diff options
Diffstat (limited to 'src/or/rendcommon.c')
-rw-r--r-- | src/or/rendcommon.c | 260 |
1 files changed, 18 insertions, 242 deletions
diff --git a/src/or/rendcommon.c b/src/or/rendcommon.c index d1b49411c..a664b5d50 100644 --- a/src/or/rendcommon.c +++ b/src/or/rendcommon.c @@ -672,79 +672,6 @@ rend_encode_v2_descriptors(smartlist_t *descs_out, return seconds_valid; } -/** Parse a service descriptor at <b>str</b> (<b>len</b> bytes). On - * success, return a newly alloced service_descriptor_t. On failure, - * return NULL. - */ -rend_service_descriptor_t * -rend_parse_service_descriptor(const char *str, size_t len) -{ - rend_service_descriptor_t *result = NULL; - int i, n_intro_points; - size_t keylen, asn1len; - const char *end, *cp, *eos; - rend_intro_point_t *intro; - - result = tor_malloc_zero(sizeof(rend_service_descriptor_t)); - cp = str; - end = str+len; - if (end-cp<2) goto truncated; - result->version = 0; - if (end-cp < 2) goto truncated; - asn1len = ntohs(get_uint16(cp)); - cp += 2; - if ((size_t)(end-cp) < asn1len) goto truncated; - result->pk = crypto_pk_asn1_decode(cp, asn1len); - if (!result->pk) goto truncated; - cp += asn1len; - if (end-cp < 4) goto truncated; - result->timestamp = (time_t) ntohl(get_uint32(cp)); - cp += 4; - result->protocols = 1<<2; /* always use intro format 2 */ - if (end-cp < 2) goto truncated; - n_intro_points = ntohs(get_uint16(cp)); - cp += 2; - - result->intro_nodes = smartlist_new(); - for (i=0;i<n_intro_points;++i) { - if (end-cp < 2) goto truncated; - eos = (const char *)memchr(cp,'\0',end-cp); - if (!eos) goto truncated; - /* Write nickname to extend info, but postpone the lookup whether - * we know that router. It's not part of the parsing process. */ - intro = tor_malloc_zero(sizeof(rend_intro_point_t)); - intro->extend_info = tor_malloc_zero(sizeof(extend_info_t)); - strlcpy(intro->extend_info->nickname, cp, - sizeof(intro->extend_info->nickname)); - smartlist_add(result->intro_nodes, intro); - cp = eos+1; - } - keylen = crypto_pk_keysize(result->pk); - tor_assert(end-cp >= 0); - if ((size_t)(end-cp) < keylen) goto truncated; - if ((size_t)(end-cp) > keylen) { - log_warn(LD_PROTOCOL, - "Signature is %d bytes too long on service descriptor.", - (int)((size_t)(end-cp) - keylen)); - goto error; - } - note_crypto_pk_op(REND_CLIENT); - if (crypto_pk_public_checksig_digest(result->pk, - (char*)str,cp-str, /* data */ - (char*)cp,end-cp /* signature*/ - )<0) { - log_warn(LD_PROTOCOL, "Bad signature on service descriptor."); - goto error; - } - - return result; - truncated: - log_warn(LD_PROTOCOL, "Truncated service descriptor."); - error: - rend_service_descriptor_free(result); - return NULL; -} - /** Sets <b>out</b> to the first 10 bytes of the digest of <b>pk</b>, * base32 encoded. NUL-terminates out. (We use this string to * identify services in directory requests and .onion URLs.) @@ -843,7 +770,7 @@ void rend_cache_purge(void) { if (rend_cache) { - log_info(LD_REND, "Purging client/v0-HS-authority HS descriptor cache"); + log_info(LD_REND, "Purging HS descriptor cache"); strmap_free(rend_cache, rend_cache_entry_free_); } rend_cache = strmap_new(); @@ -954,27 +881,6 @@ rend_cache_lookup_entry(const char *query, int version, rend_cache_entry_t **e) return 1; } -/** <b>query</b> is a base32'ed service id. If it's malformed, return -1. - * Else look it up. - * - If it is found, point *desc to it, and write its length into - * *desc_len, and return 1. - * - If it is not found, return 0. - * Note: calls to rend_cache_clean or rend_cache_store may invalidate - * *desc. - */ -int -rend_cache_lookup_desc(const char *query, int version, const char **desc, - size_t *desc_len) -{ - rend_cache_entry_t *e; - int r; - r = rend_cache_lookup_entry(query,version,&e); - if (r <= 0) return r; - *desc = e->desc; - *desc_len = e->len; - return 1; -} - /** Lookup the v2 service descriptor with base32-encoded <b>desc_id</b> and * copy the pointer to it to *<b>desc</b>. Return 1 on success, 0 on * well-formed-but-not-found, and -1 on failure. @@ -1006,130 +912,16 @@ rend_cache_lookup_v2_desc_as_dir(const char *desc_id, const char **desc) * descriptor */ #define MAX_INTRO_POINTS 10 -/** Parse *desc, calculate its service id, and store it in the cache. - * If we have a newer v0 descriptor with the same ID, ignore this one. - * If we have an older descriptor with the same ID, replace it. - * If we are acting as client due to the published flag and have any v2 - * descriptor with the same ID, reject this one in order to not get - * confused with having both versions for the same service. - * - * Return -2 if it's malformed or otherwise rejected; return -1 if we - * already have a v2 descriptor here; return 0 if it's the same or older - * than one we've already got; return 1 if it's novel. - * - * The published flag tells us if we store the descriptor - * in our role as directory (1) or if we cache it as client (0). - * - * If <b>service_id</b> is non-NULL and the descriptor is not for that - * service ID, reject it. <b>service_id</b> must be specified if and - * only if <b>published</b> is 0 (we fetched this descriptor). - */ -int -rend_cache_store(const char *desc, size_t desc_len, int published, - const char *service_id) -{ - rend_cache_entry_t *e; - rend_service_descriptor_t *parsed; - char query[REND_SERVICE_ID_LEN_BASE32+1]; - char key[REND_SERVICE_ID_LEN_BASE32+2]; /* 0<query>\0 */ - time_t now; - tor_assert(rend_cache); - parsed = rend_parse_service_descriptor(desc,desc_len); - if (!parsed) { - log_warn(LD_PROTOCOL,"Couldn't parse service descriptor."); - return -2; - } - if (rend_get_service_id(parsed->pk, query)<0) { - log_warn(LD_BUG,"Couldn't compute service ID."); - rend_service_descriptor_free(parsed); - return -2; - } - if ((service_id != NULL) && strcmp(query, service_id)) { - log_warn(LD_REND, "Received service descriptor for service ID %s; " - "expected descriptor for service ID %s.", - query, safe_str(service_id)); - rend_service_descriptor_free(parsed); - return -2; - } - now = time(NULL); - if (parsed->timestamp < now-REND_CACHE_MAX_AGE-REND_CACHE_MAX_SKEW) { - log_fn(LOG_PROTOCOL_WARN, LD_REND, - "Service descriptor %s is too old.", - safe_str_client(query)); - rend_service_descriptor_free(parsed); - return -2; - } - if (parsed->timestamp > now+REND_CACHE_MAX_SKEW) { - log_fn(LOG_PROTOCOL_WARN, LD_REND, - "Service descriptor %s is too far in the future.", - safe_str_client(query)); - rend_service_descriptor_free(parsed); - return -2; - } - /* Do we have a v2 descriptor and fetched this descriptor as a client? */ - tor_snprintf(key, sizeof(key), "2%s", query); - if (!published && strmap_get_lc(rend_cache, key)) { - log_info(LD_REND, "We already have a v2 descriptor for service %s.", - safe_str_client(query)); - rend_service_descriptor_free(parsed); - return -1; - } - if (parsed->intro_nodes && - smartlist_len(parsed->intro_nodes) > MAX_INTRO_POINTS) { - log_warn(LD_REND, "Found too many introduction points on a hidden " - "service descriptor for %s. This is probably a (misguided) " - "attempt to improve reliability, but it could also be an " - "attempt to do a guard enumeration attack. Rejecting.", - safe_str_client(query)); - rend_service_descriptor_free(parsed); - return -2; - } - tor_snprintf(key, sizeof(key), "0%s", query); - e = (rend_cache_entry_t*) strmap_get_lc(rend_cache, key); - if (e && e->parsed->timestamp > parsed->timestamp) { - log_info(LD_REND,"We already have a newer service descriptor %s with the " - "same ID and version.", - safe_str_client(query)); - rend_service_descriptor_free(parsed); - return 0; - } - if (e && e->len == desc_len && tor_memeq(desc,e->desc,desc_len)) { - log_info(LD_REND,"We already have this service descriptor %s.", - safe_str_client(query)); - e->received = time(NULL); - rend_service_descriptor_free(parsed); - return 0; - } - if (!e) { - e = tor_malloc_zero(sizeof(rend_cache_entry_t)); - strmap_set_lc(rend_cache, key, e); - } else { - rend_service_descriptor_free(e->parsed); - tor_free(e->desc); - } - e->received = time(NULL); - e->parsed = parsed; - e->len = desc_len; - e->desc = tor_malloc(desc_len); - memcpy(e->desc, desc, desc_len); - - log_debug(LD_REND,"Successfully stored rend desc '%s', len %d.", - safe_str_client(query), (int)desc_len); - return 1; -} - /** Parse the v2 service descriptor(s) in <b>desc</b> and store it/them to the * local rend cache. Don't attempt to decrypt the included list of introduction * points (as we don't have a descriptor cookie for it). * * If we have a newer descriptor with the same ID, ignore this one. * If we have an older descriptor with the same ID, replace it. - * Return -2 if we are not acting as hidden service directory; - * return -1 if the descriptor(s) were not parsable; return 0 if all - * descriptors are the same or older than those we've already got; - * return a positive number for the number of novel stored descriptors. + * + * Return an appropriate rend_cache_store_status_t. */ -int +rend_cache_store_status_t rend_cache_store_v2_desc_as_dir(const char *desc) { rend_service_descriptor_t *parsed; @@ -1149,7 +941,7 @@ rend_cache_store_v2_desc_as_dir(const char *desc) /* Cannot store descs, because we are (currently) not acting as * hidden service directory. */ log_info(LD_REND, "Cannot store descs: Not acting as hs dir"); - return -2; + return RCS_NOTDIR; } while (rend_parse_v2_service_descriptor(&parsed, desc_id, &intro_content, &intro_size, &encoded_size, @@ -1225,11 +1017,11 @@ rend_cache_store_v2_desc_as_dir(const char *desc) } if (!number_parsed) { log_info(LD_REND, "Could not parse any descriptor."); - return -1; + return RCS_BADDESC; } log_info(LD_REND, "Parsed %d and added %d descriptor%s.", number_parsed, number_stored, number_stored != 1 ? "s" : ""); - return number_stored; + return RCS_OKAY; } /** Parse the v2 service descriptor in <b>desc</b>, decrypt the included list @@ -1239,15 +1031,12 @@ rend_cache_store_v2_desc_as_dir(const char *desc) * * If we have a newer v2 descriptor with the same ID, ignore this one. * If we have an older descriptor with the same ID, replace it. - * If we have any v0 descriptor with the same ID, reject this one in order - * to not get confused with having both versions for the same service. * If the descriptor's service ID does not match * <b>rend_query</b>-\>onion_address, reject it. - * Return -2 if it's malformed or otherwise rejected; return -1 if we - * already have a v0 descriptor here; return 0 if it's the same or older - * than one we've already got; return 1 if it's novel. + * + * Return an appropriate rend_cache_store_status_t. */ -int +rend_cache_store_status_t rend_cache_store_v2_desc_as_client(const char *desc, const rend_data_t *rend_query) { @@ -1276,7 +1065,7 @@ rend_cache_store_v2_desc_as_client(const char *desc, char key[REND_SERVICE_ID_LEN_BASE32+2]; char service_id[REND_SERVICE_ID_LEN_BASE32+1]; rend_cache_entry_t *e; - int retval; + rend_cache_store_status_t retval = RCS_BADDESC; tor_assert(rend_cache); tor_assert(desc); /* Parse the descriptor. */ @@ -1284,20 +1073,17 @@ rend_cache_store_v2_desc_as_client(const char *desc, &intro_size, &encoded_size, &next_desc, desc) < 0) { log_warn(LD_REND, "Could not parse descriptor."); - retval = -2; goto err; } /* Compute service ID from public key. */ if (rend_get_service_id(parsed->pk, service_id)<0) { log_warn(LD_REND, "Couldn't compute service ID."); - retval = -2; goto err; } if (strcmp(rend_query->onion_address, service_id)) { log_warn(LD_REND, "Received service descriptor for service ID %s; " "expected descriptor for service ID %s.", service_id, safe_str(rend_query->onion_address)); - retval = -2; goto err; } /* Decode/decrypt introduction points. */ @@ -1329,7 +1115,6 @@ rend_cache_store_v2_desc_as_client(const char *desc, log_warn(LD_REND, "Failed to parse introduction points. Either the " "service has published a corrupt descriptor or you have " "provided invalid authorization data."); - retval = -2; goto err; } else if (n_intro_points > MAX_INTRO_POINTS) { log_warn(LD_REND, "Found too many introduction points on a hidden " @@ -1337,7 +1122,7 @@ rend_cache_store_v2_desc_as_client(const char *desc, "attempt to improve reliability, but it could also be an " "attempt to do a guard enumeration attack. Rejecting.", safe_str_client(rend_query->onion_address)); - retval = -2; + goto err; } } else { @@ -1350,22 +1135,12 @@ rend_cache_store_v2_desc_as_client(const char *desc, if (parsed->timestamp < now - REND_CACHE_MAX_AGE-REND_CACHE_MAX_SKEW) { log_warn(LD_REND, "Service descriptor with service ID %s is too old.", safe_str_client(service_id)); - retval = -2; goto err; } /* Is descriptor too far in the future? */ if (parsed->timestamp > now + REND_CACHE_MAX_SKEW) { log_warn(LD_REND, "Service descriptor with service ID %s is too far in " "the future.", safe_str_client(service_id)); - retval = -2; - goto err; - } - /* Do we have a v0 descriptor? */ - tor_snprintf(key, sizeof(key), "0%s", service_id); - if (strmap_get_lc(rend_cache, key)) { - log_info(LD_REND, "We already have a v0 descriptor for service ID %s.", - safe_str_client(service_id)); - retval = -1; goto err; } /* Do we already have a newer descriptor? */ @@ -1375,16 +1150,14 @@ rend_cache_store_v2_desc_as_client(const char *desc, log_info(LD_REND, "We already have a newer service descriptor for " "service ID %s with the same desc ID and version.", safe_str_client(service_id)); - retval = 0; - goto err; + goto okay; } /* Do we already have this descriptor? */ if (e && !strcmp(desc, e->desc)) { log_info(LD_REND,"We already have this service descriptor %s.", safe_str_client(service_id)); e->received = time(NULL); - retval = 0; - goto err; + goto okay; } if (!e) { e = tor_malloc_zero(sizeof(rend_cache_entry_t)); @@ -1400,7 +1173,10 @@ rend_cache_store_v2_desc_as_client(const char *desc, e->len = encoded_size; log_debug(LD_REND,"Successfully stored rend desc '%s', len %d.", safe_str_client(service_id), (int)encoded_size); - return 1; + return RCS_OKAY; + + okay: + retval = RCS_OKAY; err: rend_service_descriptor_free(parsed); |