/* * omemo.c * vim: expandtab:ts=4:sts=4:sw=4 * * Copyright (C) 2019 Paul Fariello * * 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 "log.h" #include "xmpp/connection.h" #include "xmpp/form.h" #include "xmpp/iq.h" #include "xmpp/message.h" #include "xmpp/stanza.h" #include "omemo/omemo.h" static int _omemo_receive_devicelist(xmpp_stanza_t* const stanza, void* const userdata); static int _omemo_devicelist_publish_result(xmpp_stanza_t* const stanza, void* const userdata); static int _omemo_devicelist_configure_submit(xmpp_stanza_t* const stanza, void* const userdata); static int _omemo_devicelist_configure_result(xmpp_stanza_t* const stanza, void* const userdata); static int _omemo_bundle_publish_result(xmpp_stanza_t* const stanza, void* const userdata); static int _omemo_bundle_publish_configure(xmpp_stanza_t* const stanza, void* const userdata); static int _omemo_bundle_publish_configure_result(xmpp_stanza_t* const stanza, void* const userdata); void omemo_devicelist_subscribe(void) { message_pubsub_event_handler_add(STANZA_NS_OMEMO_DEVICELIST, _omemo_receive_devicelist, NULL, NULL); caps_add_feature(XMPP_FEATURE_OMEMO_DEVICELIST_NOTIFY); } void omemo_devicelist_publish(GList* device_list) { xmpp_ctx_t* const ctx = connection_get_ctx(); xmpp_stanza_t* iq = stanza_create_omemo_devicelist_publish(ctx, device_list); log_debug("[OMEMO] publish device list"); if (connection_supports(XMPP_FEATURE_PUBSUB_PUBLISH_OPTIONS)) { stanza_attach_publish_options(ctx, iq, "pubsub#access_model", "open"); } else { log_debug("[OMEMO] Cannot publish devicelist: no PUBSUB feature announced"); } iq_id_handler_add(xmpp_stanza_get_id(iq), _omemo_devicelist_publish_result, NULL, NULL); iq_send_stanza(iq); xmpp_stanza_release(iq); } void omemo_devicelist_configure(void) { xmpp_ctx_t* const ctx = connection_get_ctx(); char* id = connection_create_stanza_id(); Jid* jid = jid_create(connection_get_fulljid()); xmpp_stanza_t* iq = stanza_create_pubsub_configure_request(ctx, id, jid->barejid, STANZA_NS_OMEMO_DEVICELIST); iq_id_handler_add(id, _omemo_devicelist_configure_submit, NULL, NULL); iq_send_stanza(iq); xmpp_stanza_release(iq); free(id); jid_destroy(jid); } void omemo_devicelist_request(const char* const jid) { xmpp_ctx_t* const ctx = connection_get_ctx(); char* id = connection_create_stanza_id(); log_debug("[OMEMO] request device list for jid: %s", jid); xmpp_stanza_t* iq = stanza_create_omemo_devicelist_request(ctx, id, jid); iq_id_handler_add(id, _omemo_receive_devicelist, NULL, NULL); iq_send_stanza(iq); free(id); xmpp_stanza_release(iq); } void omemo_bundle_publish(gboolean first) { log_debug("[OMEMO] publish own OMEMO bundle"); xmpp_ctx_t* const ctx = connection_get_ctx(); unsigned char* identity_key = NULL; size_t identity_key_length; unsigned char* signed_prekey = NULL; size_t signed_prekey_length; unsigned char* signed_prekey_signature = NULL; size_t signed_prekey_signature_length; GList *prekeys = NULL, *ids = NULL, *lengths = NULL; omemo_identity_key(&identity_key, &identity_key_length); omemo_signed_prekey(&signed_prekey, &signed_prekey_length); omemo_signed_prekey_signature(&signed_prekey_signature, &signed_prekey_signature_length); omemo_prekeys(&prekeys, &ids, &lengths); char* id = connection_create_stanza_id(); xmpp_stanza_t* iq = stanza_create_omemo_bundle_publish(ctx, id, omemo_device_id(), identity_key, identity_key_length, signed_prekey, signed_prekey_length, signed_prekey_signature, signed_prekey_signature_length, prekeys, ids, lengths); g_list_free_full(prekeys, free); g_list_free(lengths); g_list_free(ids); if (connection_supports(XMPP_FEATURE_PUBSUB_PUBLISH_OPTIONS)) { stanza_attach_publish_options_va(ctx, iq, 4, // 2 * number of key-value pairs "pubsub#persist_items", "true", "pubsub#access_model", "open"); } else { log_debug("[OMEMO] Cannot publish bundle: no PUBSUB feature announced"); } iq_id_handler_add(id, _omemo_bundle_publish_result, NULL, GINT_TO_POINTER(first)); iq_send_stanza(iq); xmpp_stanza_release(iq); free(identity_key); free(signed_prekey); free(signed_prekey_signature); free(id); } void omemo_bundle_request(const char* const jid, uint32_t device_id, ProfIqCallback func, ProfIqFreeCallback free_func, void* userdata) { xmpp_ctx_t* const ctx = connection_get_ctx(); char* id = connection_create_stanza_id(); log_debug("[OMEMO] request omemo bundle (jid: %s, device: %d)", jid, device_id); xmpp_stanza_t* iq = stanza_create_omemo_bundle_request(ctx, id, jid, device_id); iq_id_handler_add(id, func, free_func, userdata); iq_send_stanza(iq); free(id); xmpp_stanza_release(iq); } int omemo_start_device_session_handle_bundle(xmpp_stanza_t* const stanza, void* const userdata) { GList* prekeys_list = NULL; unsigned char* signed_prekey_raw = NULL; unsigned char* signed_prekey_signature_raw = NULL; char* from = NULL; const char* from_attr = xmpp_stanza_get_attribute(stanza, STANZA_ATTR_FROM); log_debug("[OMEMO] omemo_start_device_session_handle_bundle: %s", from_attr); const char* type = xmpp_stanza_get_type(stanza); if (g_strcmp0(type, "error") == 0) { log_error("[OMEMO] Error to get key for a device from : %s", from_attr); } if (!from_attr) { Jid* jid = jid_create(connection_get_fulljid()); from = strdup(jid->barejid); jid_destroy(jid); } else { from = strdup(from_attr); } if (g_strcmp0(from, userdata) != 0) { goto out; } xmpp_stanza_t* pubsub = xmpp_stanza_get_child_by_ns(stanza, STANZA_NS_PUBSUB); if (!pubsub) { goto out; } xmpp_stanza_t* items = xmpp_stanza_get_child_by_name(pubsub, "items"); if (!items) { goto out; } const char* node = xmpp_stanza_get_attribute(items, "node"); char* device_id_str = strstr(node, ":"); if (!device_id_str) { goto out; } uint32_t device_id = strtoul(++device_id_str, NULL, 10); log_debug("[OMEMO] omemo_start_device_session_handle_bundle: %d", device_id); xmpp_stanza_t* item = xmpp_stanza_get_child_by_name(items, "item"); if (!item) { goto out; } xmpp_stanza_t* bundle = xmpp_stanza_get_child_by_ns(item, STANZA_NS_OMEMO); if (!bundle) { goto out; } xmpp_stanza_t* prekeys = xmpp_stanza_get_child_by_name(bundle, "prekeys"); if (!prekeys) { goto out; } xmpp_stanza_t* prekey; for (prekey = xmpp_stanza_get_children(prekeys); prekey != NULL; prekey = xmpp_stanza_get_next(prekey)) { if (g_strcmp0(xmpp_stanza_get_name(prekey), "preKeyPublic") != 0) { continue; } omemo_key_t* key = malloc(sizeof(omemo_key_t)); key->data = NULL; const char* prekey_id_text = xmpp_stanza_get_attribute(prekey, "preKeyId"); if (!prekey_id_text) { omemo_key_free(key); continue; } key->id = strtoul(prekey_id_text, NULL, 10); xmpp_stanza_t* prekey_text = xmpp_stanza_get_children(prekey); if (!prekey_text) { omemo_key_free(key); continue; } char* prekey_b64 = xmpp_stanza_get_text(prekey_text); key->data = g_base64_decode(prekey_b64, &key->length); free(prekey_b64); if (!key->data) { omemo_key_free(key); continue; } key->prekey = TRUE; key->device_id = device_id; prekeys_list = g_list_append(prekeys_list, key); } xmpp_stanza_t* signed_prekey = xmpp_stanza_get_child_by_name(bundle, "signedPreKeyPublic"); if (!signed_prekey) { goto out; } const char* signed_prekey_id_text = xmpp_stanza_get_attribute(signed_prekey, "signedPreKeyId"); if (!signed_prekey_id_text) { goto out; } uint32_t signed_prekey_id = strtoul(signed_prekey_id_text, NULL, 10); xmpp_stanza_t* signed_prekey_text = xmpp_stanza_get_children(signed_prekey); if (!signed_prekey_text) { goto out; } size_t signed_prekey_len; char* signed_prekey_b64 = xmpp_stanza_get_text(signed_prekey_text); signed_prekey_raw = g_base64_decode(signed_prekey_b64, &signed_prekey_len); free(signed_prekey_b64); if (!signed_prekey_raw) { goto out; } xmpp_stanza_t* signed_prekey_signature = xmpp_stanza_get_child_by_name(bundle, "signedPreKeySignature"); if (!signed_prekey_signature) { goto out; } xmpp_stanza_t* signed_prekey_signature_text = xmpp_stanza_get_children(signed_prekey_signature); if (!signed_prekey_signature_text) { goto out; } size_t signed_prekey_signature_len; char* signed_prekey_signature_b64 = xmpp_stanza_get_text(signed_prekey_signature_text); signed_prekey_signature_raw = g_base64_decode(signed_prekey_signature_b64, &signed_prekey_signature_len); free(signed_prekey_signature_b64); if (!signed_prekey_signature_raw) { goto out; } xmpp_stanza_t* identity_key = xmpp_stanza_get_child_by_name(bundle, "identityKey"); if (!identity_key) { goto out; } xmpp_stanza_t* identity_key_text = xmpp_stanza_get_children(identity_key); if (!identity_key_text) { goto out; } size_t identity_key_len; char* identity_key_b64 = xmpp_stanza_get_text(identity_key_text); unsigned char* identity_key_raw = g_base64_decode(identity_key_b64, &identity_key_len); free(identity_key_b64); if (!identity_key_raw) { goto out; } omemo_start_device_session(from, device_id, prekeys_list, signed_prekey_id, signed_prekey_raw, signed_prekey_len, signed_prekey_signature_raw, signed_prekey_signature_len, identity_key_raw, identity_key_len); g_free(identity_key_raw); out: free(from); if (signed_prekey_raw) { g_free(signed_prekey_raw); } if (signed_prekey_signature_raw) { g_free(signed_prekey_signature_raw); } if (prekeys_list) { g_list_free_full(prekeys_list, (GDestroyNotify)omemo_key_free); } return 1; } char* omemo_receive_message(xmpp_stanza_t* const stanza, gboolean* trusted) { char* plaintext = NULL; const char* type = xmpp_stanza_get_type(stanza); GList* keys = NULL; unsigned char* iv_raw = NULL; unsigned char* payload_raw = NULL; char* iv_text = NULL; char* payload_text = NULL; xmpp_stanza_t* encrypted = xmpp_stanza_get_child_by_ns(stanza, STANZA_NS_OMEMO); if (!encrypted) { return NULL; } xmpp_stanza_t* header = xmpp_stanza_get_child_by_name(encrypted, "header"); if (!header) { return NULL; } const char* sid_text = xmpp_stanza_get_attribute(header, "sid"); if (!sid_text) { return NULL; } uint32_t sid = strtoul(sid_text, NULL, 10); xmpp_stanza_t* iv = xmpp_stanza_get_child_by_name(header, "iv"); if (!iv) { return NULL; } iv_text = xmpp_stanza_get_text(iv); if (!iv_text) { return NULL; } size_t iv_len; iv_raw = g_base64_decode(iv_text, &iv_len); if (!iv_raw) { goto out; } xmpp_stanza_t* payload = xmpp_stanza_get_child_by_name(encrypted, "payload"); if (!payload) { goto out; } payload_text = xmpp_stanza_get_text(payload); if (!payload_text) { goto out; } size_t payload_len; payload_raw = g_base64_decode(payload_text, &payload_len); if (!payload_raw) { goto out; } xmpp_stanza_t* key_stanza; for (key_stanza = xmpp_stanza_get_children(header); key_stanza != NULL; key_stanza = xmpp_stanza_get_next(key_stanza)) { if (g_strcmp0(xmpp_stanza_get_name(key_stanza), "key") != 0) { continue; } omemo_key_t* key = malloc(sizeof(omemo_key_t)); char* key_text = xmpp_stanza_get_text(key_stanza); if (!key_text) { goto skip; } const char* rid_text = xmpp_stanza_get_attribute(key_stanza, "rid"); key->device_id = strtoul(rid_text, NULL, 10); if (!key->device_id) { goto skip; } key->data = g_base64_decode(key_text, &key->length); free(key_text); if (!key->data) { goto skip; } key->prekey = g_strcmp0(xmpp_stanza_get_attribute(key_stanza, "prekey"), "true") == 0 || g_strcmp0(xmpp_stanza_get_attribute(key_stanza, "prekey"), "1") == 0; keys = g_list_append(keys, key); continue; skip: free(key); } const char* from = xmpp_stanza_get_from(stanza); plaintext = omemo_on_message_recv(from, sid, iv_raw, iv_len, keys, payload_raw, payload_len, g_strcmp0(type, STANZA_TYPE_GROUPCHAT) == 0, trusted); out: if (keys) { g_list_free_full(keys, (GDestroyNotify)omemo_key_free); } g_free(iv_raw); g_free(payload_raw); g_free(iv_text); g_free(payload_text); return plaintext; } static int _omemo_receive_devicelist(xmpp_stanza_t* const stanza, void* const userdata) { const char* from = xmpp_stanza_get_attribute(stanza, STANZA_ATTR_FROM); const char* type = xmpp_stanza_get_type(stanza); GList* device_list = NULL; if (g_strcmp0(type, STANZA_TYPE_ERROR) == 0) { log_error("[OMEMO] can't get OMEMO device list"); xmpp_stanza_t* error = xmpp_stanza_get_child_by_name(stanza, "error"); if (!error) { log_error("[OMEMO] missing error element in device list response"); return 1; } const char* code = xmpp_stanza_get_attribute(error, "code"); if (g_strcmp0(code, "404") == 0) { goto out; } } xmpp_stanza_t* root = NULL; xmpp_stanza_t* event = xmpp_stanza_get_child_by_ns(stanza, STANZA_NS_PUBSUB_EVENT); if (event) { root = event; } xmpp_stanza_t* pubsub = xmpp_stanza_get_child_by_ns(stanza, STANZA_NS_PUBSUB); if (pubsub) { root = pubsub; } if (!root) { return 1; } xmpp_stanza_t* items = xmpp_stanza_get_child_by_name(root, "items"); if (!items) { return 1; } // Looking for "current" item - if there is no current, take the first item. xmpp_stanza_t* first = NULL; xmpp_stanza_t* current = NULL; xmpp_stanza_t* item = xmpp_stanza_get_children(items); while (item) { if (g_strcmp0(xmpp_stanza_get_name(item), "item") == 0) { first = item; if (g_strcmp0(xmpp_stanza_get_id(item), "current") == 0) { current = item; break; } } item = xmpp_stanza_get_next(item); } if (current) { item = current; } else if (first) { log_warning("[OMEMO] User %s has a non 'current' device item list: %s.", from, xmpp_stanza_get_id(first)); item = first; } else { goto out; } xmpp_stanza_t* list = xmpp_stanza_get_child_by_ns(item, STANZA_NS_OMEMO); if (!list) { return 1; } xmpp_stanza_t* device; for (device = xmpp_stanza_get_children(list); device != NULL; device = xmpp_stanza_get_next(device)) { if (g_strcmp0(xmpp_stanza_get_name(device), "device") != 0) { continue; } const char* id = xmpp_stanza_get_id(device); if (id != NULL) { device_list = g_list_append(device_list, GINT_TO_POINTER(strtoul(id, NULL, 10))); } else { log_error("[OMEMO] received device without ID"); } } out: omemo_set_device_list(from, device_list); return 1; } static int _omemo_devicelist_publish_result(xmpp_stanza_t* const stanza, void* const userdata) { const char* type = xmpp_stanza_get_type(stanza); if (g_strcmp0(type, STANZA_TYPE_ERROR) == 0) { log_error("[OMEMO] Publishing device list failed"); xmpp_stanza_t* error = xmpp_stanza_get_child_by_name(stanza, "error"); if (!error) { log_error("[OMEMO] Missing error element in device list publication result"); return 0; } xmpp_stanza_t* pubsub_error = xmpp_stanza_get_child_by_ns(error, STANZA_NS_PUBSUB_ERROR); if (!pubsub_error) { log_error("[OMEMO] Unknown error while publishing our own device list"); cons_show_error("Unknown error while publishing our own device list"); return 0; } if (g_strcmp0(xmpp_stanza_get_name(pubsub_error), "precondition-not-met") == 0) { static gboolean reconfigured = false; if (!reconfigured) { reconfigured = true; cons_show_error("Unable to publish own OMEMO device list, reconfiguring node"); log_error("[OMEMO] Unable to publish own OMEMO device list, reconfiguring node"); omemo_devicelist_configure(); } else { cons_show_error("Unable to publish own OMEMO device list, previous reconfiguration failed. Giving up."); log_error("[OMEMO] Unable to publish own OMEMO device list, previous reconfiguration failed. Giving up."); } } } return 0; } static int _omemo_devicelist_configure_submit(xmpp_stanza_t* const stanza, void* const userdata) { log_debug("[OMEMO] _omemo_devicelist_configure_submit()"); xmpp_stanza_t* pubsub = xmpp_stanza_get_child_by_name(stanza, "pubsub"); if (!pubsub) { log_error("[OMEMO] The stanza doesn't contain a 'pubsub' child"); return 0; } xmpp_stanza_t* configure = xmpp_stanza_get_child_by_name(pubsub, STANZA_NAME_CONFIGURE); if (!configure) { log_error("[OMEMO] The stanza doesn't contain a 'configure' child"); return 0; } xmpp_stanza_t* x = xmpp_stanza_get_child_by_name(configure, "x"); if (!x) { log_error("[OMEMO] The stanza doesn't contain an 'x' child"); return 0; } DataForm* form = form_create(x); form_set_value(form, "pubsub#access_model", "open"); xmpp_ctx_t* const ctx = connection_get_ctx(); Jid* jid = jid_create(connection_get_fulljid()); char* id = connection_create_stanza_id(); xmpp_stanza_t* iq = stanza_create_pubsub_configure_submit(ctx, id, jid->barejid, STANZA_NS_OMEMO_DEVICELIST, form); iq_id_handler_add(id, _omemo_devicelist_configure_result, NULL, NULL); iq_send_stanza(iq); xmpp_stanza_release(iq); free(id); jid_destroy(jid); return 0; } static int _omemo_devicelist_configure_result(xmpp_stanza_t* const stanza, void* const userdata) { const char* type = xmpp_stanza_get_type(stanza); if (g_strcmp0(type, STANZA_TYPE_ERROR) == 0) { log_error("[OMEMO] cannot configure device list to an open access model: Result error"); return 0; } log_debug("[OMEMO] node configured"); // Try to publish char* barejid = connection_get_barejid(); omemo_devicelist_request(barejid); free(barejid); return 0; } static int _omemo_bundle_publish_result(xmpp_stanza_t* const stanza, void* const userdata) { log_debug("[OMEMO] _omemo_bundle_publish_result()"); const char* type = xmpp_stanza_get_type(stanza); if (g_strcmp0(type, STANZA_TYPE_RESULT) == 0) { log_debug("[OMEMO] bundle published successfully"); return 0; } if (!GPOINTER_TO_INT(userdata)) { log_error("[OMEMO] definitely cannot publish bundle with an open access model"); return 0; } log_debug("[OMEMO] cannot publish bundle with open access model, trying to configure node"); xmpp_ctx_t* const ctx = connection_get_ctx(); Jid* jid = jid_create(connection_get_fulljid()); char* id = connection_create_stanza_id(); char* node = g_strdup_printf("%s:%d", STANZA_NS_OMEMO_BUNDLES, omemo_device_id()); log_debug("[OMEMO] node: %s", node); xmpp_stanza_t* iq = stanza_create_pubsub_configure_request(ctx, id, jid->barejid, node); g_free(node); iq_id_handler_add(id, _omemo_bundle_publish_configure, NULL, userdata); iq_send_stanza(iq); xmpp_stanza_release(iq); free(id); jid_destroy(jid); return 0; } static int _omemo_bundle_publish_configure(xmpp_stanza_t* const stanza, void* const userdata) { log_debug("[OMEMO] _omemo_bundle_publish_configure()"); xmpp_stanza_t* pubsub = xmpp_stanza_get_child_by_name(stanza, "pubsub"); if (!pubsub) { log_error("[OMEMO] The stanza doesn't contain a 'pubsub' child"); return 0; } xmpp_stanza_t* configure = xmpp_stanza_get_child_by_name(pubsub, STANZA_NAME_CONFIGURE); if (!configure) { log_error("[OMEMO] The stanza doesn't contain a 'configure' child"); return 0; } xmpp_stanza_t* x = xmpp_stanza_get_child_by_name(configure, "x"); if (!x) { log_error("[OMEMO] The stanza doesn't contain an 'x' child"); return 0; } DataForm* form = form_create(x); form_set_value(form, "pubsub#access_model", "open"); xmpp_ctx_t* const ctx = connection_get_ctx(); Jid* jid = jid_create(connection_get_fulljid()); char* id = connection_create_stanza_id(); char* node = g_strdup_printf("%s:%d", STANZA_NS_OMEMO_BUNDLES, omemo_device_id()); xmpp_stanza_t* iq = stanza_create_pubsub_configure_submit(ctx, id, jid->barejid, node, form); g_free(node); iq_id_handler_add(id, _omemo_bundle_publish_configure_result, NULL, userdata); iq_send_stanza(iq); xmpp_stanza_release(iq); free(id); jid_destroy(jid); return 0; } static int _omemo_bundle_publish_configure_result(xmpp_stanza_t* const stanza, void* const userdata) { const char* type = xmpp_stanza_get_type(stanza); if (g_strcmp0(type, STANZA_TYPE_ERROR) == 0) { log_error("[OMEMO] cannot configure bundle to an open access model: Result error"); return 0; } log_debug("[OMEMO] node configured"); // Try to publish again omemo_bundle_publish(TRUE); return 0; }