diff options
Diffstat (limited to 'src/core/or/channeltls.c')
| -rw-r--r-- | src/core/or/channeltls.c | 51 |
1 files changed, 20 insertions, 31 deletions
diff --git a/src/core/or/channeltls.c b/src/core/or/channeltls.c index efa8e2d891..56552f0095 100644 --- a/src/core/or/channeltls.c +++ b/src/core/or/channeltls.c @@ -45,8 +45,10 @@ #include "core/or/circuitmux_ewma.h" #include "core/or/command.h" #include "app/config/config.h" +#include "app/config/resolve_addr.h" #include "core/mainloop/connection.h" #include "core/or/connection_or.h" +#include "feature/relay/relay_handshake.h" #include "feature/control/control.h" #include "feature/client/entrynodes.h" #include "trunnel/link_handshake.h" @@ -107,7 +109,7 @@ channel_tls_get_transport_name_method(channel_t *chan, char **transport_out); static const char * channel_tls_get_remote_descr_method(channel_t *chan, int flags); static int channel_tls_has_queued_writes_method(channel_t *chan); -static int channel_tls_is_canonical_method(channel_t *chan, int req); +static int channel_tls_is_canonical_method(channel_t *chan); static int channel_tls_matches_extend_info_method(channel_t *chan, extend_info_t *extend_info); @@ -563,10 +565,7 @@ channel_tls_get_transport_name_method(channel_t *chan, char **transport_out) static const char * channel_tls_get_remote_descr_method(channel_t *chan, int flags) { - /* IPv6 address, colon, port */ -#define MAX_DESCR_LEN (TOR_ADDR_BUF_LEN + 1 + 5) - - static char buf[MAX_DESCR_LEN + 1]; + static char buf[TOR_ADDRPORT_BUF_LEN]; channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan); connection_t *conn; const char *answer = NULL; @@ -579,15 +578,14 @@ channel_tls_get_remote_descr_method(channel_t *chan, int flags) switch (flags) { case 0: /* Canonical address with port*/ - tor_snprintf(buf, MAX_DESCR_LEN + 1, + tor_snprintf(buf, TOR_ADDRPORT_BUF_LEN, "%s:%u", conn->address, conn->port); answer = buf; break; case GRD_FLAG_ORIGINAL: /* Actual address with port */ addr_str = tor_addr_to_str_dup(&(tlschan->conn->real_addr)); - tor_snprintf(buf, MAX_DESCR_LEN + 1, - "%s:%u", addr_str, conn->port); + tor_snprintf(buf, TOR_ADDRPORT_BUF_LEN, "%s:%u", addr_str, conn->port); tor_free(addr_str); answer = buf; break; @@ -645,12 +643,11 @@ channel_tls_has_queued_writes_method(channel_t *chan) /** * Tell the upper layer if we're canonical. * - * This implements the is_canonical method for channel_tls_t; if req is zero, - * it returns whether this is a canonical channel, and if it is one it returns - * whether that can be relied upon. + * This implements the is_canonical method for channel_tls_t: + * it returns whether this is a canonical channel. */ static int -channel_tls_is_canonical_method(channel_t *chan, int req) +channel_tls_is_canonical_method(channel_t *chan) { int answer = 0; channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan); @@ -658,24 +655,13 @@ channel_tls_is_canonical_method(channel_t *chan, int req) tor_assert(tlschan); if (tlschan->conn) { - switch (req) { - case 0: - answer = tlschan->conn->is_canonical; - break; - case 1: - /* - * Is the is_canonical bit reliable? In protocols version 2 and up - * we get the canonical address from a NETINFO cell, but in older - * versions it might be based on an obsolete descriptor. - */ - answer = (tlschan->conn->link_proto >= 2); - break; - default: - /* This shouldn't happen; channel.c is broken if it does */ - tor_assert_nonfatal_unreached_once(); - } + /* If this bit is set to 0, and link_proto is sufficiently old, then we + * can't actually _rely_ on this being a non-canonical channel. + * Nonetheless, we're going to believe that this is a non-canonical + * channel in this case, since nobody should be using these link protocols + * any more. */ + answer = tlschan->conn->is_canonical; } - /* else return 0 for tlschan->conn == NULL */ return answer; } @@ -738,10 +724,13 @@ channel_tls_matches_target_method(channel_t *chan, * 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 + * enable someone who steals a relay's keys to covertly 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). + * + * An adversary who has stolen a relay's keys could also post a fake relay + * descriptor, but that attack is easier to detect. */ return tor_addr_eq(&(tlschan->conn->real_addr), target); } @@ -1665,7 +1654,7 @@ tor_addr_from_netinfo_addr(tor_addr_t *tor_addr, } else if (type == NETINFO_ADDR_TYPE_IPV6 && len == 16) { const uint8_t *ipv6_bytes = netinfo_addr_getconstarray_addr_ipv6( netinfo_addr); - tor_addr_from_ipv6_bytes(tor_addr, (const char *)ipv6_bytes); + tor_addr_from_ipv6_bytes(tor_addr, ipv6_bytes); } else { log_fn(LOG_PROTOCOL_WARN, LD_OR, "Cannot read address from NETINFO " "- wrong type/length."); |