responder.
Previously, responding relays would replace the remote IPv6 address with
the IPv4 address from the consensus.
(The port is replaced with the IPv6 ORPort from the consensus, we will
resolve this issue in 33898.)
Fixes bug 33899; bugfix on 0.3.1.1-alpha.
Consider IPv6 addresses when checking if a connection is canonical.
In 17604, relays assumed that a remote relay could consider an IPv6
connection canonical, but did not set the canonical flag on their side
of the connection.
Fixes bug 33899; bugfix on 0.3.1.1-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>