diff options
Diffstat (limited to 'src/or/rendcommon.c')
| -rw-r--r-- | src/or/rendcommon.c | 354 |
1 files changed, 224 insertions, 130 deletions
diff --git a/src/or/rendcommon.c b/src/or/rendcommon.c index 438fbc4d9a..458a90058f 100644 --- a/src/or/rendcommon.c +++ b/src/or/rendcommon.c @@ -1,5 +1,5 @@ /* 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 */ /** @@ -8,13 +8,18 @@ * introducers, services, clients, and rendezvous points. **/ +#define RENDCOMMON_PRIVATE + #include "or.h" #include "circuitbuild.h" #include "config.h" #include "control.h" +#include "hs_common.h" #include "rendclient.h" #include "rendcommon.h" #include "rendmid.h" +#include "hs_intropoint.h" +#include "hs_client.h" #include "rendservice.h" #include "rephist.h" #include "router.h" @@ -211,7 +216,7 @@ rend_encode_v2_intro_points(char **encoded, rend_service_descriptor_t *desc) goto done; } /* Assemble everything for this introduction point. */ - address = tor_dup_addr(&info->addr); + address = tor_addr_to_str_dup(&info->addr); res = tor_snprintf(unenc + unenc_written, unenc_len - unenc_written, "introduction-point %s\n" "ip-address %s\n" @@ -393,7 +398,7 @@ rend_encrypt_v2_intro_points_stealth(char **encrypted_out, /** Attempt to parse the given <b>desc_str</b> and return true if this * succeeds, false otherwise. */ -static int +STATIC int rend_desc_v2_is_parsable(rend_encoded_v2_service_descriptor_t *desc) { rend_service_descriptor_t *test_parsed = NULL; @@ -475,7 +480,10 @@ rend_encode_v2_descriptors(smartlist_t *descs_out, tor_assert(descriptor_cookie); } /* Obtain service_id from public key. */ - crypto_pk_get_digest(service_key, service_id); + if (crypto_pk_get_digest(service_key, service_id) < 0) { + log_warn(LD_BUG, "Couldn't compute service key digest."); + return -1; + } /* Calculate current time-period. */ time_period = get_time_period(now, period, service_id); /* Determine how many seconds the descriptor will be valid. */ @@ -691,7 +699,7 @@ rend_get_service_id(crypto_pk_t *pk, char *out) /** Return true iff <b>query</b> is a syntactically valid service ID (as * generated by rend_get_service_id). */ int -rend_valid_service_id(const char *query) +rend_valid_v2_service_id(const char *query) { if (strlen(query) != REND_SERVICE_ID_LEN_BASE32) return 0; @@ -720,6 +728,22 @@ rend_valid_descriptor_id(const char *query) return 0; } +/** Return true iff <b>client_name</b> is a syntactically valid name + * for rendezvous client authentication. */ +int +rend_valid_client_name(const char *client_name) +{ + size_t len = strlen(client_name); + if (len < 1 || len > REND_CLIENTNAME_MAX_LEN) { + return 0; + } + if (strspn(client_name, REND_LEGAL_CLIENTNAME_CHARACTERS) != len) { + return 0; + } + + return 1; +} + /** Called when we get a rendezvous-related relay cell on circuit * <b>circ</b>. Dispatch on rendezvous relay command. */ void @@ -745,7 +769,7 @@ rend_process_relay_cell(circuit_t *circ, const crypt_path_t *layer_hint, switch (command) { case RELAY_COMMAND_ESTABLISH_INTRO: if (or_circ) - r = rend_mid_establish_intro(or_circ,payload,length); + r = hs_intro_received_establish_intro(or_circ,payload,length); break; case RELAY_COMMAND_ESTABLISH_RENDEZVOUS: if (or_circ) @@ -753,15 +777,15 @@ rend_process_relay_cell(circuit_t *circ, const crypt_path_t *layer_hint, break; case RELAY_COMMAND_INTRODUCE1: if (or_circ) - r = rend_mid_introduce(or_circ,payload,length); + r = hs_intro_received_introduce1(or_circ,payload,length); break; case RELAY_COMMAND_INTRODUCE2: if (origin_circ) - r = rend_service_receive_introduction(origin_circ,payload,length); + r = hs_service_receive_introduce2(origin_circ,payload,length); break; case RELAY_COMMAND_INTRODUCE_ACK: if (origin_circ) - r = rend_client_introduction_acked(origin_circ,payload,length); + r = hs_client_receive_introduce_ack(origin_circ,payload,length); break; case RELAY_COMMAND_RENDEZVOUS1: if (or_circ) @@ -769,15 +793,15 @@ rend_process_relay_cell(circuit_t *circ, const crypt_path_t *layer_hint, break; case RELAY_COMMAND_RENDEZVOUS2: if (origin_circ) - r = rend_client_receive_rendezvous(origin_circ,payload,length); + r = hs_client_receive_rendezvous2(origin_circ,payload,length); break; case RELAY_COMMAND_INTRO_ESTABLISHED: if (origin_circ) - r = rend_service_intro_established(origin_circ,payload,length); + r = hs_service_receive_intro_established(origin_circ,payload,length); break; case RELAY_COMMAND_RENDEZVOUS_ESTABLISHED: if (origin_circ) - r = rend_client_rendezvous_acked(origin_circ,payload,length); + r = hs_client_receive_rendezvous_acked(origin_circ,payload,length); break; default: tor_fragile_assert(); @@ -788,124 +812,6 @@ rend_process_relay_cell(circuit_t *circ, const crypt_path_t *layer_hint, command); } -/** Allocate and return a new rend_data_t with the same - * contents as <b>query</b>. */ -rend_data_t * -rend_data_dup(const rend_data_t *data) -{ - rend_data_t *data_dup; - tor_assert(data); - data_dup = tor_memdup(data, sizeof(rend_data_t)); - data_dup->hsdirs_fp = smartlist_new(); - SMARTLIST_FOREACH(data->hsdirs_fp, char *, fp, - smartlist_add(data_dup->hsdirs_fp, - tor_memdup(fp, DIGEST_LEN))); - return data_dup; -} - -/** Compute descriptor ID for each replicas and save them. A valid onion - * address must be present in the <b>rend_data</b>. - * - * Return 0 on success else -1. */ -static int -compute_desc_id(rend_data_t *rend_data) -{ - int ret = 0; - unsigned replica; - time_t now = time(NULL); - - tor_assert(rend_data); - - /* Compute descriptor ID for each replicas. */ - for (replica = 0; replica < ARRAY_LENGTH(rend_data->descriptor_id); - replica++) { - ret = rend_compute_v2_desc_id(rend_data->descriptor_id[replica], - rend_data->onion_address, - rend_data->descriptor_cookie, - now, replica); - if (ret < 0) { - goto end; - } - } - - end: - return ret; -} - -/** Allocate and initialize a rend_data_t object for a service using the - * given arguments. Only the <b>onion_address</b> is not optional. - * - * Return a valid rend_data_t pointer. */ -rend_data_t * -rend_data_service_create(const char *onion_address, const char *pk_digest, - const uint8_t *cookie, rend_auth_type_t auth_type) -{ - rend_data_t *rend_data = tor_malloc_zero(sizeof(*rend_data)); - - /* We need at least one else the call is wrong. */ - tor_assert(onion_address != NULL); - - if (pk_digest) { - memcpy(rend_data->rend_pk_digest, pk_digest, - sizeof(rend_data->rend_pk_digest)); - } - if (cookie) { - memcpy(rend_data->rend_cookie, cookie, - sizeof(rend_data->rend_cookie)); - } - - strlcpy(rend_data->onion_address, onion_address, - sizeof(rend_data->onion_address)); - rend_data->auth_type = auth_type; - /* Won't be used but still need to initialize it for rend_data dup and - * free. */ - rend_data->hsdirs_fp = smartlist_new(); - - return rend_data; -} - -/** Allocate and initialize a rend_data_t object for a client request using - * the given arguments. Either an onion address or a descriptor ID is - * needed. Both can be given but only the onion address will be used to make - * the descriptor fetch. - * - * Return a valid rend_data_t pointer or NULL on error meaning the - * descriptor IDs couldn't be computed from the given data. */ -rend_data_t * -rend_data_client_create(const char *onion_address, const char *desc_id, - const char *cookie, rend_auth_type_t auth_type) -{ - rend_data_t *rend_data = tor_malloc_zero(sizeof(*rend_data)); - - /* We need at least one else the call is wrong. */ - tor_assert(onion_address != NULL || desc_id != NULL); - - if (cookie) { - memcpy(rend_data->descriptor_cookie, cookie, - sizeof(rend_data->descriptor_cookie)); - } - if (desc_id) { - memcpy(rend_data->desc_id_fetch, desc_id, - sizeof(rend_data->desc_id_fetch)); - } - if (onion_address) { - strlcpy(rend_data->onion_address, onion_address, - sizeof(rend_data->onion_address)); - if (compute_desc_id(rend_data) < 0) { - goto error; - } - } - - rend_data->auth_type = auth_type; - rend_data->hsdirs_fp = smartlist_new(); - - return rend_data; - - error: - rend_data_free(rend_data); - return NULL; -} - /** Determine the routers that are responsible for <b>id</b> (binary) and * add pointers to those routers' routerstatus_t to <b>responsible_dirs</b>. * Return -1 if we're returning an empty smartlist, else return 0. @@ -941,3 +847,191 @@ hid_serv_get_responsible_directories(smartlist_t *responsible_dirs, return smartlist_len(responsible_dirs) ? 0 : -1; } +/* Length of the 'extended' auth cookie used to encode auth type before + * base64 encoding. */ +#define REND_DESC_COOKIE_LEN_EXT (REND_DESC_COOKIE_LEN + 1) +/* Length of the zero-padded auth cookie when base64 encoded. These two + * padding bytes always (A=) are stripped off of the returned cookie. */ +#define REND_DESC_COOKIE_LEN_EXT_BASE64 (REND_DESC_COOKIE_LEN_BASE64 + 2) + +/** Encode a client authorization descriptor cookie. + * The result of this function is suitable for use in the HidServAuth + * option. The trailing padding characters are removed, and the + * auth type is encoded into the cookie. + * + * Returns a new base64-encoded cookie. This function cannot fail. + * The caller is responsible for freeing the returned value. + */ +char * +rend_auth_encode_cookie(const uint8_t *cookie_in, rend_auth_type_t auth_type) +{ + uint8_t extended_cookie[REND_DESC_COOKIE_LEN_EXT]; + char *cookie_out = tor_malloc_zero(REND_DESC_COOKIE_LEN_EXT_BASE64 + 1); + int re; + + tor_assert(cookie_in); + + memcpy(extended_cookie, cookie_in, REND_DESC_COOKIE_LEN); + extended_cookie[REND_DESC_COOKIE_LEN] = ((int)auth_type - 1) << 4; + re = base64_encode(cookie_out, REND_DESC_COOKIE_LEN_EXT_BASE64 + 1, + (const char *) extended_cookie, REND_DESC_COOKIE_LEN_EXT, + 0); + tor_assert(re == REND_DESC_COOKIE_LEN_EXT_BASE64); + + /* Remove the trailing 'A='. Auth type is encoded in the high bits + * of the last byte, so the last base64 character will always be zero + * (A). This is subtly different behavior from base64_encode_nopad. */ + cookie_out[REND_DESC_COOKIE_LEN_BASE64] = '\0'; + memwipe(extended_cookie, 0, sizeof(extended_cookie)); + return cookie_out; +} + +/** Decode a base64-encoded client authorization descriptor cookie. + * The descriptor_cookie can be truncated to REND_DESC_COOKIE_LEN_BASE64 + * characters (as given to clients), or may include the two padding + * characters (as stored by the service). + * + * The result is stored in REND_DESC_COOKIE_LEN bytes of cookie_out. + * The rend_auth_type_t decoded from the cookie is stored in the + * optional auth_type_out parameter. + * + * Return 0 on success, or -1 on error. The caller is responsible for + * freeing the returned err_msg. + */ +int +rend_auth_decode_cookie(const char *cookie_in, uint8_t *cookie_out, + rend_auth_type_t *auth_type_out, char **err_msg_out) +{ + uint8_t descriptor_cookie_decoded[REND_DESC_COOKIE_LEN_EXT + 1] = { 0 }; + char descriptor_cookie_base64ext[REND_DESC_COOKIE_LEN_EXT_BASE64 + 1]; + const char *descriptor_cookie = cookie_in; + char *err_msg = NULL; + int auth_type_val = 0; + int res = -1; + int decoded_len; + + size_t len = strlen(descriptor_cookie); + if (len == REND_DESC_COOKIE_LEN_BASE64) { + /* Add a trailing zero byte to make base64-decoding happy. */ + tor_snprintf(descriptor_cookie_base64ext, + sizeof(descriptor_cookie_base64ext), + "%sA=", descriptor_cookie); + descriptor_cookie = descriptor_cookie_base64ext; + } else if (len != REND_DESC_COOKIE_LEN_EXT_BASE64) { + tor_asprintf(&err_msg, "Authorization cookie has wrong length: %s", + escaped(cookie_in)); + goto err; + } + + decoded_len = base64_decode((char *) descriptor_cookie_decoded, + sizeof(descriptor_cookie_decoded), + descriptor_cookie, + REND_DESC_COOKIE_LEN_EXT_BASE64); + if (decoded_len != REND_DESC_COOKIE_LEN && + decoded_len != REND_DESC_COOKIE_LEN_EXT) { + tor_asprintf(&err_msg, "Authorization cookie has invalid characters: %s", + escaped(cookie_in)); + goto err; + } + + if (auth_type_out) { + auth_type_val = (descriptor_cookie_decoded[REND_DESC_COOKIE_LEN] >> 4) + 1; + if (auth_type_val < 1 || auth_type_val > 2) { + tor_asprintf(&err_msg, "Authorization cookie type is unknown: %s", + escaped(cookie_in)); + goto err; + } + *auth_type_out = auth_type_val == 1 ? REND_BASIC_AUTH : REND_STEALTH_AUTH; + } + + memcpy(cookie_out, descriptor_cookie_decoded, REND_DESC_COOKIE_LEN); + res = 0; + err: + if (err_msg_out) { + *err_msg_out = err_msg; + } else { + tor_free(err_msg); + } + memwipe(descriptor_cookie_decoded, 0, sizeof(descriptor_cookie_decoded)); + memwipe(descriptor_cookie_base64ext, 0, sizeof(descriptor_cookie_base64ext)); + return res; +} + +/* Is this a rend client or server that allows direct (non-anonymous) + * connections? + * Clients must be specifically compiled and configured in this mode. + * Onion services can be configured to start in this mode. + * Prefer rend_client_allow_non_anonymous_connection() or + * rend_service_allow_non_anonymous_connection() whenever possible, so that + * checks are specific to Single Onion Services or Tor2web. */ +int +rend_allow_non_anonymous_connection(const or_options_t* options) +{ + return (rend_client_allow_non_anonymous_connection(options) + || rend_service_allow_non_anonymous_connection(options)); +} + +/* Is this a rend client or server in non-anonymous mode? + * Clients must be specifically compiled in this mode. + * Onion services can be configured to start in this mode. + * Prefer rend_client_non_anonymous_mode_enabled() or + * rend_service_non_anonymous_mode_enabled() whenever possible, so that checks + * are specific to Single Onion Services or Tor2web. */ +int +rend_non_anonymous_mode_enabled(const or_options_t *options) +{ + return (rend_client_non_anonymous_mode_enabled(options) + || rend_service_non_anonymous_mode_enabled(options)); +} + +/* Make sure that tor only builds one-hop circuits when they would not + * compromise user anonymity. + * + * One-hop circuits are permitted in Tor2web or Single Onion modes. + * + * Tor2web or Single Onion modes are also allowed to make multi-hop circuits. + * For example, single onion HSDir circuits are 3-hop to prevent denial of + * service. + */ +void +assert_circ_anonymity_ok(const origin_circuit_t *circ, + const or_options_t *options) +{ + tor_assert(options); + tor_assert(circ); + tor_assert(circ->build_state); + + if (circ->build_state->onehop_tunnel) { + tor_assert(rend_allow_non_anonymous_connection(options)); + } +} + +/* Return 1 iff the given <b>digest</b> of a permenanent hidden service key is + * equal to the digest in the origin circuit <b>ocirc</b> of its rend data . + * If the rend data doesn't exist, 0 is returned. This function is agnostic to + * the rend data version. */ +int +rend_circuit_pk_digest_eq(const origin_circuit_t *ocirc, + const uint8_t *digest) +{ + size_t rend_pk_digest_len; + const uint8_t *rend_pk_digest; + + tor_assert(ocirc); + tor_assert(digest); + + if (ocirc->rend_data == NULL) { + goto no_match; + } + + rend_pk_digest = rend_data_get_pk_digest(ocirc->rend_data, + &rend_pk_digest_len); + if (tor_memeq(rend_pk_digest, digest, rend_pk_digest_len)) { + goto match; + } + no_match: + return 0; + match: + return 1; +} + |