/* * omemo.c * vim: expandtab:ts=4:sts=4:sw=4 * * Copyright (C) 2019 Paul Fariello * Copyright (C) 2019 - 2022 Michael Vetter * * This file is part of Profanity. * * Profanity is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * Profanity is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with Profanity. If not, see . * * In addition, as a special exception, the copyright holders give permission to * link the code of portions of this program with the OpenSSL library under * certain conditions as described in each individual source file, and * distribute linked combinations including the two. * * You must obey the GNU General Public License in all respects for all of the * code used other than OpenSSL. If you modify file(s) with this exception, you * may extend this exception to your version of the file(s), but you are not * obligated to do so. If you do not wish to do so, delete this exception * statement from your version. If you delete this exception statement from all * source files in the program, then also delete it here. * */ #include "config.h" #include #include #include #include #include #include #include #include #include #include #include #include "config/account.h" #include "config/files.h" #include "config/preferences.h" #include "log.h" #include "omemo/crypto.h" #include "omemo/omemo.h" #include "omemo/store.h" #include "ui/ui.h" #include "ui/window_list.h" #include "xmpp/connection.h" #include "xmpp/muc.h" #include "xmpp/omemo.h" #include "xmpp/roster_list.h" #include "xmpp/xmpp.h" #define AESGCM_URL_NONCE_LEN (2 * OMEMO_AESGCM_NONCE_LENGTH) #define AESGCM_URL_KEY_LEN (2 * OMEMO_AESGCM_KEY_LENGTH) static gboolean loaded; static void _generate_pre_keys(int count); static void _generate_signed_pre_key(void); static gboolean _load_identity(void); static void _load_trust(void); static void _load_sessions(void); static void _load_known_devices(void); static void _lock(void* user_data); static void _unlock(void* user_data); static void _omemo_log(int level, const char* message, size_t len, void* user_data); static gboolean _handle_own_device_list(const char* const jid, GList* device_list); static gboolean _handle_device_list_start_session(const char* const jid, GList* device_list); static char* _omemo_fingerprint(ec_public_key* identity, gboolean formatted); static unsigned char* _omemo_fingerprint_decode(const char* const fingerprint, size_t* len); static char* _omemo_unformat_fingerprint(const char* const fingerprint_formatted); static void _cache_device_identity(const char* const jid, uint32_t device_id, ec_public_key* identity); static void _g_hash_table_free(GHashTable* hash_table); static void _acquire_sender_devices_list(void); typedef gboolean (*OmemoDeviceListHandler)(const char* const jid, GList* device_list); struct omemo_context_t { pthread_mutexattr_t attr; pthread_mutex_t lock; signal_context* signal; uint32_t device_id; GHashTable* device_list; GHashTable* device_list_handler; ratchet_identity_key_pair* identity_key_pair; uint32_t registration_id; uint32_t signed_pre_key_id; signal_protocol_store_context* store; GHashTable* session_store; GHashTable* pre_key_store; GHashTable* signed_pre_key_store; identity_key_store_t identity_key_store; GString* identity_filename; GKeyFile* identity_keyfile; GString* trust_filename; GKeyFile* trust_keyfile; GString* sessions_filename; GKeyFile* sessions_keyfile; GHashTable* known_devices; GString* known_devices_filename; GKeyFile* known_devices_keyfile; GHashTable* fingerprint_ac; }; static omemo_context omemo_ctx; void omemo_init(void) { log_info("[OMEMO] initialising"); if (omemo_crypto_init() != 0) { cons_show("Error initializing OMEMO crypto: gcry_check_version() failed"); } pthread_mutexattr_init(&omemo_ctx.attr); pthread_mutexattr_settype(&omemo_ctx.attr, PTHREAD_MUTEX_RECURSIVE); pthread_mutex_init(&omemo_ctx.lock, &omemo_ctx.attr); omemo_ctx.fingerprint_ac = g_hash_table_new_full(g_str_hash, g_str_equal, free, (GDestroyNotify)autocomplete_free); } void omemo_close(void) { if (omemo_ctx.fingerprint_ac) { g_hash_table_destroy(omemo_ctx.fingerprint_ac); omemo_ctx.fingerprint_ac = NULL; } } void omemo_on_connect(ProfAccount* account) { GError* error = NULL; if (signal_context_create(&omemo_ctx.signal, &omemo_ctx) != 0) { cons_show("Error initializing OMEMO context"); return; } if (signal_context_set_log_function(omemo_ctx.signal, _omemo_log) != 0) { cons_show("Error initializing OMEMO log"); } signal_crypto_provider crypto_provider = { .random_func = omemo_random_func, .hmac_sha256_init_func = omemo_hmac_sha256_init_func, .hmac_sha256_update_func = omemo_hmac_sha256_update_func, .hmac_sha256_final_func = omemo_hmac_sha256_final_func, .hmac_sha256_cleanup_func = omemo_hmac_sha256_cleanup_func, .sha512_digest_init_func = omemo_sha512_digest_init_func, .sha512_digest_update_func = omemo_sha512_digest_update_func, .sha512_digest_final_func = omemo_sha512_digest_final_func, .sha512_digest_cleanup_func = omemo_sha512_digest_cleanup_func, .encrypt_func = omemo_encrypt_func, .decrypt_func = omemo_decrypt_func, .user_data = NULL }; if (signal_context_set_crypto_provider(omemo_ctx.signal, &crypto_provider) != 0) { cons_show("Error initializing OMEMO crypto: unable to set crypto provider"); return; } signal_context_set_locking_functions(omemo_ctx.signal, _lock, _unlock); signal_protocol_store_context_create(&omemo_ctx.store, omemo_ctx.signal); omemo_ctx.session_store = session_store_new(); signal_protocol_session_store session_store = { .load_session_func = load_session, .get_sub_device_sessions_func = get_sub_device_sessions, .store_session_func = store_session, .contains_session_func = contains_session, .delete_session_func = delete_session, .delete_all_sessions_func = delete_all_sessions, .destroy_func = NULL, .user_data = omemo_ctx.session_store }; signal_protocol_store_context_set_session_store(omemo_ctx.store, &session_store); omemo_ctx.pre_key_store = pre_key_store_new(); signal_protocol_pre_key_store pre_key_store = { .load_pre_key = load_pre_key, .store_pre_key = store_pre_key, .contains_pre_key = contains_pre_key, .remove_pre_key = remove_pre_key, .destroy_func = NULL, .user_data = omemo_ctx.pre_key_store }; signal_protocol_store_context_set_pre_key_store(omemo_ctx.store, &pre_key_store); omemo_ctx.signed_pre_key_store = signed_pre_key_store_new(); signal_protocol_signed_pre_key_store signed_pre_key_store = { .load_signed_pre_key = load_signed_pre_key, .store_signed_pre_key = store_signed_pre_key, .contains_signed_pre_key = contains_signed_pre_key, .remove_signed_pre_key = remove_signed_pre_key, .destroy_func = NULL, .user_data = omemo_ctx.signed_pre_key_store }; signal_protocol_store_context_set_signed_pre_key_store(omemo_ctx.store, &signed_pre_key_store); identity_key_store_new(&omemo_ctx.identity_key_store); signal_protocol_identity_key_store identity_key_store = { .get_identity_key_pair = get_identity_key_pair, .get_local_registration_id = get_local_registration_id, .save_identity = save_identity, .is_trusted_identity = is_trusted_identity, .destroy_func = NULL, .user_data = &omemo_ctx.identity_key_store }; signal_protocol_store_context_set_identity_key_store(omemo_ctx.store, &identity_key_store); loaded = FALSE; omemo_ctx.device_list = g_hash_table_new_full(g_str_hash, g_str_equal, free, (GDestroyNotify)g_list_free); omemo_ctx.device_list_handler = g_hash_table_new_full(g_str_hash, g_str_equal, free, NULL); omemo_ctx.known_devices = g_hash_table_new_full(g_str_hash, g_str_equal, free, (GDestroyNotify)_g_hash_table_free); gchar* omemo_dir = files_file_in_account_data_path(DIR_OMEMO, account->jid, NULL); if (!omemo_dir) { log_error("[OMEMO] failed creating directory"); return; } omemo_ctx.identity_filename = g_string_new(omemo_dir); g_string_append(omemo_ctx.identity_filename, "/identity.txt"); omemo_ctx.trust_filename = g_string_new(omemo_dir); g_string_append(omemo_ctx.trust_filename, "/trust.txt"); omemo_ctx.sessions_filename = g_string_new(omemo_dir); g_string_append(omemo_ctx.sessions_filename, "/sessions.txt"); omemo_ctx.known_devices_filename = g_string_new(omemo_dir); g_string_append(omemo_ctx.known_devices_filename, "/known_devices.txt"); g_free(omemo_dir); omemo_devicelist_subscribe(); omemo_ctx.identity_keyfile = g_key_file_new(); omemo_ctx.trust_keyfile = g_key_file_new(); omemo_ctx.sessions_keyfile = g_key_file_new(); omemo_ctx.known_devices_keyfile = g_key_file_new(); if (g_key_file_load_from_file(omemo_ctx.identity_keyfile, omemo_ctx.identity_filename->str, G_KEY_FILE_KEEP_COMMENTS, &error)) { if (!_load_identity()) { return; } } else if (error->code != G_FILE_ERROR_NOENT) { log_warning("[OMEMO] error loading identity from: %s, %s", omemo_ctx.identity_filename->str, error->message); g_error_free(error); return; } error = NULL; if (g_key_file_load_from_file(omemo_ctx.trust_keyfile, omemo_ctx.trust_filename->str, G_KEY_FILE_KEEP_COMMENTS, &error)) { _load_trust(); } else if (error->code != G_FILE_ERROR_NOENT) { log_warning("[OMEMO] error loading trust from: %s, %s", omemo_ctx.trust_filename->str, error->message); g_error_free(error); } else { log_warning("[OMEMO] no such file: %s", omemo_ctx.trust_filename->str); g_error_free(error); } error = NULL; if (g_key_file_load_from_file(omemo_ctx.sessions_keyfile, omemo_ctx.sessions_filename->str, G_KEY_FILE_KEEP_COMMENTS, &error)) { _load_sessions(); } else if (error->code != G_FILE_ERROR_NOENT) { log_warning("[OMEMO] error loading sessions from: %s, %s", omemo_ctx.sessions_filename->str, error->message); g_error_free(error); } else { log_warning("[OMEMO] no such file: %s", omemo_ctx.trust_filename->str); g_error_free(error); } error = NULL; if (g_key_file_load_from_file(omemo_ctx.known_devices_keyfile, omemo_ctx.known_devices_filename->str, G_KEY_FILE_KEEP_COMMENTS, &error)) { _load_known_devices(); } else if (error->code != G_FILE_ERROR_NOENT) { log_warning("[OMEMO] error loading known devices from: %s, %s", omemo_ctx.known_devices_filename->str, error->message); g_error_free(error); } else { log_warning("[OMEMO] no such file: %s", omemo_ctx.trust_filename->str); g_error_free(error); } } void omemo_on_disconnect(void) { if (!loaded) { return; } _g_hash_table_free(omemo_ctx.signed_pre_key_store); _g_hash_table_free(omemo_ctx.pre_key_store); _g_hash_table_free(omemo_ctx.device_list_handler); g_string_free(omemo_ctx.identity_filename, TRUE); g_key_file_free(omemo_ctx.identity_keyfile); g_string_free(omemo_ctx.trust_filename, TRUE); g_key_file_free(omemo_ctx.trust_keyfile); g_string_free(omemo_ctx.sessions_filename, TRUE); g_key_file_free(omemo_ctx.sessions_keyfile); _g_hash_table_free(omemo_ctx.session_store); g_string_free(omemo_ctx.known_devices_filename, TRUE); g_key_file_free(omemo_ctx.known_devices_keyfile); } void omemo_generate_crypto_materials(ProfAccount* account) { if (loaded) { return; } log_info("Generate long term OMEMO cryptography materials"); /* Device ID */ gcry_randomize(&omemo_ctx.device_id, 4, GCRY_VERY_STRONG_RANDOM); omemo_ctx.device_id &= 0x7fffffff; g_key_file_set_uint64(omemo_ctx.identity_keyfile, OMEMO_STORE_GROUP_IDENTITY, OMEMO_STORE_KEY_DEVICE_ID, omemo_ctx.device_id); log_info("[OMEMO] device id: %d", omemo_ctx.device_id); /* Identity key */ signal_protocol_key_helper_generate_identity_key_pair(&omemo_ctx.identity_key_pair, omemo_ctx.signal); ec_public_key_serialize(&omemo_ctx.identity_key_store.public, ratchet_identity_key_pair_get_public(omemo_ctx.identity_key_pair)); char* identity_key_public = g_base64_encode(signal_buffer_data(omemo_ctx.identity_key_store.public), signal_buffer_len(omemo_ctx.identity_key_store.public)); g_key_file_set_string(omemo_ctx.identity_keyfile, OMEMO_STORE_GROUP_IDENTITY, OMEMO_STORE_KEY_IDENTITY_KEY_PUBLIC, identity_key_public); g_free(identity_key_public); ec_private_key_serialize(&omemo_ctx.identity_key_store.private, ratchet_identity_key_pair_get_private(omemo_ctx.identity_key_pair)); char* identity_key_private = g_base64_encode(signal_buffer_data(omemo_ctx.identity_key_store.private), signal_buffer_len(omemo_ctx.identity_key_store.private)); g_key_file_set_string(omemo_ctx.identity_keyfile, OMEMO_STORE_GROUP_IDENTITY, OMEMO_STORE_KEY_IDENTITY_KEY_PRIVATE, identity_key_private); g_free(identity_key_private); /* Registration ID */ signal_protocol_key_helper_generate_registration_id(&omemo_ctx.registration_id, 0, omemo_ctx.signal); g_key_file_set_uint64(omemo_ctx.identity_keyfile, OMEMO_STORE_GROUP_IDENTITY, OMEMO_STORE_KEY_REGISTRATION_ID, omemo_ctx.registration_id); /* Pre keys */ _generate_pre_keys(100); /* Signed pre key */ _generate_signed_pre_key(); omemo_identity_keyfile_save(); loaded = TRUE; omemo_publish_crypto_materials(); omemo_start_sessions(); } void omemo_publish_crypto_materials(void) { log_debug("[OMEMO] publish crypto materials"); if (loaded != TRUE) { cons_show("OMEMO: cannot publish crypto materials before they are generated"); log_error("[OMEMO] cannot publish crypto materials before they are generated"); return; } omemo_bundle_publish(true); } static void _acquire_sender_devices_list(void) { char* barejid = connection_get_barejid(); g_hash_table_insert(omemo_ctx.device_list_handler, strdup(barejid), _handle_own_device_list); omemo_devicelist_request(barejid); free(barejid); } void omemo_start_sessions(void) { // before any session may be started, a list on // available sender devices must be acquired log_debug("[OMEMO] Acquiring sender devices list"); _acquire_sender_devices_list(); GSList* contacts = roster_get_contacts(ROSTER_ORD_NAME); if (contacts) { GSList* curr; for (curr = contacts; curr != NULL; curr = g_slist_next(curr)) { PContact contact = curr->data; const char* jid = p_contact_barejid(contact); omemo_start_session(jid); } g_slist_free(contacts); } } void omemo_start_session(const char* const barejid) { if (omemo_loaded()) { log_debug("[OMEMO] start session with %s", barejid); GList* device_list = g_hash_table_lookup(omemo_ctx.device_list, barejid); if (!device_list) { log_debug("[OMEMO] missing device list for %s", barejid); // Own devices are handled by _handle_own_device_list // We won't add _handle_device_list_start_session for ourself char* mybarejid = connection_get_barejid(); if (g_strcmp0(mybarejid, barejid) != 0) { g_hash_table_insert(omemo_ctx.device_list_handler, strdup(barejid), _handle_device_list_start_session); } free(mybarejid); omemo_devicelist_request(barejid); return; } GList* device_id; for (device_id = device_list; device_id != NULL; device_id = device_id->next) { omemo_bundle_request(barejid, GPOINTER_TO_INT(device_id->data), omemo_start_device_session_handle_bundle, free, strdup(barejid)); } } } void omemo_start_muc_sessions(const char* const roomjid) { GList* members = muc_members(roomjid); GList* iter; for (iter = members; iter != NULL; iter = iter->next) { Jid* jid = jid_create(iter->data); omemo_start_session(jid->barejid); jid_destroy(jid); } g_list_free(members); } gboolean omemo_loaded(void) { return loaded; } uint32_t omemo_device_id(void) { return omemo_ctx.device_id; } void omemo_identity_key(unsigned char** output, size_t* length) { signal_buffer* buffer = NULL; ec_public_key_serialize(&buffer, ratchet_identity_key_pair_get_public(omemo_ctx.identity_key_pair)); *length = signal_buffer_len(buffer); *output = malloc(*length); memcpy(*output, signal_buffer_data(buffer), *length); signal_buffer_free(buffer); } void omemo_signed_prekey(unsigned char** output, size_t* length) { session_signed_pre_key* signed_pre_key; signal_buffer* buffer = NULL; if (signal_protocol_signed_pre_key_load_key(omemo_ctx.store, &signed_pre_key, omemo_ctx.signed_pre_key_id) != SG_SUCCESS) { *output = NULL; *length = 0; return; } ec_public_key_serialize(&buffer, ec_key_pair_get_public(session_signed_pre_key_get_key_pair(signed_pre_key))); SIGNAL_UNREF(signed_pre_key); *length = signal_buffer_len(buffer); *output = malloc(*length); memcpy(*output, signal_buffer_data(buffer), *length); signal_buffer_free(buffer); } void omemo_signed_prekey_signature(unsigned char** output, size_t* length) { session_signed_pre_key* signed_pre_key; if (signal_protocol_signed_pre_key_load_key(omemo_ctx.store, &signed_pre_key, omemo_ctx.signed_pre_key_id) != SG_SUCCESS) { *output = NULL; *length = 0; return; } *length = session_signed_pre_key_get_signature_len(signed_pre_key); *output = malloc(*length); memcpy(*output, session_signed_pre_key_get_signature(signed_pre_key), *length); SIGNAL_UNREF(signed_pre_key); } void omemo_prekeys(GList** prekeys, GList** ids, GList** lengths) { GHashTableIter iter; gpointer id; g_hash_table_iter_init(&iter, omemo_ctx.pre_key_store); while (g_hash_table_iter_next(&iter, &id, NULL)) { session_pre_key* pre_key; int ret; ret = signal_protocol_pre_key_load_key(omemo_ctx.store, &pre_key, GPOINTER_TO_INT(id)); if (ret != SG_SUCCESS) { continue; } signal_buffer* public_key; ec_public_key_serialize(&public_key, ec_key_pair_get_public(session_pre_key_get_key_pair(pre_key))); SIGNAL_UNREF(pre_key); size_t length = signal_buffer_len(public_key); unsigned char* prekey_value = malloc(length); memcpy(prekey_value, signal_buffer_data(public_key), length); signal_buffer_free(public_key); *prekeys = g_list_append(*prekeys, prekey_value); *ids = g_list_append(*ids, GINT_TO_POINTER(id)); *lengths = g_list_append(*lengths, GINT_TO_POINTER(length)); } } void omemo_set_device_list(const char* const from, GList* device_list) { log_debug("[OMEMO] Setting device list for %s", from); Jid* jid; if (from) { jid = jid_create(from); } else { jid = jid_create(connection_get_fulljid()); } g_hash_table_insert(omemo_ctx.device_list, strdup(jid->barejid), device_list); OmemoDeviceListHandler handler = g_hash_table_lookup(omemo_ctx.device_list_handler, jid->barejid); if (handler) { gboolean keep = handler(jid->barejid, device_list); if (!keep) { g_hash_table_remove(omemo_ctx.device_list_handler, jid->barejid); } } else { log_debug("[OMEMO] No Device List Handler for %s", from); } // OMEMO trustmode ToFu if (g_strcmp0(prefs_get_string(PREF_OMEMO_TRUST_MODE), "firstusage") == 0) { log_debug("[OMEMO] Checking firstusage state for %s", jid->barejid); GHashTable* trusted = g_hash_table_lookup(omemo_ctx.identity_key_store.trusted, jid->barejid); if (trusted) { if (g_hash_table_size(trusted) > 0) { log_debug("[OMEMO] Found trusted device for %s - skip firstusage", jid->barejid); return; } } else { if (device_list) { cons_show("OMEMO: No trusted devices found for %s", jid->barejid); GList* device_id; for (device_id = device_list; device_id != NULL; device_id = device_id->next) { GHashTable* known_identities = g_hash_table_lookup(omemo_ctx.known_devices, jid->barejid); if (known_identities) { GList* fp = NULL; for (fp = g_hash_table_get_keys(known_identities); fp != NULL; fp = fp->next) { if (device_id->data == g_hash_table_lookup(known_identities, fp->data)) { cons_show("OMEMO: Adding firstusage trust for %s device %d - Fingerprint %s", jid->barejid, device_id->data, omemo_format_fingerprint(fp->data)); omemo_trust(jid->barejid, omemo_format_fingerprint(fp->data)); } } } } } } } jid_destroy(jid); } GKeyFile* omemo_identity_keyfile(void) { return omemo_ctx.identity_keyfile; } void omemo_identity_keyfile_save(void) { GError* error = NULL; if (!g_key_file_save_to_file(omemo_ctx.identity_keyfile, omemo_ctx.identity_filename->str, &error)) { log_error("[OMEMO] error saving identity to: %s, %s", omemo_ctx.identity_filename->str, error->message); } } GKeyFile* omemo_trust_keyfile(void) { return omemo_ctx.trust_keyfile; } void omemo_trust_keyfile_save(void) { GError* error = NULL; if (!g_key_file_save_to_file(omemo_ctx.trust_keyfile, omemo_ctx.trust_filename->str, &error)) { log_error("[OMEMO] error saving trust to: %s, %s", omemo_ctx.trust_filename->str, error->message); } } GKeyFile* omemo_sessions_keyfile(void) { return omemo_ctx.sessions_keyfile; } void omemo_sessions_keyfile_save(void) { GError* error = NULL; if (!g_key_file_save_to_file(omemo_ctx.sessions_keyfile, omemo_ctx.sessions_filename->str, &error)) { log_error("[OMEMO] error saving sessions to: %s, %s", omemo_ctx.sessions_filename->str, error->message); } } void omemo_known_devices_keyfile_save(void) { GError* error = NULL; if (!g_key_file_save_to_file(omemo_ctx.known_devices_keyfile, omemo_ctx.known_devices_filename->str, &error)) { log_error("[OMEMO] error saving known devices to: %s, %s", omemo_ctx.known_devices_filename->str, error->message); } } void omemo_start_device_session(const char* const jid, uint32_t device_id, GList* prekeys, uint32_t signed_prekey_id, const unsigned char* const signed_prekey_raw, size_t signed_prekey_len, const unsigned char* const signature, size_t signature_len, const unsigned char* const identity_key_raw, size_t identity_key_len) { log_debug("[OMEMO] Starting device session for %s with device %d", jid, device_id); signal_protocol_address address = { .name = jid, .name_len = strlen(jid), .device_id = device_id, }; ec_public_key* identity_key; curve_decode_point(&identity_key, identity_key_raw, identity_key_len, omemo_ctx.signal); _cache_device_identity(jid, device_id, identity_key); gboolean trusted = is_trusted_identity(&address, (uint8_t*)identity_key_raw, identity_key_len, &omemo_ctx.identity_key_store); log_debug("[OMEMO] Trust %s (%d): %d", jid, device_id, trusted); if ((g_strcmp0(prefs_get_string(PREF_OMEMO_TRUST_MODE), "blind") == 0) && !trusted) { char* fp = _omemo_fingerprint(identity_key, TRUE); cons_show("Blind trust for %s device %d (%s)", jid, device_id, fp); omemo_trust(jid, fp); free(fp); trusted = TRUE; } if (!trusted) { log_debug("[OMEMO] We don't trust device %d for %s\n", device_id, jid); goto out; } if (!contains_session(&address, omemo_ctx.session_store)) { log_debug("[OMEMO] There is no Session for %s ( %d) ,... building session.", address.name, address.device_id); int res; session_pre_key_bundle* bundle; signal_protocol_address* address; address = malloc(sizeof(signal_protocol_address)); address->name = strdup(jid); address->name_len = strlen(jid); address->device_id = device_id; session_builder* builder; res = session_builder_create(&builder, omemo_ctx.store, address, omemo_ctx.signal); if (res != 0) { log_error("[OMEMO] cannot create session builder for %s device %d", jid, device_id); goto out; } int prekey_index; gcry_randomize(&prekey_index, sizeof(int), GCRY_STRONG_RANDOM); prekey_index %= g_list_length(prekeys); omemo_key_t* prekey = g_list_nth_data(prekeys, prekey_index); ec_public_key* prekey_public; curve_decode_point(&prekey_public, prekey->data, prekey->length, omemo_ctx.signal); ec_public_key* signed_prekey; curve_decode_point(&signed_prekey, signed_prekey_raw, signed_prekey_len, omemo_ctx.signal); res = session_pre_key_bundle_create(&bundle, 0, device_id, prekey->id, prekey_public, signed_prekey_id, signed_prekey, signature, signature_len, identity_key); if (res != 0) { log_error("[OMEMO] cannot create pre key bundle for %s device %d", jid, device_id); goto out; } res = session_builder_process_pre_key_bundle(builder, bundle); if (res != 0) { log_error("[OMEMO] cannot process pre key bundle for %s device %d", jid, device_id); goto out; } log_debug("[OMEMO] create session with %s device %d", jid, device_id); } else { log_debug("[OMEMO] session with %s device %d exists", jid, device_id); } out: SIGNAL_UNREF(identity_key); } char* omemo_on_message_send(ProfWin* win, const char* const message, gboolean request_receipt, gboolean muc, const char* const replace_id) { char* id = NULL; int res; Jid* jid = jid_create(connection_get_fulljid()); GList* keys = NULL; unsigned char* key; unsigned char* iv; unsigned char* ciphertext; unsigned char* tag; unsigned char* key_tag; size_t ciphertext_len, tag_len; ciphertext_len = strlen(message); ciphertext = malloc(ciphertext_len); tag_len = AES128_GCM_TAG_LENGTH; tag = gcry_malloc_secure(tag_len); key_tag = gcry_malloc_secure(AES128_GCM_KEY_LENGTH + AES128_GCM_TAG_LENGTH); key = gcry_random_bytes_secure(AES128_GCM_KEY_LENGTH, GCRY_VERY_STRONG_RANDOM); iv = gcry_random_bytes_secure(AES128_GCM_IV_LENGTH, GCRY_VERY_STRONG_RANDOM); res = aes128gcm_encrypt(ciphertext, &ciphertext_len, tag, &tag_len, (const unsigned char* const)message, strlen(message), iv, key); if (res != 0) { log_error("[OMEMO][SEND] cannot encrypt message"); goto out; } memcpy(key_tag, key, AES128_GCM_KEY_LENGTH); memcpy(key_tag + AES128_GCM_KEY_LENGTH, tag, AES128_GCM_TAG_LENGTH); // List of barejids of the recipients of this message GList* recipients = NULL; if (muc) { ProfMucWin* mucwin = (ProfMucWin*)win; assert(mucwin->memcheck == PROFMUCWIN_MEMCHECK); GList* members = muc_members(mucwin->roomjid); GList* iter; for (iter = members; iter != NULL; iter = iter->next) { Jid* jid = jid_create(iter->data); recipients = g_list_append(recipients, strdup(jid->barejid)); jid_destroy(jid); } g_list_free(members); } else { ProfChatWin* chatwin = (ProfChatWin*)win; assert(chatwin->memcheck == PROFCHATWIN_MEMCHECK); recipients = g_list_append(recipients, strdup(chatwin->barejid)); } GList* device_ids_iter; omemo_ctx.identity_key_store.recv = false; // Encrypt keys for the recipients GList* recipients_iter; for (recipients_iter = recipients; recipients_iter != NULL; recipients_iter = recipients_iter->next) { GList* recipient_device_id = NULL; recipient_device_id = g_hash_table_lookup(omemo_ctx.device_list, recipients_iter->data); if (!recipient_device_id) { log_warning("[OMEMO][SEND] cannot find device ids for %s", recipients_iter->data); win_println(win, THEME_ERROR, "!", "Can't find a OMEMO device id for %s.\n", recipients_iter->data); continue; } for (device_ids_iter = recipient_device_id; device_ids_iter != NULL; device_ids_iter = device_ids_iter->next) { int res; ciphertext_message* ciphertext; session_cipher* cipher; signal_protocol_address address = { .name = recipients_iter->data, .name_len = strlen(recipients_iter->data), .device_id = GPOINTER_TO_INT(device_ids_iter->data) }; // Don't encrypt for this device (according to // ). // Yourself as recipients in case of MUC char* mybarejid = connection_get_barejid(); if (!g_strcmp0(mybarejid, recipients_iter->data)) { if (GPOINTER_TO_INT(device_ids_iter->data) == omemo_ctx.device_id) { free(mybarejid); log_debug("[OMEMO][SEND] Skipping %d (my device) ", GPOINTER_TO_INT(device_ids_iter->data)); continue; } } free(mybarejid); log_debug("[OMEMO][SEND] recipients with device id %d for %s", GPOINTER_TO_INT(device_ids_iter->data), recipients_iter->data); res = session_cipher_create(&cipher, omemo_ctx.store, &address, omemo_ctx.signal); if (res != SG_SUCCESS) { log_error("[OMEMO][SEND] cannot create cipher for %s device id %d - code: %d", address.name, address.device_id, res); continue; } res = session_cipher_encrypt(cipher, key_tag, AES128_GCM_KEY_LENGTH + AES128_GCM_TAG_LENGTH, &ciphertext); session_cipher_free(cipher); if (res != SG_SUCCESS) { log_info("[OMEMO][SEND] cannot encrypt key for %s device id %d - code: %d", address.name, address.device_id, res); continue; } signal_buffer* buffer = ciphertext_message_get_serialized(ciphertext); omemo_key_t* key = malloc(sizeof(omemo_key_t)); key->length = signal_buffer_len(buffer); key->data = malloc(key->length); memcpy(key->data, signal_buffer_data(buffer), key->length); key->device_id = GPOINTER_TO_INT(device_ids_iter->data); key->prekey = ciphertext_message_get_type(ciphertext) == CIPHERTEXT_PREKEY_TYPE; keys = g_list_append(keys, key); SIGNAL_UNREF(ciphertext); } } g_list_free_full(recipients, free); // Don't send the message if no key could be encrypted. // (Since none of the recipients would be able to read the message.) if (keys == NULL) { win_println(win, THEME_ERROR, "!", "This message cannot be decrypted for any recipient.\n" "You should trust your recipients' device fingerprint(s) using \"/omemo fingerprint trust FINGERPRINT\".\n" "It could also be that the key bundle of the recipient(s) have not been received. " "In this case, you could try \"omemo end\", \"omemo start\", and send the message again."); goto out; } // Encrypt keys for the sender if (!muc) { GList* sender_device_id = g_hash_table_lookup(omemo_ctx.device_list, jid->barejid); for (device_ids_iter = sender_device_id; device_ids_iter != NULL; device_ids_iter = device_ids_iter->next) { int res; ciphertext_message* ciphertext; session_cipher* cipher; signal_protocol_address address = { .name = jid->barejid, .name_len = strlen(jid->barejid), .device_id = GPOINTER_TO_INT(device_ids_iter->data) }; log_debug("[OMEMO][SEND][Sender] Sending to device %d for %s ", address.device_id, address.name); // Don't encrypt for this device (according to // ). if (address.device_id == omemo_ctx.device_id) { continue; } res = session_cipher_create(&cipher, omemo_ctx.store, &address, omemo_ctx.signal); if (res != 0) { log_info("[OMEMO][SEND][Sender] cannot create cipher for %s device id %d", address.name, address.device_id); continue; } res = session_cipher_encrypt(cipher, key_tag, AES128_GCM_KEY_LENGTH + AES128_GCM_TAG_LENGTH, &ciphertext); session_cipher_free(cipher); if (res != 0) { log_info("[OMEMO][SEND][Sender] cannot encrypt key for %s device id %d", address.name, address.device_id); continue; } signal_buffer* buffer = ciphertext_message_get_serialized(ciphertext); omemo_key_t* key = malloc(sizeof(omemo_key_t)); key->length = signal_buffer_len(buffer); key->data = malloc(key->length); memcpy(key->data, signal_buffer_data(buffer), key->length); key->device_id = GPOINTER_TO_INT(device_ids_iter->data); key->prekey = ciphertext_message_get_type(ciphertext) == CIPHERTEXT_PREKEY_TYPE; keys = g_list_append(keys, key); SIGNAL_UNREF(ciphertext); } } // Send the message if (muc) { ProfMucWin* mucwin = (ProfMucWin*)win; assert(mucwin->memcheck == PROFMUCWIN_MEMCHECK); id = message_send_chat_omemo(mucwin->roomjid, omemo_ctx.device_id, keys, iv, AES128_GCM_IV_LENGTH, ciphertext, ciphertext_len, request_receipt, TRUE, replace_id); } else { ProfChatWin* chatwin = (ProfChatWin*)win; assert(chatwin->memcheck == PROFCHATWIN_MEMCHECK); id = message_send_chat_omemo(chatwin->barejid, omemo_ctx.device_id, keys, iv, AES128_GCM_IV_LENGTH, ciphertext, ciphertext_len, request_receipt, FALSE, replace_id); } out: jid_destroy(jid); g_list_free_full(keys, (GDestroyNotify)omemo_key_free); free(ciphertext); gcry_free(key); gcry_free(iv); gcry_free(tag); gcry_free(key_tag); return id; } char* omemo_on_message_recv(const char* const from_jid, uint32_t sid, const unsigned char* const iv, size_t iv_len, GList* keys, const unsigned char* const payload, size_t payload_len, gboolean muc, gboolean* trusted) { unsigned char* plaintext = NULL; Jid* sender = NULL; Jid* from = jid_create(from_jid); if (!from) { log_error("[OMEMO][RECV] Invalid jid %s", from_jid); goto out; } int res; GList* key_iter; omemo_key_t* key = NULL; for (key_iter = keys; key_iter != NULL; key_iter = key_iter->next) { if (((omemo_key_t*)key_iter->data)->device_id == omemo_ctx.device_id) { key = key_iter->data; break; } } if (!key) { log_warning("[OMEMO][RECV] received a message with no corresponding key"); goto out; } if (muc) { GList* roster = muc_roster(from->barejid); GList* iter; for (iter = roster; iter != NULL; iter = iter->next) { Occupant* occupant = (Occupant*)iter->data; if (g_strcmp0(occupant->nick, from->resourcepart) == 0) { sender = jid_create(occupant->jid); break; } } g_list_free(roster); if (!sender) { log_warning("[OMEMO][RECV] cannot find MUC message sender fulljid"); goto out; } } else { sender = jid_create(from->barejid); } session_cipher* cipher; signal_buffer* plaintext_key; signal_protocol_address address = { .name = sender->barejid, .name_len = strlen(sender->barejid), .device_id = sid }; res = session_cipher_create(&cipher, omemo_ctx.store, &address, omemo_ctx.signal); if (res != 0) { log_error("[OMEMO][RECV] cannot create session cipher"); goto out; } if (key->prekey) { log_debug("[OMEMO][RECV] decrypting message with prekey"); pre_key_signal_message* message; ec_public_key* their_identity_key; signal_buffer* identity_buffer = NULL; omemo_ctx.identity_key_store.recv = true; pre_key_signal_message_deserialize(&message, key->data, key->length, omemo_ctx.signal); their_identity_key = pre_key_signal_message_get_identity_key(message); res = session_cipher_decrypt_pre_key_signal_message(cipher, message, NULL, &plaintext_key); omemo_ctx.identity_key_store.recv = false; /* Perform a real check of the identity */ ec_public_key_serialize(&identity_buffer, their_identity_key); *trusted = is_trusted_identity(&address, signal_buffer_data(identity_buffer), signal_buffer_len(identity_buffer), &omemo_ctx.identity_key_store); /* Replace used pre_key in bundle */ uint32_t pre_key_id = pre_key_signal_message_get_pre_key_id(message); ec_key_pair* ec_pair; session_pre_key* new_pre_key; curve_generate_key_pair(omemo_ctx.signal, &ec_pair); session_pre_key_create(&new_pre_key, pre_key_id, ec_pair); signal_protocol_pre_key_store_key(omemo_ctx.store, new_pre_key); SIGNAL_UNREF(new_pre_key); SIGNAL_UNREF(message); SIGNAL_UNREF(ec_pair); omemo_bundle_publish(true); if (res == 0) { /* Start a new session */ log_debug("[OMEMO][RECV] Res is 0 => omemo_bundle_request"); omemo_bundle_request(sender->barejid, sid, omemo_start_device_session_handle_bundle, free, strdup(sender->barejid)); } } else { log_debug("[OMEMO][RECV] decrypting message with existing session"); signal_message* message = NULL; res = signal_message_deserialize(&message, key->data, key->length, omemo_ctx.signal); if (res < 0) { log_error("[OMEMO][RECV] cannot deserialize message"); } else { res = session_cipher_decrypt_signal_message(cipher, message, NULL, &plaintext_key); *trusted = true; SIGNAL_UNREF(message); } } session_cipher_free(cipher); if (res != 0) { log_error("[OMEMO][RECV] cannot decrypt message key"); goto out; } if (signal_buffer_len(plaintext_key) != AES128_GCM_KEY_LENGTH + AES128_GCM_TAG_LENGTH) { log_error("[OMEMO][RECV] invalid key length"); signal_buffer_free(plaintext_key); goto out; } size_t plaintext_len = payload_len; plaintext = malloc(plaintext_len + 1); res = aes128gcm_decrypt(plaintext, &plaintext_len, payload, payload_len, iv, iv_len, signal_buffer_data(plaintext_key), signal_buffer_data(plaintext_key) + AES128_GCM_KEY_LENGTH); signal_buffer_free(plaintext_key); if (res != 0) { log_error("[OMEMO][RECV] cannot decrypt message: %s", gcry_strerror(res)); free(plaintext); plaintext = NULL; goto out; } plaintext[plaintext_len] = '\0'; out: jid_destroy(from); jid_destroy(sender); return (char*)plaintext; } char* omemo_format_fingerprint(const char* const fingerprint) { char* output = malloc(strlen(fingerprint) + strlen(fingerprint) / 8); int i, j; for (i = 0, j = 0; i < strlen(fingerprint); i++) { if (i > 0 && i % 8 == 0) { output[j++] = '-'; } output[j++] = fingerprint[i]; } output[j] = '\0'; return output; } static char* _omemo_unformat_fingerprint(const char* const fingerprint_formatted) { /* Unformat fingerprint */ char* fingerprint = malloc(strlen(fingerprint_formatted)); int i; int j; for (i = 0, j = 0; fingerprint_formatted[i] != '\0'; i++) { if (!g_ascii_isxdigit(fingerprint_formatted[i])) { continue; } fingerprint[j++] = fingerprint_formatted[i]; } fingerprint[j] = '\0'; return fingerprint; } char* omemo_own_fingerprint(gboolean formatted) { ec_public_key* identity = ratchet_identity_key_pair_get_public(omemo_ctx.identity_key_pair); return _omemo_fingerprint(identity, formatted); } GList* omemo_known_device_identities(const char* const jid) { GHashTable* known_identities = g_hash_table_lookup(omemo_ctx.known_devices, jid); if (!known_identities) { return NULL; } return g_hash_table_get_keys(known_identities); } gboolean omemo_is_trusted_identity(const char* const jid, const char* const fingerprint) { GHashTable* known_identities = g_hash_table_lookup(omemo_ctx.known_devices, jid); if (!known_identities) { return FALSE; } void* device_id = g_hash_table_lookup(known_identities, fingerprint); if (!device_id) { return FALSE; } signal_protocol_address address = { .name = jid, .name_len = strlen(jid), .device_id = GPOINTER_TO_INT(device_id), }; size_t fingerprint_len; unsigned char* fingerprint_raw = _omemo_fingerprint_decode(fingerprint, &fingerprint_len); unsigned char djb_type[] = { '\x05' }; signal_buffer* buffer = signal_buffer_create(djb_type, 1); buffer = signal_buffer_append(buffer, fingerprint_raw, fingerprint_len); gboolean trusted = is_trusted_identity(&address, signal_buffer_data(buffer), signal_buffer_len(buffer), &omemo_ctx.identity_key_store); log_debug("[OMEMO] Device trusted %s (%d): %d", jid, GPOINTER_TO_INT(device_id), trusted); free(fingerprint_raw); signal_buffer_free(buffer); return trusted; } static char* _omemo_fingerprint(ec_public_key* identity, gboolean formatted) { int i; signal_buffer* identity_public_key; ec_public_key_serialize(&identity_public_key, identity); size_t identity_public_key_len = signal_buffer_len(identity_public_key); unsigned char* identity_public_key_data = signal_buffer_data(identity_public_key); /* Skip first byte corresponding to signal DJB_TYPE */ identity_public_key_len--; identity_public_key_data = &identity_public_key_data[1]; char* fingerprint = malloc(identity_public_key_len * 2 + 1); for (i = 0; i < identity_public_key_len; i++) { fingerprint[i * 2] = (identity_public_key_data[i] & 0xf0) >> 4; fingerprint[i * 2] += '0'; if (fingerprint[i * 2] > '9') { fingerprint[i * 2] += 0x27; } fingerprint[(i * 2) + 1] = identity_public_key_data[i] & 0x0f; fingerprint[(i * 2) + 1] += '0'; if (fingerprint[(i * 2) + 1] > '9') { fingerprint[(i * 2) + 1] += 0x27; } } fingerprint[i * 2] = '\0'; signal_buffer_free(identity_public_key); if (!formatted) { return fingerprint; } else { char* formatted_fingerprint = omemo_format_fingerprint(fingerprint); free(fingerprint); return formatted_fingerprint; } } static unsigned char* _omemo_fingerprint_decode(const char* const fingerprint, size_t* len) { unsigned char* output = malloc(strlen(fingerprint) / 2 + 1); int i; int j; for (i = 0, j = 0; i < strlen(fingerprint);) { if (!g_ascii_isxdigit(fingerprint[i])) { i++; continue; } output[j] = g_ascii_xdigit_value(fingerprint[i++]) << 4; output[j] |= g_ascii_xdigit_value(fingerprint[i++]); j++; } *len = j; return output; } void omemo_trust(const char* const jid, const char* const fingerprint_formatted) { size_t len; GHashTable* known_identities = g_hash_table_lookup(omemo_ctx.known_devices, jid); if (!known_identities) { log_warning("[OMEMO] cannot trust unknown device: %s", fingerprint_formatted); cons_show("Cannot trust unknown device: %s", fingerprint_formatted); return; } char* fingerprint = _omemo_unformat_fingerprint(fingerprint_formatted); uint32_t device_id = GPOINTER_TO_INT(g_hash_table_lookup(known_identities, fingerprint)); free(fingerprint); if (!device_id) { log_warning("[OMEMO] cannot trust unknown device: %s", fingerprint_formatted); cons_show("Cannot trust unknown device: %s", fingerprint_formatted); return; } /* TODO should not hardcode DJB_TYPE here * should instead store identity key in known_identities along with * device_id */ signal_protocol_address address = { .name = jid, .name_len = strlen(jid), .device_id = device_id, }; unsigned char* fingerprint_raw = _omemo_fingerprint_decode(fingerprint_formatted, &len); unsigned char djb_type[] = { '\x05' }; signal_buffer* buffer = signal_buffer_create(djb_type, 1); buffer = signal_buffer_append(buffer, fingerprint_raw, len); save_identity(&address, signal_buffer_data(buffer), signal_buffer_len(buffer), &omemo_ctx.identity_key_store); free(fingerprint_raw); signal_buffer_free(buffer); omemo_bundle_request(jid, device_id, omemo_start_device_session_handle_bundle, free, strdup(jid)); } void omemo_untrust(const char* const jid, const char* const fingerprint_formatted) { size_t len; unsigned char* identity = _omemo_fingerprint_decode(fingerprint_formatted, &len); GHashTableIter iter; gpointer key, value; GHashTable* trusted = g_hash_table_lookup(omemo_ctx.identity_key_store.trusted, jid); if (!trusted) { free(identity); return; } g_hash_table_iter_init(&iter, trusted); while (g_hash_table_iter_next(&iter, &key, &value)) { signal_buffer* buffer = value; unsigned char* original = signal_buffer_data(buffer); /* Skip DJB_TYPE byte */ original++; if ((signal_buffer_len(buffer) - 1) == len && memcmp(original, identity, len) == 0) { g_hash_table_remove(trusted, key); } } free(identity); char* fingerprint = _omemo_unformat_fingerprint(fingerprint_formatted); /* Remove existing session */ GHashTable* known_identities = g_hash_table_lookup(omemo_ctx.known_devices, jid); if (!known_identities) { log_error("[OMEMO] cannot find known device while untrusting a fingerprint"); goto out; } uint32_t device_id = GPOINTER_TO_INT(g_hash_table_lookup(known_identities, fingerprint)); if (!device_id) { log_error("[OMEMO] cannot find device id while untrusting a fingerprint"); goto out; } signal_protocol_address address = { .name = jid, .name_len = strlen(jid), .device_id = device_id }; delete_session(&address, omemo_ctx.session_store); /* Remove from keyfile */ char* device_id_str = g_strdup_printf("%d", device_id); g_key_file_remove_key(omemo_ctx.trust_keyfile, jid, device_id_str, NULL); g_free(device_id_str); omemo_trust_keyfile_save(); out: free(fingerprint); } static void _lock(void* user_data) { omemo_context* ctx = (omemo_context*)user_data; pthread_mutex_lock(&ctx->lock); } static void _unlock(void* user_data) { omemo_context* ctx = (omemo_context*)user_data; pthread_mutex_unlock(&ctx->lock); } static void _omemo_log(int level, const char* message, size_t len, void* user_data) { switch (level) { case SG_LOG_ERROR: log_error("[OMEMO][SIGNAL] %s", message); break; case SG_LOG_WARNING: log_warning("[OMEMO][SIGNAL] %s", message); break; case SG_LOG_NOTICE: case SG_LOG_INFO: log_debug("[OMEMO][SIGNAL] %s", message); break; case SG_LOG_DEBUG: log_debug("[OMEMO][SIGNAL] %s", message); break; } } static gboolean _handle_own_device_list(const char* const jid, GList* device_list) { // We didn't find the own device id -> publish if (!g_list_find(device_list, GINT_TO_POINTER(omemo_ctx.device_id))) { cons_show("Could not find own OMEMO device ID. Going to publish own device ID: %d", GINT_TO_POINTER(omemo_ctx.device_id)); log_debug("[OMEMO] No device ID for our device. Publishing device list"); device_list = g_list_copy(device_list); device_list = g_list_append(device_list, GINT_TO_POINTER(omemo_ctx.device_id)); g_hash_table_insert(omemo_ctx.device_list, strdup(jid), device_list); omemo_devicelist_publish(device_list); } log_debug("[OMEMO] Request OMEMO Bundles for our devices"); GList* device_id; for (device_id = device_list; device_id != NULL; device_id = device_id->next) { omemo_bundle_request(jid, GPOINTER_TO_INT(device_id->data), omemo_start_device_session_handle_bundle, free, strdup(jid)); } return TRUE; } static gboolean _handle_device_list_start_session(const char* const jid, GList* device_list) { log_debug("[OMEMO] Start session for %s - device_list", jid); omemo_start_session(jid); return FALSE; } void omemo_key_free(omemo_key_t* key) { if (key == NULL) { return; } free(key->data); free(key); } char* omemo_fingerprint_autocomplete(const char* const search_str, gboolean previous, void* context) { Autocomplete ac = g_hash_table_lookup(omemo_ctx.fingerprint_ac, context); if (ac != NULL) { return autocomplete_complete(ac, search_str, FALSE, previous); } else { return NULL; } } void omemo_fingerprint_autocomplete_reset(void) { gpointer value; GHashTableIter iter; g_hash_table_iter_init(&iter, omemo_ctx.fingerprint_ac); while (g_hash_table_iter_next(&iter, NULL, &value)) { Autocomplete ac = value; autocomplete_reset(ac); } } gboolean omemo_automatic_start(const char* const recipient) { gboolean result = FALSE; char* account_name = session_get_account_name(); ProfAccount* account = accounts_get_account(account_name); prof_omemopolicy_t policy; if (account->omemo_policy) { // check default account setting if (g_strcmp0(account->omemo_policy, "manual") == 0) { policy = PROF_OMEMOPOLICY_MANUAL; } if (g_strcmp0(account->omemo_policy, "opportunistic") == 0) { policy = PROF_OMEMOPOLICY_AUTOMATIC; } if (g_strcmp0(account->omemo_policy, "always") == 0) { policy = PROF_OMEMOPOLICY_ALWAYS; } } else { // check global setting char* pref_omemo_policy = prefs_get_string(PREF_OMEMO_POLICY); // pref defaults to manual policy = PROF_OMEMOPOLICY_AUTOMATIC; if (strcmp(pref_omemo_policy, "manual") == 0) { policy = PROF_OMEMOPOLICY_MANUAL; } else if (strcmp(pref_omemo_policy, "always") == 0) { policy = PROF_OMEMOPOLICY_ALWAYS; } g_free(pref_omemo_policy); } switch (policy) { case PROF_OMEMOPOLICY_MANUAL: result = FALSE; break; case PROF_OMEMOPOLICY_AUTOMATIC: if (g_list_find_custom(account->omemo_enabled, recipient, (GCompareFunc)g_strcmp0)) { result = TRUE; } else if (g_list_find_custom(account->omemo_disabled, recipient, (GCompareFunc)g_strcmp0)) { result = FALSE; } else { result = FALSE; } break; case PROF_OMEMOPOLICY_ALWAYS: if (g_list_find_custom(account->omemo_disabled, recipient, (GCompareFunc)g_strcmp0)) { result = FALSE; } else { result = TRUE; } break; } account_free(account); return result; } static gboolean _load_identity(void) { GError* error = NULL; log_info("[OMEMO] Loading OMEMO identity"); /* Device ID */ error = NULL; omemo_ctx.device_id = g_key_file_get_uint64(omemo_ctx.identity_keyfile, OMEMO_STORE_GROUP_IDENTITY, OMEMO_STORE_KEY_DEVICE_ID, &error); if (error != NULL) { log_error("[OMEMO] cannot load device id: %s", error->message); return FALSE; } log_debug("[OMEMO] device id: %d", omemo_ctx.device_id); /* Registration ID */ error = NULL; omemo_ctx.registration_id = g_key_file_get_uint64(omemo_ctx.identity_keyfile, OMEMO_STORE_GROUP_IDENTITY, OMEMO_STORE_KEY_REGISTRATION_ID, &error); if (error != NULL) { log_error("[OMEMO] cannot load registration id: %s", error->message); return FALSE; } /* Identity key */ error = NULL; char* identity_key_public_b64 = g_key_file_get_string(omemo_ctx.identity_keyfile, OMEMO_STORE_GROUP_IDENTITY, OMEMO_STORE_KEY_IDENTITY_KEY_PUBLIC, &error); if (!identity_key_public_b64) { log_error("[OMEMO] cannot load identity public key: %s", error->message); return FALSE; } size_t identity_key_public_len; unsigned char* identity_key_public = g_base64_decode(identity_key_public_b64, &identity_key_public_len); g_free(identity_key_public_b64); omemo_ctx.identity_key_store.public = signal_buffer_create(identity_key_public, identity_key_public_len); error = NULL; char* identity_key_private_b64 = g_key_file_get_string(omemo_ctx.identity_keyfile, OMEMO_STORE_GROUP_IDENTITY, OMEMO_STORE_KEY_IDENTITY_KEY_PRIVATE, &error); if (!identity_key_private_b64) { log_error("[OMEMO] cannot load identity private key: %s", error->message); return FALSE; } size_t identity_key_private_len; unsigned char* identity_key_private = g_base64_decode(identity_key_private_b64, &identity_key_private_len); g_free(identity_key_private_b64); omemo_ctx.identity_key_store.private = signal_buffer_create(identity_key_private, identity_key_private_len); ec_public_key* public_key; curve_decode_point(&public_key, identity_key_public, identity_key_public_len, omemo_ctx.signal); ec_private_key* private_key; curve_decode_private_point(&private_key, identity_key_private, identity_key_private_len, omemo_ctx.signal); ratchet_identity_key_pair_create(&omemo_ctx.identity_key_pair, public_key, private_key); g_free(identity_key_public); g_free(identity_key_private); char** keys = NULL; int i; /* Pre keys */ i = 0; keys = g_key_file_get_keys(omemo_ctx.identity_keyfile, OMEMO_STORE_GROUP_PREKEYS, NULL, NULL); if (keys) { for (i = 0; keys[i] != NULL; i++) { char* pre_key_b64 = g_key_file_get_string(omemo_ctx.identity_keyfile, OMEMO_STORE_GROUP_PREKEYS, keys[i], NULL); size_t pre_key_len; unsigned char* pre_key = g_base64_decode(pre_key_b64, &pre_key_len); g_free(pre_key_b64); signal_buffer* buffer = signal_buffer_create(pre_key, pre_key_len); g_free(pre_key); g_hash_table_insert(omemo_ctx.pre_key_store, GINT_TO_POINTER(strtoul(keys[i], NULL, 10)), buffer); } g_strfreev(keys); } /* Ensure we have at least 100 pre keys */ if (i < 100) { _generate_pre_keys(100 - i); } /* Signed pre keys */ i = 0; keys = g_key_file_get_keys(omemo_ctx.identity_keyfile, OMEMO_STORE_GROUP_SIGNED_PREKEYS, NULL, NULL); if (keys) { for (i = 0; keys[i] != NULL; i++) { char* signed_pre_key_b64 = g_key_file_get_string(omemo_ctx.identity_keyfile, OMEMO_STORE_GROUP_SIGNED_PREKEYS, keys[i], NULL); size_t signed_pre_key_len; unsigned char* signed_pre_key = g_base64_decode(signed_pre_key_b64, &signed_pre_key_len); g_free(signed_pre_key_b64); signal_buffer* buffer = signal_buffer_create(signed_pre_key, signed_pre_key_len); g_free(signed_pre_key); g_hash_table_insert(omemo_ctx.signed_pre_key_store, GINT_TO_POINTER(strtoul(keys[i], NULL, 10)), buffer); omemo_ctx.signed_pre_key_id = strtoul(keys[i], NULL, 10); } g_strfreev(keys); } if (i == 0) { _generate_signed_pre_key(); } loaded = TRUE; omemo_identity_keyfile_save(); omemo_start_sessions(); return TRUE; } static void _load_trust(void) { char** keys = NULL; char** groups = g_key_file_get_groups(omemo_ctx.trust_keyfile, NULL); if (groups) { int i; for (i = 0; groups[i] != NULL; i++) { GHashTable* trusted; trusted = g_hash_table_lookup(omemo_ctx.identity_key_store.trusted, groups[i]); if (!trusted) { trusted = g_hash_table_new_full(g_direct_hash, g_direct_equal, NULL, (GDestroyNotify)signal_buffer_free); g_hash_table_insert(omemo_ctx.identity_key_store.trusted, strdup(groups[i]), trusted); } keys = g_key_file_get_keys(omemo_ctx.trust_keyfile, groups[i], NULL, NULL); int j; for (j = 0; keys[j] != NULL; j++) { char* key_b64 = g_key_file_get_string(omemo_ctx.trust_keyfile, groups[i], keys[j], NULL); size_t key_len; unsigned char* key = g_base64_decode(key_b64, &key_len); g_free(key_b64); signal_buffer* buffer = signal_buffer_create(key, key_len); g_free(key); uint32_t device_id = strtoul(keys[j], NULL, 10); g_hash_table_insert(trusted, GINT_TO_POINTER(device_id), buffer); } g_strfreev(keys); } g_strfreev(groups); } } static void _load_sessions(void) { int i; char** groups = g_key_file_get_groups(omemo_ctx.sessions_keyfile, NULL); if (groups) { for (i = 0; groups[i] != NULL; i++) { int j; GHashTable* device_store = NULL; device_store = g_hash_table_lookup(omemo_ctx.session_store, groups[i]); if (!device_store) { device_store = g_hash_table_new_full(g_direct_hash, g_direct_equal, NULL, (GDestroyNotify)signal_buffer_free); g_hash_table_insert(omemo_ctx.session_store, strdup(groups[i]), device_store); } char** keys = g_key_file_get_keys(omemo_ctx.sessions_keyfile, groups[i], NULL, NULL); for (j = 0; keys[j] != NULL; j++) { uint32_t id = strtoul(keys[j], NULL, 10); char* record_b64 = g_key_file_get_string(omemo_ctx.sessions_keyfile, groups[i], keys[j], NULL); size_t record_len; unsigned char* record = g_base64_decode(record_b64, &record_len); g_free(record_b64); signal_buffer* buffer = signal_buffer_create(record, record_len); g_free(record); g_hash_table_insert(device_store, GINT_TO_POINTER(id), buffer); } g_strfreev(keys); } g_strfreev(groups); } } static void _load_known_devices(void) { int i; char** groups = g_key_file_get_groups(omemo_ctx.known_devices_keyfile, NULL); if (groups) { for (i = 0; groups[i] != NULL; i++) { int j; GHashTable* known_identities = NULL; known_identities = g_hash_table_lookup(omemo_ctx.known_devices, groups[i]); if (!known_identities) { known_identities = g_hash_table_new_full(g_str_hash, g_str_equal, free, NULL); g_hash_table_insert(omemo_ctx.known_devices, strdup(groups[i]), known_identities); } char** keys = g_key_file_get_keys(omemo_ctx.known_devices_keyfile, groups[i], NULL, NULL); for (j = 0; keys[j] != NULL; j++) { uint32_t device_id = strtoul(keys[j], NULL, 10); char* fingerprint = g_key_file_get_string(omemo_ctx.known_devices_keyfile, groups[i], keys[j], NULL); g_hash_table_insert(known_identities, strdup(fingerprint), GINT_TO_POINTER(device_id)); g_free(fingerprint); } g_strfreev(keys); } g_strfreev(groups); } } static void _cache_device_identity(const char* const jid, uint32_t device_id, ec_public_key* identity) { GHashTable* known_identities = g_hash_table_lookup(omemo_ctx.known_devices, jid); if (!known_identities) { known_identities = g_hash_table_new_full(g_str_hash, g_str_equal, free, NULL); g_hash_table_insert(omemo_ctx.known_devices, strdup(jid), known_identities); } char* fingerprint = _omemo_fingerprint(identity, FALSE); log_debug("[OMEMO] cache identity for %s:%d: %s", jid, device_id, fingerprint); g_hash_table_insert(known_identities, strdup(fingerprint), GINT_TO_POINTER(device_id)); char* device_id_str = g_strdup_printf("%d", device_id); g_key_file_set_string(omemo_ctx.known_devices_keyfile, jid, device_id_str, fingerprint); g_free(device_id_str); omemo_known_devices_keyfile_save(); Autocomplete ac = g_hash_table_lookup(omemo_ctx.fingerprint_ac, jid); if (ac == NULL) { ac = autocomplete_new(); g_hash_table_insert(omemo_ctx.fingerprint_ac, strdup(jid), ac); } char* formatted_fingerprint = omemo_format_fingerprint(fingerprint); autocomplete_add(ac, formatted_fingerprint); free(formatted_fingerprint); free(fingerprint); } static void _g_hash_table_free(GHashTable* hash_table) { g_hash_table_remove_all(hash_table); g_hash_table_unref(hash_table); } static void _generate_pre_keys(int count) { unsigned int start; gcry_randomize(&start, sizeof(unsigned int), GCRY_VERY_STRONG_RANDOM); signal_protocol_key_helper_pre_key_list_node* pre_keys_head; signal_protocol_key_helper_generate_pre_keys(&pre_keys_head, start, count, omemo_ctx.signal); signal_protocol_key_helper_pre_key_list_node* p; for (p = pre_keys_head; p != NULL; p = signal_protocol_key_helper_key_list_next(p)) { session_pre_key* prekey = signal_protocol_key_helper_key_list_element(p); signal_protocol_pre_key_store_key(omemo_ctx.store, prekey); } signal_protocol_key_helper_key_list_free(pre_keys_head); } static void _generate_signed_pre_key(void) { session_signed_pre_key* signed_pre_key; struct timeval tv; gettimeofday(&tv, NULL); unsigned long long timestamp = (unsigned long long)(tv.tv_sec) * 1000 + (unsigned long long)(tv.tv_usec) / 1000; omemo_ctx.signed_pre_key_id = 1; signal_protocol_key_helper_generate_signed_pre_key(&signed_pre_key, omemo_ctx.identity_key_pair, omemo_ctx.signed_pre_key_id, timestamp, omemo_ctx.signal); signal_protocol_signed_pre_key_store_key(omemo_ctx.store, signed_pre_key); SIGNAL_UNREF(signed_pre_key); } void omemo_free(void* a) { gcry_free(a); } char* omemo_encrypt_file(FILE* in, FILE* out, off_t file_size, int* gcry_res) { unsigned char* key = gcry_random_bytes_secure( OMEMO_AESGCM_KEY_LENGTH, GCRY_VERY_STRONG_RANDOM); // Create nonce/IV with random bytes. unsigned char nonce[OMEMO_AESGCM_NONCE_LENGTH]; gcry_create_nonce(nonce, OMEMO_AESGCM_NONCE_LENGTH); char* fragment = aes256gcm_create_secure_fragment(key, nonce); *gcry_res = aes256gcm_crypt_file(in, out, file_size, key, nonce, true); if (*gcry_res != GPG_ERR_NO_ERROR) { gcry_free(fragment); fragment = NULL; } gcry_free(key); return fragment; } void _bytes_from_hex(const char* hex, size_t hex_size, unsigned char* bytes, size_t bytes_size) { const unsigned char ht[] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, // 01234567 0x08, 0x09, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 89:;<=>? 0x00, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x00, // @ABCDEFG }; const size_t ht_size = sizeof(ht); unsigned char b0; unsigned char b1; memset(bytes, 0, bytes_size); for (int i = 0; (i < hex_size) && (i / 2 < bytes_size); i += 2) { b0 = ((unsigned char)hex[i + 0] & 0x1f) ^ 0x10; b1 = ((unsigned char)hex[i + 1] & 0x1f) ^ 0x10; if (b0 <= ht_size && b1 <= ht_size) { bytes[i / 2] = (unsigned char)(ht[b0] << 4) | ht[b1]; } } } gcry_error_t omemo_decrypt_file(FILE* in, FILE* out, off_t file_size, const char* fragment) { char nonce_hex[AESGCM_URL_NONCE_LEN]; char key_hex[AESGCM_URL_KEY_LEN]; const int nonce_pos = 0; const int key_pos = AESGCM_URL_NONCE_LEN; memcpy(nonce_hex, &(fragment[nonce_pos]), AESGCM_URL_NONCE_LEN); memcpy(key_hex, &(fragment[key_pos]), AESGCM_URL_KEY_LEN); unsigned char nonce[OMEMO_AESGCM_NONCE_LENGTH]; unsigned char* key = gcry_malloc_secure(OMEMO_AESGCM_KEY_LENGTH); _bytes_from_hex(nonce_hex, AESGCM_URL_NONCE_LEN, nonce, OMEMO_AESGCM_NONCE_LENGTH); _bytes_from_hex(key_hex, AESGCM_URL_KEY_LEN, key, OMEMO_AESGCM_KEY_LENGTH); gcry_error_t crypt_res; crypt_res = aes256gcm_crypt_file(in, out, file_size, key, nonce, false); gcry_free(key); return crypt_res; } int omemo_parse_aesgcm_url(const char* aesgcm_url, char** https_url, char** fragment) { CURLUcode ret; CURLU* url = curl_url(); // Required to allow for the "aesgcm://" scheme that OMEMO Media Sharing // uses. unsigned int curl_flags = CURLU_NON_SUPPORT_SCHEME; ret = curl_url_set(url, CURLUPART_URL, aesgcm_url, curl_flags); if (ret) { goto out; } ret = curl_url_get(url, CURLUPART_FRAGMENT, fragment, curl_flags); if (ret) { goto out; } if (strlen(*fragment) != AESGCM_URL_NONCE_LEN + AESGCM_URL_KEY_LEN) { ret = 1; goto out; } // Clear fragment from HTTPS URL as it's not required for download. ret = curl_url_set(url, CURLUPART_FRAGMENT, NULL, curl_flags); if (ret) { goto out; } ret = curl_url_set(url, CURLUPART_SCHEME, "https", curl_flags); if (ret) { goto out; } ret = curl_url_get(url, CURLUPART_URL, https_url, curl_flags); if (ret) { goto out; } out: curl_url_cleanup(url); return ret; } /* returns a string in the format `xmpp:?omemo-sid-=` * used for verification over QR codes */ char* omemo_qrcode_str() { char* mybarejid = connection_get_barejid(); char* fingerprint = omemo_own_fingerprint(TRUE); uint32_t sid = omemo_device_id(); char* qrstr = g_strdup_printf("xmpp:%s?omemo-sid-%d=%s", mybarejid, sid, fingerprint); free(mybarejid); free(fingerprint); return qrstr; }