diff options
| -rw-r--r-- | ChangeLog | 3 | ||||
| -rw-r--r-- | src/or/circuitbuild.c | 8 |
2 files changed, 10 insertions, 1 deletions
@@ -38,6 +38,9 @@ Changes in version 0.2.1.13-alpha - 2009-02-09 manner, to avoid platform-dependent behavior on malformed input. - Build correctly when configured to build outside the main source path. Patch from Michael Gold. + - We were already rejecting relay begin cells with destination port + of 0. Now also reject extend cells with destination port or address + of 0. Suggested by lark. o Minor bugfixes (on 0.2.1.x): - Don't re-extend introduction circuits if we ran out of RELAY_EARLY diff --git a/src/or/circuitbuild.c b/src/or/circuitbuild.c index 42da9e6fe..1cda8e870 100644 --- a/src/or/circuitbuild.c +++ b/src/or/circuitbuild.c @@ -762,7 +762,13 @@ circuit_extend(cell_t *cell, circuit_t *circ) id_digest = cell->payload+RELAY_HEADER_SIZE+4+2+ONIONSKIN_CHALLENGE_LEN; tor_addr_from_ipv4h(&n_addr, n_addr32); - /* First, check if they asked us for 0000..0000. We support using + if (!n_port || !n_addr32) { + log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, + "Client asked me to extend to zero destination port or addr."); + return -1; + } + + /* Check if they asked us for 0000..0000. We support using * an empty fingerprint for the first hop (e.g. for a bridge relay), * but we don't want to let people send us extend cells for empty * fingerprints -- a) because it opens the user up to a mitm attack, |