1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889909192939495969798991001011021031041051061071081091101111121131141151161171181191201211221231241251261271281291301311321331341351361371381391401411421431441451461471481491501511521531541551561571581591601611621631641651661671681691701711721731741751761771781791801811821831841851861871881891901911921931941951961971981992002012022032042052062072082092102112122132142152162172182192202212222232242252262272282292302312322332342352362372382392402412422432442452462472482492502512522532542552562572582592602612622632642652662672682692702712722732742752762772782792802812822832842852862872882892902912922932942952962972982993003013023033043053063073083093103113123133143153163173183193203213223233243253263273283293303313323333343353363373383393403413423433443453463473483493503513523533543553563573583593603613623633643653663673683693703713723733743753763773783793803813823833843853863873883893903913923933943953963973983994004014024034044054064074084094104114124134144154164174184194204214224234244254264274284294304314324334344354364374384394404414424434444454464474484494504514524534544554564574584594604614624634644654664674684694704714724734744754764774784794804814824834844854864874884894904914924934944954964974984995005015025035045055065075085095105115125135145155165175185195205215225235245255265275285295305315325335345355365375385395405415425435445455465475485495505515525535545555565575585595605615625635645655665675685695705715725735745755765775785795805815825835845855865875885895905915925935945955965975985996006016026036046056066076086096106116126136146156166176186196206216226236246256266276286296306316326336346356366376386396406416426436446456466476486496506516526536546556566576586596606616626636646656666676686696706716726736746756766776786796806816826836846856866876886896906916926936946956966976986997007017027037047057067077087097107117127137147157167177187197207217227237247257267277287297307317327337347357367377387397407417427437447457467477487497507517527537547557567577587597607617627637647657667677687697707717727737747757767777787797807817827837847857867877887897907917927937947957967977987998008018028038048058068078088098108118128138148158168178188198208218228238248258268278288298308318328338348358368378388398408418428438448458468478488498508518528538548558568578588598608618628638648658668678688698708718728738748758768778788798808818828838848858868878888898908918928938948958968978988999009019029039049059069079089099109119129139149159169179189199209219229239249259269279289299309319329339349359369379389399409419429439449459469479489499509519529539549559569579589599609619629639649659669679689699709719729739749759769779789799809819829839849859869879889899909919929939949959969979989991000100110021003100410051006100710081009101010111012101310141015101610171018101910201021102210231024102510261027102810291030103110321033103410351036103710381039104010411042104310441045104610471048104910501051105210531054105510561057105810591060106110621063106410651066106710681069107010711072107310741075107610771078107910801081108210831084108510861087108810891090109110921093109410951096109710981099110011011102110311041105110611071108110911101111111211131114111511161117111811191120112111221123112411251126112711281129113011311132113311341135113611371138113911401141114211431144114511461147114811491150115111521153115411551156115711581159116011611162116311641165116611671168116911701171117211731174117511761177117811791180118111821183118411851186118711881189119011911192119311941195119611971198119912001201120212031204120512061207120812091210121112121213121412151216121712181219122012211222122312241225122612271228122912301231123212331234123512361237123812391240124112421243124412451246124712481249125012511252125312541255125612571258125912601261126212631264126512661267126812691270127112721273127412751276127712781279128012811282128312841285128612871288128912901291129212931294129512961297129812991300130113021303130413051306130713081309131013111312131313141315131613171318131913201321132213231324132513261327132813291330133113321333133413351336133713381339 |
- /* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
- * Copyright (c) 2007-2013, The Tor Project, Inc. */
- /* See LICENSE for licensing information */
- /**
- * \file rendclient.c
- * \brief Client code to access location-hidden services.
- **/
- #include "or.h"
- #include "circuitbuild.h"
- #include "circuitlist.h"
- #include "circuituse.h"
- #include "config.h"
- #include "connection.h"
- #include "connection_edge.h"
- #include "directory.h"
- #include "main.h"
- #include "nodelist.h"
- #include "relay.h"
- #include "rendclient.h"
- #include "rendcommon.h"
- #include "rephist.h"
- #include "router.h"
- #include "routerlist.h"
- #include "routerset.h"
- static extend_info_t *rend_client_get_random_intro_impl(
- const rend_cache_entry_t *rend_query,
- const int strict, const int warnings);
- /** Purge all potentially remotely-detectable state held in the hidden
- * service client code. Called on SIGNAL NEWNYM. */
- void
- rend_client_purge_state(void)
- {
- rend_cache_purge();
- rend_client_cancel_descriptor_fetches();
- rend_client_purge_last_hid_serv_requests();
- }
- /** 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;
- }
- /* Set timestamp_dirty, because circuit_expire_building expects it,
- * and the rend cookie also means we've used the circ. */
- circ->base_.timestamp_dirty = time(NULL);
- /* We've attempted to use this circuit. Probe it if we fail */
- pathbias_count_use_attempt(circ);
- 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;
- }
- /** Extend the introduction circuit <b>circ</b> to another valid
- * introduction point for the hidden service it is trying to connect
- * to, or mark it and launch a new circuit if we can't extend it.
- * Return 0 on success or possible success. Return -1 and mark the
- * introduction circuit for close on permanent failure.
- *
- * On failure, the caller is responsible for marking the associated
- * rendezvous circuit for close. */
- static int
- rend_client_reextend_intro_circuit(origin_circuit_t *circ)
- {
- 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 usable introduction points left for %s. Closing.",
- safe_str_client(circ->rend_data->onion_address));
- circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL);
- return -1;
- }
- // XXX: should we not re-extend if hs_circ_has_timed_out?
- if (circ->remaining_relay_early_cells) {
- log_info(LD_REND,
- "Re-extending circ %u, this time to %s.",
- (unsigned)circ->base_.n_circ_id,
- safe_str_client(extend_info_describe(extend_info)));
- result = circuit_extend_to_new_exit(circ, extend_info);
- } else {
- log_info(LD_REND,
- "Closing intro circ %u (out of RELAY_EARLY cells).",
- (unsigned)circ->base_.n_circ_id);
- circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_FINISHED);
- /* connection_ap_handshake_attach_circuit will launch a new intro circ. */
- result = 0;
- }
- extend_info_free(extend_info);
- return result;
- }
- /** 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_t *intro_key = NULL;
- int status = 0;
- 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));
- #ifndef NON_ANONYMOUS_MODE_ENABLED
- tor_assert(!(introcirc->build_state->onehop_tunnel));
- tor_assert(!(rendcirc->build_state->onehop_tunnel));
- #endif
- if (rend_cache_lookup_entry(introcirc->rend_data->onion_address, -1,
- &entry) < 1) {
- log_info(LD_REND,
- "query %s didn't have valid rend desc in cache. "
- "Refetching descriptor.",
- safe_str_client(introcirc->rend_data->onion_address));
- rend_client_refetch_v2_renddesc(introcirc->rend_data);
- {
- connection_t *conn;
- while ((conn = connection_get_by_type_state_rendquery(CONN_TYPE_AP,
- AP_CONN_STATE_CIRCUIT_WAIT,
- introcirc->rend_data->onion_address))) {
- conn->state = AP_CONN_STATE_RENDDESC_WAIT;
- }
- }
- status = -1;
- goto cleanup;
- }
- /* first 20 bytes of payload are the hash of Bob's pk */
- intro_key = NULL;
- SMARTLIST_FOREACH(entry->parsed->intro_nodes, rend_intro_point_t *,
- intro, {
- if (tor_memeq(introcirc->build_state->chosen_exit->identity_digest,
- intro->extend_info->identity_digest, DIGEST_LEN)) {
- intro_key = intro->intro_key;
- break;
- }
- });
- if (!intro_key) {
- log_info(LD_REND, "Could not find intro key for %s at %s; we "
- "have a v2 rend desc with %d intro points. "
- "Trying a different intro point...",
- safe_str_client(introcirc->rend_data->onion_address),
- safe_str_client(extend_info_describe(
- introcirc->build_state->chosen_exit)),
- smartlist_len(entry->parsed->intro_nodes));
- if (rend_client_reextend_intro_circuit(introcirc)) {
- status = -2;
- goto perm_err;
- } else {
- status = -1;
- goto cleanup;
- }
- }
- if (crypto_pk_get_digest(intro_key, payload)<0) {
- log_warn(LD_BUG, "Internal error: couldn't hash public key.");
- status = -2;
- goto perm_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->rend_dh_handshake_state = crypto_dh_new(DH_TYPE_REND))) {
- log_warn(LD_BUG, "Internal error: couldn't allocate DH.");
- status = -2;
- goto perm_err;
- }
- if (crypto_dh_generate_public(cpath->rend_dh_handshake_state)<0) {
- log_warn(LD_BUG, "Internal error: couldn't generate g^x.");
- status = -2;
- goto perm_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->rend_dh_handshake_state, tmp+dh_offset,
- DH_KEY_LEN)<0) {
- log_warn(LD_BUG, "Internal error: couldn't extract g^x.");
- status = -2;
- goto perm_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,
- sizeof(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.");
- status = -2;
- goto perm_err;
- }
- payload_len = DIGEST_LEN + r;
- tor_assert(payload_len <= RELAY_PAYLOAD_SIZE); /* we overran something */
- /* Copy the rendezvous cookie from rendcirc to introcirc, so that
- * when introcirc gets an ack, we can change the state of the right
- * rendezvous circuit. */
- memcpy(introcirc->rend_data->rend_cookie, rendcirc->rend_data->rend_cookie,
- REND_COOKIE_LEN);
- 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");
- status = -2;
- goto cleanup;
- }
- /* Now, we wait for an ACK or NAK on this circuit. */
- circuit_change_purpose(TO_CIRCUIT(introcirc),
- CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT);
- /* Set timestamp_dirty, because circuit_expire_building expects it
- * to specify when a circuit entered the _C_INTRODUCE_ACK_WAIT
- * state. */
- introcirc->base_.timestamp_dirty = time(NULL);
- pathbias_count_use_attempt(introcirc);
- goto cleanup;
- perm_err:
- if (!introcirc->base_.marked_for_close)
- circuit_mark_for_close(TO_CIRCUIT(introcirc), END_CIRC_REASON_INTERNAL);
- circuit_mark_for_close(TO_CIRCUIT(rendcirc), END_CIRC_REASON_INTERNAL);
- cleanup:
- memwipe(payload, 0, sizeof(payload));
- memwipe(tmp, 0, sizeof(tmp));
- return status;
- }
- /** 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 to close other intro circuits we launched in parallel
- * due to timeout.
- */
- static void
- rend_client_close_other_intros(const char *onion_address)
- {
- circuit_t *c;
- /* abort parallel intro circs, if any */
- for (c = circuit_get_global_list_(); c; c = c->next) {
- if ((c->purpose == CIRCUIT_PURPOSE_C_INTRODUCING ||
- c->purpose == CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT) &&
- !c->marked_for_close && CIRCUIT_IS_ORIGIN(c)) {
- origin_circuit_t *oc = TO_ORIGIN_CIRCUIT(c);
- if (oc->rend_data &&
- !rend_cmp_service_ids(onion_address,
- oc->rend_data->onion_address)) {
- log_info(LD_REND|LD_CIRC, "Closing introduction circuit %d that we "
- "built in parallel (Purpose %d).", oc->global_identifier,
- c->purpose);
- circuit_mark_for_close(c, END_CIRC_REASON_TIMEOUT);
- }
- }
- }
- }
- /** Called when get an ACK or a NAK for a REND_INTRODUCE1 cell.
- */
- int
- rend_client_introduction_acked(origin_circuit_t *circ,
- const uint8_t *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 %u.",
- (unsigned)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);
- #ifndef NON_ANONYMOUS_MODE_ENABLED
- tor_assert(!(circ->build_state->onehop_tunnel));
- #endif
- tor_assert(circ->rend_data);
- /* For path bias: This circuit was used successfully. Valid
- * nacks and acks count. */
- pathbias_mark_use_success(circ);
- 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_ready_rend_circ_by_rend_data(circ->rend_data);
- if (rendcirc) { /* remember the ack */
- #ifndef NON_ANONYMOUS_MODE_ENABLED
- tor_assert(!(rendcirc->build_state->onehop_tunnel));
- #endif
- circuit_change_purpose(TO_CIRCUIT(rendcirc),
- CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED);
- /* Set timestamp_dirty, because circuit_expire_building expects
- * it to specify when a circuit entered the
- * _C_REND_READY_INTRO_ACKED state. */
- rendcirc->base_.timestamp_dirty = time(NULL);
- } else {
- log_info(LD_REND,"...Found no rend circ. Dropping on the floor.");
- }
- /* close the circuit: we won't need it anymore. */
- circuit_change_purpose(TO_CIRCUIT(circ),
- CIRCUIT_PURPOSE_C_INTRODUCE_ACKED);
- circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_FINISHED);
- /* close any other intros launched in parallel */
- rend_client_close_other_intros(circ->rend_data->onion_address);
- } else {
- /* It's a NAK; the introduction point didn't relay our request. */
- circuit_change_purpose(TO_CIRCUIT(circ), 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.
- */
- log_info(LD_REND, "Got nack for %s from %s...",
- safe_str_client(circ->rend_data->onion_address),
- safe_str_client(extend_info_describe(circ->build_state->chosen_exit)));
- if (rend_client_report_intro_point_failure(circ->build_state->chosen_exit,
- circ->rend_data,
- INTRO_POINT_FAILURE_GENERIC)>0) {
- /* There are introduction points left. Re-extend the circuit to
- * another intro point and try again. */
- int result = rend_client_reextend_intro_circuit(circ);
- /* XXXX If that call failed, should we close the rend circuit,
- * too? */
- 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; each key is a string consisting of the
- * concatenation of a base32-encoded HS directory identity digest, a
- * base32-encoded HS descriptor ID, and a hidden service address
- * (without the ".onion" part); each value is a pointer to a time_t
- * holding the time of the last request for that descriptor ID to that
- * HS directory. */
- static strmap_t *last_hid_serv_requests_ = NULL;
- /** Returns last_hid_serv_requests_, initializing it to a new strmap if
- * necessary. */
- static strmap_t *
- get_last_hid_serv_requests(void)
- {
- if (!last_hid_serv_requests_)
- last_hid_serv_requests_ = strmap_new();
- return last_hid_serv_requests_;
- }
- #define LAST_HID_SERV_REQUEST_KEY_LEN (REND_DESC_ID_V2_LEN_BASE32 + \
- REND_DESC_ID_V2_LEN_BASE32 + \
- REND_SERVICE_ID_LEN_BASE32)
- /** Look up the last request time to hidden service directory <b>hs_dir</b>
- * for descriptor ID <b>desc_id_base32</b> for the service specified in
- * <b>rend_query</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,
- const rend_data_t *rend_query,
- time_t now, int set)
- {
- char hsdir_id_base32[REND_DESC_ID_V2_LEN_BASE32 + 1];
- char hsdir_desc_comb_id[LAST_HID_SERV_REQUEST_KEY_LEN + 1];
- time_t *last_request_ptr;
- strmap_t *last_hid_serv_requests = get_last_hid_serv_requests();
- 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%s",
- hsdir_id_base32,
- desc_id_base32,
- rend_query->onion_address);
- /* XXX023 tor_assert(strlen(hsdir_desc_comb_id) ==
- LAST_HID_SERV_REQUEST_KEY_LEN); */
- if (set) {
- time_t *oldptr;
- last_request_ptr = tor_malloc_zero(sizeof(time_t));
- *last_request_ptr = now;
- oldptr = strmap_set(last_hid_serv_requests, hsdir_desc_comb_id,
- last_request_ptr);
- tor_free(oldptr);
- } 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(time_t now)
- {
- strmap_iter_t *iter;
- time_t cutoff = now - REND_HID_SERV_DIR_REQUERY_PERIOD;
- strmap_t *last_hid_serv_requests = get_last_hid_serv_requests();
- 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);
- }
- }
- }
- /** Remove all requests related to the hidden service named
- * <b>onion_address</b> from the history of times of requests to
- * hidden service directories. */
- static void
- purge_hid_serv_from_last_hid_serv_requests(const char *onion_address)
- {
- strmap_iter_t *iter;
- strmap_t *last_hid_serv_requests = get_last_hid_serv_requests();
- /* XXX023 tor_assert(strlen(onion_address) == REND_SERVICE_ID_LEN_BASE32); */
- for (iter = strmap_iter_init(last_hid_serv_requests);
- !strmap_iter_done(iter); ) {
- const char *key;
- void *val;
- strmap_iter_get(iter, &key, &val);
- /* XXX023 tor_assert(strlen(key) == LAST_HID_SERV_REQUEST_KEY_LEN); */
- if (tor_memeq(key + LAST_HID_SERV_REQUEST_KEY_LEN -
- REND_SERVICE_ID_LEN_BASE32,
- onion_address,
- REND_SERVICE_ID_LEN_BASE32)) {
- iter = strmap_iter_next_rmv(last_hid_serv_requests, iter);
- tor_free(val);
- } else {
- iter = strmap_iter_next(last_hid_serv_requests, iter);
- }
- }
- }
- /** Purge the history of request times to hidden service directories,
- * so that future lookups of an HS descriptor will not fail because we
- * accessed all of the HSDir relays responsible for the descriptor
- * recently. */
- void
- rend_client_purge_last_hid_serv_requests(void)
- {
- /* Don't create the table if it doesn't exist yet (and it may very
- * well not exist if the user hasn't accessed any HSes)... */
- strmap_t *old_last_hid_serv_requests = last_hid_serv_requests_;
- /* ... and let get_last_hid_serv_requests re-create it for us if
- * necessary. */
- last_hid_serv_requests_ = NULL;
- if (old_last_hid_serv_requests != NULL) {
- log_info(LD_REND, "Purging client last-HS-desc-request-time table");
- strmap_free(old_last_hid_serv_requests, tor_free_);
- }
- }
- /** Determine the responsible hidden service directories for <b>desc_id</b>
- * and fetch the descriptor with that ID from one of them. Only
- * send a request to a hidden service directory that we have not yet tried
- * during this attempt to connect to this hidden service; 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. */
- static int
- directory_get_from_hs_dir(const char *desc_id, const rend_data_t *rend_query)
- {
- smartlist_t *responsible_dirs = smartlist_new();
- 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];
- int tor2web_mode = get_options()->Tor2webMode;
- 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. */
- 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. */
- /* Clean request history first. */
- directory_clean_last_hid_serv_requests(now);
- SMARTLIST_FOREACH(responsible_dirs, routerstatus_t *, dir, {
- time_t last = lookup_last_hid_serv_request(
- dir, desc_id_base32, rend_query, 0, 0);
- const node_t *node = node_get_by_id(dir->identity_digest);
- if (last + REND_HID_SERV_DIR_REQUERY_PERIOD >= now ||
- !node || !node_has_descriptor(node))
- 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, rend_query, 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] = '\0';
- } 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,
- tor2web_mode?DIRIND_ONEHOP:DIRIND_ANONYMOUS,
- 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",
- rend_query->onion_address, desc_id_base32,
- rend_query->auth_type,
- (rend_query->auth_type == REND_NO_AUTH ? "[none]" :
- escaped_safe_str_client(descriptor_cookie_base64)),
- routerstatus_describe(hs_dir));
- return 1;
- }
- /** Unless we already have a descriptor for <b>rend_query</b> with at least
- * one (possibly) working introduction point in it, start a connection to a
- * hidden service directory to fetch a v2 rendezvous service descriptor. */
- 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;
- rend_cache_entry_t *e = 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 a usable descriptor here. */
- if (rend_cache_lookup_entry(rend_query->onion_address, -1, &e) > 0 &&
- rend_client_any_intro_points_usable(e)) {
- log_info(LD_REND, "We would fetch a v2 rendezvous descriptor, but we "
- "already have a usable descriptor here. Not fetching.");
- return;
- }
- log_debug(LD_REND, "Fetching v2 rendezvous descriptor for service %s",
- safe_str_client(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.");
- /*
- * Hmm, can this write anything to descriptor_id and still fail?
- * Let's clear it just to be safe.
- *
- * From here on, any returns should goto done which clears
- * descriptor_id so we don't leave key-derived material on the stack.
- */
- goto done;
- }
- if (directory_get_from_hs_dir(descriptor_id, rend_query) != 0)
- goto done; /* 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. */
- rend_client_desc_trynow(rend_query->onion_address);
- done:
- memwipe(descriptor_id, 0, sizeof(descriptor_id));
- return;
- }
- /** Cancel all rendezvous descriptor fetches currently in progress.
- */
- void
- rend_client_cancel_descriptor_fetches(void)
- {
- smartlist_t *connection_array = get_connection_array();
- SMARTLIST_FOREACH_BEGIN(connection_array, connection_t *, conn) {
- if (conn->type == CONN_TYPE_DIR &&
- (conn->purpose == DIR_PURPOSE_FETCH_RENDDESC ||
- conn->purpose == DIR_PURPOSE_FETCH_RENDDESC_V2)) {
- /* It's a rendezvous descriptor fetch in progress -- cancel it
- * by marking the connection for close.
- *
- * Even if this connection has already reached EOF, this is
- * enough to make sure that if the descriptor hasn't been
- * processed yet, it won't be. See the end of
- * connection_handle_read; connection_reached_eof (indirectly)
- * processes whatever response the connection received. */
- const rend_data_t *rd = (TO_DIR_CONN(conn))->rend_data;
- if (!rd) {
- log_warn(LD_BUG | LD_REND,
- "Marking for close dir conn fetching rendezvous "
- "descriptor for unknown service!");
- } else {
- log_debug(LD_REND, "Marking for close dir conn fetching "
- "rendezvous descriptor for service %s",
- safe_str(rd->onion_address));
- }
- connection_mark_for_close(conn);
- }
- } SMARTLIST_FOREACH_END(conn);
- }
- /** Mark <b>failed_intro</b> as a failed introduction point for the
- * hidden service specified by <b>rend_query</b>. If the HS now has no
- * usable intro points, or we do not have an HS descriptor for it,
- * then launch a new renddesc fetch.
- *
- * If <b>failure_type</b> is INTRO_POINT_FAILURE_GENERIC, remove the
- * intro point from (our parsed copy of) the HS descriptor.
- *
- * If <b>failure_type</b> is INTRO_POINT_FAILURE_TIMEOUT, mark the
- * intro point as 'timed out'; it will not be retried until the
- * current hidden service connection attempt has ended or it has
- * appeared in a newly fetched rendezvous descriptor.
- *
- * If <b>failure_type</b> is INTRO_POINT_FAILURE_UNREACHABLE,
- * increment the intro point's reachability-failure count; if it has
- * now failed MAX_INTRO_POINT_REACHABILITY_FAILURES or more times,
- * remove the intro point from (our parsed copy of) the HS descriptor.
- *
- * Return -1 if error, 0 if no usable intro points remain or service
- * unrecognized, 1 if recognized and some intro points remain.
- */
- int
- rend_client_report_intro_point_failure(extend_info_t *failed_intro,
- const rend_data_t *rend_query,
- unsigned int failure_type)
- {
- 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_client(rend_query->onion_address));
- return -1;
- }
- if (r==0) {
- log_info(LD_REND, "Unknown service %s. Re-fetching descriptor.",
- escaped_safe_str_client(rend_query->onion_address));
- rend_client_refetch_v2_renddesc(rend_query);
- 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 (tor_memeq(failed_intro->identity_digest,
- intro->extend_info->identity_digest, DIGEST_LEN)) {
- switch (failure_type) {
- default:
- log_warn(LD_BUG, "Unknown failure type %u. Removing intro point.",
- failure_type);
- tor_fragile_assert();
- /* fall through */
- case INTRO_POINT_FAILURE_GENERIC:
- rend_intro_point_free(intro);
- smartlist_del(ent->parsed->intro_nodes, i);
- break;
- case INTRO_POINT_FAILURE_TIMEOUT:
- intro->timed_out = 1;
- break;
- case INTRO_POINT_FAILURE_UNREACHABLE:
- ++(intro->unreachable_count);
- {
- int zap_intro_point =
- intro->unreachable_count >= MAX_INTRO_POINT_REACHABILITY_FAILURES;
- log_info(LD_REND, "Failed to reach this intro point %u times.%s",
- intro->unreachable_count,
- zap_intro_point ? " Removing from descriptor.": "");
- if (zap_intro_point) {
- rend_intro_point_free(intro);
- smartlist_del(ent->parsed->intro_nodes, i);
- }
- }
- break;
- }
- break;
- }
- }
- if (! rend_client_any_intro_points_usable(ent)) {
- log_info(LD_REND,
- "No more intro points remain for %s. Re-fetching descriptor.",
- escaped_safe_str_client(rend_query->onion_address));
- rend_client_refetch_v2_renddesc(rend_query);
- /* 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))) {
- 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_client(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 uint8_t *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.");
- circuit_change_purpose(TO_CIRCUIT(circ), CIRCUIT_PURPOSE_C_REND_READY);
- /* Set timestamp_dirty, because circuit_expire_building expects it
- * to specify when a circuit entered the _C_REND_READY state. */
- circ->base_.timestamp_dirty = time(NULL);
- /* From a path bias point of view, this circuit is now successfully used.
- * Waiting any longer opens us up to attacks from Bob. He could induce
- * Alice to attempt to connect to his hidden service and never reply
- * to her rend requests */
- pathbias_mark_use_success(circ);
- /* XXXX 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 uint8_t *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->rend_dh_handshake_state);
- if (crypto_dh_compute_secret(LOG_PROTOCOL_WARN,
- hop->rend_dh_handshake_state, (char*)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 (tor_memneq(keys, request+DH_KEY_LEN, DIGEST_LEN)) {
- log_warn(LD_PROTOCOL, "Incorrect digest of key material.");
- goto err;
- }
- crypto_dh_free(hop->rend_dh_handshake_state);
- hop->rend_dh_handshake_state = NULL;
- /* All is well. Extend the circuit. */
- circuit_change_purpose(TO_CIRCUIT(circ), 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;
- /* Now that this circuit has finished connecting to its destination,
- * make sure circuit_get_open_circ_or_launch is willing to return it
- * so we can actually use it. */
- circ->hs_circ_has_timed_out = 0;
- onion_append_to_cpath(&circ->cpath, hop);
- circ->build_state->pending_final_cpath = NULL; /* prevent double-free */
- circuit_try_attaching_streams(circ);
- memwipe(keys, 0, sizeof(keys));
- return 0;
- err:
- memwipe(keys, 0, sizeof(keys));
- 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 <b>query</b>. If there's a working cache entry here with at
- * least one intro point, move them to the next state. */
- void
- rend_client_desc_trynow(const char *query)
- {
- entry_connection_t *conn;
- rend_cache_entry_t *entry;
- const rend_data_t *rend_data;
- time_t now = time(NULL);
- smartlist_t *conns = get_connection_array();
- SMARTLIST_FOREACH_BEGIN(conns, connection_t *, base_conn) {
- if (base_conn->type != CONN_TYPE_AP ||
- base_conn->state != AP_CONN_STATE_RENDDESC_WAIT ||
- base_conn->marked_for_close)
- continue;
- conn = TO_ENTRY_CONN(base_conn);
- rend_data = ENTRY_TO_EDGE_CONN(conn)->rend_data;
- if (!rend_data)
- continue;
- if (rend_cmp_service_ids(query, rend_data->onion_address))
- continue;
- assert_connection_ok(base_conn, now);
- if (rend_cache_lookup_entry(rend_data->onion_address, -1,
- &entry) == 1 &&
- rend_client_any_intro_points_usable(entry)) {
- /* 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.");
- base_conn->state = AP_CONN_STATE_CIRCUIT_WAIT;
- /* restart their timeout values, so they get a fair shake at
- * connecting to the hidden service. */
- base_conn->timestamp_created = now;
- base_conn->timestamp_lastread = now;
- base_conn->timestamp_lastwritten = now;
- if (connection_ap_handshake_attach_circuit(conn) < 0) {
- /* it will never work */
- log_warn(LD_REND,"Rendezvous attempt failed. Closing.");
- if (!base_conn->marked_for_close)
- connection_mark_unattached_ap(conn, END_STREAM_REASON_CANT_ATTACH);
- }
- } else { /* 404, or fetch didn't get that far */
- log_notice(LD_REND,"Closing stream for '%s.onion': hidden service is "
- "unavailable (try again later).",
- safe_str_client(query));
- connection_mark_unattached_ap(conn, END_STREAM_REASON_RESOLVEFAILED);
- rend_client_note_connection_attempt_ended(query);
- }
- } SMARTLIST_FOREACH_END(base_conn);
- }
- /** Clear temporary state used only during an attempt to connect to
- * the hidden service named <b>onion_address</b>. Called when a
- * connection attempt has ended; may be called occasionally at other
- * times, and should be reasonably harmless. */
- void
- rend_client_note_connection_attempt_ended(const char *onion_address)
- {
- rend_cache_entry_t *cache_entry = NULL;
- rend_cache_lookup_entry(onion_address, -1, &cache_entry);
- log_info(LD_REND, "Connection attempt for %s has ended; "
- "cleaning up temporary state.",
- safe_str_client(onion_address));
- /* Clear the timed_out flag on all remaining intro points for this HS. */
- if (cache_entry != NULL) {
- SMARTLIST_FOREACH(cache_entry->parsed->intro_nodes,
- rend_intro_point_t *, ip,
- ip->timed_out = 0; );
- }
- /* Remove the HS's entries in last_hid_serv_requests. */
- purge_hid_serv_from_last_hid_serv_requests(onion_address);
- }
- /** 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)
- {
- extend_info_t *result;
- rend_cache_entry_t *entry;
- 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_client(rend_query->onion_address));
- return NULL;
- }
- /* See if we can get a node that complies with ExcludeNodes */
- if ((result = rend_client_get_random_intro_impl(entry, 1, 1)))
- return result;
- /* If not, and StrictNodes is not set, see if we can return any old node
- */
- if (!get_options()->StrictNodes)
- return rend_client_get_random_intro_impl(entry, 0, 1);
- return NULL;
- }
- /** As rend_client_get_random_intro, except assume that StrictNodes is set
- * iff <b>strict</b> is true. If <b>warnings</b> is false, don't complain
- * to the user when we're out of nodes, even if StrictNodes is true.
- */
- static extend_info_t *
- rend_client_get_random_intro_impl(const rend_cache_entry_t *entry,
- const int strict,
- const int warnings)
- {
- int i;
- rend_intro_point_t *intro;
- const or_options_t *options = get_options();
- smartlist_t *usable_nodes;
- int n_excluded = 0;
- /* We'll keep a separate list of the usable nodes. If this becomes empty,
- * no nodes are usable. */
- usable_nodes = smartlist_new();
- smartlist_add_all(usable_nodes, entry->parsed->intro_nodes);
- /* Remove the intro points that have timed out during this HS
- * connection attempt from our list of usable nodes. */
- SMARTLIST_FOREACH(usable_nodes, rend_intro_point_t *, ip,
- if (ip->timed_out) {
- SMARTLIST_DEL_CURRENT(usable_nodes, ip);
- });
- again:
- if (smartlist_len(usable_nodes) == 0) {
- if (n_excluded && get_options()->StrictNodes && warnings) {
- /* We only want to warn if StrictNodes is really set. Otherwise
- * we're just about to retry anyways.
- */
- log_warn(LD_REND, "All introduction points for hidden service are "
- "at excluded relays, and StrictNodes is set. Skipping.");
- }
- smartlist_free(usable_nodes);
- return NULL;
- }
- i = crypto_rand_int(smartlist_len(usable_nodes));
- intro = smartlist_get(usable_nodes, i);
- /* Do we need to look up the router or is the extend info complete? */
- if (!intro->extend_info->onion_key) {
- const node_t *node;
- extend_info_t *new_extend_info;
- if (tor_digest_is_zero(intro->extend_info->identity_digest))
- node = node_get_by_hex_id(intro->extend_info->nickname);
- else
- node = node_get_by_id(intro->extend_info->identity_digest);
- if (!node) {
- log_info(LD_REND, "Unknown router with nickname '%s'; trying another.",
- intro->extend_info->nickname);
- smartlist_del(usable_nodes, i);
- goto again;
- }
- new_extend_info = extend_info_from_node(node, 0);
- if (!new_extend_info) {
- log_info(LD_REND, "We don't have a descriptor for the intro-point relay "
- "'%s'; trying another.",
- extend_info_describe(intro->extend_info));
- smartlist_del(usable_nodes, i);
- goto again;
- } else {
- extend_info_free(intro->extend_info);
- intro->extend_info = new_extend_info;
- }
- tor_assert(intro->extend_info != NULL);
- }
- /* Check if we should refuse to talk to this router. */
- if (strict &&
- routerset_contains_extendinfo(options->ExcludeNodes,
- intro->extend_info)) {
- n_excluded++;
- smartlist_del(usable_nodes, i);
- goto again;
- }
- smartlist_free(usable_nodes);
- return extend_info_dup(intro->extend_info);
- }
- /** Return true iff any introduction points still listed in <b>entry</b> are
- * usable. */
- int
- rend_client_any_intro_points_usable(const rend_cache_entry_t *entry)
- {
- extend_info_t *extend_info =
- rend_client_get_random_intro_impl(entry, get_options()->StrictNodes, 0);
- int rv = (extend_info != NULL);
- extend_info_free(extend_info);
- return rv;
- }
- /** 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(const or_options_t *options,
- int validate_only)
- {
- config_line_t *line;
- int res = -1;
- strmap_t *parsed = strmap_new();
- smartlist_t *sl = smartlist_new();
- rend_service_authorization_t *auth = NULL;
- char descriptor_cookie_tmp[REND_DESC_COOKIE_LEN+2];
- char descriptor_cookie_base64ext[REND_DESC_COOKIE_LEN_BASE64+2+1];
- for (line = options->HidServAuth; line; line = line->next) {
- char *onion_address, *descriptor_cookie;
- 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 = (((uint8_t)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:
- 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);
- }
- memwipe(descriptor_cookie_tmp, 0, sizeof(descriptor_cookie_tmp));
- memwipe(descriptor_cookie_base64ext, 0, sizeof(descriptor_cookie_base64ext));
- return res;
- }
|