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Diffstat (limited to 'src/or/hs_service.c')
| -rw-r--r-- | src/or/hs_service.c | 3378 |
1 files changed, 3378 insertions, 0 deletions
diff --git a/src/or/hs_service.c b/src/or/hs_service.c new file mode 100644 index 0000000000..408625c3ac --- /dev/null +++ b/src/or/hs_service.c @@ -0,0 +1,3378 @@ +/* Copyright (c) 2016-2017, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file hs_service.c + * \brief Implement next generation hidden service functionality + **/ + +#define HS_SERVICE_PRIVATE + +#include "or.h" +#include "circpathbias.h" +#include "circuitbuild.h" +#include "circuitlist.h" +#include "circuituse.h" +#include "config.h" +#include "connection.h" +#include "directory.h" +#include "main.h" +#include "networkstatus.h" +#include "nodelist.h" +#include "relay.h" +#include "rendservice.h" +#include "router.h" +#include "routerkeys.h" +#include "routerlist.h" +#include "shared_random_state.h" +#include "statefile.h" + +#include "hs_circuit.h" +#include "hs_common.h" +#include "hs_config.h" +#include "hs_circuit.h" +#include "hs_descriptor.h" +#include "hs_ident.h" +#include "hs_intropoint.h" +#include "hs_service.h" + +/* Trunnel */ +#include "ed25519_cert.h" +#include "hs/cell_common.h" +#include "hs/cell_establish_intro.h" + +/* Helper macro. Iterate over every service in the global map. The var is the + * name of the service pointer. */ +#define FOR_EACH_SERVICE_BEGIN(var) \ + STMT_BEGIN \ + hs_service_t **var##_iter, *var; \ + HT_FOREACH(var##_iter, hs_service_ht, hs_service_map) { \ + var = *var##_iter; +#define FOR_EACH_SERVICE_END } STMT_END ; + +/* Helper macro. Iterate over both current and previous descriptor of a + * service. The var is the name of the descriptor pointer. This macro skips + * any descriptor object of the service that is NULL. */ +#define FOR_EACH_DESCRIPTOR_BEGIN(service, var) \ + STMT_BEGIN \ + hs_service_descriptor_t *var; \ + for (int var ## _loop_idx = 0; var ## _loop_idx < 2; \ + ++var ## _loop_idx) { \ + (var ## _loop_idx == 0) ? (var = service->desc_current) : \ + (var = service->desc_next); \ + if (var == NULL) continue; +#define FOR_EACH_DESCRIPTOR_END } STMT_END ; + +/* Onion service directory file names. */ +static const char fname_keyfile_prefix[] = "hs_ed25519"; +static const char fname_hostname[] = "hostname"; +static const char address_tld[] = "onion"; + +/* Staging list of service object. When configuring service, we add them to + * this list considered a staging area and they will get added to our global + * map once the keys have been loaded. These two steps are seperated because + * loading keys requires that we are an actual running tor process. */ +static smartlist_t *hs_service_staging_list; + +/** True if the list of available router descriptors might have changed which + * might result in an altered hash ring. Check if the hash ring changed and + * reupload if needed */ +static int consider_republishing_hs_descriptors = 0; + +static void set_descriptor_revision_counter(hs_descriptor_t *hs_desc); +static void move_descriptors(hs_service_t *src, hs_service_t *dst); + +/* Helper: Function to compare two objects in the service map. Return 1 if the + * two service have the same master public identity key. */ +static inline int +hs_service_ht_eq(const hs_service_t *first, const hs_service_t *second) +{ + tor_assert(first); + tor_assert(second); + /* Simple key compare. */ + return ed25519_pubkey_eq(&first->keys.identity_pk, + &second->keys.identity_pk); +} + +/* Helper: Function for the service hash table code below. The key used is the + * master public identity key which is ultimately the onion address. */ +static inline unsigned int +hs_service_ht_hash(const hs_service_t *service) +{ + tor_assert(service); + return (unsigned int) siphash24g(service->keys.identity_pk.pubkey, + sizeof(service->keys.identity_pk.pubkey)); +} + +/* This is _the_ global hash map of hidden services which indexed the service + * contained in it by master public identity key which is roughly the onion + * address of the service. */ +static struct hs_service_ht *hs_service_map; + +/* Register the service hash table. */ +HT_PROTOTYPE(hs_service_ht, /* Name of hashtable. */ + hs_service_t, /* Object contained in the map. */ + hs_service_node, /* The name of the HT_ENTRY member. */ + hs_service_ht_hash, /* Hashing function. */ + hs_service_ht_eq) /* Compare function for objects. */ + +HT_GENERATE2(hs_service_ht, hs_service_t, hs_service_node, + hs_service_ht_hash, hs_service_ht_eq, + 0.6, tor_reallocarray, tor_free_) + +/* Query the given service map with a public key and return a service object + * if found else NULL. It is also possible to set a directory path in the + * search query. If pk is NULL, then it will be set to zero indicating the + * hash table to compare the directory path instead. */ +STATIC hs_service_t * +find_service(hs_service_ht *map, const ed25519_public_key_t *pk) +{ + hs_service_t dummy_service; + tor_assert(map); + tor_assert(pk); + memset(&dummy_service, 0, sizeof(dummy_service)); + ed25519_pubkey_copy(&dummy_service.keys.identity_pk, pk); + return HT_FIND(hs_service_ht, map, &dummy_service); +} + +/* Register the given service in the given map. If the service already exists + * in the map, -1 is returned. On success, 0 is returned and the service + * ownership has been transfered to the global map. */ +STATIC int +register_service(hs_service_ht *map, hs_service_t *service) +{ + tor_assert(map); + tor_assert(service); + tor_assert(!ed25519_public_key_is_zero(&service->keys.identity_pk)); + + if (find_service(map, &service->keys.identity_pk)) { + /* Existing service with the same key. Do not register it. */ + return -1; + } + /* Taking ownership of the object at this point. */ + HT_INSERT(hs_service_ht, map, service); + return 0; +} + +/* Remove a given service from the given map. If service is NULL or the + * service key is unset, return gracefully. */ +STATIC void +remove_service(hs_service_ht *map, hs_service_t *service) +{ + hs_service_t *elm; + + tor_assert(map); + + /* Ignore if no service or key is zero. */ + if (BUG(service == NULL) || + BUG(ed25519_public_key_is_zero(&service->keys.identity_pk))) { + return; + } + + elm = HT_REMOVE(hs_service_ht, map, service); + if (elm) { + tor_assert(elm == service); + } else { + log_warn(LD_BUG, "Could not find service in the global map " + "while removing service %s", + escaped(service->config.directory_path)); + } +} + +/* Set the default values for a service configuration object <b>c</b>. */ +static void +set_service_default_config(hs_service_config_t *c, + const or_options_t *options) +{ + (void) options; + tor_assert(c); + c->ports = smartlist_new(); + c->directory_path = NULL; + c->max_streams_per_rdv_circuit = 0; + c->max_streams_close_circuit = 0; + c->num_intro_points = NUM_INTRO_POINTS_DEFAULT; + c->allow_unknown_ports = 0; + c->is_single_onion = 0; + c->dir_group_readable = 0; + c->is_ephemeral = 0; +} + +/* From a service configuration object config, clear everything from it + * meaning free allocated pointers and reset the values. */ +static void +service_clear_config(hs_service_config_t *config) +{ + if (config == NULL) { + return; + } + tor_free(config->directory_path); + if (config->ports) { + SMARTLIST_FOREACH(config->ports, rend_service_port_config_t *, p, + rend_service_port_config_free(p);); + smartlist_free(config->ports); + } + memset(config, 0, sizeof(*config)); +} + +/* Helper function to return a human readable description of the given intro + * point object. + * + * This function is not thread-safe. Each call to this invalidates the + * previous values returned by it. */ +static const char * +describe_intro_point(const hs_service_intro_point_t *ip) +{ + /* Hex identity digest of the IP prefixed by the $ sign and ends with NUL + * byte hence the plus two. */ + static char buf[HEX_DIGEST_LEN + 2]; + const char *legacy_id = NULL; + + SMARTLIST_FOREACH_BEGIN(ip->base.link_specifiers, + const hs_desc_link_specifier_t *, lspec) { + if (lspec->type == LS_LEGACY_ID) { + legacy_id = (const char *) lspec->u.legacy_id; + break; + } + } SMARTLIST_FOREACH_END(lspec); + + /* For now, we only print the identity digest but we could improve this with + * much more information such as the ed25519 identity has well. */ + buf[0] = '$'; + if (legacy_id) { + base16_encode(buf + 1, HEX_DIGEST_LEN + 1, legacy_id, DIGEST_LEN); + } + + return buf; +} + +/* Return the lower bound of maximum INTRODUCE2 cells per circuit before we + * rotate intro point (defined by a consensus parameter or the default + * value). */ +static int32_t +get_intro_point_min_introduce2(void) +{ + /* The [0, 2147483647] range is quite large to accomodate anything we decide + * in the future. */ + return networkstatus_get_param(NULL, "hs_intro_min_introduce2", + INTRO_POINT_MIN_LIFETIME_INTRODUCTIONS, + 0, INT32_MAX); +} + +/* Return the upper bound of maximum INTRODUCE2 cells per circuit before we + * rotate intro point (defined by a consensus parameter or the default + * value). */ +static int32_t +get_intro_point_max_introduce2(void) +{ + /* The [0, 2147483647] range is quite large to accomodate anything we decide + * in the future. */ + return networkstatus_get_param(NULL, "hs_intro_max_introduce2", + INTRO_POINT_MAX_LIFETIME_INTRODUCTIONS, + 0, INT32_MAX); +} + +/* Return the minimum lifetime in seconds of an introduction point defined by a + * consensus parameter or the default value. */ +static int32_t +get_intro_point_min_lifetime(void) +{ +#define MIN_INTRO_POINT_LIFETIME_TESTING 10 + if (get_options()->TestingTorNetwork) { + return MIN_INTRO_POINT_LIFETIME_TESTING; + } + + /* The [0, 2147483647] range is quite large to accomodate anything we decide + * in the future. */ + return networkstatus_get_param(NULL, "hs_intro_min_lifetime", + INTRO_POINT_LIFETIME_MIN_SECONDS, + 0, INT32_MAX); +} + +/* Return the maximum lifetime in seconds of an introduction point defined by a + * consensus parameter or the default value. */ +static int32_t +get_intro_point_max_lifetime(void) +{ +#define MAX_INTRO_POINT_LIFETIME_TESTING 30 + if (get_options()->TestingTorNetwork) { + return MAX_INTRO_POINT_LIFETIME_TESTING; + } + + /* The [0, 2147483647] range is quite large to accomodate anything we decide + * in the future. */ + return networkstatus_get_param(NULL, "hs_intro_max_lifetime", + INTRO_POINT_LIFETIME_MAX_SECONDS, + 0, INT32_MAX); +} + +/* Return the number of extra introduction point defined by a consensus + * parameter or the default value. */ +static int32_t +get_intro_point_num_extra(void) +{ + /* The [0, 128] range bounds the number of extra introduction point allowed. + * Above 128 intro points, it's getting a bit crazy. */ + return networkstatus_get_param(NULL, "hs_intro_num_extra", + NUM_INTRO_POINTS_EXTRA, 0, 128); +} + +/* Helper: Function that needs to return 1 for the HT for each loop which + * frees every service in an hash map. */ +static int +ht_free_service_(struct hs_service_t *service, void *data) +{ + (void) data; + hs_service_free(service); + /* This function MUST return 1 so the given object is then removed from the + * service map leading to this free of the object being safe. */ + return 1; +} + +/* Free every service that can be found in the global map. Once done, clear + * and free the global map. */ +static void +service_free_all(void) +{ + if (hs_service_map) { + /* The free helper function returns 1 so this is safe. */ + hs_service_ht_HT_FOREACH_FN(hs_service_map, ht_free_service_, NULL); + HT_CLEAR(hs_service_ht, hs_service_map); + tor_free(hs_service_map); + hs_service_map = NULL; + } + + if (hs_service_staging_list) { + /* Cleanup staging list. */ + SMARTLIST_FOREACH(hs_service_staging_list, hs_service_t *, s, + hs_service_free(s)); + smartlist_free(hs_service_staging_list); + hs_service_staging_list = NULL; + } +} + +/* Free a given service intro point object. */ +STATIC void +service_intro_point_free(hs_service_intro_point_t *ip) +{ + if (!ip) { + return; + } + memwipe(&ip->auth_key_kp, 0, sizeof(ip->auth_key_kp)); + memwipe(&ip->enc_key_kp, 0, sizeof(ip->enc_key_kp)); + crypto_pk_free(ip->legacy_key); + replaycache_free(ip->replay_cache); + hs_intropoint_clear(&ip->base); + tor_free(ip); +} + +/* Helper: free an hs_service_intro_point_t object. This function is used by + * digest256map_free() which requires a void * pointer. */ +static void +service_intro_point_free_(void *obj) +{ + service_intro_point_free(obj); +} + +/* Return a newly allocated service intro point and fully initialized from the + * given extend_info_t ei if non NULL. If is_legacy is true, we also generate + * the legacy key. On error, NULL is returned. + * + * If ei is NULL, returns a hs_service_intro_point_t with an empty link + * specifier list and no onion key. (This is used for testing.) + * + * ei must be an extend_info_t containing an IPv4 address. (We will add supoort + * for IPv6 in a later release.) When calling extend_info_from_node(), pass + * 0 in for_direct_connection to make sure ei always has an IPv4 address. */ +STATIC hs_service_intro_point_t * +service_intro_point_new(const extend_info_t *ei, unsigned int is_legacy) +{ + hs_desc_link_specifier_t *ls; + hs_service_intro_point_t *ip; + + ip = tor_malloc_zero(sizeof(*ip)); + /* We'll create the key material. No need for extra strong, those are short + * term keys. */ + ed25519_keypair_generate(&ip->auth_key_kp, 0); + + { /* Set introduce2 max cells limit */ + int32_t min_introduce2_cells = get_intro_point_min_introduce2(); + int32_t max_introduce2_cells = get_intro_point_max_introduce2(); + if (BUG(max_introduce2_cells < min_introduce2_cells)) { + goto err; + } + ip->introduce2_max = crypto_rand_int_range(min_introduce2_cells, + max_introduce2_cells); + } + { /* Set intro point lifetime */ + int32_t intro_point_min_lifetime = get_intro_point_min_lifetime(); + int32_t intro_point_max_lifetime = get_intro_point_max_lifetime(); + if (BUG(intro_point_max_lifetime < intro_point_min_lifetime)) { + goto err; + } + ip->time_to_expire = time(NULL) + + crypto_rand_int_range(intro_point_min_lifetime,intro_point_max_lifetime); + } + + ip->replay_cache = replaycache_new(0, 0); + + /* Initialize the base object. We don't need the certificate object. */ + ip->base.link_specifiers = smartlist_new(); + + /* Generate the encryption key for this intro point. */ + curve25519_keypair_generate(&ip->enc_key_kp, 0); + /* Figure out if this chosen node supports v3 or is legacy only. */ + if (is_legacy) { + ip->base.is_only_legacy = 1; + /* Legacy mode that is doesn't support v3+ with ed25519 auth key. */ + ip->legacy_key = crypto_pk_new(); + if (crypto_pk_generate_key(ip->legacy_key) < 0) { + goto err; + } + } + + if (ei == NULL) { + goto done; + } + + /* We'll try to add all link specifiers. Legacy is mandatory. + * IPv4 or IPv6 is required, and we always send IPv4. */ + ls = hs_desc_link_specifier_new(ei, LS_IPV4); + /* It is impossible to have an extend info object without a v4. */ + if (BUG(!ls)) { + goto err; + } + smartlist_add(ip->base.link_specifiers, ls); + + ls = hs_desc_link_specifier_new(ei, LS_LEGACY_ID); + /* It is impossible to have an extend info object without an identity + * digest. */ + if (BUG(!ls)) { + goto err; + } + smartlist_add(ip->base.link_specifiers, ls); + + /* ed25519 identity key is optional for intro points */ + ls = hs_desc_link_specifier_new(ei, LS_ED25519_ID); + if (ls) { + smartlist_add(ip->base.link_specifiers, ls); + } + + /* IPv6 is not supported in this release. */ + + /* Finally, copy onion key from the extend_info_t object. */ + memcpy(&ip->onion_key, &ei->curve25519_onion_key, sizeof(ip->onion_key)); + + done: + return ip; + err: + service_intro_point_free(ip); + return NULL; +} + +/* Add the given intro point object to the given intro point map. The intro + * point MUST have its RSA encryption key set if this is a legacy type or the + * authentication key set otherwise. */ +STATIC void +service_intro_point_add(digest256map_t *map, hs_service_intro_point_t *ip) +{ + hs_service_intro_point_t *old_ip_entry; + + tor_assert(map); + tor_assert(ip); + + old_ip_entry = digest256map_set(map, ip->auth_key_kp.pubkey.pubkey, ip); + /* Make sure we didn't just try to double-add an intro point */ + tor_assert_nonfatal(!old_ip_entry); +} + +/* For a given service, remove the intro point from that service's descriptors + * (check both current and next descriptor) */ +STATIC void +service_intro_point_remove(const hs_service_t *service, + const hs_service_intro_point_t *ip) +{ + tor_assert(service); + tor_assert(ip); + + /* Trying all descriptors. */ + FOR_EACH_DESCRIPTOR_BEGIN(service, desc) { + /* We'll try to remove the descriptor on both descriptors which is not + * very expensive to do instead of doing loopup + remove. */ + digest256map_remove(desc->intro_points.map, + ip->auth_key_kp.pubkey.pubkey); + } FOR_EACH_DESCRIPTOR_END; +} + +/* For a given service and authentication key, return the intro point or NULL + * if not found. This will check both descriptors in the service. */ +STATIC hs_service_intro_point_t * +service_intro_point_find(const hs_service_t *service, + const ed25519_public_key_t *auth_key) +{ + hs_service_intro_point_t *ip = NULL; + + tor_assert(service); + tor_assert(auth_key); + + /* Trying all descriptors to find the right intro point. + * + * Even if we use the same node as intro point in both descriptors, the node + * will have a different intro auth key for each descriptor since we generate + * a new one everytime we pick an intro point. + * + * After #22893 gets implemented, intro points will be moved to be + * per-service instead of per-descriptor so this function will need to + * change. + */ + FOR_EACH_DESCRIPTOR_BEGIN(service, desc) { + if ((ip = digest256map_get(desc->intro_points.map, + auth_key->pubkey)) != NULL) { + break; + } + } FOR_EACH_DESCRIPTOR_END; + + return ip; +} + +/* For a given service and intro point, return the descriptor for which the + * intro point is assigned to. NULL is returned if not found. */ +STATIC hs_service_descriptor_t * +service_desc_find_by_intro(const hs_service_t *service, + const hs_service_intro_point_t *ip) +{ + hs_service_descriptor_t *descp = NULL; + + tor_assert(service); + tor_assert(ip); + + FOR_EACH_DESCRIPTOR_BEGIN(service, desc) { + if (digest256map_get(desc->intro_points.map, + ip->auth_key_kp.pubkey.pubkey)) { + descp = desc; + break; + } + } FOR_EACH_DESCRIPTOR_END; + + return descp; +} + +/* From a circuit identifier, get all the possible objects associated with the + * ident. If not NULL, service, ip or desc are set if the object can be found. + * They are untouched if they can't be found. + * + * This is an helper function because we do those lookups often so it's more + * convenient to simply call this functions to get all the things at once. */ +STATIC void +get_objects_from_ident(const hs_ident_circuit_t *ident, + hs_service_t **service, hs_service_intro_point_t **ip, + hs_service_descriptor_t **desc) +{ + hs_service_t *s; + + tor_assert(ident); + + /* Get service object from the circuit identifier. */ + s = find_service(hs_service_map, &ident->identity_pk); + if (s && service) { + *service = s; + } + + /* From the service object, get the intro point object of that circuit. The + * following will query both descriptors intro points list. */ + if (s && ip) { + *ip = service_intro_point_find(s, &ident->intro_auth_pk); + } + + /* Get the descriptor for this introduction point and service. */ + if (s && ip && *ip && desc) { + *desc = service_desc_find_by_intro(s, *ip); + } +} + +/* From a given intro point, return the first link specifier of type + * encountered in the link specifier list. Return NULL if it can't be found. + * + * The caller does NOT have ownership of the object, the intro point does. */ +static hs_desc_link_specifier_t * +get_link_spec_by_type(const hs_service_intro_point_t *ip, uint8_t type) +{ + hs_desc_link_specifier_t *lnk_spec = NULL; + + tor_assert(ip); + + SMARTLIST_FOREACH_BEGIN(ip->base.link_specifiers, + hs_desc_link_specifier_t *, ls) { + if (ls->type == type) { + lnk_spec = ls; + goto end; + } + } SMARTLIST_FOREACH_END(ls); + + end: + return lnk_spec; +} + +/* Given a service intro point, return the node_t associated to it. This can + * return NULL if the given intro point has no legacy ID or if the node can't + * be found in the consensus. */ +STATIC const node_t * +get_node_from_intro_point(const hs_service_intro_point_t *ip) +{ + const hs_desc_link_specifier_t *ls; + + tor_assert(ip); + + ls = get_link_spec_by_type(ip, LS_LEGACY_ID); + if (BUG(!ls)) { + return NULL; + } + /* XXX In the future, we want to only use the ed25519 ID (#22173). */ + return node_get_by_id((const char *) ls->u.legacy_id); +} + +/* Given a service intro point, return the extend_info_t for it. This can + * return NULL if the node can't be found for the intro point or the extend + * info can't be created for the found node. If direct_conn is set, the extend + * info is validated on if we can connect directly. */ +static extend_info_t * +get_extend_info_from_intro_point(const hs_service_intro_point_t *ip, + unsigned int direct_conn) +{ + extend_info_t *info = NULL; + const node_t *node; + + tor_assert(ip); + + node = get_node_from_intro_point(ip); + if (node == NULL) { + /* This can happen if the relay serving as intro point has been removed + * from the consensus. In that case, the intro point will be removed from + * the descriptor during the scheduled events. */ + goto end; + } + + /* In the case of a direct connection (single onion service), it is possible + * our firewall policy won't allow it so this can return a NULL value. */ + info = extend_info_from_node(node, direct_conn); + + end: + return info; +} + +/* Return the number of introduction points that are established for the + * given descriptor. */ +static unsigned int +count_desc_circuit_established(const hs_service_descriptor_t *desc) +{ + unsigned int count = 0; + + tor_assert(desc); + + DIGEST256MAP_FOREACH(desc->intro_points.map, key, + const hs_service_intro_point_t *, ip) { + count += ip->circuit_established; + } DIGEST256MAP_FOREACH_END; + + return count; +} + +/* For a given service and descriptor of that service, close all active + * directory connections. */ +static void +close_directory_connections(const hs_service_t *service, + const hs_service_descriptor_t *desc) +{ + unsigned int count = 0; + smartlist_t *dir_conns; + + tor_assert(service); + tor_assert(desc); + + /* Close pending HS desc upload connections for the blinded key of 'desc'. */ + dir_conns = connection_list_by_type_purpose(CONN_TYPE_DIR, + DIR_PURPOSE_UPLOAD_HSDESC); + SMARTLIST_FOREACH_BEGIN(dir_conns, connection_t *, conn) { + dir_connection_t *dir_conn = TO_DIR_CONN(conn); + if (ed25519_pubkey_eq(&dir_conn->hs_ident->identity_pk, + &service->keys.identity_pk) && + ed25519_pubkey_eq(&dir_conn->hs_ident->blinded_pk, + &desc->blinded_kp.pubkey)) { + connection_mark_for_close(conn); + count++; + continue; + } + } SMARTLIST_FOREACH_END(conn); + + log_info(LD_REND, "Closed %u active service directory connections for " + "descriptor %s of service %s", + count, safe_str_client(ed25519_fmt(&desc->blinded_kp.pubkey)), + safe_str_client(service->onion_address)); + /* We don't have ownership of the objects in this list. */ + smartlist_free(dir_conns); +} + +/* Close all rendezvous circuits for the given service. */ +static void +close_service_rp_circuits(hs_service_t *service) +{ + origin_circuit_t *ocirc = NULL; + + tor_assert(service); + + /* The reason we go over all circuit instead of using the circuitmap API is + * because most hidden service circuits are rendezvous circuits so there is + * no real improvement at getting all rendezvous circuits from the + * circuitmap and then going over them all to find the right ones. + * Furthermore, another option would have been to keep a list of RP cookies + * for a service but it creates an engineering complexity since we don't + * have a "RP circuit closed" event to clean it up properly so we avoid a + * memory DoS possibility. */ + + while ((ocirc = circuit_get_next_service_rp_circ(ocirc))) { + /* Only close circuits that are v3 and for this service. */ + if (ocirc->hs_ident != NULL && + ed25519_pubkey_eq(ô->hs_ident->identity_pk, + &service->keys.identity_pk)) { + /* Reason is FINISHED because service has been removed and thus the + * circuit is considered old/uneeded. When freed, it is removed from the + * hs circuitmap. */ + circuit_mark_for_close(TO_CIRCUIT(ocirc), END_CIRC_REASON_FINISHED); + } + } +} + +/* Close the circuit(s) for the given map of introduction points. */ +static void +close_intro_circuits(hs_service_intropoints_t *intro_points) +{ + tor_assert(intro_points); + + DIGEST256MAP_FOREACH(intro_points->map, key, + const hs_service_intro_point_t *, ip) { + origin_circuit_t *ocirc = hs_circ_service_get_intro_circ(ip); + if (ocirc) { + /* Reason is FINISHED because service has been removed and thus the + * circuit is considered old/uneeded. When freed, the circuit is removed + * from the HS circuitmap. */ + circuit_mark_for_close(TO_CIRCUIT(ocirc), END_CIRC_REASON_FINISHED); + } + } DIGEST256MAP_FOREACH_END; +} + +/* Close all introduction circuits for the given service. */ +static void +close_service_intro_circuits(hs_service_t *service) +{ + tor_assert(service); + + FOR_EACH_DESCRIPTOR_BEGIN(service, desc) { + close_intro_circuits(&desc->intro_points); + } FOR_EACH_DESCRIPTOR_END; +} + +/* Close any circuits related to the given service. */ +static void +close_service_circuits(hs_service_t *service) +{ + tor_assert(service); + + /* Only support for version >= 3. */ + if (BUG(service->config.version < HS_VERSION_THREE)) { + return; + } + /* Close intro points. */ + close_service_intro_circuits(service); + /* Close rendezvous points. */ + close_service_rp_circuits(service); +} + +/* Move every ephemeral services from the src service map to the dst service + * map. It is possible that a service can't be register to the dst map which + * won't stop the process of moving them all but will trigger a log warn. */ +static void +move_ephemeral_services(hs_service_ht *src, hs_service_ht *dst) +{ + hs_service_t **iter, **next; + + tor_assert(src); + tor_assert(dst); + + /* Iterate over the map to find ephemeral service and move them to the other + * map. We loop using this method to have a safe removal process. */ + for (iter = HT_START(hs_service_ht, src); iter != NULL; iter = next) { + hs_service_t *s = *iter; + if (!s->config.is_ephemeral) { + /* Yeah, we are in a very manual loop :). */ + next = HT_NEXT(hs_service_ht, src, iter); + continue; + } + /* Remove service from map and then register to it to the other map. + * Reminder that "*iter" and "s" are the same thing. */ + next = HT_NEXT_RMV(hs_service_ht, src, iter); + if (register_service(dst, s) < 0) { + log_warn(LD_BUG, "Ephemeral service key is already being used. " + "Skipping."); + } + } +} + +/* Return a const string of the directory path escaped. If this is an + * ephemeral service, it returns "[EPHEMERAL]". This can only be called from + * the main thread because escaped() uses a static variable. */ +static const char * +service_escaped_dir(const hs_service_t *s) +{ + return (s->config.is_ephemeral) ? "[EPHEMERAL]" : + escaped(s->config.directory_path); +} + +/** Move the hidden service state from <b>src</b> to <b>dst</b>. We do this + * when we receive a SIGHUP: <b>dst</b> is the post-HUP service */ +static void +move_hs_state(hs_service_t *src_service, hs_service_t *dst_service) +{ + tor_assert(src_service); + tor_assert(dst_service); + + hs_service_state_t *src = &src_service->state; + hs_service_state_t *dst = &dst_service->state; + + /* Let's do a shallow copy */ + dst->intro_circ_retry_started_time = src->intro_circ_retry_started_time; + dst->num_intro_circ_launched = src->num_intro_circ_launched; + /* Freeing a NULL replaycache triggers an info LD_BUG. */ + if (dst->replay_cache_rend_cookie != NULL) { + replaycache_free(dst->replay_cache_rend_cookie); + } + dst->replay_cache_rend_cookie = src->replay_cache_rend_cookie; + dst->next_rotation_time = src->next_rotation_time; + + src->replay_cache_rend_cookie = NULL; /* steal pointer reference */ +} + +/* Register services that are in the staging list. Once this function returns, + * the global service map will be set with the right content and all non + * surviving services will be cleaned up. */ +static void +register_all_services(void) +{ + struct hs_service_ht *new_service_map; + + tor_assert(hs_service_staging_list); + + /* Allocate a new map that will replace the current one. */ + new_service_map = tor_malloc_zero(sizeof(*new_service_map)); + HT_INIT(hs_service_ht, new_service_map); + + /* First step is to transfer all ephemeral services from the current global + * map to the new one we are constructing. We do not prune ephemeral + * services as the only way to kill them is by deleting it from the control + * port or stopping the tor daemon. */ + move_ephemeral_services(hs_service_map, new_service_map); + + SMARTLIST_FOREACH_BEGIN(hs_service_staging_list, hs_service_t *, snew) { + hs_service_t *s; + + /* Check if that service is already in our global map and if so, we'll + * transfer the intro points to it. */ + s = find_service(hs_service_map, &snew->keys.identity_pk); + if (s) { + /* Pass ownership of the descriptors from s (the current service) to + * snew (the newly configured one). */ + move_descriptors(s, snew); + move_hs_state(s, snew); + /* Remove the service from the global map because after this, we need to + * go over the remaining service in that map that aren't surviving the + * reload to close their circuits. */ + remove_service(hs_service_map, s); + hs_service_free(s); + } + /* Great, this service is now ready to be added to our new map. */ + if (BUG(register_service(new_service_map, snew) < 0)) { + /* This should never happen because prior to registration, we validate + * every service against the entire set. Not being able to register a + * service means we failed to validate correctly. In that case, don't + * break tor and ignore the service but tell user. */ + log_warn(LD_BUG, "Unable to register service with directory %s", + service_escaped_dir(snew)); + SMARTLIST_DEL_CURRENT(hs_service_staging_list, snew); + hs_service_free(snew); + } + } SMARTLIST_FOREACH_END(snew); + + /* Close any circuits associated with the non surviving services. Every + * service in the current global map are roaming. */ + FOR_EACH_SERVICE_BEGIN(service) { + close_service_circuits(service); + } FOR_EACH_SERVICE_END; + + /* Time to make the switch. We'll clear the staging list because its content + * has now changed ownership to the map. */ + smartlist_clear(hs_service_staging_list); + service_free_all(); + hs_service_map = new_service_map; +} + +/* Write the onion address of a given service to the given filename fname_ in + * the service directory. Return 0 on success else -1 on error. */ +STATIC int +write_address_to_file(const hs_service_t *service, const char *fname_) +{ + int ret = -1; + char *fname = NULL; + char *addr_buf = NULL; + + tor_assert(service); + tor_assert(fname_); + + /* Construct the full address with the onion tld and write the hostname file + * to disk. */ + tor_asprintf(&addr_buf, "%s.%s\n", service->onion_address, address_tld); + /* Notice here that we use the given "fname_". */ + fname = hs_path_from_filename(service->config.directory_path, fname_); + if (write_str_to_file(fname, addr_buf, 0) < 0) { + log_warn(LD_REND, "Could not write onion address to hostname file %s", + escaped(fname)); + goto end; + } + +#ifndef _WIN32 + if (service->config.dir_group_readable) { + /* Mode to 0640. */ + if (chmod(fname, S_IRUSR | S_IWUSR | S_IRGRP) < 0) { + log_warn(LD_FS, "Unable to make onion service hostname file %s " + "group-readable.", escaped(fname)); + } + } +#endif /* !defined(_WIN32) */ + + /* Success. */ + ret = 0; + end: + tor_free(fname); + tor_free(addr_buf); + return ret; +} + +/* Load and/or generate private keys for the given service. On success, the + * hostname file will be written to disk along with the master private key iff + * the service is not configured for offline keys. Return 0 on success else -1 + * on failure. */ +static int +load_service_keys(hs_service_t *service) +{ + int ret = -1; + char *fname = NULL; + ed25519_keypair_t *kp; + const hs_service_config_t *config; + + tor_assert(service); + + config = &service->config; + + /* Create and fix permission on service directory. We are about to write + * files to that directory so make sure it exists and has the right + * permissions. We do this here because at this stage we know that Tor is + * actually running and the service we have has been validated. */ + if (hs_check_service_private_dir(get_options()->User, + config->directory_path, + config->dir_group_readable, 1) < 0) { + goto end; + } + + /* Try to load the keys from file or generate it if not found. */ + fname = hs_path_from_filename(config->directory_path, fname_keyfile_prefix); + /* Don't ask for key creation, we want to know if we were able to load it or + * we had to generate it. Better logging! */ + kp = ed_key_init_from_file(fname, INIT_ED_KEY_SPLIT, LOG_INFO, NULL, 0, 0, + 0, NULL); + if (!kp) { + log_info(LD_REND, "Unable to load keys from %s. Generating it...", fname); + /* We'll now try to generate the keys and for it we want the strongest + * randomness for it. The keypair will be written in different files. */ + uint32_t key_flags = INIT_ED_KEY_CREATE | INIT_ED_KEY_EXTRA_STRONG | + INIT_ED_KEY_SPLIT; + kp = ed_key_init_from_file(fname, key_flags, LOG_WARN, NULL, 0, 0, 0, + NULL); + if (!kp) { + log_warn(LD_REND, "Unable to generate keys and save in %s.", fname); + goto end; + } + } + + /* Copy loaded or generated keys to service object. */ + ed25519_pubkey_copy(&service->keys.identity_pk, &kp->pubkey); + memcpy(&service->keys.identity_sk, &kp->seckey, + sizeof(service->keys.identity_sk)); + /* This does a proper memory wipe. */ + ed25519_keypair_free(kp); + + /* Build onion address from the newly loaded keys. */ + tor_assert(service->config.version <= UINT8_MAX); + hs_build_address(&service->keys.identity_pk, + (uint8_t) service->config.version, + service->onion_address); + + /* Write onion address to hostname file. */ + if (write_address_to_file(service, fname_hostname) < 0) { + goto end; + } + + /* Succes. */ + ret = 0; + end: + tor_free(fname); + return ret; +} + +/* Free a given service descriptor object and all key material is wiped. */ +STATIC void +service_descriptor_free(hs_service_descriptor_t *desc) +{ + if (!desc) { + return; + } + hs_descriptor_free(desc->desc); + memwipe(&desc->signing_kp, 0, sizeof(desc->signing_kp)); + memwipe(&desc->blinded_kp, 0, sizeof(desc->blinded_kp)); + /* Cleanup all intro points. */ + digest256map_free(desc->intro_points.map, service_intro_point_free_); + digestmap_free(desc->intro_points.failed_id, tor_free_); + if (desc->previous_hsdirs) { + SMARTLIST_FOREACH(desc->previous_hsdirs, char *, s, tor_free(s)); + smartlist_free(desc->previous_hsdirs); + } + tor_free(desc); +} + +/* Return a newly allocated service descriptor object. */ +STATIC hs_service_descriptor_t * +service_descriptor_new(void) +{ + hs_service_descriptor_t *sdesc = tor_malloc_zero(sizeof(*sdesc)); + sdesc->desc = tor_malloc_zero(sizeof(hs_descriptor_t)); + /* Initialize the intro points map. */ + sdesc->intro_points.map = digest256map_new(); + sdesc->intro_points.failed_id = digestmap_new(); + sdesc->previous_hsdirs = smartlist_new(); + return sdesc; +} + +/* Move descriptor(s) from the src service to the dst service. We do this + * during SIGHUP when we re-create our hidden services. */ +static void +move_descriptors(hs_service_t *src, hs_service_t *dst) +{ + tor_assert(src); + tor_assert(dst); + + if (src->desc_current) { + /* Nothing should be there, but clean it up just in case */ + if (BUG(dst->desc_current)) { + service_descriptor_free(dst->desc_current); + } + dst->desc_current = src->desc_current; + src->desc_current = NULL; + } + + if (src->desc_next) { + /* Nothing should be there, but clean it up just in case */ + if (BUG(dst->desc_next)) { + service_descriptor_free(dst->desc_next); + } + dst->desc_next = src->desc_next; + src->desc_next = NULL; + } +} + +/* From the given service, remove all expired failing intro points for each + * descriptor. */ +static void +remove_expired_failing_intro(hs_service_t *service, time_t now) +{ + tor_assert(service); + + /* For both descriptors, cleanup the failing intro points list. */ + FOR_EACH_DESCRIPTOR_BEGIN(service, desc) { + DIGESTMAP_FOREACH_MODIFY(desc->intro_points.failed_id, key, time_t *, t) { + time_t failure_time = *t; + if ((failure_time + INTRO_CIRC_RETRY_PERIOD) <= now) { + MAP_DEL_CURRENT(key); + tor_free(t); + } + } DIGESTMAP_FOREACH_END; + } FOR_EACH_DESCRIPTOR_END; +} + +/* For the given descriptor desc, put all node_t object found from its failing + * intro point list and put them in the given node_list. */ +static void +setup_intro_point_exclude_list(const hs_service_descriptor_t *desc, + smartlist_t *node_list) +{ + tor_assert(desc); + tor_assert(node_list); + + DIGESTMAP_FOREACH(desc->intro_points.failed_id, key, time_t *, t) { + (void) t; /* Make gcc happy. */ + const node_t *node = node_get_by_id(key); + if (node) { + smartlist_add(node_list, (void *) node); + } + } DIGESTMAP_FOREACH_END; +} + +/* For the given failing intro point ip, we add its time of failure to the + * failed map and index it by identity digest (legacy ID) in the descriptor + * desc failed id map. */ +static void +remember_failing_intro_point(const hs_service_intro_point_t *ip, + hs_service_descriptor_t *desc, time_t now) +{ + time_t *time_of_failure, *prev_ptr; + const hs_desc_link_specifier_t *legacy_ls; + + tor_assert(ip); + tor_assert(desc); + + time_of_failure = tor_malloc_zero(sizeof(time_t)); + *time_of_failure = now; + legacy_ls = get_link_spec_by_type(ip, LS_LEGACY_ID); + tor_assert(legacy_ls); + prev_ptr = digestmap_set(desc->intro_points.failed_id, + (const char *) legacy_ls->u.legacy_id, + time_of_failure); + tor_free(prev_ptr); +} + +/* Copy the descriptor link specifier object from src to dst. */ +static void +link_specifier_copy(hs_desc_link_specifier_t *dst, + const hs_desc_link_specifier_t *src) +{ + tor_assert(dst); + tor_assert(src); + memcpy(dst, src, sizeof(hs_desc_link_specifier_t)); +} + +/* Using a given descriptor signing keypair signing_kp, a service intro point + * object ip and the time now, setup the content of an already allocated + * descriptor intro desc_ip. + * + * Return 0 on success else a negative value. */ +static int +setup_desc_intro_point(const ed25519_keypair_t *signing_kp, + const hs_service_intro_point_t *ip, + time_t now, hs_desc_intro_point_t *desc_ip) +{ + int ret = -1; + time_t nearest_hour = now - (now % 3600); + + tor_assert(signing_kp); + tor_assert(ip); + tor_assert(desc_ip); + + /* Copy the onion key. */ + memcpy(&desc_ip->onion_key, &ip->onion_key, sizeof(desc_ip->onion_key)); + + /* Key and certificate material. */ + desc_ip->auth_key_cert = tor_cert_create(signing_kp, + CERT_TYPE_AUTH_HS_IP_KEY, + &ip->auth_key_kp.pubkey, + nearest_hour, + HS_DESC_CERT_LIFETIME, + CERT_FLAG_INCLUDE_SIGNING_KEY); + if (desc_ip->auth_key_cert == NULL) { + log_warn(LD_REND, "Unable to create intro point auth-key certificate"); + goto done; + } + + /* Copy link specifier(s). */ + SMARTLIST_FOREACH_BEGIN(ip->base.link_specifiers, + const hs_desc_link_specifier_t *, ls) { + hs_desc_link_specifier_t *copy = tor_malloc_zero(sizeof(*copy)); + link_specifier_copy(copy, ls); + smartlist_add(desc_ip->link_specifiers, copy); + } SMARTLIST_FOREACH_END(ls); + + /* For a legacy intro point, we'll use an RSA/ed cross certificate. */ + if (ip->base.is_only_legacy) { + desc_ip->legacy.key = crypto_pk_dup_key(ip->legacy_key); + /* Create cross certification cert. */ + ssize_t cert_len = tor_make_rsa_ed25519_crosscert( + &signing_kp->pubkey, + desc_ip->legacy.key, + nearest_hour + HS_DESC_CERT_LIFETIME, + &desc_ip->legacy.cert.encoded); + if (cert_len < 0) { + log_warn(LD_REND, "Unable to create enc key legacy cross cert."); + goto done; + } + desc_ip->legacy.cert.len = cert_len; + } + + /* Encryption key and its cross certificate. */ + { + ed25519_public_key_t ed25519_pubkey; + + /* Use the public curve25519 key. */ + memcpy(&desc_ip->enc_key, &ip->enc_key_kp.pubkey, + sizeof(desc_ip->enc_key)); + /* The following can't fail. */ + ed25519_public_key_from_curve25519_public_key(&ed25519_pubkey, + &ip->enc_key_kp.pubkey, + 0); + desc_ip->enc_key_cert = tor_cert_create(signing_kp, + CERT_TYPE_CROSS_HS_IP_KEYS, + &ed25519_pubkey, nearest_hour, + HS_DESC_CERT_LIFETIME, + CERT_FLAG_INCLUDE_SIGNING_KEY); + if (desc_ip->enc_key_cert == NULL) { + log_warn(LD_REND, "Unable to create enc key curve25519 cross cert."); + goto done; + } + } + /* Success. */ + ret = 0; + + done: + return ret; +} + +/* Using the given descriptor from the given service, build the descriptor + * intro point list so we can then encode the descriptor for publication. This + * function does not pick intro points, they have to be in the descriptor + * current map. Cryptographic material (keys) must be initialized in the + * descriptor for this function to make sense. */ +static void +build_desc_intro_points(const hs_service_t *service, + hs_service_descriptor_t *desc, time_t now) +{ + hs_desc_encrypted_data_t *encrypted; + + tor_assert(service); + tor_assert(desc); + + /* Ease our life. */ + encrypted = &desc->desc->encrypted_data; + /* Cleanup intro points, we are about to set them from scratch. */ + hs_descriptor_clear_intro_points(desc->desc); + + DIGEST256MAP_FOREACH(desc->intro_points.map, key, + const hs_service_intro_point_t *, ip) { + hs_desc_intro_point_t *desc_ip = hs_desc_intro_point_new(); + if (setup_desc_intro_point(&desc->signing_kp, ip, now, desc_ip) < 0) { + hs_desc_intro_point_free(desc_ip); + continue; + } + /* We have a valid descriptor intro point. Add it to the list. */ + smartlist_add(encrypted->intro_points, desc_ip); + } DIGEST256MAP_FOREACH_END; +} + +/* Populate the descriptor encrypted section fomr the given service object. + * This will generate a valid list of introduction points that can be used + * after for circuit creation. Return 0 on success else -1 on error. */ +static int +build_service_desc_encrypted(const hs_service_t *service, + hs_service_descriptor_t *desc) +{ + hs_desc_encrypted_data_t *encrypted; + + tor_assert(service); + tor_assert(desc); + + encrypted = &desc->desc->encrypted_data; + + encrypted->create2_ntor = 1; + encrypted->single_onion_service = service->config.is_single_onion; + + /* Setup introduction points from what we have in the service. */ + if (encrypted->intro_points == NULL) { + encrypted->intro_points = smartlist_new(); + } + /* We do NOT build introduction point yet, we only do that once the circuit + * have been opened. Until we have the right number of introduction points, + * we do not encode anything in the descriptor. */ + + /* XXX: Support client authorization (#20700). */ + encrypted->intro_auth_types = NULL; + return 0; +} + +/* Populare the descriptor plaintext section from the given service object. + * The caller must make sure that the keys in the descriptors are valid that + * is are non-zero. Return 0 on success else -1 on error. */ +static int +build_service_desc_plaintext(const hs_service_t *service, + hs_service_descriptor_t *desc, time_t now) +{ + int ret = -1; + hs_desc_plaintext_data_t *plaintext; + + tor_assert(service); + tor_assert(desc); + /* XXX: Use a "assert_desc_ok()" ? */ + tor_assert(!tor_mem_is_zero((char *) &desc->blinded_kp, + sizeof(desc->blinded_kp))); + tor_assert(!tor_mem_is_zero((char *) &desc->signing_kp, + sizeof(desc->signing_kp))); + + /* Set the subcredential. */ + hs_get_subcredential(&service->keys.identity_pk, &desc->blinded_kp.pubkey, + desc->desc->subcredential); + + plaintext = &desc->desc->plaintext_data; + + plaintext->version = service->config.version; + plaintext->lifetime_sec = HS_DESC_DEFAULT_LIFETIME; + plaintext->signing_key_cert = + tor_cert_create(&desc->blinded_kp, CERT_TYPE_SIGNING_HS_DESC, + &desc->signing_kp.pubkey, now, HS_DESC_CERT_LIFETIME, + CERT_FLAG_INCLUDE_SIGNING_KEY); + if (plaintext->signing_key_cert == NULL) { + log_warn(LD_REND, "Unable to create descriptor signing certificate for " + "service %s", + safe_str_client(service->onion_address)); + goto end; + } + /* Copy public key material to go in the descriptor. */ + ed25519_pubkey_copy(&plaintext->signing_pubkey, &desc->signing_kp.pubkey); + ed25519_pubkey_copy(&plaintext->blinded_pubkey, &desc->blinded_kp.pubkey); + /* Success. */ + ret = 0; + + end: + return ret; +} + +/* For the given service and descriptor object, create the key material which + * is the blinded keypair and the descriptor signing keypair. Return 0 on + * success else -1 on error where the generated keys MUST be ignored. */ +static int +build_service_desc_keys(const hs_service_t *service, + hs_service_descriptor_t *desc, + uint64_t time_period_num) +{ + int ret = 0; + ed25519_keypair_t kp; + + tor_assert(desc); + tor_assert(!tor_mem_is_zero((char *) &service->keys.identity_pk, + ED25519_PUBKEY_LEN)); + + /* XXX: Support offline key feature (#18098). */ + + /* Copy the identity keys to the keypair so we can use it to create the + * blinded key. */ + memcpy(&kp.pubkey, &service->keys.identity_pk, sizeof(kp.pubkey)); + memcpy(&kp.seckey, &service->keys.identity_sk, sizeof(kp.seckey)); + /* Build blinded keypair for this time period. */ + hs_build_blinded_keypair(&kp, NULL, 0, time_period_num, &desc->blinded_kp); + /* Let's not keep too much traces of our keys in memory. */ + memwipe(&kp, 0, sizeof(kp)); + + /* No need for extra strong, this is a temporary key only for this + * descriptor. Nothing long term. */ + if (ed25519_keypair_generate(&desc->signing_kp, 0) < 0) { + log_warn(LD_REND, "Can't generate descriptor signing keypair for " + "service %s", + safe_str_client(service->onion_address)); + ret = -1; + } + + return ret; +} + +/* Given a service and the current time, build a descriptor for the service. + * This function does not pick introduction point, this needs to be done by + * the update function. On success, desc_out will point to the newly allocated + * descriptor object. + * + * This can error if we are unable to create keys or certificate. */ +static void +build_service_descriptor(hs_service_t *service, time_t now, + uint64_t time_period_num, + hs_service_descriptor_t **desc_out) +{ + char *encoded_desc; + hs_service_descriptor_t *desc; + + tor_assert(service); + tor_assert(desc_out); + + desc = service_descriptor_new(); + desc->time_period_num = time_period_num; + + /* Create the needed keys so we can setup the descriptor content. */ + if (build_service_desc_keys(service, desc, time_period_num) < 0) { + goto err; + } + /* Setup plaintext descriptor content. */ + if (build_service_desc_plaintext(service, desc, now) < 0) { + goto err; + } + /* Setup encrypted descriptor content. */ + if (build_service_desc_encrypted(service, desc) < 0) { + goto err; + } + + /* Set the revision counter for this descriptor */ + set_descriptor_revision_counter(desc->desc); + + /* Let's make sure that we've created a descriptor that can actually be + * encoded properly. This function also checks if the encoded output is + * decodable after. */ + if (BUG(hs_desc_encode_descriptor(desc->desc, &desc->signing_kp, + &encoded_desc) < 0)) { + goto err; + } + tor_free(encoded_desc); + + /* Assign newly built descriptor to the next slot. */ + *desc_out = desc; + return; + + err: + service_descriptor_free(desc); +} + +/* Build both descriptors for the given service that has just booted up. + * Because it's a special case, it deserves its special function ;). */ +static void +build_descriptors_for_new_service(hs_service_t *service, time_t now) +{ + uint64_t current_desc_tp, next_desc_tp; + + tor_assert(service); + /* These are the conditions for a new service. */ + tor_assert(!service->desc_current); + tor_assert(!service->desc_next); + + /* + * +------------------------------------------------------------------+ + * | | + * | 00:00 12:00 00:00 12:00 00:00 12:00 | + * | SRV#1 TP#1 SRV#2 TP#2 SRV#3 TP#3 | + * | | + * | $==========|-----------$===========|-----------$===========| | + * | ^ ^ | + * | A B | + * +------------------------------------------------------------------+ + * + * Case A: The service boots up before a new time period, the current time + * period is thus TP#1 and the next is TP#2 which for both we have access to + * their SRVs. + * + * Case B: The service boots up inside TP#2, we can't use the TP#3 for the + * next descriptor because we don't have the SRV#3 so the current should be + * TP#1 and next TP#2. + */ + + if (hs_in_period_between_tp_and_srv(NULL, now)) { + /* Case B from the above, inside of the new time period. */ + current_desc_tp = hs_get_previous_time_period_num(0); /* TP#1 */ + next_desc_tp = hs_get_time_period_num(0); /* TP#2 */ + } else { + /* Case A from the above, outside of the new time period. */ + current_desc_tp = hs_get_time_period_num(0); /* TP#1 */ + next_desc_tp = hs_get_next_time_period_num(0); /* TP#2 */ + } + + /* Build descriptors. */ + build_service_descriptor(service, now, current_desc_tp, + &service->desc_current); + build_service_descriptor(service, now, next_desc_tp, + &service->desc_next); + log_info(LD_REND, "Hidden service %s has just started. Both descriptors " + "built. Now scheduled for upload.", + safe_str_client(service->onion_address)); +} + +/* Build descriptors for each service if needed. There are conditions to build + * a descriptor which are details in the function. */ +STATIC void +build_all_descriptors(time_t now) +{ + FOR_EACH_SERVICE_BEGIN(service) { + + /* A service booting up will have both descriptors to NULL. No other cases + * makes both descriptor non existent. */ + if (service->desc_current == NULL && service->desc_next == NULL) { + build_descriptors_for_new_service(service, now); + continue; + } + + /* Reaching this point means we are pass bootup so at runtime. We should + * *never* have an empty current descriptor. If the next descriptor is + * empty, we'll try to build it for the next time period. This only + * happens when we rotate meaning that we are guaranteed to have a new SRV + * at that point for the next time period. */ + tor_assert(service->desc_current); + + if (service->desc_next == NULL) { + build_service_descriptor(service, now, hs_get_next_time_period_num(0), + &service->desc_next); + log_info(LD_REND, "Hidden service %s next descriptor successfully " + "built. Now scheduled for upload.", + safe_str_client(service->onion_address)); + } + } FOR_EACH_DESCRIPTOR_END; +} + +/* Randomly pick a node to become an introduction point but not present in the + * given exclude_nodes list. The chosen node is put in the exclude list + * regardless of success or not because in case of failure, the node is simply + * unsusable from that point on. + * + * If direct_conn is set, try to pick a node that our local firewall/policy + * allows us to connect to directly. If we can't find any, return NULL. + * This function supports selecting dual-stack nodes for direct single onion + * service IPv6 connections. But it does not send IPv6 addresses in link + * specifiers. (Current clients don't use IPv6 addresses to extend, and + * direct client connections to intro points are not supported.) + * + * Return a newly allocated service intro point ready to be used for encoding. + * Return NULL on error. */ +static hs_service_intro_point_t * +pick_intro_point(unsigned int direct_conn, smartlist_t *exclude_nodes) +{ + const node_t *node; + extend_info_t *info = NULL; + hs_service_intro_point_t *ip = NULL; + /* Normal 3-hop introduction point flags. */ + router_crn_flags_t flags = CRN_NEED_UPTIME | CRN_NEED_DESC; + /* Single onion flags. */ + router_crn_flags_t direct_flags = flags | CRN_PREF_ADDR | CRN_DIRECT_CONN; + + node = router_choose_random_node(exclude_nodes, get_options()->ExcludeNodes, + direct_conn ? direct_flags : flags); + /* Unable to find a node. When looking for a node for a direct connection, + * we could try a 3-hop path instead. We'll add support for this in a later + * release. */ + if (!node) { + goto err; + } + + /* We have a suitable node, add it to the exclude list. We do this *before* + * we can validate the extend information because even in case of failure, + * we don't want to use that node anymore. */ + smartlist_add(exclude_nodes, (void *) node); + + /* We do this to ease our life but also this call makes appropriate checks + * of the node object such as validating ntor support for instance. + * + * We must provide an extend_info for clients to connect over a 3-hop path, + * so we don't pass direct_conn here. */ + info = extend_info_from_node(node, 0); + if (BUG(info == NULL)) { + goto err; + } + + /* Let's do a basic sanity check here so that we don't end up advertising the + * ed25519 identity key of relays that don't actually support the link + * protocol */ + if (!node_supports_ed25519_link_authentication(node)) { + tor_assert_nonfatal(ed25519_public_key_is_zero(&info->ed_identity)); + } else { + /* Make sure we *do* have an ed key if we support the link authentication. + * Sending an empty key would result in a failure to extend. */ + tor_assert_nonfatal(!ed25519_public_key_is_zero(&info->ed_identity)); + } + + /* Create our objects and populate them with the node information. */ + ip = service_intro_point_new(info, !node_supports_ed25519_hs_intro(node)); + if (ip == NULL) { + goto err; + } + + log_info(LD_REND, "Picked intro point: %s", extend_info_describe(info)); + extend_info_free(info); + return ip; + err: + service_intro_point_free(ip); + extend_info_free(info); + return NULL; +} + +/* For a given descriptor from the given service, pick any needed intro points + * and update the current map with those newly picked intro points. Return the + * number node that might have been added to the descriptor current map. */ +static unsigned int +pick_needed_intro_points(hs_service_t *service, + hs_service_descriptor_t *desc) +{ + int i = 0, num_needed_ip; + smartlist_t *exclude_nodes = smartlist_new(); + + tor_assert(service); + tor_assert(desc); + + /* Compute how many intro points we actually need to open. */ + num_needed_ip = service->config.num_intro_points - + digest256map_size(desc->intro_points.map); + if (BUG(num_needed_ip < 0)) { + /* Let's not make tor freak out here and just skip this. */ + goto done; + } + + /* We want to end up with config.num_intro_points intro points, but if we + * have no intro points at all (chances are they all cycled or we are + * starting up), we launch get_intro_point_num_extra() extra circuits and + * use the first config.num_intro_points that complete. See proposal #155, + * section 4 for the rationale of this which is purely for performance. + * + * The ones after the first config.num_intro_points will be converted to + * 'General' internal circuits and then we'll drop them from the list of + * intro points. */ + if (digest256map_size(desc->intro_points.map) == 0) { + num_needed_ip += get_intro_point_num_extra(); + } + + /* Build an exclude list of nodes of our intro point(s). The expiring intro + * points are OK to pick again because this is afterall a concept of round + * robin so they are considered valid nodes to pick again. */ + DIGEST256MAP_FOREACH(desc->intro_points.map, key, + hs_service_intro_point_t *, ip) { + const node_t *intro_node = get_node_from_intro_point(ip); + if (intro_node) { + smartlist_add(exclude_nodes, (void*)intro_node); + } + } DIGEST256MAP_FOREACH_END; + /* Also, add the failing intro points that our descriptor encounteered in + * the exclude node list. */ + setup_intro_point_exclude_list(desc, exclude_nodes); + + for (i = 0; i < num_needed_ip; i++) { + hs_service_intro_point_t *ip; + + /* This function will add the picked intro point node to the exclude nodes + * list so we don't pick the same one at the next iteration. */ + ip = pick_intro_point(service->config.is_single_onion, exclude_nodes); + if (ip == NULL) { + /* If we end up unable to pick an introduction point it is because we + * can't find suitable node and calling this again is highly unlikely to + * give us a valid node all of the sudden. */ + log_info(LD_REND, "Unable to find a suitable node to be an " + "introduction point for service %s.", + safe_str_client(service->onion_address)); + goto done; + } + /* Valid intro point object, add it to the descriptor current map. */ + service_intro_point_add(desc->intro_points.map, ip); + } + /* We've successfully picked all our needed intro points thus none are + * missing which will tell our upload process to expect the number of + * circuits to be the number of configured intro points circuits and not the + * number of intro points object that we have. */ + desc->missing_intro_points = 0; + + /* Success. */ + done: + /* We don't have ownership of the node_t object in this list. */ + smartlist_free(exclude_nodes); + return i; +} + +/** Clear previous cached HSDirs in <b>desc</b>. */ +static void +service_desc_clear_previous_hsdirs(hs_service_descriptor_t *desc) +{ + if (BUG(!desc->previous_hsdirs)) { + return; + } + + SMARTLIST_FOREACH(desc->previous_hsdirs, char*, s, tor_free(s)); + smartlist_clear(desc->previous_hsdirs); +} + +/** Note that we attempted to upload <b>desc</b> to <b>hsdir</b>. */ +static void +service_desc_note_upload(hs_service_descriptor_t *desc, const node_t *hsdir) +{ + char b64_digest[BASE64_DIGEST_LEN+1] = {0}; + digest_to_base64(b64_digest, hsdir->identity); + + if (BUG(!desc->previous_hsdirs)) { + return; + } + + if (!smartlist_contains_string(desc->previous_hsdirs, b64_digest)) { + smartlist_add_strdup(desc->previous_hsdirs, b64_digest); + } +} + +/** Schedule an upload of <b>desc</b>. If <b>descriptor_changed</b> is set, it + * means that this descriptor is dirty. */ +STATIC void +service_desc_schedule_upload(hs_service_descriptor_t *desc, + time_t now, + int descriptor_changed) + +{ + desc->next_upload_time = now; + + /* If the descriptor changed, clean up the old HSDirs list. We want to + * re-upload no matter what. */ + if (descriptor_changed) { + service_desc_clear_previous_hsdirs(desc); + } +} + +/* Update the given descriptor from the given service. The possible update + * actions includes: + * - Picking missing intro points if needed. + * - Incrementing the revision counter if needed. + */ +static void +update_service_descriptor(hs_service_t *service, + hs_service_descriptor_t *desc, time_t now) +{ + unsigned int num_intro_points; + + tor_assert(service); + tor_assert(desc); + tor_assert(desc->desc); + + num_intro_points = digest256map_size(desc->intro_points.map); + + /* Pick any missing introduction point(s). */ + if (num_intro_points < service->config.num_intro_points) { + unsigned int num_new_intro_points = pick_needed_intro_points(service, + desc); + if (num_new_intro_points != 0) { + log_info(LD_REND, "Service %s just picked %u intro points and wanted " + "%u for %s descriptor. It currently has %d intro " + "points. Launching ESTABLISH_INTRO circuit shortly.", + safe_str_client(service->onion_address), + num_new_intro_points, + service->config.num_intro_points - num_intro_points, + (desc == service->desc_current) ? "current" : "next", + num_intro_points); + /* We'll build those introduction point into the descriptor once we have + * confirmation that the circuits are opened and ready. However, + * indicate that this descriptor should be uploaded from now on. */ + service_desc_schedule_upload(desc, now, 1); + } + /* Were we able to pick all the intro points we needed? If not, we'll + * flag the descriptor that it's missing intro points because it + * couldn't pick enough which will trigger a descriptor upload. */ + if ((num_new_intro_points + num_intro_points) < + service->config.num_intro_points) { + desc->missing_intro_points = 1; + } + } +} + +/* Update descriptors for each service if needed. */ +STATIC void +update_all_descriptors(time_t now) +{ + FOR_EACH_SERVICE_BEGIN(service) { + /* We'll try to update each descriptor that is if certain conditions apply + * in order for the descriptor to be updated. */ + FOR_EACH_DESCRIPTOR_BEGIN(service, desc) { + update_service_descriptor(service, desc, now); + } FOR_EACH_DESCRIPTOR_END; + } FOR_EACH_SERVICE_END; +} + +/* Return true iff the given intro point has expired that is it has been used + * for too long or we've reached our max seen INTRODUCE2 cell. */ +STATIC int +intro_point_should_expire(const hs_service_intro_point_t *ip, + time_t now) +{ + tor_assert(ip); + + if (ip->introduce2_count >= ip->introduce2_max) { + goto expired; + } + + if (ip->time_to_expire <= now) { + goto expired; + } + + /* Not expiring. */ + return 0; + expired: + return 1; +} + +/* Go over the given set of intro points for each service and remove any + * invalid ones. The conditions for removal are: + * + * - The node doesn't exists anymore (not in consensus) + * OR + * - The intro point maximum circuit retry count has been reached and no + * circuit can be found associated with it. + * OR + * - The intro point has expired and we should pick a new one. + * + * If an intro point is removed, the circuit (if any) is immediately close. + * If a circuit can't be found, the intro point is kept if it hasn't reached + * its maximum circuit retry value and thus should be retried. */ +static void +cleanup_intro_points(hs_service_t *service, time_t now) +{ + /* List of intro points to close. We can't mark the intro circuits for close + * in the modify loop because doing so calls + * hs_service_intro_circ_has_closed() which does a digest256map_get() on the + * intro points map (that we are iterating over). This can't be done in a + * single iteration after a MAP_DEL_CURRENT, the object will still be + * returned leading to a use-after-free. So, we close the circuits and free + * the intro points after the loop if any. */ + smartlist_t *ips_to_free = smartlist_new(); + + tor_assert(service); + + /* For both descriptors, cleanup the intro points. */ + FOR_EACH_DESCRIPTOR_BEGIN(service, desc) { + /* Go over the current intro points we have, make sure they are still + * valid and remove any of them that aren't. */ + DIGEST256MAP_FOREACH_MODIFY(desc->intro_points.map, key, + hs_service_intro_point_t *, ip) { + const node_t *node = get_node_from_intro_point(ip); + int has_expired = intro_point_should_expire(ip, now); + + /* We cleanup an intro point if it has expired or if we do not know the + * node_t anymore (removed from our latest consensus) or if we've + * reached the maximum number of retry with a non existing circuit. */ + if (has_expired || node == NULL || + ip->circuit_retries > MAX_INTRO_POINT_CIRCUIT_RETRIES) { + log_info(LD_REND, "Intro point %s%s (retried: %u times). " + "Removing it.", + describe_intro_point(ip), + has_expired ? " has expired" : + (node == NULL) ? " fell off the consensus" : "", + ip->circuit_retries); + + /* We've retried too many times, remember it as a failed intro point + * so we don't pick it up again for INTRO_CIRC_RETRY_PERIOD sec. */ + if (ip->circuit_retries > MAX_INTRO_POINT_CIRCUIT_RETRIES) { + remember_failing_intro_point(ip, desc, approx_time()); + } + + /* Remove intro point from descriptor map and add it to the list of + * ips to free for which we'll also try to close the intro circuit. */ + MAP_DEL_CURRENT(key); + smartlist_add(ips_to_free, ip); + } + } DIGEST256MAP_FOREACH_END; + } FOR_EACH_DESCRIPTOR_END; + + /* Go over the intro points to free and close their circuit if any. */ + SMARTLIST_FOREACH_BEGIN(ips_to_free, hs_service_intro_point_t *, ip) { + /* See if we need to close the intro point circuit as well */ + + /* XXX: Legacy code does NOT close circuits like this: it keeps the circuit + * open until a new descriptor is uploaded and then closed all expiring + * intro point circuit. Here, we close immediately and because we just + * discarded the intro point, a new one will be selected, a new descriptor + * created and uploaded. There is no difference to an attacker between the + * timing of a new consensus and intro point rotation (possibly?). */ + origin_circuit_t *ocirc = hs_circ_service_get_intro_circ(ip); + if (ocirc && !TO_CIRCUIT(ocirc)->marked_for_close) { + circuit_mark_for_close(TO_CIRCUIT(ocirc), END_CIRC_REASON_FINISHED); + } + + /* Cleanup the intro point */ + service_intro_point_free(ip); + } SMARTLIST_FOREACH_END(ip); + + smartlist_free(ips_to_free); +} + +/* Set the next rotation time of the descriptors for the given service for the + * time now. */ +static void +set_rotation_time(hs_service_t *service, time_t now) +{ + time_t valid_after; + const networkstatus_t *ns = networkstatus_get_live_consensus(now); + if (ns) { + valid_after = ns->valid_after; + } else { + valid_after = now; + } + + tor_assert(service); + service->state.next_rotation_time = + sr_state_get_start_time_of_current_protocol_run(valid_after) + + sr_state_get_protocol_run_duration(); + + { + char fmt_time[ISO_TIME_LEN + 1]; + format_local_iso_time(fmt_time, service->state.next_rotation_time); + log_info(LD_REND, "Next descriptor rotation time set to %s for %s", + fmt_time, safe_str_client(service->onion_address)); + } +} + +/* Return true iff the service should rotate its descriptor. The time now is + * only used to fetch the live consensus and if none can be found, this + * returns false. */ +static unsigned int +should_rotate_descriptors(hs_service_t *service, time_t now) +{ + const networkstatus_t *ns; + + tor_assert(service); + + ns = networkstatus_get_live_consensus(now); + if (ns == NULL) { + goto no_rotation; + } + + if (ns->valid_after >= service->state.next_rotation_time) { + goto rotation; + } + + no_rotation: + return 0; + rotation: + return 1; +} + +/* Rotate the service descriptors of the given service. The current descriptor + * will be freed, the next one put in as the current and finally the next + * descriptor pointer is NULLified. */ +static void +rotate_service_descriptors(hs_service_t *service, time_t now) +{ + if (service->desc_current) { + /* Close all IP circuits for the descriptor. */ + close_intro_circuits(&service->desc_current->intro_points); + /* We don't need this one anymore, we won't serve any clients coming with + * this service descriptor. */ + service_descriptor_free(service->desc_current); + } + /* The next one become the current one and emptying the next will trigger + * a descriptor creation for it. */ + service->desc_current = service->desc_next; + service->desc_next = NULL; + + /* We've just rotated, set the next time for the rotation. */ + set_rotation_time(service, now); +} + +/* Rotate descriptors for each service if needed. A non existing current + * descriptor will trigger a descriptor build for the next time period. */ +STATIC void +rotate_all_descriptors(time_t now) +{ + /* XXX We rotate all our service descriptors at once. In the future it might + * be wise, to rotate service descriptors independently to hide that all + * those descriptors are on the same tor instance */ + + FOR_EACH_SERVICE_BEGIN(service) { + + /* Note for a service booting up: Both descriptors are NULL in that case + * so this function might return true if we are in the timeframe for a + * rotation leading to basically swapping two NULL pointers which is + * harmless. However, the side effect is that triggering a rotation will + * update the service state and avoid doing anymore rotations after the + * two descriptors have been built. */ + if (!should_rotate_descriptors(service, now)) { + continue; + } + + tor_assert(service->desc_current); + tor_assert(service->desc_next); + + log_info(LD_REND, "Time to rotate our descriptors (%p / %p) for %s", + service->desc_current, service->desc_next, + safe_str_client(service->onion_address)); + + rotate_service_descriptors(service, now); + } FOR_EACH_SERVICE_END; +} + +/* Scheduled event run from the main loop. Make sure all our services are up + * to date and ready for the other scheduled events. This includes looking at + * the introduction points status and descriptor rotation time. */ +STATIC void +run_housekeeping_event(time_t now) +{ + /* Note that nothing here opens circuit(s) nor uploads descriptor(s). We are + * simply moving things around or removing unneeded elements. */ + + FOR_EACH_SERVICE_BEGIN(service) { + + /* If the service is starting off, set the rotation time. We can't do that + * at configure time because the get_options() needs to be set for setting + * that time that uses the voting interval. */ + if (service->state.next_rotation_time == 0) { + /* Set the next rotation time of the descriptors. If it's Oct 25th + * 23:47:00, the next rotation time is when the next SRV is computed + * which is at Oct 26th 00:00:00 that is in 13 minutes. */ + set_rotation_time(service, now); + } + + /* Cleanup invalid intro points from the service descriptor. */ + cleanup_intro_points(service, now); + + /* Remove expired failing intro point from the descriptor failed list. We + * reset them at each INTRO_CIRC_RETRY_PERIOD. */ + remove_expired_failing_intro(service, now); + + /* At this point, the service is now ready to go through the scheduled + * events guaranteeing a valid state. Intro points might be missing from + * the descriptors after the cleanup but the update/build process will + * make sure we pick those missing ones. */ + } FOR_EACH_SERVICE_END; +} + +/* Scheduled event run from the main loop. Make sure all descriptors are up to + * date. Once this returns, each service descriptor needs to be considered for + * new introduction circuits and then for upload. */ +static void +run_build_descriptor_event(time_t now) +{ + /* For v2 services, this step happens in the upload event. */ + + /* Run v3+ events. */ + /* We start by rotating the descriptors only if needed. */ + rotate_all_descriptors(now); + + /* Then, we'll try to build new descriptors that we might need. The + * condition is that the next descriptor is non existing because it has + * been rotated or we just started up. */ + build_all_descriptors(now); + + /* Finally, we'll check if we should update the descriptors. Missing + * introduction points will be picked in this function which is useful for + * newly built descriptors. */ + update_all_descriptors(now); +} + +/* For the given service, launch any intro point circuits that could be + * needed. This considers every descriptor of the service. */ +static void +launch_intro_point_circuits(hs_service_t *service) +{ + tor_assert(service); + + /* For both descriptors, try to launch any missing introduction point + * circuits using the current map. */ + FOR_EACH_DESCRIPTOR_BEGIN(service, desc) { + /* Keep a ref on if we need a direct connection. We use this often. */ + unsigned int direct_conn = service->config.is_single_onion; + + DIGEST256MAP_FOREACH_MODIFY(desc->intro_points.map, key, + hs_service_intro_point_t *, ip) { + extend_info_t *ei; + + /* Skip the intro point that already has an existing circuit + * (established or not). */ + if (hs_circ_service_get_intro_circ(ip)) { + continue; + } + + ei = get_extend_info_from_intro_point(ip, direct_conn); + if (ei == NULL) { + /* This is possible if we can get a node_t but not the extend info out + * of it. In this case, we remove the intro point and a new one will + * be picked at the next main loop callback. */ + MAP_DEL_CURRENT(key); + service_intro_point_free(ip); + continue; + } + + /* Launch a circuit to the intro point. */ + ip->circuit_retries++; + if (hs_circ_launch_intro_point(service, ip, ei) < 0) { + log_info(LD_REND, "Unable to launch intro circuit to node %s " + "for service %s.", + safe_str_client(extend_info_describe(ei)), + safe_str_client(service->onion_address)); + /* Intro point will be retried if possible after this. */ + } + extend_info_free(ei); + } DIGEST256MAP_FOREACH_END; + } FOR_EACH_DESCRIPTOR_END; +} + +/* Don't try to build more than this many circuits before giving up for a + * while. Dynamically calculated based on the configured number of intro + * points for the given service and how many descriptor exists. The default + * use case of 3 introduction points and two descriptors will allow 28 + * circuits for a retry period (((3 + 2) + (3 * 3)) * 2). */ +static unsigned int +get_max_intro_circ_per_period(const hs_service_t *service) +{ + unsigned int count = 0; + unsigned int multiplier = 0; + unsigned int num_wanted_ip; + + tor_assert(service); + tor_assert(service->config.num_intro_points <= + HS_CONFIG_V3_MAX_INTRO_POINTS); + +/* For a testing network, allow to do it for the maximum amount so circuit + * creation and rotation and so on can actually be tested without limit. */ +#define MAX_INTRO_POINT_CIRCUIT_RETRIES_TESTING -1 + if (get_options()->TestingTorNetwork) { + return MAX_INTRO_POINT_CIRCUIT_RETRIES_TESTING; + } + + num_wanted_ip = service->config.num_intro_points; + + /* The calculation is as follow. We have a number of intro points that we + * want configured as a torrc option (num_intro_points). We then add an + * extra value so we can launch multiple circuits at once and pick the + * quickest ones. For instance, we want 3 intros, we add 2 extra so we'll + * pick 5 intros and launch 5 circuits. */ + count += (num_wanted_ip + get_intro_point_num_extra()); + + /* Then we add the number of retries that is possible to do for each intro + * point. If we want 3 intros, we'll allow 3 times the number of possible + * retry. */ + count += (num_wanted_ip * MAX_INTRO_POINT_CIRCUIT_RETRIES); + + /* Then, we multiply by a factor of 2 if we have both descriptor or 0 if we + * have none. */ + multiplier += (service->desc_current) ? 1 : 0; + multiplier += (service->desc_next) ? 1 : 0; + + return (count * multiplier); +} + +/* For the given service, return 1 if the service is allowed to launch more + * introduction circuits else 0 if the maximum has been reached for the retry + * period of INTRO_CIRC_RETRY_PERIOD. */ +STATIC int +can_service_launch_intro_circuit(hs_service_t *service, time_t now) +{ + tor_assert(service); + + /* Consider the intro circuit retry period of the service. */ + if (now > (service->state.intro_circ_retry_started_time + + INTRO_CIRC_RETRY_PERIOD)) { + service->state.intro_circ_retry_started_time = now; + service->state.num_intro_circ_launched = 0; + goto allow; + } + /* Check if we can still launch more circuits in this period. */ + if (service->state.num_intro_circ_launched <= + get_max_intro_circ_per_period(service)) { + goto allow; + } + + /* Rate limit log that we've reached our circuit creation limit. */ + { + char *msg; + time_t elapsed_time = now - service->state.intro_circ_retry_started_time; + static ratelim_t rlimit = RATELIM_INIT(INTRO_CIRC_RETRY_PERIOD); + if ((msg = rate_limit_log(&rlimit, now))) { + log_info(LD_REND, "Hidden service %s exceeded its circuit launch limit " + "of %u per %d seconds. It launched %u circuits in " + "the last %ld seconds. Will retry in %ld seconds.", + safe_str_client(service->onion_address), + get_max_intro_circ_per_period(service), + INTRO_CIRC_RETRY_PERIOD, + service->state.num_intro_circ_launched, + (long int) elapsed_time, + (long int) (INTRO_CIRC_RETRY_PERIOD - elapsed_time)); + tor_free(msg); + } + } + + /* Not allow. */ + return 0; + allow: + return 1; +} + +/* Scheduled event run from the main loop. Make sure we have all the circuits + * we need for each service. */ +static void +run_build_circuit_event(time_t now) +{ + /* Make sure we can actually have enough information or able to build + * internal circuits as required by services. */ + if (router_have_consensus_path() == CONSENSUS_PATH_UNKNOWN || + !have_completed_a_circuit()) { + return; + } + + /* Run v2 check. */ + if (rend_num_services() > 0) { + rend_consider_services_intro_points(now); + } + + /* Run v3+ check. */ + FOR_EACH_SERVICE_BEGIN(service) { + /* For introduction circuit, we need to make sure we don't stress too much + * circuit creation so make sure this service is respecting that limit. */ + if (can_service_launch_intro_circuit(service, now)) { + /* Launch intro point circuits if needed. */ + launch_intro_point_circuits(service); + /* Once the circuits have opened, we'll make sure to update the + * descriptor intro point list and cleanup any extraneous. */ + } + } FOR_EACH_SERVICE_END; +} + +/* Encode and sign the service descriptor desc and upload it to the given + * hidden service directory. This does nothing if PublishHidServDescriptors + * is false. */ +static void +upload_descriptor_to_hsdir(const hs_service_t *service, + hs_service_descriptor_t *desc, const node_t *hsdir) +{ + char version_str[4] = {0}, *encoded_desc = NULL; + directory_request_t *dir_req; + hs_ident_dir_conn_t ident; + + tor_assert(service); + tor_assert(desc); + tor_assert(hsdir); + + memset(&ident, 0, sizeof(ident)); + + /* Let's avoid doing that if tor is configured to not publish. */ + if (!get_options()->PublishHidServDescriptors) { + log_info(LD_REND, "Service %s not publishing descriptor. " + "PublishHidServDescriptors is set to 1.", + safe_str_client(service->onion_address)); + goto end; + } + + /* First of all, we'll encode the descriptor. This should NEVER fail but + * just in case, let's make sure we have an actual usable descriptor. */ + if (BUG(hs_desc_encode_descriptor(desc->desc, &desc->signing_kp, + &encoded_desc) < 0)) { + goto end; + } + + /* Setup the connection identifier. */ + hs_ident_dir_conn_init(&service->keys.identity_pk, &desc->blinded_kp.pubkey, + &ident); + + /* This is our resource when uploading which is used to construct the URL + * with the version number: "/tor/hs/<version>/publish". */ + tor_snprintf(version_str, sizeof(version_str), "%u", + service->config.version); + + /* Build the directory request for this HSDir. */ + dir_req = directory_request_new(DIR_PURPOSE_UPLOAD_HSDESC); + directory_request_set_routerstatus(dir_req, hsdir->rs); + directory_request_set_indirection(dir_req, DIRIND_ANONYMOUS); + directory_request_set_resource(dir_req, version_str); + directory_request_set_payload(dir_req, encoded_desc, + strlen(encoded_desc)); + /* The ident object is copied over the directory connection object once + * the directory request is initiated. */ + directory_request_upload_set_hs_ident(dir_req, &ident); + + /* Initiate the directory request to the hsdir.*/ + directory_initiate_request(dir_req); + directory_request_free(dir_req); + + /* Add this node to previous_hsdirs list */ + service_desc_note_upload(desc, hsdir); + + /* Logging so we know where it was sent. */ + { + int is_next_desc = (service->desc_next == desc); + const uint8_t *idx = (is_next_desc) ? hsdir->hsdir_index->store_second: + hsdir->hsdir_index->store_first; + log_info(LD_REND, "Service %s %s descriptor of revision %" PRIu64 + " initiated upload request to %s with index %s", + safe_str_client(service->onion_address), + (is_next_desc) ? "next" : "current", + desc->desc->plaintext_data.revision_counter, + safe_str_client(node_describe(hsdir)), + safe_str_client(hex_str((const char *) idx, 32))); + } + + /* XXX: Inform control port of the upload event (#20699). */ + end: + tor_free(encoded_desc); + return; +} + +/** Return a newly-allocated string for our state file which contains revision + * counter information for <b>desc</b>. The format is: + * + * HidServRevCounter <blinded_pubkey> <rev_counter> + */ +STATIC char * +encode_desc_rev_counter_for_state(const hs_service_descriptor_t *desc) +{ + char *state_str = NULL; + char blinded_pubkey_b64[ED25519_BASE64_LEN+1]; + uint64_t rev_counter = desc->desc->plaintext_data.revision_counter; + const ed25519_public_key_t *blinded_pubkey = &desc->blinded_kp.pubkey; + + /* Turn the blinded key into b64 so that we save it on state */ + tor_assert(blinded_pubkey); + if (ed25519_public_to_base64(blinded_pubkey_b64, blinded_pubkey) < 0) { + goto done; + } + + /* Format is: <blinded key> <rev counter> */ + tor_asprintf(&state_str, "%s %" PRIu64, blinded_pubkey_b64, rev_counter); + + log_info(LD_GENERAL, "[!] Adding rev counter %" PRIu64 " for %s!", + rev_counter, blinded_pubkey_b64); + + done: + return state_str; +} + +/** Update HS descriptor revision counters in our state by removing the old + * ones and writing down the ones that are currently active. */ +static void +update_revision_counters_in_state(void) +{ + config_line_t *lines = NULL; + config_line_t **nextline = &lines; + or_state_t *state = get_or_state(); + + /* Prepare our state structure with the rev counters */ + FOR_EACH_SERVICE_BEGIN(service) { + FOR_EACH_DESCRIPTOR_BEGIN(service, desc) { + /* We don't want to save zero counters */ + if (desc->desc->plaintext_data.revision_counter == 0) { + continue; + } + + *nextline = tor_malloc_zero(sizeof(config_line_t)); + (*nextline)->key = tor_strdup("HidServRevCounter"); + (*nextline)->value = encode_desc_rev_counter_for_state(desc); + nextline = &(*nextline)->next; + } FOR_EACH_DESCRIPTOR_END; + } FOR_EACH_SERVICE_END; + + /* Remove the old rev counters, and replace them with the new ones */ + config_free_lines(state->HidServRevCounter); + state->HidServRevCounter = lines; + + /* Set the state as dirty since we just edited it */ + if (!get_options()->AvoidDiskWrites) { + or_state_mark_dirty(state, 0); + } +} + +/** Scan the string <b>state_line</b> for the revision counter of the service + * with <b>blinded_pubkey</b>. Set <b>service_found_out</b> to True if the + * line is relevant to this service, and return the cached revision + * counter. Else set <b>service_found_out</b> to False. */ +STATIC uint64_t +check_state_line_for_service_rev_counter(const char *state_line, + const ed25519_public_key_t *blinded_pubkey, + int *service_found_out) +{ + smartlist_t *items = NULL; + int ok; + ed25519_public_key_t pubkey_in_state; + uint64_t rev_counter = 0; + + tor_assert(service_found_out); + tor_assert(state_line); + tor_assert(blinded_pubkey); + + /* Assume that the line is not for this service */ + *service_found_out = 0; + + /* Start parsing the state line */ + items = smartlist_new(); + smartlist_split_string(items, state_line, NULL, + SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, -1); + if (smartlist_len(items) < 2) { + log_warn(LD_GENERAL, "Incomplete rev counter line. Ignoring."); + goto done; + } + + char *b64_key_str = smartlist_get(items, 0); + char *saved_rev_counter_str = smartlist_get(items, 1); + + /* Parse blinded key to check if it's for this hidden service */ + if (ed25519_public_from_base64(&pubkey_in_state, b64_key_str) < 0) { + log_warn(LD_GENERAL, "Unable to base64 key in revcount line. Ignoring."); + goto done; + } + /* State line not for this hidden service */ + if (!ed25519_pubkey_eq(&pubkey_in_state, blinded_pubkey)) { + goto done; + } + + rev_counter = tor_parse_uint64(saved_rev_counter_str, + 10, 0, UINT64_MAX, &ok, NULL); + if (!ok) { + log_warn(LD_GENERAL, "Unable to parse rev counter. Ignoring."); + goto done; + } + + /* Since we got this far, the line was for this service */ + *service_found_out = 1; + + log_info(LD_GENERAL, "Found rev counter for %s: %" PRIu64, + b64_key_str, rev_counter); + + done: + tor_assert(items); + SMARTLIST_FOREACH(items, char*, s, tor_free(s)); + smartlist_free(items); + + return rev_counter; +} + +/** Dig into our state file and find the current revision counter for the + * service with blinded key <b>blinded_pubkey</b>. If no revision counter is + * found, return 0. */ +static uint64_t +get_rev_counter_for_service(const ed25519_public_key_t *blinded_pubkey) +{ + or_state_t *state = get_or_state(); + config_line_t *line; + + /* Set default value for rev counters (if not found) to 0 */ + uint64_t final_rev_counter = 0; + + for (line = state->HidServRevCounter ; line ; line = line->next) { + int service_found = 0; + uint64_t rev_counter = 0; + + tor_assert(!strcmp(line->key, "HidServRevCounter")); + + /* Scan all the HidServRevCounter lines till we find the line for this + service: */ + rev_counter = check_state_line_for_service_rev_counter(line->value, + blinded_pubkey, + &service_found); + if (service_found) { + final_rev_counter = rev_counter; + goto done; + } + } + + done: + return final_rev_counter; +} + +/** Update the value of the revision counter for <b>hs_desc</b> and save it on + our state file. */ +static void +increment_descriptor_revision_counter(hs_descriptor_t *hs_desc) +{ + /* Find stored rev counter if it exists */ + uint64_t rev_counter = + get_rev_counter_for_service(&hs_desc->plaintext_data.blinded_pubkey); + + /* Increment the revision counter of <b>hs_desc</b> so the next update (which + * will trigger an upload) will have the right value. We do this at this + * stage to only do it once because a descriptor can have many updates before + * being uploaded. By doing it at upload, we are sure to only increment by 1 + * and thus avoid leaking how many operations we made on the descriptor from + * the previous one before uploading. */ + rev_counter++; + hs_desc->plaintext_data.revision_counter = rev_counter; + + update_revision_counters_in_state(); +} + +/** Set the revision counter in <b>hs_desc</b>, using the state file to find + * the current counter value if it exists. */ +static void +set_descriptor_revision_counter(hs_descriptor_t *hs_desc) +{ + /* Find stored rev counter if it exists */ + uint64_t rev_counter = + get_rev_counter_for_service(&hs_desc->plaintext_data.blinded_pubkey); + + hs_desc->plaintext_data.revision_counter = rev_counter; +} + +/* Encode and sign the service descriptor desc and upload it to the + * responsible hidden service directories. If for_next_period is true, the set + * of directories are selected using the next hsdir_index. This does nothing + * if PublishHidServDescriptors is false. */ +STATIC void +upload_descriptor_to_all(const hs_service_t *service, + hs_service_descriptor_t *desc) +{ + smartlist_t *responsible_dirs = NULL; + + tor_assert(service); + tor_assert(desc); + + /* We'll first cancel any directory request that are ongoing for this + * descriptor. It is possible that we can trigger multiple uploads in a + * short time frame which can lead to a race where the second upload arrives + * before the first one leading to a 400 malformed descriptor response from + * the directory. Closing all pending requests avoids that. */ + close_directory_connections(service, desc); + + /* Get our list of responsible HSDir. */ + responsible_dirs = smartlist_new(); + /* The parameter 0 means that we aren't a client so tell the function to use + * the spread store consensus paremeter. */ + hs_get_responsible_hsdirs(&desc->blinded_kp.pubkey, desc->time_period_num, + service->desc_next == desc, 0, responsible_dirs); + + /** Clear list of previous hsdirs since we are about to upload to a new + * list. Let's keep it up to date. */ + service_desc_clear_previous_hsdirs(desc); + + /* For each responsible HSDir we have, initiate an upload command. */ + SMARTLIST_FOREACH_BEGIN(responsible_dirs, const routerstatus_t *, + hsdir_rs) { + const node_t *hsdir_node = node_get_by_id(hsdir_rs->identity_digest); + /* Getting responsible hsdir implies that the node_t object exists for the + * routerstatus_t found in the consensus else we have a problem. */ + tor_assert(hsdir_node); + /* Upload this descriptor to the chosen directory. */ + upload_descriptor_to_hsdir(service, desc, hsdir_node); + } SMARTLIST_FOREACH_END(hsdir_rs); + + /* Set the next upload time for this descriptor. Even if we are configured + * to not upload, we still want to follow the right cycle of life for this + * descriptor. */ + desc->next_upload_time = + (time(NULL) + crypto_rand_int_range(HS_SERVICE_NEXT_UPLOAD_TIME_MIN, + HS_SERVICE_NEXT_UPLOAD_TIME_MAX)); + { + char fmt_next_time[ISO_TIME_LEN+1]; + format_local_iso_time(fmt_next_time, desc->next_upload_time); + log_debug(LD_REND, "Service %s set to upload a descriptor at %s", + safe_str_client(service->onion_address), fmt_next_time); + } + + /* Update the revision counter of this descriptor */ + increment_descriptor_revision_counter(desc->desc); + + smartlist_free(responsible_dirs); + return; +} + +/** The set of HSDirs have changed: check if the change affects our descriptor + * HSDir placement, and if it does, reupload the desc. */ +STATIC int +service_desc_hsdirs_changed(const hs_service_t *service, + const hs_service_descriptor_t *desc) +{ + int should_reupload = 0; + smartlist_t *responsible_dirs = smartlist_new(); + + /* No desc upload has happened yet: it will happen eventually */ + if (!desc->previous_hsdirs || !smartlist_len(desc->previous_hsdirs)) { + goto done; + } + + /* Get list of responsible hsdirs */ + hs_get_responsible_hsdirs(&desc->blinded_kp.pubkey, desc->time_period_num, + service->desc_next == desc, 0, responsible_dirs); + + /* Check if any new hsdirs have been added to the responsible hsdirs set: + * Iterate over the list of new hsdirs, and reupload if any of them is not + * present in the list of previous hsdirs. + */ + SMARTLIST_FOREACH_BEGIN(responsible_dirs, const routerstatus_t *, hsdir_rs) { + char b64_digest[BASE64_DIGEST_LEN+1] = {0}; + digest_to_base64(b64_digest, hsdir_rs->identity_digest); + + if (!smartlist_contains_string(desc->previous_hsdirs, b64_digest)) { + should_reupload = 1; + break; + } + } SMARTLIST_FOREACH_END(hsdir_rs); + + done: + smartlist_free(responsible_dirs); + + return should_reupload; +} + +/* Return 1 if the given descriptor from the given service can be uploaded + * else return 0 if it can not. */ +static int +should_service_upload_descriptor(const hs_service_t *service, + const hs_service_descriptor_t *desc, time_t now) +{ + unsigned int num_intro_points; + + tor_assert(service); + tor_assert(desc); + + /* If this descriptors has missing intro points that is that it couldn't get + * them all when it was time to pick them, it means that we should upload + * instead of waiting an arbitrary amount of time breaking the service. + * Else, if we have no missing intro points, we use the value taken from the + * service configuration. */ + if (desc->missing_intro_points) { + num_intro_points = digest256map_size(desc->intro_points.map); + } else { + num_intro_points = service->config.num_intro_points; + } + + /* This means we tried to pick intro points but couldn't get any so do not + * upload descriptor in this case. We need at least one for the service to + * be reachable. */ + if (desc->missing_intro_points && num_intro_points == 0) { + goto cannot; + } + + /* Check if all our introduction circuit have been established for all the + * intro points we have selected. */ + if (count_desc_circuit_established(desc) != num_intro_points) { + goto cannot; + } + + /* Is it the right time to upload? */ + if (desc->next_upload_time > now) { + goto cannot; + } + + /* Don't upload desc if we don't have a live consensus */ + if (!networkstatus_get_live_consensus(now)) { + goto cannot; + } + + /* Do we know enough router descriptors to have adequate vision of the HSDir + hash ring? */ + if (!router_have_minimum_dir_info()) { + goto cannot; + } + + /* Can upload! */ + return 1; + cannot: + return 0; +} + +/* Scheduled event run from the main loop. Try to upload the descriptor for + * each service. */ +STATIC void +run_upload_descriptor_event(time_t now) +{ + /* v2 services use the same function for descriptor creation and upload so + * we do everything here because the intro circuits were checked before. */ + if (rend_num_services() > 0) { + rend_consider_services_upload(now); + rend_consider_descriptor_republication(); + } + + /* Run v3+ check. */ + FOR_EACH_SERVICE_BEGIN(service) { + FOR_EACH_DESCRIPTOR_BEGIN(service, desc) { + /* If we were asked to re-examine the hash ring, and it changed, then + schedule an upload */ + if (consider_republishing_hs_descriptors && + service_desc_hsdirs_changed(service, desc)) { + service_desc_schedule_upload(desc, now, 0); + } + + /* Can this descriptor be uploaded? */ + if (!should_service_upload_descriptor(service, desc, now)) { + continue; + } + + log_info(LD_REND, "Initiating upload for hidden service %s descriptor " + "for service %s with %u/%u introduction points%s.", + (desc == service->desc_current) ? "current" : "next", + safe_str_client(service->onion_address), + digest256map_size(desc->intro_points.map), + service->config.num_intro_points, + (desc->missing_intro_points) ? " (couldn't pick more)" : ""); + + /* At this point, we have to upload the descriptor so start by building + * the intro points descriptor section which we are now sure to be + * accurate because all circuits have been established. */ + build_desc_intro_points(service, desc, now); + + upload_descriptor_to_all(service, desc); + } FOR_EACH_DESCRIPTOR_END; + } FOR_EACH_SERVICE_END; + + /* We are done considering whether to republish rend descriptors */ + consider_republishing_hs_descriptors = 0; +} + +/* Called when the introduction point circuit is done building and ready to be + * used. */ +static void +service_intro_circ_has_opened(origin_circuit_t *circ) +{ + hs_service_t *service = NULL; + hs_service_intro_point_t *ip = NULL; + hs_service_descriptor_t *desc = NULL; + + tor_assert(circ); + + /* Let's do some basic sanity checking of the circ state */ + if (BUG(!circ->cpath)) { + return; + } + if (BUG(TO_CIRCUIT(circ)->purpose != CIRCUIT_PURPOSE_S_ESTABLISH_INTRO)) { + return; + } + if (BUG(!circ->hs_ident)) { + return; + } + + /* Get the corresponding service and intro point. */ + get_objects_from_ident(circ->hs_ident, &service, &ip, &desc); + + if (service == NULL) { + log_warn(LD_REND, "Unknown service identity key %s on the introduction " + "circuit %u. Can't find onion service.", + safe_str_client(ed25519_fmt(&circ->hs_ident->identity_pk)), + TO_CIRCUIT(circ)->n_circ_id); + goto err; + } + if (ip == NULL) { + log_warn(LD_REND, "Unknown introduction point auth key on circuit %u " + "for service %s", + TO_CIRCUIT(circ)->n_circ_id, + safe_str_client(service->onion_address)); + goto err; + } + /* We can't have an IP object without a descriptor. */ + tor_assert(desc); + + if (hs_circ_service_intro_has_opened(service, ip, desc, circ)) { + /* Getting here means that the circuit has been re-purposed because we + * have enough intro circuit opened. Remove the IP from the service. */ + service_intro_point_remove(service, ip); + service_intro_point_free(ip); + } + + goto done; + + err: + /* Close circuit, we can't use it. */ + circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_NOSUCHSERVICE); + done: + return; +} + +/* Called when a rendezvous circuit is done building and ready to be used. */ +static void +service_rendezvous_circ_has_opened(origin_circuit_t *circ) +{ + hs_service_t *service = NULL; + + tor_assert(circ); + tor_assert(circ->cpath); + /* Getting here means this is a v3 rendezvous circuit. */ + tor_assert(circ->hs_ident); + tor_assert(TO_CIRCUIT(circ)->purpose == CIRCUIT_PURPOSE_S_CONNECT_REND); + + /* Declare the circuit dirty to avoid reuse, and for path-bias. We set the + * timestamp regardless of its content because that circuit could have been + * cannibalized so in any cases, we are about to use that circuit more. */ + TO_CIRCUIT(circ)->timestamp_dirty = time(NULL); + pathbias_count_use_attempt(circ); + + /* Get the corresponding service and intro point. */ + get_objects_from_ident(circ->hs_ident, &service, NULL, NULL); + if (service == NULL) { + log_warn(LD_REND, "Unknown service identity key %s on the rendezvous " + "circuit %u with cookie %s. Can't find onion service.", + safe_str_client(ed25519_fmt(&circ->hs_ident->identity_pk)), + TO_CIRCUIT(circ)->n_circ_id, + hex_str((const char *) circ->hs_ident->rendezvous_cookie, + REND_COOKIE_LEN)); + goto err; + } + + /* If the cell can't be sent, the circuit will be closed within this + * function. */ + hs_circ_service_rp_has_opened(service, circ); + goto done; + + err: + circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_NOSUCHSERVICE); + done: + return; +} + +/* We've been expecting an INTRO_ESTABLISHED cell on this circuit and it just + * arrived. Handle the INTRO_ESTABLISHED cell arriving on the given + * introduction circuit. Return 0 on success else a negative value. */ +static int +service_handle_intro_established(origin_circuit_t *circ, + const uint8_t *payload, + size_t payload_len) +{ + hs_service_t *service = NULL; + hs_service_intro_point_t *ip = NULL; + + tor_assert(circ); + tor_assert(payload); + tor_assert(TO_CIRCUIT(circ)->purpose == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO); + + /* We need the service and intro point for this cell. */ + get_objects_from_ident(circ->hs_ident, &service, &ip, NULL); + + /* Get service object from the circuit identifier. */ + if (service == NULL) { + log_warn(LD_REND, "Unknown service identity key %s on the introduction " + "circuit %u. Can't find onion service.", + safe_str_client(ed25519_fmt(&circ->hs_ident->identity_pk)), + TO_CIRCUIT(circ)->n_circ_id); + goto err; + } + if (ip == NULL) { + /* We don't recognize the key. */ + log_warn(LD_REND, "Introduction circuit established without an intro " + "point object on circuit %u for service %s", + TO_CIRCUIT(circ)->n_circ_id, + safe_str_client(service->onion_address)); + goto err; + } + + /* Try to parse the payload into a cell making sure we do actually have a + * valid cell. On success, the ip object and circuit purpose is updated to + * reflect the fact that the introduction circuit is established. */ + if (hs_circ_handle_intro_established(service, ip, circ, payload, + payload_len) < 0) { + goto err; + } + + /* Flag that we have an established circuit for this intro point. This value + * is what indicates the upload scheduled event if we are ready to build the + * intro point into the descriptor and upload. */ + ip->circuit_established = 1; + + log_info(LD_REND, "Successfully received an INTRO_ESTABLISHED cell " + "on circuit %u for service %s", + TO_CIRCUIT(circ)->n_circ_id, + safe_str_client(service->onion_address)); + return 0; + + err: + return -1; +} + +/* We just received an INTRODUCE2 cell on the established introduction circuit + * circ. Handle the cell and return 0 on success else a negative value. */ +static int +service_handle_introduce2(origin_circuit_t *circ, const uint8_t *payload, + size_t payload_len) +{ + hs_service_t *service = NULL; + hs_service_intro_point_t *ip = NULL; + hs_service_descriptor_t *desc = NULL; + + tor_assert(circ); + tor_assert(payload); + tor_assert(TO_CIRCUIT(circ)->purpose == CIRCUIT_PURPOSE_S_INTRO); + + /* We'll need every object associated with this circuit. */ + get_objects_from_ident(circ->hs_ident, &service, &ip, &desc); + + /* Get service object from the circuit identifier. */ + if (service == NULL) { + log_warn(LD_BUG, "Unknown service identity key %s when handling " + "an INTRODUCE2 cell on circuit %u", + safe_str_client(ed25519_fmt(&circ->hs_ident->identity_pk)), + TO_CIRCUIT(circ)->n_circ_id); + goto err; + } + if (ip == NULL) { + /* We don't recognize the key. */ + log_warn(LD_BUG, "Unknown introduction auth key when handling " + "an INTRODUCE2 cell on circuit %u for service %s", + TO_CIRCUIT(circ)->n_circ_id, + safe_str_client(service->onion_address)); + goto err; + } + /* If we have an IP object, we MUST have a descriptor object. */ + tor_assert(desc); + + /* The following will parse, decode and launch the rendezvous point circuit. + * Both current and legacy cells are handled. */ + if (hs_circ_handle_introduce2(service, circ, ip, desc->desc->subcredential, + payload, payload_len) < 0) { + goto err; + } + + return 0; + err: + return -1; +} + +/* Add to list every filename used by service. This is used by the sandbox + * subsystem. */ +static void +service_add_fnames_to_list(const hs_service_t *service, smartlist_t *list) +{ + const char *s_dir; + char fname[128] = {0}; + + tor_assert(service); + tor_assert(list); + + /* Ease our life. */ + s_dir = service->config.directory_path; + /* The hostname file. */ + smartlist_add(list, hs_path_from_filename(s_dir, fname_hostname)); + /* The key files splitted in two. */ + tor_snprintf(fname, sizeof(fname), "%s_secret_key", fname_keyfile_prefix); + smartlist_add(list, hs_path_from_filename(s_dir, fname)); + tor_snprintf(fname, sizeof(fname), "%s_public_key", fname_keyfile_prefix); + smartlist_add(list, hs_path_from_filename(s_dir, fname)); +} + +/* ========== */ +/* Public API */ +/* ========== */ + +/* Return the number of service we have configured and usable. */ +unsigned int +hs_service_get_num_services(void) +{ + if (hs_service_map == NULL) { + return 0; + } + return HT_SIZE(hs_service_map); +} + +/* Called once an introduction circuit is closed. If the circuit doesn't have + * a v3 identifier, it is ignored. */ +void +hs_service_intro_circ_has_closed(origin_circuit_t *circ) +{ + hs_service_t *service = NULL; + hs_service_intro_point_t *ip = NULL; + hs_service_descriptor_t *desc = NULL; + + tor_assert(circ); + + if (circ->hs_ident == NULL) { + /* This is not a v3 circuit, ignore. */ + goto end; + } + + get_objects_from_ident(circ->hs_ident, &service, &ip, &desc); + if (service == NULL) { + log_warn(LD_REND, "Unable to find any hidden service associated " + "identity key %s on intro circuit %u.", + ed25519_fmt(&circ->hs_ident->identity_pk), + TO_CIRCUIT(circ)->n_circ_id); + goto end; + } + if (ip == NULL) { + /* The introduction point object has already been removed probably by our + * cleanup process so ignore. */ + goto end; + } + /* Can't have an intro point object without a descriptor. */ + tor_assert(desc); + + /* Circuit disappeared so make sure the intro point is updated. By + * keeping the object in the descriptor, we'll be able to retry. */ + ip->circuit_established = 0; + + end: + return; +} + +/* Given conn, a rendezvous edge connection acting as an exit stream, look up + * the hidden service for the circuit circ, and look up the port and address + * based on the connection port. Assign the actual connection address. + * + * Return 0 on success. Return -1 on failure and the caller should NOT close + * the circuit. Return -2 on failure and the caller MUST close the circuit for + * security reasons. */ +int +hs_service_set_conn_addr_port(const origin_circuit_t *circ, + edge_connection_t *conn) +{ + hs_service_t *service = NULL; + + tor_assert(circ); + tor_assert(conn); + tor_assert(TO_CIRCUIT(circ)->purpose == CIRCUIT_PURPOSE_S_REND_JOINED); + tor_assert(circ->hs_ident); + + get_objects_from_ident(circ->hs_ident, &service, NULL, NULL); + + if (service == NULL) { + log_warn(LD_REND, "Unable to find any hidden service associated " + "identity key %s on rendezvous circuit %u.", + ed25519_fmt(&circ->hs_ident->identity_pk), + TO_CIRCUIT(circ)->n_circ_id); + /* We want the caller to close the circuit because it's not a valid + * service so no danger. Attempting to bruteforce the entire key space by + * opening circuits to learn which service is being hosted here is + * impractical. */ + goto err_close; + } + + /* Enforce the streams-per-circuit limit, and refuse to provide a mapping if + * this circuit will exceed the limit. */ + if (service->config.max_streams_per_rdv_circuit > 0 && + (circ->hs_ident->num_rdv_streams >= + service->config.max_streams_per_rdv_circuit)) { +#define MAX_STREAM_WARN_INTERVAL 600 + static struct ratelim_t stream_ratelim = + RATELIM_INIT(MAX_STREAM_WARN_INTERVAL); + log_fn_ratelim(&stream_ratelim, LOG_WARN, LD_REND, + "Maximum streams per circuit limit reached on " + "rendezvous circuit %u for service %s. Circuit has " + "%" PRIu64 " out of %" PRIu64 " streams. %s.", + TO_CIRCUIT(circ)->n_circ_id, + service->onion_address, + circ->hs_ident->num_rdv_streams, + service->config.max_streams_per_rdv_circuit, + service->config.max_streams_close_circuit ? + "Closing circuit" : "Ignoring open stream request"); + if (service->config.max_streams_close_circuit) { + /* Service explicitly configured to close immediately. */ + goto err_close; + } + /* Exceeding the limit makes tor silently ignore the stream creation + * request and keep the circuit open. */ + goto err_no_close; + } + + /* Find a virtual port of that service mathcing the one in the connection if + * succesful, set the address in the connection. */ + if (hs_set_conn_addr_port(service->config.ports, conn) < 0) { + log_info(LD_REND, "No virtual port mapping exists for port %d for " + "hidden service %s.", + TO_CONN(conn)->port, service->onion_address); + if (service->config.allow_unknown_ports) { + /* Service explicitly allow connection to unknown ports so close right + * away because we do not care about port mapping. */ + goto err_close; + } + /* If the service didn't explicitly allow it, we do NOT close the circuit + * here to raise the bar in terms of performance for port mapping. */ + goto err_no_close; + } + + /* Success. */ + return 0; + err_close: + /* Indicate the caller that the circuit should be closed. */ + return -2; + err_no_close: + /* Indicate the caller to NOT close the circuit. */ + return -1; +} + +/* Add to file_list every filename used by a configured hidden service, and to + * dir_list every directory path used by a configured hidden service. This is + * used by the sandbox subsystem to whitelist those. */ +void +hs_service_lists_fnames_for_sandbox(smartlist_t *file_list, + smartlist_t *dir_list) +{ + tor_assert(file_list); + tor_assert(dir_list); + + /* Add files and dirs for legacy services. */ + rend_services_add_filenames_to_lists(file_list, dir_list); + + /* Add files and dirs for v3+. */ + FOR_EACH_SERVICE_BEGIN(service) { + /* Skip ephemeral service, they don't touch the disk. */ + if (service->config.is_ephemeral) { + continue; + } + service_add_fnames_to_list(service, file_list); + smartlist_add_strdup(dir_list, service->config.directory_path); + } FOR_EACH_DESCRIPTOR_END; +} + +/* Called when our internal view of the directory has changed. We might have + * received a new batch of descriptors which might affect the shape of the + * HSDir hash ring. Signal that we should reexamine the hash ring and + * re-upload our HS descriptors if needed. */ +void +hs_service_dir_info_changed(void) +{ + if (hs_service_get_num_services() > 0) { + /* New directory information usually goes every consensus so rate limit + * every 30 minutes to not be too conservative. */ + static struct ratelim_t dir_info_changed_ratelim = RATELIM_INIT(30 * 60); + log_fn_ratelim(&dir_info_changed_ratelim, LOG_INFO, LD_REND, + "New dirinfo arrived: consider reuploading descriptor"); + consider_republishing_hs_descriptors = 1; + } +} + +/* Called when we get an INTRODUCE2 cell on the circ. Respond to the cell and + * launch a circuit to the rendezvous point. */ +int +hs_service_receive_introduce2(origin_circuit_t *circ, const uint8_t *payload, + size_t payload_len) +{ + int ret = -1; + + tor_assert(circ); + tor_assert(payload); + + /* Do some initial validation and logging before we parse the cell */ + if (TO_CIRCUIT(circ)->purpose != CIRCUIT_PURPOSE_S_INTRO) { + log_warn(LD_PROTOCOL, "Received an INTRODUCE2 cell on a " + "non introduction circuit of purpose %d", + TO_CIRCUIT(circ)->purpose); + goto done; + } + + if (circ->hs_ident) { + ret = service_handle_introduce2(circ, payload, payload_len); + } else { + ret = rend_service_receive_introduction(circ, payload, payload_len); + } + + done: + return ret; +} + +/* Called when we get an INTRO_ESTABLISHED cell. Mark the circuit as an + * established introduction point. Return 0 on success else a negative value + * and the circuit is closed. */ +int +hs_service_receive_intro_established(origin_circuit_t *circ, + const uint8_t *payload, + size_t payload_len) +{ + int ret = -1; + + tor_assert(circ); + tor_assert(payload); + + if (TO_CIRCUIT(circ)->purpose != CIRCUIT_PURPOSE_S_ESTABLISH_INTRO) { + log_warn(LD_PROTOCOL, "Received an INTRO_ESTABLISHED cell on a " + "non introduction circuit of purpose %d", + TO_CIRCUIT(circ)->purpose); + goto err; + } + + /* Handle both version. v2 uses rend_data and v3 uses the hs circuit + * identifier hs_ident. Can't be both. */ + if (circ->hs_ident) { + ret = service_handle_intro_established(circ, payload, payload_len); + } else { + ret = rend_service_intro_established(circ, payload, payload_len); + } + + if (ret < 0) { + goto err; + } + return 0; + err: + circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_TORPROTOCOL); + return -1; +} + +/* Called when any kind of hidden service circuit is done building thus + * opened. This is the entry point from the circuit subsystem. */ +void +hs_service_circuit_has_opened(origin_circuit_t *circ) +{ + tor_assert(circ); + + /* Handle both version. v2 uses rend_data and v3 uses the hs circuit + * identifier hs_ident. Can't be both. */ + switch (TO_CIRCUIT(circ)->purpose) { + case CIRCUIT_PURPOSE_S_ESTABLISH_INTRO: + if (circ->hs_ident) { + service_intro_circ_has_opened(circ); + } else { + rend_service_intro_has_opened(circ); + } + break; + case CIRCUIT_PURPOSE_S_CONNECT_REND: + if (circ->hs_ident) { + service_rendezvous_circ_has_opened(circ); + } else { + rend_service_rendezvous_has_opened(circ); + } + break; + default: + tor_assert(0); + } +} + +/* Load and/or generate keys for all onion services including the client + * authorization if any. Return 0 on success, -1 on failure. */ +int +hs_service_load_all_keys(void) +{ + /* Load v2 service keys if we have v2. */ + if (rend_num_services() != 0) { + if (rend_service_load_all_keys(NULL) < 0) { + goto err; + } + } + + /* Load or/and generate them for v3+. */ + SMARTLIST_FOREACH_BEGIN(hs_service_staging_list, hs_service_t *, service) { + /* Ignore ephemeral service, they already have their keys set. */ + if (service->config.is_ephemeral) { + continue; + } + log_info(LD_REND, "Loading v3 onion service keys from %s", + service_escaped_dir(service)); + if (load_service_keys(service) < 0) { + goto err; + } + /* XXX: Load/Generate client authorization keys. (#20700) */ + } SMARTLIST_FOREACH_END(service); + + /* Final step, the staging list contains service in a quiescent state that + * is ready to be used. Register them to the global map. Once this is over, + * the staging list will be cleaned up. */ + register_all_services(); + + /* All keys have been loaded successfully. */ + return 0; + err: + return -1; +} + +/* Put all service object in the given service list. After this, the caller + * looses ownership of every elements in the list and responsible to free the + * list pointer. */ +void +hs_service_stage_services(const smartlist_t *service_list) +{ + tor_assert(service_list); + /* This list is freed at registration time but this function can be called + * multiple time. */ + if (hs_service_staging_list == NULL) { + hs_service_staging_list = smartlist_new(); + } + /* Add all service object to our staging list. Caller is responsible for + * freeing the service_list. */ + smartlist_add_all(hs_service_staging_list, service_list); +} + +/* Allocate and initilize a service object. The service configuration will + * contain the default values. Return the newly allocated object pointer. This + * function can't fail. */ +hs_service_t * +hs_service_new(const or_options_t *options) +{ + hs_service_t *service = tor_malloc_zero(sizeof(hs_service_t)); + /* Set default configuration value. */ + set_service_default_config(&service->config, options); + /* Set the default service version. */ + service->config.version = HS_SERVICE_DEFAULT_VERSION; + /* Allocate the CLIENT_PK replay cache in service state. */ + service->state.replay_cache_rend_cookie = + replaycache_new(REND_REPLAY_TIME_INTERVAL, REND_REPLAY_TIME_INTERVAL); + + return service; +} + +/* Free the given <b>service</b> object and all its content. This function + * also takes care of wiping service keys from memory. It is safe to pass a + * NULL pointer. */ +void +hs_service_free(hs_service_t *service) +{ + if (service == NULL) { + return; + } + + /* Free descriptors. Go over both descriptor with this loop. */ + FOR_EACH_DESCRIPTOR_BEGIN(service, desc) { + service_descriptor_free(desc); + } FOR_EACH_DESCRIPTOR_END; + + /* Free service configuration. */ + service_clear_config(&service->config); + + /* Free replay cache from state. */ + if (service->state.replay_cache_rend_cookie) { + replaycache_free(service->state.replay_cache_rend_cookie); + } + + /* Wipe service keys. */ + memwipe(&service->keys.identity_sk, 0, sizeof(service->keys.identity_sk)); + + tor_free(service); +} + +/* Periodic callback. Entry point from the main loop to the HS service + * subsystem. This is call every second. This is skipped if tor can't build a + * circuit or the network is disabled. */ +void +hs_service_run_scheduled_events(time_t now) +{ + /* First thing we'll do here is to make sure our services are in a + * quiescent state for the scheduled events. */ + run_housekeeping_event(now); + + /* Order matters here. We first make sure the descriptor object for each + * service contains the latest data. Once done, we check if we need to open + * new introduction circuit. Finally, we try to upload the descriptor for + * each service. */ + + /* Make sure descriptors are up to date. */ + run_build_descriptor_event(now); + /* Make sure services have enough circuits. */ + run_build_circuit_event(now); + /* Upload the descriptors if needed/possible. */ + run_upload_descriptor_event(now); +} + +/* Initialize the service HS subsystem. */ +void +hs_service_init(void) +{ + /* Should never be called twice. */ + tor_assert(!hs_service_map); + tor_assert(!hs_service_staging_list); + + /* v2 specific. */ + rend_service_init(); + + hs_service_map = tor_malloc_zero(sizeof(struct hs_service_ht)); + HT_INIT(hs_service_ht, hs_service_map); + + hs_service_staging_list = smartlist_new(); +} + +/* Release all global storage of the hidden service subsystem. */ +void +hs_service_free_all(void) +{ + rend_service_free_all(); + service_free_all(); +} + +#ifdef TOR_UNIT_TESTS + +/* Return the global service map size. Only used by unit test. */ +STATIC unsigned int +get_hs_service_map_size(void) +{ + return HT_SIZE(hs_service_map); +} + +/* Return the staging list size. Only used by unit test. */ +STATIC int +get_hs_service_staging_list_size(void) +{ + return smartlist_len(hs_service_staging_list); +} + +STATIC hs_service_ht * +get_hs_service_map(void) +{ + return hs_service_map; +} + +STATIC hs_service_t * +get_first_service(void) +{ + hs_service_t **obj = HT_START(hs_service_ht, hs_service_map); + if (obj == NULL) { + return NULL; + } + return *obj; +} + +#endif /* defined(TOR_UNIT_TESTS) */ + |