rendclient.c
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上传日期:2019-07-14
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- /* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
- * Copyright (c) 2007-2009, The Tor Project, Inc. */
- /* See LICENSE for licensing information */
- /**
- * file rendclient.c
- * brief Client code to access location-hidden services.
- **/
- #include "or.h"
- /** Called when we've established a circuit to an introduction point:
- * send the introduction request. */
- void
- rend_client_introcirc_has_opened(origin_circuit_t *circ)
- {
- tor_assert(circ->_base.purpose == CIRCUIT_PURPOSE_C_INTRODUCING);
- tor_assert(circ->cpath);
- log_info(LD_REND,"introcirc is open");
- connection_ap_attach_pending();
- }
- /** Send the establish-rendezvous cell along a rendezvous circuit. if
- * it fails, mark the circ for close and return -1. else return 0.
- */
- static int
- rend_client_send_establish_rendezvous(origin_circuit_t *circ)
- {
- tor_assert(circ->_base.purpose == CIRCUIT_PURPOSE_C_ESTABLISH_REND);
- tor_assert(circ->rend_data);
- log_info(LD_REND, "Sending an ESTABLISH_RENDEZVOUS cell");
- if (crypto_rand(circ->rend_data->rend_cookie, REND_COOKIE_LEN) < 0) {
- log_warn(LD_BUG, "Internal error: Couldn't produce random cookie.");
- circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL);
- return -1;
- }
- if (relay_send_command_from_edge(0, TO_CIRCUIT(circ),
- RELAY_COMMAND_ESTABLISH_RENDEZVOUS,
- circ->rend_data->rend_cookie,
- REND_COOKIE_LEN,
- circ->cpath->prev)<0) {
- /* circ is already marked for close */
- log_warn(LD_GENERAL, "Couldn't send ESTABLISH_RENDEZVOUS cell");
- return -1;
- }
- return 0;
- }
- /** Called when we're trying to connect an ap conn; sends an INTRODUCE1 cell
- * down introcirc if possible.
- */
- int
- rend_client_send_introduction(origin_circuit_t *introcirc,
- origin_circuit_t *rendcirc)
- {
- size_t payload_len;
- int r, v3_shift = 0;
- char payload[RELAY_PAYLOAD_SIZE];
- char tmp[RELAY_PAYLOAD_SIZE];
- rend_cache_entry_t *entry;
- crypt_path_t *cpath;
- off_t dh_offset;
- crypto_pk_env_t *intro_key; /* either Bob's public key or an intro key. */
- tor_assert(introcirc->_base.purpose == CIRCUIT_PURPOSE_C_INTRODUCING);
- tor_assert(rendcirc->_base.purpose == CIRCUIT_PURPOSE_C_REND_READY);
- tor_assert(introcirc->rend_data);
- tor_assert(rendcirc->rend_data);
- tor_assert(!rend_cmp_service_ids(introcirc->rend_data->onion_address,
- rendcirc->rend_data->onion_address));
- if (rend_cache_lookup_entry(introcirc->rend_data->onion_address, -1,
- &entry) < 1) {
- log_warn(LD_REND,
- "query %s didn't have valid rend desc in cache. Failing.",
- escaped_safe_str(introcirc->rend_data->onion_address));
- goto err;
- }
- /* first 20 bytes of payload are the hash of Bob's pk */
- if (entry->parsed->version == 0) { /* un-versioned descriptor */
- intro_key = entry->parsed->pk;
- } else { /* versioned descriptor */
- intro_key = NULL;
- SMARTLIST_FOREACH(entry->parsed->intro_nodes, rend_intro_point_t *,
- intro, {
- if (!memcmp(introcirc->build_state->chosen_exit->identity_digest,
- intro->extend_info->identity_digest, DIGEST_LEN)) {
- intro_key = intro->intro_key;
- break;
- }
- });
- if (!intro_key) {
- /** XXX This case probably means that the intro point vanished while
- * we were building a circuit to it. In the future, we should find
- * out how that happened and whether we should kill the circuits to
- * removed intro points immediately. See task 1073. */
- int num_intro_points = smartlist_len(entry->parsed->intro_nodes);
- if (rend_cache_lookup_entry(introcirc->rend_data->onion_address,
- 0, &entry) > 0) {
- log_info(LD_REND, "We have both a v0 and a v2 rend desc for this "
- "service. The v2 desc doesn't contain the introduction "
- "point (and key) to send an INTRODUCE1/2 cell to this "
- "introduction point. Assuming the introduction point "
- "is for v0 rend clients and using the service key "
- "from the v0 desc instead. (This is probably a bug, "
- "because we shouldn't even have both a v0 and a v2 "
- "descriptor for the same service.)");
- /* See flyspray task 1024. */
- intro_key = entry->parsed->pk;
- } else {
- log_info(LD_REND, "Internal error: could not find intro key; we "
- "only have a v2 rend desc with %d intro points.",
- num_intro_points);
- goto err;
- }
- }
- }
- if (crypto_pk_get_digest(intro_key, payload)<0) {
- log_warn(LD_BUG, "Internal error: couldn't hash public key.");
- goto err;
- }
- /* Initialize the pending_final_cpath and start the DH handshake. */
- cpath = rendcirc->build_state->pending_final_cpath;
- if (!cpath) {
- cpath = rendcirc->build_state->pending_final_cpath =
- tor_malloc_zero(sizeof(crypt_path_t));
- cpath->magic = CRYPT_PATH_MAGIC;
- if (!(cpath->dh_handshake_state = crypto_dh_new())) {
- log_warn(LD_BUG, "Internal error: couldn't allocate DH.");
- goto err;
- }
- if (crypto_dh_generate_public(cpath->dh_handshake_state)<0) {
- log_warn(LD_BUG, "Internal error: couldn't generate g^x.");
- goto err;
- }
- }
- /* If version is 3, write (optional) auth data and timestamp. */
- if (entry->parsed->protocols & (1<<3)) {
- tmp[0] = 3; /* version 3 of the cell format */
- tmp[1] = (uint8_t)introcirc->rend_data->auth_type; /* auth type, if any */
- v3_shift = 1;
- if (introcirc->rend_data->auth_type != REND_NO_AUTH) {
- set_uint16(tmp+2, htons(REND_DESC_COOKIE_LEN));
- memcpy(tmp+4, introcirc->rend_data->descriptor_cookie,
- REND_DESC_COOKIE_LEN);
- v3_shift += 2+REND_DESC_COOKIE_LEN;
- }
- set_uint32(tmp+v3_shift+1, htonl((uint32_t)time(NULL)));
- v3_shift += 4;
- } /* if version 2 only write version number */
- else if (entry->parsed->protocols & (1<<2)) {
- tmp[0] = 2; /* version 2 of the cell format */
- }
- /* write the remaining items into tmp */
- if (entry->parsed->protocols & (1<<3) || entry->parsed->protocols & (1<<2)) {
- /* version 2 format */
- extend_info_t *extend_info = rendcirc->build_state->chosen_exit;
- int klen;
- /* nul pads */
- set_uint32(tmp+v3_shift+1, tor_addr_to_ipv4h(&extend_info->addr));
- set_uint16(tmp+v3_shift+5, htons(extend_info->port));
- memcpy(tmp+v3_shift+7, extend_info->identity_digest, DIGEST_LEN);
- klen = crypto_pk_asn1_encode(extend_info->onion_key,
- tmp+v3_shift+7+DIGEST_LEN+2,
- sizeof(tmp)-(v3_shift+7+DIGEST_LEN+2));
- set_uint16(tmp+v3_shift+7+DIGEST_LEN, htons(klen));
- memcpy(tmp+v3_shift+7+DIGEST_LEN+2+klen, rendcirc->rend_data->rend_cookie,
- REND_COOKIE_LEN);
- dh_offset = v3_shift+7+DIGEST_LEN+2+klen+REND_COOKIE_LEN;
- } else {
- /* Version 0. */
- strncpy(tmp, rendcirc->build_state->chosen_exit->nickname,
- (MAX_NICKNAME_LEN+1)); /* nul pads */
- memcpy(tmp+MAX_NICKNAME_LEN+1, rendcirc->rend_data->rend_cookie,
- REND_COOKIE_LEN);
- dh_offset = MAX_NICKNAME_LEN+1+REND_COOKIE_LEN;
- }
- if (crypto_dh_get_public(cpath->dh_handshake_state, tmp+dh_offset,
- DH_KEY_LEN)<0) {
- log_warn(LD_BUG, "Internal error: couldn't extract g^x.");
- goto err;
- }
- note_crypto_pk_op(REND_CLIENT);
- /*XXX maybe give crypto_pk_public_hybrid_encrypt a max_len arg,
- * to avoid buffer overflows? */
- r = crypto_pk_public_hybrid_encrypt(intro_key, payload+DIGEST_LEN,
- tmp,
- (int)(dh_offset+DH_KEY_LEN),
- PK_PKCS1_OAEP_PADDING, 0);
- if (r<0) {
- log_warn(LD_BUG,"Internal error: hybrid pk encrypt failed.");
- goto err;
- }
- payload_len = DIGEST_LEN + r;
- tor_assert(payload_len <= RELAY_PAYLOAD_SIZE); /* we overran something */
- log_info(LD_REND, "Sending an INTRODUCE1 cell");
- if (relay_send_command_from_edge(0, TO_CIRCUIT(introcirc),
- RELAY_COMMAND_INTRODUCE1,
- payload, payload_len,
- introcirc->cpath->prev)<0) {
- /* introcirc is already marked for close. leave rendcirc alone. */
- log_warn(LD_BUG, "Couldn't send INTRODUCE1 cell");
- return -1;
- }
- /* Now, we wait for an ACK or NAK on this circuit. */
- introcirc->_base.purpose = CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT;
- return 0;
- err:
- circuit_mark_for_close(TO_CIRCUIT(introcirc), END_CIRC_REASON_INTERNAL);
- circuit_mark_for_close(TO_CIRCUIT(rendcirc), END_CIRC_REASON_INTERNAL);
- return -1;
- }
- /** Called when a rendezvous circuit is open; sends a establish
- * rendezvous circuit as appropriate. */
- void
- rend_client_rendcirc_has_opened(origin_circuit_t *circ)
- {
- tor_assert(circ->_base.purpose == CIRCUIT_PURPOSE_C_ESTABLISH_REND);
- log_info(LD_REND,"rendcirc is open");
- /* generate a rendezvous cookie, store it in circ */
- if (rend_client_send_establish_rendezvous(circ) < 0) {
- return;
- }
- }
- /** Called when get an ACK or a NAK for a REND_INTRODUCE1 cell.
- */
- int
- rend_client_introduction_acked(origin_circuit_t *circ,
- const char *request, size_t request_len)
- {
- origin_circuit_t *rendcirc;
- (void) request; // XXXX Use this.
- if (circ->_base.purpose != CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT) {
- log_warn(LD_PROTOCOL,
- "Received REND_INTRODUCE_ACK on unexpected circuit %d.",
- circ->_base.n_circ_id);
- circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_TORPROTOCOL);
- return -1;
- }
- tor_assert(circ->build_state->chosen_exit);
- tor_assert(circ->rend_data);
- if (request_len == 0) {
- /* It's an ACK; the introduction point relayed our introduction request. */
- /* Locate the rend circ which is waiting to hear about this ack,
- * and tell it.
- */
- log_info(LD_REND,"Received ack. Telling rend circ...");
- rendcirc = circuit_get_by_rend_query_and_purpose(
- circ->rend_data->onion_address, CIRCUIT_PURPOSE_C_REND_READY);
- if (rendcirc) { /* remember the ack */
- rendcirc->_base.purpose = CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED;
- } else {
- log_info(LD_REND,"...Found no rend circ. Dropping on the floor.");
- }
- /* close the circuit: we won't need it anymore. */
- circ->_base.purpose = CIRCUIT_PURPOSE_C_INTRODUCE_ACKED;
- circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_FINISHED);
- } else {
- /* It's a NAK; the introduction point didn't relay our request. */
- circ->_base.purpose = CIRCUIT_PURPOSE_C_INTRODUCING;
- /* Remove this intro point from the set of viable introduction
- * points. If any remain, extend to a new one and try again.
- * If none remain, refetch the service descriptor.
- */
- if (rend_client_remove_intro_point(circ->build_state->chosen_exit,
- circ->rend_data) > 0) {
- /* There are introduction points left. Re-extend the circuit to
- * another intro point and try again. */
- extend_info_t *extend_info;
- int result;
- extend_info = rend_client_get_random_intro(circ->rend_data);
- if (!extend_info) {
- log_warn(LD_REND, "No introduction points left for %s. Closing.",
- escaped_safe_str(circ->rend_data->onion_address));
- circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL);
- return -1;
- }
- if (circ->remaining_relay_early_cells) {
- log_info(LD_REND,
- "Got nack for %s from %s. Re-extending circ %d, "
- "this time to %s.",
- escaped_safe_str(circ->rend_data->onion_address),
- circ->build_state->chosen_exit->nickname,
- circ->_base.n_circ_id, extend_info->nickname);
- result = circuit_extend_to_new_exit(circ, extend_info);
- } else {
- log_info(LD_REND,
- "Got nack for %s from %s. Building a new introduction "
- "circuit, this time to %s.",
- escaped_safe_str(circ->rend_data->onion_address),
- circ->build_state->chosen_exit->nickname,
- extend_info->nickname);
- circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_FINISHED);
- if (!circuit_launch_by_extend_info(CIRCUIT_PURPOSE_C_INTRODUCING,
- extend_info,
- CIRCLAUNCH_IS_INTERNAL)) {
- log_warn(LD_REND, "Building introduction circuit failed.");
- result = -1;
- } else {
- result = 0;
- }
- }
- extend_info_free(extend_info);
- return result;
- }
- }
- return 0;
- }
- /** The period for which a hidden service directory cannot be queried for
- * the same descriptor ID again. */
- #define REND_HID_SERV_DIR_REQUERY_PERIOD (15 * 60)
- /** Contains the last request times to hidden service directories for
- * certain queries; keys are strings consisting of base32-encoded
- * hidden service directory identities and base32-encoded descriptor IDs;
- * values are pointers to timestamps of the last requests. */
- static strmap_t *last_hid_serv_requests = NULL;
- /** Look up the last request time to hidden service directory <b>hs_dir</b>
- * for descriptor ID <b>desc_id_base32</b>. If <b>set</b> is non-zero,
- * assign the current time <b>now</b> and return that. Otherwise, return
- * the most recent request time, or 0 if no such request has been sent
- * before. */
- static time_t
- lookup_last_hid_serv_request(routerstatus_t *hs_dir,
- const char *desc_id_base32, time_t now, int set)
- {
- char hsdir_id_base32[REND_DESC_ID_V2_LEN_BASE32 + 1];
- char hsdir_desc_comb_id[2 * REND_DESC_ID_V2_LEN_BASE32 + 1];
- time_t *last_request_ptr;
- base32_encode(hsdir_id_base32, sizeof(hsdir_id_base32),
- hs_dir->identity_digest, DIGEST_LEN);
- tor_snprintf(hsdir_desc_comb_id, sizeof(hsdir_desc_comb_id), "%s%s",
- hsdir_id_base32, desc_id_base32);
- if (set) {
- last_request_ptr = tor_malloc_zero(sizeof(time_t *));
- *last_request_ptr = now;
- strmap_set(last_hid_serv_requests, hsdir_desc_comb_id, last_request_ptr);
- } else
- last_request_ptr = strmap_get_lc(last_hid_serv_requests,
- hsdir_desc_comb_id);
- return (last_request_ptr) ? *last_request_ptr : 0;
- }
- /** Clean the history of request times to hidden service directories, so that
- * it does not contain requests older than REND_HID_SERV_DIR_REQUERY_PERIOD
- * seconds any more. */
- static void
- directory_clean_last_hid_serv_requests(void)
- {
- strmap_iter_t *iter;
- time_t cutoff = time(NULL) - REND_HID_SERV_DIR_REQUERY_PERIOD;
- if (!last_hid_serv_requests)
- last_hid_serv_requests = strmap_new();
- for (iter = strmap_iter_init(last_hid_serv_requests);
- !strmap_iter_done(iter); ) {
- const char *key;
- void *val;
- time_t *ent;
- strmap_iter_get(iter, &key, &val);
- ent = (time_t *) val;
- if (*ent < cutoff) {
- iter = strmap_iter_next_rmv(last_hid_serv_requests, iter);
- tor_free(ent);
- } else {
- iter = strmap_iter_next(last_hid_serv_requests, iter);
- }
- }
- }
- /** Determine the responsible hidden service directories for <b>desc_id</b>
- * and fetch the descriptor belonging to that ID from one of them. Only
- * send a request to hidden service directories that we did not try within
- * the last REND_HID_SERV_DIR_REQUERY_PERIOD seconds; on success, return 1,
- * in the case that no hidden service directory is left to ask for the
- * descriptor, return 0, and in case of a failure -1. <b>query</b> is only
- * passed for pretty log statements. */
- static int
- directory_get_from_hs_dir(const char *desc_id, const rend_data_t *rend_query)
- {
- smartlist_t *responsible_dirs = smartlist_create();
- routerstatus_t *hs_dir;
- char desc_id_base32[REND_DESC_ID_V2_LEN_BASE32 + 1];
- time_t now = time(NULL);
- char descriptor_cookie_base64[3*REND_DESC_COOKIE_LEN_BASE64];
- tor_assert(desc_id);
- tor_assert(rend_query);
- /* Determine responsible dirs. Even if we can't get all we want,
- * work with the ones we have. If it's empty, we'll notice below. */
- (int) hid_serv_get_responsible_directories(responsible_dirs, desc_id);
- base32_encode(desc_id_base32, sizeof(desc_id_base32),
- desc_id, DIGEST_LEN);
- /* Only select those hidden service directories to which we did not send
- * a request recently and for which we have a router descriptor here. */
- directory_clean_last_hid_serv_requests(); /* Clean request history first. */
- SMARTLIST_FOREACH(responsible_dirs, routerstatus_t *, dir, {
- if (lookup_last_hid_serv_request(dir, desc_id_base32, 0, 0) +
- REND_HID_SERV_DIR_REQUERY_PERIOD >= now ||
- !router_get_by_digest(dir->identity_digest))
- SMARTLIST_DEL_CURRENT(responsible_dirs, dir);
- });
- hs_dir = smartlist_choose(responsible_dirs);
- smartlist_free(responsible_dirs);
- if (!hs_dir) {
- log_info(LD_REND, "Could not pick one of the responsible hidden "
- "service directories, because we requested them all "
- "recently without success.");
- return 0;
- }
- /* Remember, that we are requesting a descriptor from this hidden service
- * directory now. */
- lookup_last_hid_serv_request(hs_dir, desc_id_base32, now, 1);
- /* Encode descriptor cookie for logging purposes. */
- if (rend_query->auth_type != REND_NO_AUTH) {
- if (base64_encode(descriptor_cookie_base64,
- sizeof(descriptor_cookie_base64),
- rend_query->descriptor_cookie, REND_DESC_COOKIE_LEN)<0) {
- log_warn(LD_BUG, "Could not base64-encode descriptor cookie.");
- return 0;
- }
- /* Remove == signs and newline. */
- descriptor_cookie_base64[strlen(descriptor_cookie_base64)-3] = ' ';
- } else {
- strlcpy(descriptor_cookie_base64, "(none)",
- sizeof(descriptor_cookie_base64));
- }
- /* Send fetch request. (Pass query and possibly descriptor cookie so that
- * they can be written to the directory connection and be referred to when
- * the response arrives. */
- directory_initiate_command_routerstatus_rend(hs_dir,
- DIR_PURPOSE_FETCH_RENDDESC_V2,
- ROUTER_PURPOSE_GENERAL,
- 1, desc_id_base32, NULL, 0, 0,
- rend_query);
- log_info(LD_REND, "Sending fetch request for v2 descriptor for "
- "service '%s' with descriptor ID '%s', auth type %d, "
- "and descriptor cookie '%s' to hidden service "
- "directory '%s' on port %d.",
- rend_query->onion_address, desc_id_base32,
- rend_query->auth_type,
- (rend_query->auth_type == REND_NO_AUTH ? "[none]" :
- escaped_safe_str(descriptor_cookie_base64)),
- hs_dir->nickname, hs_dir->dir_port);
- return 1;
- }
- /** If we are not currently fetching a rendezvous service descriptor
- * for the service ID <b>query</b>, start a directory connection to fetch a
- * new one.
- */
- void
- rend_client_refetch_renddesc(const char *query)
- {
- if (!get_options()->FetchHidServDescriptors)
- return;
- log_info(LD_REND, "Fetching rendezvous descriptor for service %s",
- escaped_safe_str(query));
- if (connection_get_by_type_state_rendquery(CONN_TYPE_DIR, 0, query, 0)) {
- log_info(LD_REND,"Would fetch a new renddesc here (for %s), but one is "
- "already in progress.", escaped_safe_str(query));
- } else {
- /* not one already; initiate a dir rend desc lookup */
- directory_get_from_dirserver(DIR_PURPOSE_FETCH_RENDDESC,
- ROUTER_PURPOSE_GENERAL, query,
- PDS_RETRY_IF_NO_SERVERS);
- }
- }
- /** Start a connection to a hidden service directory to fetch a v2
- * rendezvous service descriptor for the base32-encoded service ID
- * <b>query</b>.
- */
- void
- rend_client_refetch_v2_renddesc(const rend_data_t *rend_query)
- {
- char descriptor_id[DIGEST_LEN];
- int replicas_left_to_try[REND_NUMBER_OF_NON_CONSECUTIVE_REPLICAS];
- int i, tries_left, r;
- rend_cache_entry_t *e = NULL;
- time_t now = time(NULL);
- tor_assert(rend_query);
- /* Are we configured to fetch descriptors? */
- if (!get_options()->FetchHidServDescriptors) {
- log_warn(LD_REND, "We received an onion address for a v2 rendezvous "
- "service descriptor, but are not fetching service descriptors.");
- return;
- }
- /* Before fetching, check if we already have the descriptor here. */
- r = rend_cache_lookup_entry(rend_query->onion_address, -1, &e);
- if (r > 0 && now - e->received < NUM_SECONDS_BEFORE_HS_REFETCH) {
- log_info(LD_REND, "We would fetch a v2 rendezvous descriptor, but we "
- "already have a fresh copy of that descriptor here. "
- "Not fetching.");
- return;
- }
- log_debug(LD_REND, "Fetching v2 rendezvous descriptor for service %s",
- safe_str(rend_query->onion_address));
- /* Randomly iterate over the replicas until a descriptor can be fetched
- * from one of the consecutive nodes, or no options are left. */
- tries_left = REND_NUMBER_OF_NON_CONSECUTIVE_REPLICAS;
- for (i = 0; i < REND_NUMBER_OF_NON_CONSECUTIVE_REPLICAS; i++)
- replicas_left_to_try[i] = i;
- while (tries_left > 0) {
- int rand = crypto_rand_int(tries_left);
- int chosen_replica = replicas_left_to_try[rand];
- replicas_left_to_try[rand] = replicas_left_to_try[--tries_left];
- if (rend_compute_v2_desc_id(descriptor_id, rend_query->onion_address,
- rend_query->auth_type == REND_STEALTH_AUTH ?
- rend_query->descriptor_cookie : NULL,
- time(NULL), chosen_replica) < 0) {
- log_warn(LD_REND, "Internal error: Computing v2 rendezvous "
- "descriptor ID did not succeed.");
- return;
- }
- if (directory_get_from_hs_dir(descriptor_id, rend_query) != 0)
- return; /* either success or failure, but we're done */
- }
- /* If we come here, there are no hidden service directories left. */
- log_info(LD_REND, "Could not pick one of the responsible hidden "
- "service directories to fetch descriptors, because "
- "we already tried them all unsuccessfully.");
- /* Close pending connections (unless a v0 request is still going on). */
- rend_client_desc_trynow(rend_query->onion_address, 2);
- return;
- }
- /** Remove failed_intro from ent. If ent now has no intro points, or
- * service is unrecognized, then launch a new renddesc fetch.
- *
- * Return -1 if error, 0 if no intro points remain or service
- * unrecognized, 1 if recognized and some intro points remain.
- */
- int
- rend_client_remove_intro_point(extend_info_t *failed_intro,
- const rend_data_t *rend_query)
- {
- int i, r;
- rend_cache_entry_t *ent;
- connection_t *conn;
- r = rend_cache_lookup_entry(rend_query->onion_address, -1, &ent);
- if (r<0) {
- log_warn(LD_BUG, "Malformed service ID %s.",
- escaped_safe_str(rend_query->onion_address));
- return -1;
- }
- if (r==0) {
- log_info(LD_REND, "Unknown service %s. Re-fetching descriptor.",
- escaped_safe_str(rend_query->onion_address));
- /* Fetch both, v0 and v2 rend descriptors in parallel. Use whichever
- * arrives first. Exception: When using client authorization, only
- * fetch v2 descriptors.*/
- rend_client_refetch_v2_renddesc(rend_query);
- if (rend_query->auth_type == REND_NO_AUTH)
- rend_client_refetch_renddesc(rend_query->onion_address);
- return 0;
- }
- for (i = 0; i < smartlist_len(ent->parsed->intro_nodes); i++) {
- rend_intro_point_t *intro = smartlist_get(ent->parsed->intro_nodes, i);
- if (!memcmp(failed_intro->identity_digest,
- intro->extend_info->identity_digest, DIGEST_LEN)) {
- rend_intro_point_free(intro);
- smartlist_del(ent->parsed->intro_nodes, i);
- break;
- }
- }
- if (smartlist_len(ent->parsed->intro_nodes) == 0) {
- log_info(LD_REND,
- "No more intro points remain for %s. Re-fetching descriptor.",
- escaped_safe_str(rend_query->onion_address));
- /* Fetch both, v0 and v2 rend descriptors in parallel. Use whichever
- * arrives first. Exception: When using client authorization, only
- * fetch v2 descriptors.*/
- rend_client_refetch_v2_renddesc(rend_query);
- if (rend_query->auth_type == REND_NO_AUTH)
- rend_client_refetch_renddesc(rend_query->onion_address);
- /* move all pending streams back to renddesc_wait */
- while ((conn = connection_get_by_type_state_rendquery(CONN_TYPE_AP,
- AP_CONN_STATE_CIRCUIT_WAIT,
- rend_query->onion_address, -1))) {
- conn->state = AP_CONN_STATE_RENDDESC_WAIT;
- }
- return 0;
- }
- log_info(LD_REND,"%d options left for %s.",
- smartlist_len(ent->parsed->intro_nodes),
- escaped_safe_str(rend_query->onion_address));
- return 1;
- }
- /** Called when we receive a RENDEZVOUS_ESTABLISHED cell; changes the state of
- * the circuit to C_REND_READY.
- */
- int
- rend_client_rendezvous_acked(origin_circuit_t *circ, const char *request,
- size_t request_len)
- {
- (void) request;
- (void) request_len;
- /* we just got an ack for our establish-rendezvous. switch purposes. */
- if (circ->_base.purpose != CIRCUIT_PURPOSE_C_ESTABLISH_REND) {
- log_warn(LD_PROTOCOL,"Got a rendezvous ack when we weren't expecting one. "
- "Closing circ.");
- circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_TORPROTOCOL);
- return -1;
- }
- log_info(LD_REND,"Got rendezvous ack. This circuit is now ready for "
- "rendezvous.");
- circ->_base.purpose = CIRCUIT_PURPOSE_C_REND_READY;
- /* XXXX022 This is a pretty brute-force approach. It'd be better to
- * attach only the connections that are waiting on this circuit, rather
- * than trying to attach them all. See comments bug 743. */
- /* If we already have the introduction circuit built, make sure we send
- * the INTRODUCE cell _now_ */
- connection_ap_attach_pending();
- return 0;
- }
- /** Bob sent us a rendezvous cell; join the circuits. */
- int
- rend_client_receive_rendezvous(origin_circuit_t *circ, const char *request,
- size_t request_len)
- {
- crypt_path_t *hop;
- char keys[DIGEST_LEN+CPATH_KEY_MATERIAL_LEN];
- if ((circ->_base.purpose != CIRCUIT_PURPOSE_C_REND_READY &&
- circ->_base.purpose != CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED)
- || !circ->build_state->pending_final_cpath) {
- log_warn(LD_PROTOCOL,"Got rendezvous2 cell from hidden service, but not "
- "expecting it. Closing.");
- circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_TORPROTOCOL);
- return -1;
- }
- if (request_len != DH_KEY_LEN+DIGEST_LEN) {
- log_warn(LD_PROTOCOL,"Incorrect length (%d) on RENDEZVOUS2 cell.",
- (int)request_len);
- goto err;
- }
- log_info(LD_REND,"Got RENDEZVOUS2 cell from hidden service.");
- /* first DH_KEY_LEN bytes are g^y from bob. Finish the dh handshake...*/
- tor_assert(circ->build_state);
- tor_assert(circ->build_state->pending_final_cpath);
- hop = circ->build_state->pending_final_cpath;
- tor_assert(hop->dh_handshake_state);
- if (crypto_dh_compute_secret(hop->dh_handshake_state, request, DH_KEY_LEN,
- keys, DIGEST_LEN+CPATH_KEY_MATERIAL_LEN)<0) {
- log_warn(LD_GENERAL, "Couldn't complete DH handshake.");
- goto err;
- }
- /* ... and set up cpath. */
- if (circuit_init_cpath_crypto(hop, keys+DIGEST_LEN, 0)<0)
- goto err;
- /* Check whether the digest is right... */
- if (memcmp(keys, request+DH_KEY_LEN, DIGEST_LEN)) {
- log_warn(LD_PROTOCOL, "Incorrect digest of key material.");
- goto err;
- }
- crypto_dh_free(hop->dh_handshake_state);
- hop->dh_handshake_state = NULL;
- /* All is well. Extend the circuit. */
- circ->_base.purpose = CIRCUIT_PURPOSE_C_REND_JOINED;
- hop->state = CPATH_STATE_OPEN;
- /* set the windows to default. these are the windows
- * that alice thinks bob has.
- */
- hop->package_window = circuit_initial_package_window();
- hop->deliver_window = CIRCWINDOW_START;
- onion_append_to_cpath(&circ->cpath, hop);
- circ->build_state->pending_final_cpath = NULL; /* prevent double-free */
- /* XXXX022 This is a pretty brute-force approach. It'd be better to
- * attach only the connections that are waiting on this circuit, rather
- * than trying to attach them all. See comments bug 743. */
- connection_ap_attach_pending();
- return 0;
- err:
- circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_TORPROTOCOL);
- return -1;
- }
- /** Find all the apconns in state AP_CONN_STATE_RENDDESC_WAIT that
- * are waiting on query. If there's a working cache entry here
- * with at least one intro point, move them to the next state. If
- * <b>rend_version</b> is non-negative, fail connections that have
- * requested <b>query</b> unless there are still descriptor fetch
- * requests in progress for other descriptor versions than
- * <b>rend_version</b>.
- */
- void
- rend_client_desc_trynow(const char *query, int rend_version)
- {
- edge_connection_t *conn;
- rend_cache_entry_t *entry;
- time_t now = time(NULL);
- smartlist_t *conns = get_connection_array();
- SMARTLIST_FOREACH(conns, connection_t *, _conn,
- {
- if (_conn->type != CONN_TYPE_AP ||
- _conn->state != AP_CONN_STATE_RENDDESC_WAIT ||
- _conn->marked_for_close)
- continue;
- conn = TO_EDGE_CONN(_conn);
- if (!conn->rend_data)
- continue;
- if (rend_cmp_service_ids(query, conn->rend_data->onion_address))
- continue;
- assert_connection_ok(TO_CONN(conn), now);
- if (rend_cache_lookup_entry(conn->rend_data->onion_address, -1,
- &entry) == 1 &&
- smartlist_len(entry->parsed->intro_nodes) > 0) {
- /* either this fetch worked, or it failed but there was a
- * valid entry from before which we should reuse */
- log_info(LD_REND,"Rend desc is usable. Launching circuits.");
- conn->_base.state = AP_CONN_STATE_CIRCUIT_WAIT;
- /* restart their timeout values, so they get a fair shake at
- * connecting to the hidden service. */
- conn->_base.timestamp_created = now;
- conn->_base.timestamp_lastread = now;
- conn->_base.timestamp_lastwritten = now;
- if (connection_ap_handshake_attach_circuit(conn) < 0) {
- /* it will never work */
- log_warn(LD_REND,"Rendezvous attempt failed. Closing.");
- if (!conn->_base.marked_for_close)
- connection_mark_unattached_ap(conn, END_STREAM_REASON_CANT_ATTACH);
- }
- } else { /* 404, or fetch didn't get that far */
- /* Unless there are requests for another descriptor version pending,
- * close the connection. */
- if (rend_version >= 0 &&
- !connection_get_by_type_state_rendquery(CONN_TYPE_DIR, 0, query,
- rend_version == 0 ? 2 : 0)) {
- log_notice(LD_REND,"Closing stream for '%s.onion': hidden service is "
- "unavailable (try again later).", safe_str(query));
- connection_mark_unattached_ap(conn, END_STREAM_REASON_RESOLVEFAILED);
- }
- }
- });
- }
- /** Return a newly allocated extend_info_t* for a randomly chosen introduction
- * point for the named hidden service. Return NULL if all introduction points
- * have been tried and failed.
- */
- extend_info_t *
- rend_client_get_random_intro(const rend_data_t *rend_query)
- {
- int i;
- rend_cache_entry_t *entry;
- rend_intro_point_t *intro;
- routerinfo_t *router;
- if (rend_cache_lookup_entry(rend_query->onion_address, -1, &entry) < 1) {
- log_warn(LD_REND,
- "Query '%s' didn't have valid rend desc in cache. Failing.",
- safe_str(rend_query->onion_address));
- return NULL;
- }
- again:
- if (smartlist_len(entry->parsed->intro_nodes) == 0)
- return NULL;
- i = crypto_rand_int(smartlist_len(entry->parsed->intro_nodes));
- intro = smartlist_get(entry->parsed->intro_nodes, i);
- /* Do we need to look up the router or is the extend info complete? */
- if (!intro->extend_info->onion_key) {
- router = router_get_by_nickname(intro->extend_info->nickname, 0);
- if (!router) {
- log_info(LD_REND, "Unknown router with nickname '%s'; trying another.",
- intro->extend_info->nickname);
- rend_intro_point_free(intro);
- smartlist_del(entry->parsed->intro_nodes, i);
- goto again;
- }
- extend_info_free(intro->extend_info);
- intro->extend_info = extend_info_from_router(router);
- }
- return extend_info_dup(intro->extend_info);
- }
- /** Client-side authorizations for hidden services; map of onion address to
- * rend_service_authorization_t*. */
- static strmap_t *auth_hid_servs = NULL;
- /** Look up the client-side authorization for the hidden service with
- * <b>onion_address</b>. Return NULL if no authorization is available for
- * that address. */
- rend_service_authorization_t*
- rend_client_lookup_service_authorization(const char *onion_address)
- {
- tor_assert(onion_address);
- if (!auth_hid_servs) return NULL;
- return strmap_get(auth_hid_servs, onion_address);
- }
- /** Helper: Free storage held by rend_service_authorization_t. */
- static void
- rend_service_authorization_free(rend_service_authorization_t *auth)
- {
- tor_free(auth);
- }
- /** Helper for strmap_free. */
- static void
- rend_service_authorization_strmap_item_free(void *service_auth)
- {
- rend_service_authorization_free(service_auth);
- }
- /** Release all the storage held in auth_hid_servs.
- */
- void
- rend_service_authorization_free_all(void)
- {
- if (!auth_hid_servs) {
- return;
- }
- strmap_free(auth_hid_servs, rend_service_authorization_strmap_item_free);
- auth_hid_servs = NULL;
- }
- /** Parse <b>config_line</b> as a client-side authorization for a hidden
- * service and add it to the local map of hidden service authorizations.
- * Return 0 for success and -1 for failure. */
- int
- rend_parse_service_authorization(or_options_t *options, int validate_only)
- {
- config_line_t *line;
- int res = -1;
- strmap_t *parsed = strmap_new();
- smartlist_t *sl = smartlist_create();
- rend_service_authorization_t *auth = NULL;
- for (line = options->HidServAuth; line; line = line->next) {
- char *onion_address, *descriptor_cookie;
- char descriptor_cookie_tmp[REND_DESC_COOKIE_LEN+2];
- char descriptor_cookie_base64ext[REND_DESC_COOKIE_LEN_BASE64+2+1];
- int auth_type_val = 0;
- auth = NULL;
- SMARTLIST_FOREACH(sl, char *, c, tor_free(c););
- smartlist_clear(sl);
- smartlist_split_string(sl, line->value, " ",
- SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 3);
- if (smartlist_len(sl) < 2) {
- log_warn(LD_CONFIG, "Configuration line does not consist of "
- ""onion-address authorization-cookie [service-name]": "
- "'%s'", line->value);
- goto err;
- }
- auth = tor_malloc_zero(sizeof(rend_service_authorization_t));
- /* Parse onion address. */
- onion_address = smartlist_get(sl, 0);
- if (strlen(onion_address) != REND_SERVICE_ADDRESS_LEN ||
- strcmpend(onion_address, ".onion")) {
- log_warn(LD_CONFIG, "Onion address has wrong format: '%s'",
- onion_address);
- goto err;
- }
- strlcpy(auth->onion_address, onion_address, REND_SERVICE_ID_LEN_BASE32+1);
- if (!rend_valid_service_id(auth->onion_address)) {
- log_warn(LD_CONFIG, "Onion address has wrong format: '%s'",
- onion_address);
- goto err;
- }
- /* Parse descriptor cookie. */
- descriptor_cookie = smartlist_get(sl, 1);
- if (strlen(descriptor_cookie) != REND_DESC_COOKIE_LEN_BASE64) {
- log_warn(LD_CONFIG, "Authorization cookie has wrong length: '%s'",
- descriptor_cookie);
- goto err;
- }
- /* Add trailing zero bytes (AA) to make base64-decoding happy. */
- tor_snprintf(descriptor_cookie_base64ext,
- REND_DESC_COOKIE_LEN_BASE64+2+1,
- "%sAA", descriptor_cookie);
- if (base64_decode(descriptor_cookie_tmp, sizeof(descriptor_cookie_tmp),
- descriptor_cookie_base64ext,
- strlen(descriptor_cookie_base64ext)) < 0) {
- log_warn(LD_CONFIG, "Decoding authorization cookie failed: '%s'",
- descriptor_cookie);
- goto err;
- }
- auth_type_val = (descriptor_cookie_tmp[16] >> 4) + 1;
- if (auth_type_val < 1 || auth_type_val > 2) {
- log_warn(LD_CONFIG, "Authorization cookie has unknown authorization "
- "type encoded.");
- goto err;
- }
- auth->auth_type = auth_type_val == 1 ? REND_BASIC_AUTH : REND_STEALTH_AUTH;
- memcpy(auth->descriptor_cookie, descriptor_cookie_tmp,
- REND_DESC_COOKIE_LEN);
- if (strmap_get(parsed, auth->onion_address)) {
- log_warn(LD_CONFIG, "Duplicate authorization for the same hidden "
- "service.");
- goto err;
- }
- strmap_set(parsed, auth->onion_address, auth);
- auth = NULL;
- }
- res = 0;
- goto done;
- err:
- res = -1;
- done:
- if (auth)
- rend_service_authorization_free(auth);
- SMARTLIST_FOREACH(sl, char *, c, tor_free(c););
- smartlist_free(sl);
- if (!validate_only && res == 0) {
- rend_service_authorization_free_all();
- auth_hid_servs = parsed;
- } else {
- strmap_free(parsed, rend_service_authorization_strmap_item_free);
- }
- return res;
- }