commit 427ae164f33aad6004290fc407d53ab3315b399a Author: Nick Mathewson nickm@torproject.org Date: Wed Sep 20 09:38:50 2017 -0400

Fix a comment that misunderstood is_canonical

is_canonical doesn't mean "am I connected to the one true address of this relay"; it means "does this relay tell me that the address I'm connected to belong to it." The point is to prevent TCP-based MITM, not to prevent the relay from multi-homing.

Related to 22890. --- src/or/channeltls.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/src/or/channeltls.c b/src/or/channeltls.c index 7f6882448..827781318 100644 --- a/src/or/channeltls.c +++ b/src/or/channeltls.c @@ -1793,12 +1793,11 @@ channel_tls_process_netinfo_cell(cell_t *cell, channel_tls_t *chan) return; } /* A relay can connect from anywhere and be canonical, so - * long as it tells you from where it came. This may be a bit - * concerning.. Luckily we have another check in - * channel_tls_matches_target_method() to ensure that extends - * only go to the IP they ask for. - * - * XXX: Bleh. That check is not used if the connection is canonical. + * long as it tells you from where it came. This may sound a bit + * concerning... but that's what "canonical" means: that the + * address is one that the relay itself has claimed. The relay + * might be doing something funny, but nobody else is doing a MITM + * on the relay's TCP. */ if (tor_addr_eq(&addr, &(chan->conn->real_addr))) { connection_or_set_canonical(chan->conn, 1);