diff options
Diffstat (limited to 'src/or/channeltls.c')
| -rw-r--r-- | src/or/channeltls.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/src/or/channeltls.c b/src/or/channeltls.c index 155684c0ce..4f2663adab 100644 --- a/src/or/channeltls.c +++ b/src/or/channeltls.c @@ -739,6 +739,15 @@ channel_tls_matches_target_method(channel_t *chan, return 0; } + /* real_addr is the address this connection came from. + * base_.addr is updated by connection_or_init_conn_from_address() + * to be the address in the descriptor. It may be tempting to + * allow either address to be allowed, but if we did so, it would + * enable someone who steals a relay's keys to impersonate/MITM it + * from anywhere on the Internet! (Because they could make long-lived + * TLS connections from anywhere to all relays, and wait for them to + * be used for extends). + */ return tor_addr_eq(&(tlschan->conn->real_addr), target); } @@ -1667,6 +1676,7 @@ channel_tls_process_netinfo_cell(cell_t *cell, channel_tls_t *chan) const uint8_t *cp, *end; uint8_t n_other_addrs; time_t now = time(NULL); + const routerinfo_t *me = router_get_my_routerinfo(); long apparent_skew = 0; tor_addr_t my_apparent_addr = TOR_ADDR_NULL; @@ -1745,8 +1755,20 @@ channel_tls_process_netinfo_cell(cell_t *cell, channel_tls_t *chan) if (my_addr_type == RESOLVED_TYPE_IPV4 && my_addr_len == 4) { tor_addr_from_ipv4n(&my_apparent_addr, get_uint32(my_addr_ptr)); + + if (!get_options()->BridgeRelay && me && + get_uint32(my_addr_ptr) == htonl(me->addr)) { + chan->base_.is_canonical_to_peer = 1; + } + } else if (my_addr_type == RESOLVED_TYPE_IPV6 && my_addr_len == 16) { tor_addr_from_ipv6_bytes(&my_apparent_addr, (const char *) my_addr_ptr); + + if (!get_options()->BridgeRelay && me && + !tor_addr_is_null(&me->ipv6_addr) && + tor_addr_eq(&my_apparent_addr, &me->ipv6_addr)) { + chan->base_.is_canonical_to_peer = 1; + } } n_other_addrs = (uint8_t) *cp++; @@ -1762,6 +1784,14 @@ channel_tls_process_netinfo_cell(cell_t *cell, channel_tls_t *chan) connection_or_close_for_error(chan->conn, 0); 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. + */ if (tor_addr_eq(&addr, &(chan->conn->real_addr))) { connection_or_set_canonical(chan->conn, 1); break; @@ -1770,6 +1800,18 @@ channel_tls_process_netinfo_cell(cell_t *cell, channel_tls_t *chan) --n_other_addrs; } + if (me && !chan->base_.is_canonical_to_peer && chan->conn->is_canonical) { + log_info(LD_OR, + "We made a connection to a relay at %s (fp=%s) but we think " + "they will not consider this connection canonical. They " + "think we are at %s, but we think its %s.", + safe_str(chan->base_.get_remote_descr(&chan->base_, 0)), + safe_str(hex_str(chan->conn->identity_digest, DIGEST_LEN)), + safe_str(tor_addr_is_null(&my_apparent_addr) ? + "<none>" : fmt_and_decorate_addr(&my_apparent_addr)), + safe_str(fmt_addr32(me->addr))); + } + /* Act on apparent skew. */ /** Warn when we get a netinfo skew with at least this value. */ #define NETINFO_NOTICE_SKEW 3600 |