diff options
Diffstat (limited to 'src/or/circuitbuild.c')
| -rw-r--r-- | src/or/circuitbuild.c | 737 |
1 files changed, 465 insertions, 272 deletions
diff --git a/src/or/circuitbuild.c b/src/or/circuitbuild.c index 79962e8dbb..b36fed63b3 100644 --- a/src/or/circuitbuild.c +++ b/src/or/circuitbuild.c @@ -1,7 +1,7 @@ /* Copyright (c) 2001 Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2016, The Tor Project, Inc. */ + * Copyright (c) 2007-2017, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -46,6 +46,7 @@ #include "crypto.h" #include "directory.h" #include "entrynodes.h" +#include "hs_ntor.h" #include "main.h" #include "microdesc.h" #include "networkstatus.h" @@ -70,11 +71,15 @@ static channel_t * channel_connect_for_circuit(const tor_addr_t *addr, static int circuit_deliver_create_cell(circuit_t *circ, const create_cell_t *create_cell, int relayed); -static int onion_pick_cpath_exit(origin_circuit_t *circ, extend_info_t *exit); +static int onion_pick_cpath_exit(origin_circuit_t *circ, extend_info_t *exit, + int is_hs_v3_rp_circuit); static crypt_path_t *onion_next_hop_in_cpath(crypt_path_t *cpath); static int onion_extend_cpath(origin_circuit_t *circ); -static int count_acceptable_nodes(smartlist_t *routers); static int onion_append_hop(crypt_path_t **head_ptr, extend_info_t *choice); +static int circuit_send_first_onion_skin(origin_circuit_t *circ); +static int circuit_build_no_more_hops(origin_circuit_t *circ); +static int circuit_send_intermediate_onion_skin(origin_circuit_t *circ, + crypt_path_t *hop); /** This function tries to get a channel to the specified endpoint, * and then calls command_setup_channel() to give it the right @@ -285,14 +290,9 @@ circuit_list_path_impl(origin_circuit_t *circ, int verbose, int verbose_names) base16_encode(elt+1, HEX_DIGEST_LEN+1, id, DIGEST_LEN); } } else { /* ! verbose_names */ - node = node_get_by_id(id); - if (node && node_is_named(node)) { - elt = tor_strdup(node_get_nickname(node)); - } else { - elt = tor_malloc(HEX_DIGEST_LEN+2); - elt[0] = '$'; - base16_encode(elt+1, HEX_DIGEST_LEN+1, id, DIGEST_LEN); - } + elt = tor_malloc(HEX_DIGEST_LEN+2); + elt[0] = '$'; + base16_encode(elt+1, HEX_DIGEST_LEN+1, id, DIGEST_LEN); } tor_assert(elt); if (verbose) { @@ -501,10 +501,15 @@ circuit_establish_circuit(uint8_t purpose, extend_info_t *exit_ei, int flags) { origin_circuit_t *circ; int err_reason = 0; + int is_hs_v3_rp_circuit = 0; + + if (flags & CIRCLAUNCH_IS_V3_RP) { + is_hs_v3_rp_circuit = 1; + } circ = origin_circuit_init(purpose, flags); - if (onion_pick_cpath_exit(circ, exit_ei) < 0 || + if (onion_pick_cpath_exit(circ, exit_ei, is_hs_v3_rp_circuit) < 0 || onion_populate_cpath(circ) < 0) { circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_NOPATH); return NULL; @@ -817,12 +822,7 @@ should_use_create_fast_for_circuit(origin_circuit_t *circ) * creating on behalf of others. */ return 0; } - if (options->FastFirstHopPK == -1) { - /* option is "auto", so look at the consensus. */ - return networkstatus_get_param(NULL, "usecreatefast", 1, 0, 1); - } - - return options->FastFirstHopPK; + return networkstatus_get_param(NULL, "usecreatefast", 0, 0, 1); } /** Return true if <b>circ</b> is the type of circuit we want to count @@ -918,225 +918,275 @@ circuit_purpose_may_omit_guard(int purpose) * If circ's first hop is closed, then we need to build a create * cell and send it forward. * - * Otherwise, we need to build a relay extend cell and send it - * forward. + * Otherwise, if circ's cpath still has any non-open hops, we need to + * build a relay extend cell and send it forward to the next non-open hop. + * + * If all hops on the cpath are open, we're done building the circuit + * and we should do housekeeping for the newly opened circuit. * * Return -reason if we want to tear down circ, else return 0. */ int circuit_send_next_onion_skin(origin_circuit_t *circ) { - crypt_path_t *hop; - const node_t *node; - tor_assert(circ); if (circ->cpath->state == CPATH_STATE_CLOSED) { - /* This is the first hop. */ - create_cell_t cc; - int fast; - int len; - log_debug(LD_CIRC,"First skin; sending create cell."); - memset(&cc, 0, sizeof(cc)); - if (circ->build_state->onehop_tunnel) - control_event_bootstrap(BOOTSTRAP_STATUS_ONEHOP_CREATE, 0); - else - control_event_bootstrap(BOOTSTRAP_STATUS_CIRCUIT_CREATE, 0); + /* Case one: we're on the first hop. */ + return circuit_send_first_onion_skin(circ); + } - node = node_get_by_id(circ->base_.n_chan->identity_digest); - fast = should_use_create_fast_for_circuit(circ); - if (!fast) { - /* We are an OR and we know the right onion key: we should - * send a create cell. - */ - circuit_pick_create_handshake(&cc.cell_type, &cc.handshake_type, - circ->cpath->extend_info); - } else { - /* We are not an OR, and we're building the first hop of a circuit to a - * new OR: we can be speedy and use CREATE_FAST to save an RSA operation - * and a DH operation. */ - cc.cell_type = CELL_CREATE_FAST; - cc.handshake_type = ONION_HANDSHAKE_TYPE_FAST; - } + tor_assert(circ->cpath->state == CPATH_STATE_OPEN); + tor_assert(circ->base_.state == CIRCUIT_STATE_BUILDING); + crypt_path_t *hop = onion_next_hop_in_cpath(circ->cpath); - len = onion_skin_create(cc.handshake_type, - circ->cpath->extend_info, - &circ->cpath->handshake_state, - cc.onionskin); - if (len < 0) { - log_warn(LD_CIRC,"onion_skin_create (first hop) failed."); - return - END_CIRC_REASON_INTERNAL; - } - cc.handshake_len = len; + if (hop) { + /* Case two: we're on a hop after the first. */ + return circuit_send_intermediate_onion_skin(circ, hop); + } - if (circuit_deliver_create_cell(TO_CIRCUIT(circ), &cc, 0) < 0) - return - END_CIRC_REASON_RESOURCELIMIT; + /* Case three: the circuit is finished. Do housekeeping tasks on it. */ + return circuit_build_no_more_hops(circ); +} - circ->cpath->state = CPATH_STATE_AWAITING_KEYS; - circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_BUILDING); - log_info(LD_CIRC,"First hop: finished sending %s cell to '%s'", - fast ? "CREATE_FAST" : "CREATE", - node ? node_describe(node) : "<unnamed>"); +/** + * Called from circuit_send_next_onion_skin() when we find ourselves connected + * to the first hop in <b>circ</b>: Send a CREATE or CREATE2 or CREATE_FAST + * cell to that hop. Return 0 on success; -reason on failure (if the circuit + * should be torn down). + */ +static int +circuit_send_first_onion_skin(origin_circuit_t *circ) +{ + int fast; + int len; + const node_t *node; + create_cell_t cc; + memset(&cc, 0, sizeof(cc)); + + log_debug(LD_CIRC,"First skin; sending create cell."); + + if (circ->build_state->onehop_tunnel) { + control_event_bootstrap(BOOTSTRAP_STATUS_ONEHOP_CREATE, 0); } else { - extend_cell_t ec; - int len; - tor_assert(circ->cpath->state == CPATH_STATE_OPEN); - tor_assert(circ->base_.state == CIRCUIT_STATE_BUILDING); - log_debug(LD_CIRC,"starting to send subsequent skin."); - hop = onion_next_hop_in_cpath(circ->cpath); - memset(&ec, 0, sizeof(ec)); - if (!hop) { - /* done building the circuit. whew. */ - guard_usable_t r; - if (! circ->guard_state) { - if (circuit_get_cpath_len(circ) != 1 && - ! circuit_purpose_may_omit_guard(circ->base_.purpose) && - get_options()->UseEntryGuards) { - log_warn(LD_BUG, "%d-hop circuit %p with purpose %d has no " - "guard state", - circuit_get_cpath_len(circ), circ, circ->base_.purpose); - } - r = GUARD_USABLE_NOW; - } else { - r = entry_guard_succeeded(&circ->guard_state); - } - const int is_usable_for_streams = (r == GUARD_USABLE_NOW); - if (r == GUARD_USABLE_NOW) { - circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_OPEN); - } else if (r == GUARD_MAYBE_USABLE_LATER) { - // Wait till either a better guard succeeds, or till - // all better guards fail. - circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_GUARD_WAIT); - } else { - tor_assert_nonfatal(r == GUARD_USABLE_NEVER); - return - END_CIRC_REASON_INTERNAL; - } + control_event_bootstrap(BOOTSTRAP_STATUS_CIRCUIT_CREATE, 0); - /* XXXX #21422 -- the rest of this branch needs careful thought! - * Some of the things here need to happen when a circuit becomes - * mechanically open; some need to happen when it is actually usable. - * I think I got them right, but more checking would be wise. -NM - */ + /* If this is not a one-hop tunnel, the channel is being used + * for traffic that wants anonymity and protection from traffic + * analysis (such as netflow record retention). That means we want + * to pad it. + */ + if (circ->base_.n_chan->channel_usage < CHANNEL_USED_FOR_FULL_CIRCS) + circ->base_.n_chan->channel_usage = CHANNEL_USED_FOR_FULL_CIRCS; + } - if (circuit_timeout_want_to_count_circ(circ)) { - struct timeval end; - long timediff; - tor_gettimeofday(&end); - timediff = tv_mdiff(&circ->base_.timestamp_began, &end); + node = node_get_by_id(circ->base_.n_chan->identity_digest); + fast = should_use_create_fast_for_circuit(circ); + if (!fast) { + /* We know the right onion key: we should send a create cell. */ + circuit_pick_create_handshake(&cc.cell_type, &cc.handshake_type, + circ->cpath->extend_info); + } else { + /* We don't know an onion key, so we need to fall back to CREATE_FAST. */ + cc.cell_type = CELL_CREATE_FAST; + cc.handshake_type = ONION_HANDSHAKE_TYPE_FAST; + } - /* - * If the circuit build time is much greater than we would have cut - * it off at, we probably had a suspend event along this codepath, - * and we should discard the value. - */ - if (timediff < 0 || - timediff > 2*get_circuit_build_close_time_ms()+1000) { - log_notice(LD_CIRC, "Strange value for circuit build time: %ldmsec. " - "Assuming clock jump. Purpose %d (%s)", timediff, - circ->base_.purpose, - circuit_purpose_to_string(circ->base_.purpose)); - } else if (!circuit_build_times_disabled(get_options())) { - /* Only count circuit times if the network is live */ - if (circuit_build_times_network_check_live( - get_circuit_build_times())) { - circuit_build_times_add_time(get_circuit_build_times_mutable(), - (build_time_t)timediff); - circuit_build_times_set_timeout(get_circuit_build_times_mutable()); - } - - if (circ->base_.purpose != CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT) { - circuit_build_times_network_circ_success( - get_circuit_build_times_mutable()); - } - } - } - log_info(LD_CIRC,"circuit built!"); - circuit_reset_failure_count(0); + len = onion_skin_create(cc.handshake_type, + circ->cpath->extend_info, + &circ->cpath->handshake_state, + cc.onionskin); + if (len < 0) { + log_warn(LD_CIRC,"onion_skin_create (first hop) failed."); + return - END_CIRC_REASON_INTERNAL; + } + cc.handshake_len = len; - if (circ->build_state->onehop_tunnel || circ->has_opened) { - control_event_bootstrap(BOOTSTRAP_STATUS_REQUESTING_STATUS, 0); - } + if (circuit_deliver_create_cell(TO_CIRCUIT(circ), &cc, 0) < 0) + return - END_CIRC_REASON_RESOURCELIMIT; - pathbias_count_build_success(circ); - circuit_rep_hist_note_result(circ); - if (is_usable_for_streams) - circuit_has_opened(circ); /* do other actions as necessary */ - - if (!have_completed_a_circuit() && !circ->build_state->onehop_tunnel) { - const or_options_t *options = get_options(); - note_that_we_completed_a_circuit(); - /* FFFF Log a count of known routers here */ - log_notice(LD_GENERAL, - "Tor has successfully opened a circuit. " - "Looks like client functionality is working."); - if (control_event_bootstrap(BOOTSTRAP_STATUS_DONE, 0) == 0) { - log_notice(LD_GENERAL, - "Tor has successfully opened a circuit. " - "Looks like client functionality is working."); - } - control_event_client_status(LOG_NOTICE, "CIRCUIT_ESTABLISHED"); - clear_broken_connection_map(1); - if (server_mode(options) && !check_whether_orport_reachable(options)) { - inform_testing_reachability(); - consider_testing_reachability(1, 1); - } + circ->cpath->state = CPATH_STATE_AWAITING_KEYS; + circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_BUILDING); + log_info(LD_CIRC,"First hop: finished sending %s cell to '%s'", + fast ? "CREATE_FAST" : "CREATE", + node ? node_describe(node) : "<unnamed>"); + return 0; +} + +/** + * Called from circuit_send_next_onion_skin() when we find that we have no + * more hops: mark the circuit as finished, and perform the necessary + * bookkeeping. Return 0 on success; -reason on failure (if the circuit + * should be torn down). + */ +static int +circuit_build_no_more_hops(origin_circuit_t *circ) +{ + guard_usable_t r; + if (! circ->guard_state) { + if (circuit_get_cpath_len(circ) != 1 && + ! circuit_purpose_may_omit_guard(circ->base_.purpose) && + get_options()->UseEntryGuards) { + log_warn(LD_BUG, "%d-hop circuit %p with purpose %d has no " + "guard state", + circuit_get_cpath_len(circ), circ, circ->base_.purpose); + } + r = GUARD_USABLE_NOW; + } else { + r = entry_guard_succeeded(&circ->guard_state); + } + const int is_usable_for_streams = (r == GUARD_USABLE_NOW); + if (r == GUARD_USABLE_NOW) { + circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_OPEN); + } else if (r == GUARD_MAYBE_USABLE_LATER) { + // Wait till either a better guard succeeds, or till + // all better guards fail. + circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_GUARD_WAIT); + } else { + tor_assert_nonfatal(r == GUARD_USABLE_NEVER); + return - END_CIRC_REASON_INTERNAL; + } + + /* XXXX #21422 -- the rest of this branch needs careful thought! + * Some of the things here need to happen when a circuit becomes + * mechanically open; some need to happen when it is actually usable. + * I think I got them right, but more checking would be wise. -NM + */ + + if (circuit_timeout_want_to_count_circ(circ)) { + struct timeval end; + long timediff; + tor_gettimeofday(&end); + timediff = tv_mdiff(&circ->base_.timestamp_began, &end); + + /* + * If the circuit build time is much greater than we would have cut + * it off at, we probably had a suspend event along this codepath, + * and we should discard the value. + */ + if (timediff < 0 || + timediff > 2*get_circuit_build_close_time_ms()+1000) { + log_notice(LD_CIRC, "Strange value for circuit build time: %ldmsec. " + "Assuming clock jump. Purpose %d (%s)", timediff, + circ->base_.purpose, + circuit_purpose_to_string(circ->base_.purpose)); + } else if (!circuit_build_times_disabled(get_options())) { + /* Only count circuit times if the network is live */ + if (circuit_build_times_network_check_live( + get_circuit_build_times())) { + circuit_build_times_add_time(get_circuit_build_times_mutable(), + (build_time_t)timediff); + circuit_build_times_set_timeout(get_circuit_build_times_mutable()); } - /* We're done with measurement circuits here. Just close them */ - if (circ->base_.purpose == CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT) { - circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_FINISHED); + if (circ->base_.purpose != CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT) { + circuit_build_times_network_circ_success( + get_circuit_build_times_mutable()); } - return 0; } - - if (tor_addr_family(&hop->extend_info->addr) != AF_INET) { - log_warn(LD_BUG, "Trying to extend to a non-IPv4 address."); - return - END_CIRC_REASON_INTERNAL; + } + log_info(LD_CIRC,"circuit built!"); + circuit_reset_failure_count(0); + + if (circ->build_state->onehop_tunnel || circ->has_opened) { + control_event_bootstrap(BOOTSTRAP_STATUS_REQUESTING_STATUS, 0); + } + + pathbias_count_build_success(circ); + circuit_rep_hist_note_result(circ); + if (is_usable_for_streams) + circuit_has_opened(circ); /* do other actions as necessary */ + + if (!have_completed_a_circuit() && !circ->build_state->onehop_tunnel) { + const or_options_t *options = get_options(); + note_that_we_completed_a_circuit(); + /* FFFF Log a count of known routers here */ + log_notice(LD_GENERAL, + "Tor has successfully opened a circuit. " + "Looks like client functionality is working."); + if (control_event_bootstrap(BOOTSTRAP_STATUS_DONE, 0) == 0) { + log_notice(LD_GENERAL, + "Tor has successfully opened a circuit. " + "Looks like client functionality is working."); } - - circuit_pick_extend_handshake(&ec.cell_type, - &ec.create_cell.cell_type, - &ec.create_cell.handshake_type, - hop->extend_info); - - tor_addr_copy(&ec.orport_ipv4.addr, &hop->extend_info->addr); - ec.orport_ipv4.port = hop->extend_info->port; - tor_addr_make_unspec(&ec.orport_ipv6.addr); - memcpy(ec.node_id, hop->extend_info->identity_digest, DIGEST_LEN); - /* Set the ED25519 identity too -- it will only get included - * in the extend2 cell if we're configured to use it, though. */ - ed25519_pubkey_copy(&ec.ed_pubkey, &hop->extend_info->ed_identity); - - len = onion_skin_create(ec.create_cell.handshake_type, - hop->extend_info, - &hop->handshake_state, - ec.create_cell.onionskin); - if (len < 0) { - log_warn(LD_CIRC,"onion_skin_create failed."); - return - END_CIRC_REASON_INTERNAL; + control_event_client_status(LOG_NOTICE, "CIRCUIT_ESTABLISHED"); + clear_broken_connection_map(1); + if (server_mode(options) && !check_whether_orport_reachable(options)) { + inform_testing_reachability(); + consider_testing_reachability(1, 1); } - ec.create_cell.handshake_len = len; + } - log_info(LD_CIRC,"Sending extend relay cell."); - { - uint8_t command = 0; - uint16_t payload_len=0; - uint8_t payload[RELAY_PAYLOAD_SIZE]; - if (extend_cell_format(&command, &payload_len, payload, &ec)<0) { - log_warn(LD_CIRC,"Couldn't format extend cell"); - return -END_CIRC_REASON_INTERNAL; - } + /* We're done with measurement circuits here. Just close them */ + if (circ->base_.purpose == CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT) { + circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_FINISHED); + } + return 0; +} + +/** + * Called from circuit_send_next_onion_skin() when we find that we have a hop + * other than the first that we need to extend to: use <b>hop</b>'s + * information to extend the circuit another step. Return 0 on success; + * -reason on failure (if the circuit should be torn down). + */ +static int +circuit_send_intermediate_onion_skin(origin_circuit_t *circ, + crypt_path_t *hop) +{ + int len; + extend_cell_t ec; + memset(&ec, 0, sizeof(ec)); + + log_debug(LD_CIRC,"starting to send subsequent skin."); + + if (tor_addr_family(&hop->extend_info->addr) != AF_INET) { + log_warn(LD_BUG, "Trying to extend to a non-IPv4 address."); + return - END_CIRC_REASON_INTERNAL; + } + + circuit_pick_extend_handshake(&ec.cell_type, + &ec.create_cell.cell_type, + &ec.create_cell.handshake_type, + hop->extend_info); + + tor_addr_copy(&ec.orport_ipv4.addr, &hop->extend_info->addr); + ec.orport_ipv4.port = hop->extend_info->port; + tor_addr_make_unspec(&ec.orport_ipv6.addr); + memcpy(ec.node_id, hop->extend_info->identity_digest, DIGEST_LEN); + /* Set the ED25519 identity too -- it will only get included + * in the extend2 cell if we're configured to use it, though. */ + ed25519_pubkey_copy(&ec.ed_pubkey, &hop->extend_info->ed_identity); + + len = onion_skin_create(ec.create_cell.handshake_type, + hop->extend_info, + &hop->handshake_state, + ec.create_cell.onionskin); + if (len < 0) { + log_warn(LD_CIRC,"onion_skin_create failed."); + return - END_CIRC_REASON_INTERNAL; + } + ec.create_cell.handshake_len = len; - /* send it to hop->prev, because it will transfer - * it to a create cell and then send to hop */ - if (relay_send_command_from_edge(0, TO_CIRCUIT(circ), - command, - (char*)payload, payload_len, - hop->prev) < 0) - return 0; /* circuit is closed */ + log_info(LD_CIRC,"Sending extend relay cell."); + { + uint8_t command = 0; + uint16_t payload_len=0; + uint8_t payload[RELAY_PAYLOAD_SIZE]; + if (extend_cell_format(&command, &payload_len, payload, &ec)<0) { + log_warn(LD_CIRC,"Couldn't format extend cell"); + return -END_CIRC_REASON_INTERNAL; } - hop->state = CPATH_STATE_AWAITING_KEYS; + + /* send it to hop->prev, because that relay will transfer + * it to a create cell and then send to hop */ + if (relay_send_command_from_edge(0, TO_CIRCUIT(circ), + command, + (char*)payload, payload_len, + hop->prev) < 0) + return 0; /* circuit is closed */ } + hop->state = CPATH_STATE_AWAITING_KEYS; return 0; } @@ -1322,40 +1372,77 @@ circuit_extend(cell_t *cell, circuit_t *circ) return 0; } -/** Initialize cpath-\>{f|b}_{crypto|digest} from the key material in - * key_data. key_data must contain CPATH_KEY_MATERIAL bytes, which are - * used as follows: +/** Initialize cpath-\>{f|b}_{crypto|digest} from the key material in key_data. + * + * If <b>is_hs_v3</b> is set, this cpath will be used for next gen hidden + * service circuits and <b>key_data</b> must be at least + * HS_NTOR_KEY_EXPANSION_KDF_OUT_LEN bytes in length. + * + * If <b>is_hs_v3</b> is not set, key_data must contain CPATH_KEY_MATERIAL_LEN + * bytes, which are used as follows: * - 20 to initialize f_digest * - 20 to initialize b_digest * - 16 to key f_crypto * - 16 to key b_crypto * * (If 'reverse' is true, then f_XX and b_XX are swapped.) + * + * Return 0 if init was successful, else -1 if it failed. */ int -circuit_init_cpath_crypto(crypt_path_t *cpath, const char *key_data, - int reverse) +circuit_init_cpath_crypto(crypt_path_t *cpath, + const char *key_data, size_t key_data_len, + int reverse, int is_hs_v3) { crypto_digest_t *tmp_digest; crypto_cipher_t *tmp_crypto; + size_t digest_len = 0; + size_t cipher_key_len = 0; tor_assert(cpath); tor_assert(key_data); tor_assert(!(cpath->f_crypto || cpath->b_crypto || cpath->f_digest || cpath->b_digest)); - cpath->f_digest = crypto_digest_new(); - crypto_digest_add_bytes(cpath->f_digest, key_data, DIGEST_LEN); - cpath->b_digest = crypto_digest_new(); - crypto_digest_add_bytes(cpath->b_digest, key_data+DIGEST_LEN, DIGEST_LEN); + /* Basic key size validation */ + if (is_hs_v3 && BUG(key_data_len != HS_NTOR_KEY_EXPANSION_KDF_OUT_LEN)) { + return -1; + } else if (!is_hs_v3 && BUG(key_data_len != CPATH_KEY_MATERIAL_LEN)) { + return -1; + } + + /* If we are using this cpath for next gen onion services use SHA3-256, + otherwise use good ol' SHA1 */ + if (is_hs_v3) { + digest_len = DIGEST256_LEN; + cipher_key_len = CIPHER256_KEY_LEN; + cpath->f_digest = crypto_digest256_new(DIGEST_SHA3_256); + cpath->b_digest = crypto_digest256_new(DIGEST_SHA3_256); + } else { + digest_len = DIGEST_LEN; + cipher_key_len = CIPHER_KEY_LEN; + cpath->f_digest = crypto_digest_new(); + cpath->b_digest = crypto_digest_new(); + } + + tor_assert(digest_len != 0); + tor_assert(cipher_key_len != 0); + const int cipher_key_bits = (int) cipher_key_len * 8; + + crypto_digest_add_bytes(cpath->f_digest, key_data, digest_len); + crypto_digest_add_bytes(cpath->b_digest, key_data+digest_len, digest_len); - if (!(cpath->f_crypto = - crypto_cipher_new(key_data+(2*DIGEST_LEN)))) { + cpath->f_crypto = crypto_cipher_new_with_bits(key_data+(2*digest_len), + cipher_key_bits); + if (!cpath->f_crypto) { log_warn(LD_BUG,"Forward cipher initialization failed."); return -1; } - if (!(cpath->b_crypto = - crypto_cipher_new(key_data+(2*DIGEST_LEN)+CIPHER_KEY_LEN))) { + + cpath->b_crypto = crypto_cipher_new_with_bits( + key_data+(2*digest_len)+cipher_key_len, + cipher_key_bits); + if (!cpath->b_crypto) { log_warn(LD_BUG,"Backward cipher initialization failed."); return -1; } @@ -1421,7 +1508,7 @@ circuit_finish_handshake(origin_circuit_t *circ, onion_handshake_state_release(&hop->handshake_state); - if (circuit_init_cpath_crypto(hop, keys, 0)<0) { + if (circuit_init_cpath_crypto(hop, keys, sizeof(keys), 0, 0)<0) { return -END_CIRC_REASON_TORPROTOCOL; } @@ -1479,7 +1566,7 @@ circuit_truncated(origin_circuit_t *circ, crypt_path_t *layer, int reason) log_info(LD_CIRC, "finished"); return 0; -#endif +#endif /* 0 */ } /** Given a response payload and keys, initialize, then send a created @@ -1488,12 +1575,14 @@ circuit_truncated(origin_circuit_t *circ, crypt_path_t *layer, int reason) int onionskin_answer(or_circuit_t *circ, const created_cell_t *created_cell, - const char *keys, + const char *keys, size_t keys_len, const uint8_t *rend_circ_nonce) { cell_t cell; crypt_path_t *tmp_cpath; + tor_assert(keys_len == CPATH_KEY_MATERIAL_LEN); + if (created_cell_format(&cell, created_cell) < 0) { log_warn(LD_BUG,"couldn't format created cell (type=%d, len=%d)", (int)created_cell->cell_type, (int)created_cell->handshake_len); @@ -1509,7 +1598,7 @@ onionskin_answer(or_circuit_t *circ, log_debug(LD_CIRC,"init digest forward 0x%.8x, backward 0x%.8x.", (unsigned int)get_uint32(keys), (unsigned int)get_uint32(keys+20)); - if (circuit_init_cpath_crypto(tmp_cpath, keys, 0)<0) { + if (circuit_init_cpath_crypto(tmp_cpath, keys, keys_len, 0, 0)<0) { log_warn(LD_BUG,"Circuit initialization failed"); tor_free(tmp_cpath); return -1; @@ -1523,12 +1612,12 @@ onionskin_answer(or_circuit_t *circ, memcpy(circ->rend_circ_nonce, rend_circ_nonce, DIGEST_LEN); - circ->is_first_hop = (created_cell->cell_type == CELL_CREATED_FAST); + int used_create_fast = (created_cell->cell_type == CELL_CREATED_FAST); append_cell_to_circuit_queue(TO_CIRCUIT(circ), circ->p_chan, &cell, CELL_DIRECTION_IN, 0); log_debug(LD_CIRC,"Finished sending '%s' cell.", - circ->is_first_hop ? "created_fast" : "created"); + used_create_fast ? "created_fast" : "created"); /* Ignore the local bit when ExtendAllowPrivateAddresses is set: * it violates the assumption that private addresses are local. @@ -1546,13 +1635,98 @@ onionskin_answer(or_circuit_t *circ, return 0; } -/** Choose a length for a circuit of purpose <b>purpose</b>: three + the - * number of endpoints that would give something away about our destination. +/** Helper for new_route_len(). Choose a circuit length for purpose + * <b>purpose</b>: DEFAULT_ROUTE_LEN (+ 1 if someone else chose the + * exit). If someone else chose the exit, they could be colluding + * with the exit, so add a randomly selected node to preserve + * anonymity. + * + * Here, "exit node" sometimes means an OR acting as an internal + * endpoint, rather than as a relay to an external endpoint. This + * means there need to be at least DEFAULT_ROUTE_LEN routers between + * us and the internal endpoint to preserve the same anonymity + * properties that we would get when connecting to an external + * endpoint. These internal endpoints can include: + * + * - Connections to a directory of hidden services + * (CIRCUIT_PURPOSE_C_GENERAL) + * + * - A client connecting to an introduction point, which the hidden + * service picked (CIRCUIT_PURPOSE_C_INTRODUCING, via + * circuit_get_open_circ_or_launch() which rewrites it from + * CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT) + * + * - A hidden service connecting to a rendezvous point, which the + * client picked (CIRCUIT_PURPOSE_S_CONNECT_REND, via + * rend_service_receive_introduction() and + * rend_service_relaunch_rendezvous) + * + * There are currently two situations where we picked the exit node + * ourselves, making DEFAULT_ROUTE_LEN a safe circuit length: + * + * - We are a hidden service connecting to an introduction point + * (CIRCUIT_PURPOSE_S_ESTABLISH_INTRO, via + * rend_service_launch_establish_intro()) + * + * - We are a router testing its own reachabiity + * (CIRCUIT_PURPOSE_TESTING, via consider_testing_reachability()) + * + * onion_pick_cpath_exit() bypasses us (by not calling + * new_route_len()) in the one-hop tunnel case, so we don't need to + * handle that. + */ +static int +route_len_for_purpose(uint8_t purpose, extend_info_t *exit_ei) +{ + int routelen = DEFAULT_ROUTE_LEN; + int known_purpose = 0; + + if (!exit_ei) + return routelen; + + switch (purpose) { + /* These two purposes connect to a router that we chose, so + * DEFAULT_ROUTE_LEN is safe. */ + case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO: + /* hidden service connecting to introduction point */ + case CIRCUIT_PURPOSE_TESTING: + /* router reachability testing */ + known_purpose = 1; + break; + + /* These three purposes connect to a router that someone else + * might have chosen, so add an extra hop to protect anonymity. */ + case CIRCUIT_PURPOSE_C_GENERAL: + /* connecting to hidden service directory */ + case CIRCUIT_PURPOSE_C_INTRODUCING: + /* client connecting to introduction point */ + case CIRCUIT_PURPOSE_S_CONNECT_REND: + /* hidden service connecting to rendezvous point */ + known_purpose = 1; + routelen++; + break; + + default: + /* Got a purpose not listed above along with a chosen exit. + * Increase the circuit length by one anyway for safety. */ + routelen++; + break; + } + + if (BUG(exit_ei && !known_purpose)) { + log_warn(LD_BUG, "Unhandled purpose %d with a chosen exit; " + "assuming routelen %d.", purpose, routelen); + } + return routelen; +} + +/** Choose a length for a circuit of purpose <b>purpose</b> and check + * if enough routers are available. * * If the routerlist <b>nodes</b> doesn't have enough routers * to handle the desired path length, return -1. */ -static int +STATIC int new_route_len(uint8_t purpose, extend_info_t *exit_ei, smartlist_t *nodes) { int num_acceptable_routers; @@ -1560,11 +1734,7 @@ new_route_len(uint8_t purpose, extend_info_t *exit_ei, smartlist_t *nodes) tor_assert(nodes); - routelen = DEFAULT_ROUTE_LEN; - if (exit_ei && - purpose != CIRCUIT_PURPOSE_TESTING && - purpose != CIRCUIT_PURPOSE_S_ESTABLISH_INTRO) - routelen++; + routelen = route_len_for_purpose(purpose, exit_ei); num_acceptable_routers = count_acceptable_nodes(nodes); @@ -1748,15 +1918,16 @@ choose_good_exit_server_general(int need_uptime, int need_capacity) * we'll retry later in this function with need_update and * need_capacity set to 0. */ } - if (!(node->is_valid || options->AllowInvalid_ & ALLOW_INVALID_EXIT)) { + if (!(node->is_valid)) { /* if it's invalid and we don't want it */ n_supported[i] = -1; // log_fn(LOG_DEBUG,"Skipping node %s (index %d) -- invalid router.", // router->nickname, i); continue; /* skip invalid routers */ } - if (options->ExcludeSingleHopRelays && - node_allows_single_hop_exits(node)) { + /* We do not allow relays that allow single hop exits by default. Option + * was deprecated in 0.2.9.2-alpha and removed in 0.3.1.0-alpha. */ + if (node_allows_single_hop_exits(node)) { n_supported[i] = -1; continue; } @@ -1871,9 +2042,10 @@ choose_good_exit_server_general(int need_uptime, int need_capacity) } if (options->ExitNodes) { log_warn(LD_CIRC, - "No specified %sexit routers seem to be running: " + "No exits in ExitNodes%s seem to be running: " "can't choose an exit.", - options->ExcludeExitNodesUnion_ ? "non-excluded " : ""); + options->ExcludeExitNodesUnion_ ? + ", except possibly those excluded by your configuration, " : ""); } return NULL; } @@ -1888,7 +2060,6 @@ pick_tor2web_rendezvous_node(router_crn_flags_t flags, const or_options_t *options) { const node_t *rp_node = NULL; - const int allow_invalid = (flags & CRN_ALLOW_INVALID) != 0; const int need_desc = (flags & CRN_NEED_DESC) != 0; const int pref_addr = (flags & CRN_PREF_ADDR) != 0; const int direct_conn = (flags & CRN_DIRECT_CONN) != 0; @@ -1900,7 +2071,6 @@ pick_tor2web_rendezvous_node(router_crn_flags_t flags, /* Add all running nodes to all_live_nodes */ router_add_running_nodes_to_smartlist(all_live_nodes, - allow_invalid, 0, 0, 0, need_desc, pref_addr, @@ -1934,7 +2104,7 @@ pick_tor2web_rendezvous_node(router_crn_flags_t flags, return rp_node; } -#endif +#endif /* defined(ENABLE_TOR2WEB_MODE) || defined(TOR_UNIT_TESTS) */ /* Pick a Rendezvous Point for our HS circuits according to <b>flags</b>. */ static const node_t * @@ -1942,9 +2112,6 @@ pick_rendezvous_node(router_crn_flags_t flags) { const or_options_t *options = get_options(); - if (options->AllowInvalid_ & ALLOW_INVALID_RENDEZVOUS) - flags |= CRN_ALLOW_INVALID; - #ifdef ENABLE_TOR2WEB_MODE /* We want to connect directly to the node if we can */ router_crn_flags_t direct_flags = flags; @@ -1973,7 +2140,7 @@ pick_rendezvous_node(router_crn_flags_t flags) "Unable to find a random rendezvous point that is reachable via " "a direct connection, falling back to a 3-hop path."); } -#endif +#endif /* defined(ENABLE_TOR2WEB_MODE) */ return router_choose_random_node(NULL, options->ExcludeNodes, flags); } @@ -1990,7 +2157,8 @@ pick_rendezvous_node(router_crn_flags_t flags) */ static const node_t * choose_good_exit_server(uint8_t purpose, - int need_uptime, int need_capacity, int is_internal) + int need_uptime, int need_capacity, int is_internal, + int need_hs_v3) { const or_options_t *options = get_options(); router_crn_flags_t flags = CRN_NEED_DESC; @@ -1998,11 +2166,11 @@ choose_good_exit_server(uint8_t purpose, flags |= CRN_NEED_UPTIME; if (need_capacity) flags |= CRN_NEED_CAPACITY; + if (need_hs_v3) + flags |= CRN_RENDEZVOUS_V3; switch (purpose) { case CIRCUIT_PURPOSE_C_GENERAL: - if (options->AllowInvalid_ & ALLOW_INVALID_MIDDLE) - flags |= CRN_ALLOW_INVALID; if (is_internal) /* pick it like a middle hop */ return router_choose_random_node(NULL, options->ExcludeNodes, flags); else @@ -2099,9 +2267,15 @@ warn_if_last_router_excluded(origin_circuit_t *circ, /** Decide a suitable length for circ's cpath, and pick an exit * router (or use <b>exit</b> if provided). Store these in the - * cpath. Return 0 if ok, -1 if circuit should be closed. */ + * cpath. + * + * If <b>is_hs_v3_rp_circuit</b> is set, then this exit should be suitable to + * be used as an HS v3 rendezvous point. + * + * Return 0 if ok, -1 if circuit should be closed. */ static int -onion_pick_cpath_exit(origin_circuit_t *circ, extend_info_t *exit_ei) +onion_pick_cpath_exit(origin_circuit_t *circ, extend_info_t *exit_ei, + int is_hs_v3_rp_circuit) { cpath_build_state_t *state = circ->build_state; @@ -2125,7 +2299,8 @@ onion_pick_cpath_exit(origin_circuit_t *circ, extend_info_t *exit_ei) } else { /* we have to decide one */ const node_t *node = choose_good_exit_server(circ->base_.purpose, state->need_uptime, - state->need_capacity, state->is_internal); + state->need_capacity, state->is_internal, + is_hs_v3_rp_circuit); if (!node) { log_warn(LD_CIRC,"Failed to choose an exit server"); return -1; @@ -2188,8 +2363,8 @@ circuit_extend_to_new_exit(origin_circuit_t *circ, extend_info_t *exit_ei) /** Return the number of routers in <b>routers</b> that are currently up * and available for building circuits through. */ -static int -count_acceptable_nodes(smartlist_t *nodes) +MOCK_IMPL(STATIC int, +count_acceptable_nodes, (smartlist_t *nodes)) { int num=0; @@ -2200,10 +2375,6 @@ count_acceptable_nodes(smartlist_t *nodes) if (! node->is_running) // log_debug(LD_CIRC,"Nope, the directory says %d is not running.",i); continue; - /* XXX This clause makes us count incorrectly: if AllowInvalidRouters - * allows this node in some places, then we're getting an inaccurate - * count. For now, be conservative and don't count it. But later we - * should try to be smarter. */ if (! node->is_valid) // log_debug(LD_CIRC,"Nope, the directory says %d is not valid.",i); continue; @@ -2237,6 +2408,30 @@ onion_append_to_cpath(crypt_path_t **head_ptr, crypt_path_t *new_hop) } } +#ifdef TOR_UNIT_TESTS + +/** Unittest helper function: Count number of hops in cpath linked list. */ +unsigned int +cpath_get_n_hops(crypt_path_t **head_ptr) +{ + unsigned int n_hops = 0; + crypt_path_t *tmp; + + if (!*head_ptr) { + return 0; + } + + tmp = *head_ptr; + do { + n_hops++; + tmp = tmp->next; + } while (tmp != *head_ptr); + + return n_hops; +} + +#endif /* defined(TOR_UNIT_TESTS) */ + /** A helper function used by onion_extend_cpath(). Use <b>purpose</b> * and <b>state</b> and the cpath <b>head</b> (currently populated only * to length <b>cur_len</b> to decide a suitable middle hop for a @@ -2258,8 +2453,8 @@ choose_good_middle_server(uint8_t purpose, tor_assert(CIRCUIT_PURPOSE_MIN_ <= purpose && purpose <= CIRCUIT_PURPOSE_MAX_); - log_debug(LD_CIRC, "Contemplating intermediate hop %d: random choice.", - cur_len); + log_debug(LD_CIRC, "Contemplating intermediate hop #%d: random choice.", + cur_len+1); excluded = smartlist_new(); if ((r = build_state_get_exit_node(state))) { nodelist_add_node_and_family(excluded, r); @@ -2274,8 +2469,6 @@ choose_good_middle_server(uint8_t purpose, flags |= CRN_NEED_UPTIME; if (state->need_capacity) flags |= CRN_NEED_CAPACITY; - if (options->AllowInvalid_ & ALLOW_INVALID_MIDDLE) - flags |= CRN_ALLOW_INVALID; choice = router_choose_random_node(excluded, options->ExcludeNodes, flags); smartlist_free(excluded); return choice; @@ -2286,9 +2479,6 @@ choose_good_middle_server(uint8_t purpose, * router (if we're an OR), and respect firewall settings; if we're * configured to use entry guards, return one. * - * If <b>state</b> is NULL, we're choosing a router to serve as an entry - * guard, not for any particular circuit. - * * Set *<b>guard_state_out</b> to information about the guard that * we're selecting, which we'll use later to remember whether the * guard worked or not. @@ -2306,6 +2496,11 @@ choose_good_entry_server(uint8_t purpose, cpath_build_state_t *state, CRN_DIRECT_CONN); const node_t *node; + /* Once we used this function to select a node to be a guard. We had + * 'state == NULL' be the signal for that. But we don't do that any more. + */ + tor_assert_nonfatal(state); + if (state && options->UseEntryGuards && (purpose != CIRCUIT_PURPOSE_TESTING || options->BridgeRelay)) { /* This request is for an entry server to use for a regular circuit, @@ -2328,8 +2523,6 @@ choose_good_entry_server(uint8_t purpose, cpath_build_state_t *state, if (state->need_capacity) flags |= CRN_NEED_CAPACITY; } - if (options->AllowInvalid_ & ALLOW_INVALID_ENTRY) - flags |= CRN_ALLOW_INVALID; choice = router_choose_random_node(excluded, options->ExcludeNodes, flags); smartlist_free(excluded); @@ -2397,12 +2590,12 @@ onion_extend_cpath(origin_circuit_t *circ) } if (!info) { - log_warn(LD_CIRC,"Failed to find node for hop %d of our path. Discarding " - "this circuit.", cur_len); + log_warn(LD_CIRC,"Failed to find node for hop #%d of our path. Discarding " + "this circuit.", cur_len+1); return -1; } - log_debug(LD_CIRC,"Chose router %s for hop %d (exit is %s)", + log_debug(LD_CIRC,"Chose router %s for hop #%d (exit is %s)", extend_info_describe(info), cur_len+1, build_state_get_exit_nickname(state)); @@ -2510,7 +2703,7 @@ extend_info_from_node(const node_t *node, int for_direct_connect) ed_pubkey = node_get_ed25519_id(node); } else if (node_get_ed25519_id(node)) { log_info(LD_CIRC, "Not including the ed25519 ID for %s, since it won't " - " be able to authenticate it.", + "be able to authenticate it.", node_describe(node)); } |