diff options
Diffstat (limited to 'src/feature/hs/hs_cache.c')
| -rw-r--r-- | src/feature/hs/hs_cache.c | 282 |
1 files changed, 221 insertions, 61 deletions
diff --git a/src/feature/hs/hs_cache.c b/src/feature/hs/hs_cache.c index 042ec55fa4..ef5e88e947 100644 --- a/src/feature/hs/hs_cache.c +++ b/src/feature/hs/hs_cache.c @@ -1,4 +1,4 @@ -/* Copyright (c) 2016-2019, The Tor Project, Inc. */ +/* Copyright (c) 2016-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -28,12 +28,27 @@ static int cached_client_descriptor_has_expired(time_t now, const hs_cache_client_descriptor_t *cached_desc); +/** Helper function: Return true iff the cache entry has a decrypted + * descriptor. + * + * A NULL desc object in the entry means that we were not able to decrypt the + * descriptor because we are likely lacking client authorization. It is still + * a valid entry but some operations can't be done without the decrypted + * descriptor thus this function MUST be used to safe guard access to the + * decrypted desc object. */ +static inline bool +entry_has_decrypted_descriptor(const hs_cache_client_descriptor_t *entry) +{ + tor_assert(entry); + return (entry->desc != NULL); +} + /********************** Directory HS cache ******************/ -/* Directory descriptor cache. Map indexed by blinded key. */ +/** Directory descriptor cache. Map indexed by blinded key. */ static digest256map_t *hs_cache_v3_dir; -/* Remove a given descriptor from our cache. */ +/** Remove a given descriptor from our cache. */ static void remove_v3_desc_as_dir(const hs_cache_dir_descriptor_t *desc) { @@ -41,7 +56,7 @@ remove_v3_desc_as_dir(const hs_cache_dir_descriptor_t *desc) digest256map_remove(hs_cache_v3_dir, desc->key); } -/* Store a given descriptor in our cache. */ +/** Store a given descriptor in our cache. */ static void store_v3_desc_as_dir(hs_cache_dir_descriptor_t *desc) { @@ -49,7 +64,7 @@ store_v3_desc_as_dir(hs_cache_dir_descriptor_t *desc) digest256map_set(hs_cache_v3_dir, desc->key, desc); } -/* Query our cache and return the entry or NULL if not found. */ +/** Query our cache and return the entry or NULL if not found. */ static hs_cache_dir_descriptor_t * lookup_v3_desc_as_dir(const uint8_t *key) { @@ -60,7 +75,7 @@ lookup_v3_desc_as_dir(const uint8_t *key) #define cache_dir_desc_free(val) \ FREE_AND_NULL(hs_cache_dir_descriptor_t, cache_dir_desc_free_, (val)) -/* Free a directory descriptor object. */ +/** Free a directory descriptor object. */ static void cache_dir_desc_free_(hs_cache_dir_descriptor_t *desc) { @@ -72,7 +87,7 @@ cache_dir_desc_free_(hs_cache_dir_descriptor_t *desc) tor_free(desc); } -/* Helper function: Use by the free all function using the digest256map +/** Helper function: Use by the free all function using the digest256map * interface to cache entries. */ static void cache_dir_desc_free_void(void *ptr) @@ -80,7 +95,7 @@ cache_dir_desc_free_void(void *ptr) cache_dir_desc_free_(ptr); } -/* Create a new directory cache descriptor object from a encoded descriptor. +/** Create a new directory cache descriptor object from a encoded descriptor. * On success, return the heap-allocated cache object, otherwise return NULL if * we can't decode the descriptor. */ static hs_cache_dir_descriptor_t * @@ -110,7 +125,7 @@ cache_dir_desc_new(const char *desc) return NULL; } -/* Return the size of a cache entry in bytes. */ +/** Return the size of a cache entry in bytes. */ static size_t cache_get_dir_entry_size(const hs_cache_dir_descriptor_t *entry) { @@ -118,7 +133,7 @@ cache_get_dir_entry_size(const hs_cache_dir_descriptor_t *entry) + strlen(entry->encoded_desc)); } -/* Try to store a valid version 3 descriptor in the directory cache. Return 0 +/** Try to store a valid version 3 descriptor in the directory cache. Return 0 * on success else a negative value is returned indicating that we have a * newer version in our cache. On error, caller is responsible to free the * given descriptor desc. */ @@ -168,7 +183,7 @@ cache_store_v3_as_dir(hs_cache_dir_descriptor_t *desc) return -1; } -/* Using the query which is the base64 encoded blinded key of a version 3 +/** Using the query which is the base64 encoded blinded key of a version 3 * descriptor, lookup in our directory cache the entry. If found, 1 is * returned and desc_out is populated with a newly allocated string being the * encoded descriptor. If not found, 0 is returned and desc_out is untouched. @@ -203,7 +218,7 @@ cache_lookup_v3_as_dir(const char *query, const char **desc_out) return -1; } -/* Clean the v3 cache by removing any entry that has expired using the +/** Clean the v3 cache by removing any entry that has expired using the * <b>global_cutoff</b> value. If <b>global_cutoff</b> is 0, the cleaning * process will use the lifetime found in the plaintext data section. Return * the number of bytes cleaned. */ @@ -253,7 +268,7 @@ cache_clean_v3_as_dir(time_t now, time_t global_cutoff) return bytes_removed; } -/* Given an encoded descriptor, store it in the directory cache depending on +/** Given an encoded descriptor, store it in the directory cache depending on * which version it is. Return a negative value on error. On success, 0 is * returned. */ int @@ -288,7 +303,7 @@ hs_cache_store_as_dir(const char *desc) return -1; } -/* Using the query, lookup in our directory cache the entry. If found, 1 is +/** Using the query, lookup in our directory cache the entry. If found, 1 is * returned and desc_out is populated with a newly allocated string being * the encoded descriptor. If not found, 0 is returned and desc_out is * untouched. On error, a negative value is returned and desc_out is @@ -313,7 +328,7 @@ hs_cache_lookup_as_dir(uint32_t version, const char *query, return found; } -/* Clean all directory caches using the current time now. */ +/** Clean all directory caches using the current time now. */ void hs_cache_clean_as_dir(time_t now) { @@ -330,23 +345,38 @@ hs_cache_clean_as_dir(time_t now) /********************** Client-side HS cache ******************/ -/* Client-side HS descriptor cache. Map indexed by service identity key. */ +/** Client-side HS descriptor cache. Map indexed by service identity key. */ static digest256map_t *hs_cache_v3_client; -/* Client-side introduction point state cache. Map indexed by service public +/** Client-side introduction point state cache. Map indexed by service public * identity key (onion address). It contains hs_cache_client_intro_state_t * objects all related to a specific service. */ static digest256map_t *hs_cache_client_intro_state; -/* Return the size of a client cache entry in bytes. */ +/** Return the size of a client cache entry in bytes. */ static size_t cache_get_client_entry_size(const hs_cache_client_descriptor_t *entry) { - return sizeof(*entry) + - strlen(entry->encoded_desc) + hs_desc_obj_size(entry->desc); + size_t size = 0; + + if (entry == NULL) { + goto end; + } + size += sizeof(*entry); + + if (entry->encoded_desc) { + size += strlen(entry->encoded_desc); + } + + if (entry_has_decrypted_descriptor(entry)) { + size += hs_desc_obj_size(entry->desc); + } + + end: + return size; } -/* Remove a given descriptor from our cache. */ +/** Remove a given descriptor from our cache. */ static void remove_v3_desc_as_client(const hs_cache_client_descriptor_t *desc) { @@ -356,7 +386,7 @@ remove_v3_desc_as_client(const hs_cache_client_descriptor_t *desc) rend_cache_decrement_allocation(cache_get_client_entry_size(desc)); } -/* Store a given descriptor in our cache. */ +/** Store a given descriptor in our cache. */ static void store_v3_desc_as_client(hs_cache_client_descriptor_t *desc) { @@ -366,7 +396,7 @@ store_v3_desc_as_client(hs_cache_client_descriptor_t *desc) rend_cache_increment_allocation(cache_get_client_entry_size(desc)); } -/* Query our cache and return the entry or NULL if not found or if expired. */ +/** Query our cache and return the entry or NULL if not found or if expired. */ STATIC hs_cache_client_descriptor_t * lookup_v3_desc_as_client(const uint8_t *key) { @@ -389,15 +419,17 @@ lookup_v3_desc_as_client(const uint8_t *key) return cached_desc; } -/* Parse the encoded descriptor in <b>desc_str</b> using - * <b>service_identity_pk<b> to decrypt it first. +/** Parse the encoded descriptor in <b>desc_str</b> using + * <b>service_identity_pk</b> to decrypt it first. * * If everything goes well, allocate and return a new * hs_cache_client_descriptor_t object. In case of error, return NULL. */ static hs_cache_client_descriptor_t * cache_client_desc_new(const char *desc_str, - const ed25519_public_key_t *service_identity_pk) + const ed25519_public_key_t *service_identity_pk, + hs_desc_decode_status_t *decode_status_out) { + hs_desc_decode_status_t ret; hs_descriptor_t *desc = NULL; hs_cache_client_descriptor_t *client_desc = NULL; @@ -405,10 +437,24 @@ cache_client_desc_new(const char *desc_str, tor_assert(service_identity_pk); /* Decode the descriptor we just fetched. */ - if (hs_client_decode_descriptor(desc_str, service_identity_pk, &desc) < 0) { + ret = hs_client_decode_descriptor(desc_str, service_identity_pk, &desc); + if (ret != HS_DESC_DECODE_OK && + ret != HS_DESC_DECODE_NEED_CLIENT_AUTH && + ret != HS_DESC_DECODE_BAD_CLIENT_AUTH) { + /* In the case of a missing or bad client authorization, we'll keep the + * descriptor in the cache because those credentials can arrive later. */ goto end; } - tor_assert(desc); + /* Make sure we do have a descriptor if decoding was successful. */ + if (ret == HS_DESC_DECODE_OK) { + tor_assert(desc); + } else { + if (BUG(desc != NULL)) { + /* We are not suppose to have a descriptor if the decoding code is not + * indicating success. Just in case, bail early to recover. */ + goto end; + } + } /* All is good: make a cache object for this descriptor */ client_desc = tor_malloc_zero(sizeof(hs_cache_client_descriptor_t)); @@ -421,6 +467,9 @@ cache_client_desc_new(const char *desc_str, client_desc->encoded_desc = tor_strdup(desc_str); end: + if (decode_status_out) { + *decode_status_out = ret; + } return client_desc; } @@ -449,7 +498,7 @@ cache_client_desc_free_void(void *ptr) cache_client_desc_free(desc); } -/* Return a newly allocated and initialized hs_cache_intro_state_t object. */ +/** Return a newly allocated and initialized hs_cache_intro_state_t object. */ static hs_cache_intro_state_t * cache_intro_state_new(void) { @@ -461,21 +510,21 @@ cache_intro_state_new(void) #define cache_intro_state_free(val) \ FREE_AND_NULL(hs_cache_intro_state_t, cache_intro_state_free_, (val)) -/* Free an hs_cache_intro_state_t object. */ +/** Free an hs_cache_intro_state_t object. */ static void cache_intro_state_free_(hs_cache_intro_state_t *state) { tor_free(state); } -/* Helper function: used by the free all function. */ +/** Helper function: used by the free all function. */ static void cache_intro_state_free_void(void *state) { cache_intro_state_free_(state); } -/* Return a newly allocated and initialized hs_cache_client_intro_state_t +/** Return a newly allocated and initialized hs_cache_client_intro_state_t * object. */ static hs_cache_client_intro_state_t * cache_client_intro_state_new(void) @@ -489,7 +538,7 @@ cache_client_intro_state_new(void) FREE_AND_NULL(hs_cache_client_intro_state_t, \ cache_client_intro_state_free_, (val)) -/* Free a cache_client_intro_state object. */ +/** Free a cache_client_intro_state object. */ static void cache_client_intro_state_free_(hs_cache_client_intro_state_t *cache) { @@ -500,14 +549,14 @@ cache_client_intro_state_free_(hs_cache_client_intro_state_t *cache) tor_free(cache); } -/* Helper function: used by the free all function. */ +/** Helper function: used by the free all function. */ static void cache_client_intro_state_free_void(void *entry) { cache_client_intro_state_free_(entry); } -/* For the given service identity key service_pk and an introduction +/** For the given service identity key service_pk and an introduction * authentication key auth_key, lookup the intro state object. Return 1 if * found and put it in entry if not NULL. Return 0 if not found and entry is * untouched. */ @@ -542,7 +591,7 @@ cache_client_intro_state_lookup(const ed25519_public_key_t *service_pk, return 0; } -/* Note the given failure in state. */ +/** Note the given failure in state. */ static void cache_client_intro_state_note(hs_cache_intro_state_t *state, rend_intro_point_failure_t failure) @@ -564,7 +613,7 @@ cache_client_intro_state_note(hs_cache_intro_state_t *state, } } -/* For the given service identity key service_pk and an introduction +/** For the given service identity key service_pk and an introduction * authentication key auth_key, add an entry in the client intro state cache * If no entry exists for the service, it will create one. If state is non * NULL, it will point to the new intro state entry. */ @@ -598,7 +647,7 @@ cache_client_intro_state_add(const ed25519_public_key_t *service_pk, } } -/* Remove every intro point state entry from cache that has been created +/** Remove every intro point state entry from cache that has been created * before or at the cutoff. */ static void cache_client_intro_state_clean(time_t cutoff, @@ -615,7 +664,7 @@ cache_client_intro_state_clean(time_t cutoff, } DIGEST256MAP_FOREACH_END; } -/* Return true iff no intro points are in this cache. */ +/** Return true iff no intro points are in this cache. */ static int cache_client_intro_state_is_empty(const hs_cache_client_intro_state_t *cache) { @@ -636,9 +685,25 @@ cache_store_as_client(hs_cache_client_descriptor_t *client_desc) tor_assert(client_desc); /* Check if we already have a descriptor from this HS in cache. If we do, - * check if this descriptor is newer than the cached one */ + * check if this descriptor is newer than the cached one only if we have a + * decoded descriptor. We do keep non-decoded descriptor that requires + * client authorization. */ cache_entry = lookup_v3_desc_as_client(client_desc->key.pubkey); if (cache_entry != NULL) { + /* If the current or the new cache entry don't have a decrypted descriptor + * (missing client authorization), we always replace the current one with + * the new one. Reason is that we can't inspect the revision counter + * within the plaintext data so we blindly replace. */ + if (!entry_has_decrypted_descriptor(cache_entry) || + !entry_has_decrypted_descriptor(client_desc)) { + remove_v3_desc_as_client(cache_entry); + cache_client_desc_free(cache_entry); + goto store; + } + + /* From this point on, we know that the decrypted descriptor is in the + * current entry and new object thus safe to access. */ + /* If we have an entry in our cache that has a revision counter greater * than the one we just fetched, discard the one we fetched. */ if (cache_entry->desc->plaintext_data.revision_counter > @@ -658,6 +723,7 @@ cache_store_as_client(hs_cache_client_descriptor_t *client_desc) cache_client_desc_free(cache_entry); } + store: /* Store descriptor in cache */ store_v3_desc_as_client(client_desc); @@ -665,7 +731,7 @@ cache_store_as_client(hs_cache_client_descriptor_t *client_desc) return 0; } -/* Return true iff the cached client descriptor at <b>cached_desc</b has +/** Return true iff the cached client descriptor at <b>cached_desc</b> has * expired. */ static int cached_client_descriptor_has_expired(time_t now, @@ -690,7 +756,7 @@ cached_client_descriptor_has_expired(time_t now, return 0; } -/* clean the client cache using now as the current time. Return the total size +/** clean the client cache using now as the current time. Return the total size * of removed bytes from the cache. */ static size_t cache_clean_v3_as_client(time_t now) @@ -713,6 +779,15 @@ cache_clean_v3_as_client(time_t now) MAP_DEL_CURRENT(key); entry_size = cache_get_client_entry_size(entry); bytes_removed += entry_size; + + /* We just removed an old descriptor. We need to close all intro circuits + * if the descriptor is decrypted so we don't have leftovers that can be + * selected while lacking a descriptor. Circuits are selected by intro + * authentication key thus we need the descriptor. We leave the rendezvous + * circuits opened because they could be in use. */ + if (entry_has_decrypted_descriptor(entry)) { + hs_client_close_intro_circuits_from_desc(entry->desc); + } /* Entry is not in the cache anymore, destroy it. */ cache_client_desc_free(entry); /* Update our OOM. We didn't use the remove() function because we are in @@ -750,7 +825,9 @@ hs_cache_lookup_encoded_as_client(const ed25519_public_key_t *key) } /** Public API: Given the HS ed25519 identity public key in <b>key</b>, return - * its HS descriptor if it's stored in our cache, or NULL if not. */ + * its HS descriptor if it's stored in our cache, or NULL if not or if the + * descriptor was never decrypted. The later can happen if we are waiting for + * client authorization to be added. */ const hs_descriptor_t * hs_cache_lookup_as_client(const ed25519_public_key_t *key) { @@ -759,27 +836,41 @@ hs_cache_lookup_as_client(const ed25519_public_key_t *key) tor_assert(key); cached_desc = lookup_v3_desc_as_client(key->pubkey); - if (cached_desc) { - tor_assert(cached_desc->desc); + if (cached_desc && entry_has_decrypted_descriptor(cached_desc)) { return cached_desc->desc; } return NULL; } -/** Public API: Given an encoded descriptor, store it in the client HS - * cache. Return -1 on error, 0 on success .*/ -int +/** Public API: Given an encoded descriptor, store it in the client HS cache. + * Return a decode status which changes how we handle the SOCKS connection + * depending on its value: + * + * HS_DESC_DECODE_OK: Returned on success. Descriptor was properly decoded + * and is now stored. + * + * HS_DESC_DECODE_NEED_CLIENT_AUTH: Client authorization is needed but the + * descriptor was still stored. + * + * HS_DESC_DECODE_BAD_CLIENT_AUTH: Client authorization for this descriptor + * was not usable but the descriptor was + * still stored. + * + * Any other codes means indicate where the error occured and the descriptor + * was not stored. */ +hs_desc_decode_status_t hs_cache_store_as_client(const char *desc_str, const ed25519_public_key_t *identity_pk) { + hs_desc_decode_status_t ret; hs_cache_client_descriptor_t *client_desc = NULL; tor_assert(desc_str); tor_assert(identity_pk); /* Create client cache descriptor object */ - client_desc = cache_client_desc_new(desc_str, identity_pk); + client_desc = cache_client_desc_new(desc_str, identity_pk, &ret); if (!client_desc) { log_warn(LD_GENERAL, "HSDesc parsing failed!"); log_debug(LD_GENERAL, "Failed to parse HSDesc: %s.", escaped(desc_str)); @@ -788,17 +879,54 @@ hs_cache_store_as_client(const char *desc_str, /* Push it to the cache */ if (cache_store_as_client(client_desc) < 0) { + ret = HS_DESC_DECODE_GENERIC_ERROR; goto err; } - return 0; + return ret; err: cache_client_desc_free(client_desc); - return -1; + return ret; } -/* Clean all client caches using the current time now. */ +/** Remove and free a client cache descriptor entry for the given onion + * service ed25519 public key. If the descriptor is decoded, the intro + * circuits are closed if any. + * + * This does nothing if no descriptor exists for the given key. */ +void +hs_cache_remove_as_client(const ed25519_public_key_t *key) +{ + hs_cache_client_descriptor_t *cached_desc = NULL; + + tor_assert(key); + + cached_desc = lookup_v3_desc_as_client(key->pubkey); + if (!cached_desc) { + return; + } + /* If we have a decrypted/decoded descriptor, attempt to close its + * introduction circuit(s). We shouldn't have circuit(s) without a + * descriptor else it will lead to a failure. */ + if (entry_has_decrypted_descriptor(cached_desc)) { + hs_client_close_intro_circuits_from_desc(cached_desc->desc); + } + /* Remove and free. */ + remove_v3_desc_as_client(cached_desc); + cache_client_desc_free(cached_desc); + + /* Logging. */ + { + char key_b64[BASE64_DIGEST256_LEN + 1]; + digest256_to_base64(key_b64, (const char *) key); + log_info(LD_REND, "Onion service v3 descriptor '%s' removed " + "from client cache", + safe_str_client(key_b64)); + } +} + +/** Clean all client caches using the current time now. */ void hs_cache_clean_as_client(time_t now) { @@ -809,7 +937,7 @@ hs_cache_clean_as_client(time_t now) cache_clean_v3_as_client(now); } -/* Purge the client descriptor cache. */ +/** Purge the client descriptor cache. */ void hs_cache_purge_as_client(void) { @@ -826,7 +954,7 @@ hs_cache_purge_as_client(void) log_info(LD_REND, "Hidden service client descriptor cache purged."); } -/* For a given service identity public key and an introduction authentication +/** For a given service identity public key and an introduction authentication * key, note the given failure in the client intro state cache. */ void hs_cache_client_intro_state_note(const ed25519_public_key_t *service_pk, @@ -848,7 +976,7 @@ hs_cache_client_intro_state_note(const ed25519_public_key_t *service_pk, cache_client_intro_state_note(entry, failure); } -/* For a given service identity public key and an introduction authentication +/** For a given service identity public key and an introduction authentication * key, return true iff it is present in the failure cache. */ const hs_cache_intro_state_t * hs_cache_client_intro_state_find(const ed25519_public_key_t *service_pk, @@ -859,7 +987,7 @@ hs_cache_client_intro_state_find(const ed25519_public_key_t *service_pk, return state; } -/* Cleanup the client introduction state cache. */ +/** Cleanup the client introduction state cache. */ void hs_cache_client_intro_state_clean(time_t now) { @@ -879,7 +1007,7 @@ hs_cache_client_intro_state_clean(time_t now) } DIGEST256MAP_FOREACH_END; } -/* Purge the client introduction state cache. */ +/** Purge the client introduction state cache. */ void hs_cache_client_intro_state_purge(void) { @@ -893,9 +1021,41 @@ hs_cache_client_intro_state_purge(void) "cache purged."); } +/* This is called when new client authorization was added to the global state. + * It attemps to decode the descriptor of the given service identity key. + * + * Return true if decoding was successful else false. */ +bool +hs_cache_client_new_auth_parse(const ed25519_public_key_t *service_pk) +{ + bool ret = false; + hs_cache_client_descriptor_t *cached_desc = NULL; + + tor_assert(service_pk); + + if (!hs_cache_v3_client) { + return false; + } + + cached_desc = lookup_v3_desc_as_client(service_pk->pubkey); + if (cached_desc == NULL || entry_has_decrypted_descriptor(cached_desc)) { + /* No entry for that service or the descriptor is already decoded. */ + goto end; + } + + /* Attempt a decode. If we are successful, inform the caller. */ + if (hs_client_decode_descriptor(cached_desc->encoded_desc, service_pk, + &cached_desc->desc) == HS_DESC_DECODE_OK) { + ret = true; + } + + end: + return ret; +} + /**************** Generics *********************************/ -/* Do a round of OOM cleanup on all directory caches. Return the amount of +/** Do a round of OOM cleanup on all directory caches. Return the amount of * removed bytes. It is possible that the returned value is lower than * min_remove_bytes if the caches get emptied out so the caller should be * aware of this. */ @@ -949,7 +1109,7 @@ hs_cache_handle_oom(time_t now, size_t min_remove_bytes) return bytes_removed; } -/* Return the maximum size of a v3 HS descriptor. */ +/** Return the maximum size of a v3 HS descriptor. */ unsigned int hs_cache_get_max_descriptor_size(void) { @@ -958,7 +1118,7 @@ hs_cache_get_max_descriptor_size(void) HS_DESC_MAX_LEN, 1, INT32_MAX); } -/* Initialize the hidden service cache subsystem. */ +/** Initialize the hidden service cache subsystem. */ void hs_cache_init(void) { @@ -973,7 +1133,7 @@ hs_cache_init(void) hs_cache_client_intro_state = digest256map_new(); } -/* Cleanup the hidden service cache subsystem. */ +/** Cleanup the hidden service cache subsystem. */ void hs_cache_free_all(void) { |