using Gee; using Xmpp; using Xmpp; using Xmpp.Xep; using Signal; namespace Dino.Plugins.Omemo { private const string NS_URI = "eu.siacs.conversations.axolotl"; private const string NODE_DEVICELIST = NS_URI + ".devicelist"; private const string NODE_BUNDLES = NS_URI + ".bundles"; private const string NODE_VERIFICATION = NS_URI + ".verification"; private const int NUM_KEYS_TO_PUBLISH = 100; public class StreamModule : XmppStreamModule { public static Xmpp.ModuleIdentity IDENTITY = new Xmpp.ModuleIdentity(NS_URI, "omemo_module"); private Store store; private ConcurrentSet active_bundle_requests = new ConcurrentSet(); private ConcurrentSet active_devicelist_requests = new ConcurrentSet(); private Map> device_lists = new HashMap>(Jid.hash_bare_func, Jid.equals_bare_func); private Map> ignored_devices = new HashMap>(Jid.hash_bare_func, Jid.equals_bare_func); private ReceivedPipelineListener received_pipeline_listener; public signal void store_created(Store store); public signal void device_list_loaded(Jid jid); public signal void bundle_fetched(Jid jid, int device_id, Bundle bundle); public EncryptState encrypt(MessageStanza message, Jid self_jid) { EncryptState status = new EncryptState(); if (!Plugin.ensure_context()) return status; if (message.to == null) return status; try { if (!device_lists.has_key(self_jid)) return status; status.own_list = true; status.own_devices = device_lists.get(self_jid).size; if (!device_lists.has_key(message.to)) return status; status.other_list = true; status.other_devices = device_lists.get(message.to).size; if (status.own_devices == 0 || status.other_devices == 0) return status; uint8[] key = new uint8[16]; Plugin.get_context().randomize(key); uint8[] iv = new uint8[16]; Plugin.get_context().randomize(iv); uint8[] ciphertext = aes_encrypt(Cipher.AES_GCM_NOPADDING, key, iv, message.body.data); StanzaNode header; StanzaNode encrypted = new StanzaNode.build("encrypted", NS_URI).add_self_xmlns() .put_node(header = new StanzaNode.build("header", NS_URI) .put_attribute("sid", store.local_registration_id.to_string()) .put_node(new StanzaNode.build("iv", NS_URI) .put_node(new StanzaNode.text(Base64.encode(iv))))) .put_node(new StanzaNode.build("payload", NS_URI) .put_node(new StanzaNode.text(Base64.encode(ciphertext)))); Address address = new Address(message.to.bare_jid.to_string(), 0); foreach(int32 device_id in device_lists[message.to]) { if (is_ignored_device(message.to, device_id)) { status.other_lost++; continue; } try { address.device_id = (int) device_id; StanzaNode key_node = create_encrypted_key(key, address); header.put_node(key_node); status.other_success++; } catch (Error e) { if (e.code == ErrorCode.UNKNOWN) status.other_unknown++; else status.other_failure++; } } address.name = self_jid.bare_jid.to_string(); foreach(int32 device_id in device_lists[self_jid]) { if (is_ignored_device(self_jid, device_id)) { status.own_lost++; continue; } if (device_id != store.local_registration_id) { address.device_id = (int) device_id; try { StanzaNode key_node = create_encrypted_key(key, address); header.put_node(key_node); status.own_success++; } catch (Error e) { if (e.code == ErrorCode.UNKNOWN) status.own_unknown++; else status.own_failure++; } } } message.stanza.put_node(encrypted); Xep.ExplicitEncryption.add_encryption_tag_to_message(message, NS_URI, "OMEMO"); message.body = "[This message is OMEMO encrypted]"; status.encrypted = true; } catch (Error e) { if (Plugin.DEBUG) print(@"OMEMO: Signal error while encrypting message: $(e.message)\n"); } return status; } public void untrust_device(Jid jid, int device_id) { if(device_lists.has_key(jid) && device_lists[jid].contains(device_id)) device_lists[jid].remove(device_id); if(store.contains_session(new Address(jid.bare_jid.to_string(), device_id))) store.delete_session(new Address(jid.bare_jid.to_string(), device_id)); } public void trust_device(Jid jid, int device_id) { if(is_ignored_device(jid, device_id)){ ignored_devices[jid].remove(device_id); } if(!device_lists.has_key(jid)) device_lists[jid] = new ArrayList(); if(!device_lists[jid].contains(device_id)) device_lists[jid].add(device_id); } private StanzaNode create_encrypted_key(uint8[] key, Address address) throws GLib.Error { SessionCipher cipher = store.create_session_cipher(address); CiphertextMessage device_key = cipher.encrypt(key); StanzaNode key_node = new StanzaNode.build("key", NS_URI) .put_attribute("rid", address.device_id.to_string()) .put_node(new StanzaNode.text(Base64.encode(device_key.serialized))); if (device_key.type == CiphertextType.PREKEY) key_node.put_attribute("prekey", "true"); return key_node; } public override void attach(XmppStream stream) { if (!Plugin.ensure_context()) return; this.store = Plugin.get_context().create_store(); store_created(store); received_pipeline_listener = new ReceivedPipelineListener(store); stream.get_module(MessageModule.IDENTITY).received_pipeline.connect(received_pipeline_listener); stream.get_module(Pubsub.Module.IDENTITY).add_filtered_notification(stream, NODE_DEVICELIST, (stream, jid, id, node) => on_devicelist(stream, jid, id, node)); } public override void detach(XmppStream stream) { stream.get_module(MessageModule.IDENTITY).received_pipeline.disconnect(received_pipeline_listener); } public void request_user_devicelist(XmppStream stream, Jid jid) { if (active_devicelist_requests.add(jid)) { if (Plugin.DEBUG) print(@"OMEMO: requesting device list for $jid\n"); stream.get_module(Pubsub.Module.IDENTITY).request(stream, jid, NODE_DEVICELIST, (stream, jid, id, node) => on_devicelist(stream, jid, id, node)); } } public void on_devicelist(XmppStream stream, Jid jid, string? id, StanzaNode? node_) { StanzaNode node = node_ ?? new StanzaNode.build("list", NS_URI).add_self_xmlns(); Jid? my_jid = stream.get_flag(Bind.Flag.IDENTITY).my_jid; if (my_jid == null) return; if (jid.equals_bare(my_jid) && store.local_registration_id != 0) { bool am_on_devicelist = false; foreach (StanzaNode device_node in node.get_subnodes("device")) { int device_id = device_node.get_attribute_int("id"); if (store.local_registration_id == device_id) { am_on_devicelist = true; } } if (!am_on_devicelist) { if (Plugin.DEBUG) print(@"OMEMO: Not on device list, adding id\n"); node.put_node(new StanzaNode.build("device", NS_URI).put_attribute("id", store.local_registration_id.to_string())); stream.get_module(Pubsub.Module.IDENTITY).publish(stream, jid, NODE_DEVICELIST, NODE_DEVICELIST, id, node); } else { publish_bundles_if_needed(stream, jid); } } lock(device_lists) { device_lists[jid] = new ArrayList(); foreach (StanzaNode device_node in node.get_subnodes("device")) { device_lists[jid].add(device_node.get_attribute_int("id")); } } active_devicelist_requests.remove(jid); device_list_loaded(jid); } public void fetch_bundles(XmppStream stream, Jid jid) { if (!device_lists.has_key(jid)) { return; } Address address = new Address(jid.bare_jid.to_string(), 0); foreach(int32 device_id in device_lists[jid]) { if (!is_ignored_device(jid, device_id)) { address.device_id = device_id; try { if (!store.contains_session(address)) { fetch_bundle(stream, jid, device_id); } } catch (Error e) { // Ignore } } } address.device_id = 0; } public void fetch_bundle(XmppStream stream, Jid jid, int device_id) { if (active_bundle_requests.add(jid.bare_jid.to_string() + @":$device_id")) { if (Plugin.DEBUG) print(@"OMEMO: Asking for bundle from $(jid.bare_jid.to_string()):$device_id\n"); stream.get_module(Pubsub.Module.IDENTITY).request(stream, jid.bare_jid, @"$NODE_BUNDLES:$device_id", (stream, jid, id, node) => { on_other_bundle_result(stream, jid, device_id, id, node); }); } } public ArrayList get_device_list(Jid jid) { if (is_known_address(jid)) { return device_lists[jid]; } else { return new ArrayList(); } } public bool is_known_address(Jid jid) { return device_lists.has_key(jid); } public void ignore_device(Jid jid, int32 device_id) { if (device_id <= 0) return; lock (ignored_devices) { if (!ignored_devices.has_key(jid)) { ignored_devices[jid] = new ArrayList(); } ignored_devices[jid].add(device_id); } } public bool is_ignored_device(Jid jid, int32 device_id) { if (device_id <= 0) return true; lock (ignored_devices) { return ignored_devices.has_key(jid) && ignored_devices[jid].contains(device_id); } } private void on_other_bundle_result(XmppStream stream, Jid jid, int device_id, string? id, StanzaNode? node) { if (node == null) { // Device not registered, shouldn't exist stream.get_module(IDENTITY).ignore_device(jid, device_id); } else { Bundle bundle = new Bundle(node); bundle_fetched(jid, device_id, bundle); } stream.get_module(IDENTITY).active_bundle_requests.remove(jid.bare_jid.to_string() + @":$device_id"); } public bool start_session(XmppStream stream, Jid jid, int32 device_id, Bundle bundle) { bool fail = false; int32 signed_pre_key_id = bundle.signed_pre_key_id; ECPublicKey? signed_pre_key = bundle.signed_pre_key; uint8[] signed_pre_key_signature = bundle.signed_pre_key_signature; ECPublicKey? identity_key = bundle.identity_key; ArrayList pre_keys = bundle.pre_keys; if (signed_pre_key_id < 0 || signed_pre_key == null || identity_key == null || pre_keys.size == 0) { fail = true; } else { int pre_key_idx = Random.int_range(0, pre_keys.size); int32 pre_key_id = pre_keys[pre_key_idx].key_id; ECPublicKey? pre_key = pre_keys[pre_key_idx].key; if (pre_key_id < 0 || pre_key == null) { fail = true; } else { Address address = new Address(jid.bare_jid.to_string(), device_id); try { if (store.contains_session(address)) { return false; } SessionBuilder builder = store.create_session_builder(address); builder.process_pre_key_bundle(create_pre_key_bundle(device_id, device_id, pre_key_id, pre_key, signed_pre_key_id, signed_pre_key, signed_pre_key_signature, identity_key)); } catch (Error e) { fail = true; } address.device_id = 0; // TODO: Hack to have address obj live longer } } if (fail) { stream.get_module(IDENTITY).ignore_device(jid, device_id); } return true; } public void publish_bundles_if_needed(XmppStream stream, Jid jid) { if (active_bundle_requests.add(jid.bare_jid.to_string() + @":$(store.local_registration_id)")) { stream.get_module(Pubsub.Module.IDENTITY).request(stream, jid, @"$NODE_BUNDLES:$(store.local_registration_id)", on_self_bundle_result); } } private void on_self_bundle_result(XmppStream stream, Jid jid, string? id, StanzaNode? node) { if (!Plugin.ensure_context()) return; Map keys = new HashMap(); ECPublicKey? identity_key = null; int32 signed_pre_key_id = -1; ECPublicKey? signed_pre_key = null; SignedPreKeyRecord? signed_pre_key_record = null; bool changed = false; if (node == null) { identity_key = store.identity_key_pair.public; changed = true; } else { Bundle bundle = new Bundle(node); foreach (Bundle.PreKey prekey in bundle.pre_keys) { ECPublicKey? key = prekey.key; if (key != null) { keys[prekey.key_id] = (!)key; } } identity_key = bundle.identity_key; signed_pre_key_id = bundle.signed_pre_key_id;; signed_pre_key = bundle.signed_pre_key; } try { // Validate IdentityKey if (identity_key == null || store.identity_key_pair.public.compare((!)identity_key) != 0) { changed = true; } IdentityKeyPair identity_key_pair = store.identity_key_pair; // Validate signedPreKeyRecord + ID if (signed_pre_key == null || signed_pre_key_id == -1 || !store.contains_signed_pre_key(signed_pre_key_id) || store.load_signed_pre_key(signed_pre_key_id).key_pair.public.compare((!)signed_pre_key) != 0) { signed_pre_key_id = Random.int_range(1, int32.MAX); // TODO: No random, use ordered number signed_pre_key_record = Plugin.get_context().generate_signed_pre_key(identity_key_pair, signed_pre_key_id); store.store_signed_pre_key((!)signed_pre_key_record); changed = true; } else { signed_pre_key_record = store.load_signed_pre_key(signed_pre_key_id); } // Validate PreKeys Set pre_key_records = new HashSet(); foreach (var entry in keys.entries) { if (store.contains_pre_key(entry.key)) { PreKeyRecord record = store.load_pre_key(entry.key); if (record.key_pair.public.compare(entry.value) == 0) { pre_key_records.add(record); } } } int new_keys = NUM_KEYS_TO_PUBLISH - pre_key_records.size; if (new_keys > 0) { int32 next_id = Random.int_range(1, int32.MAX); // TODO: No random, use ordered number Set new_records = Plugin.get_context().generate_pre_keys((uint)next_id, (uint)new_keys); pre_key_records.add_all(new_records); foreach (PreKeyRecord record in new_records) { store.store_pre_key(record); } changed = true; } if (changed) { publish_bundles(stream, (!)signed_pre_key_record, identity_key_pair, pre_key_records, (int32) store.local_registration_id); } } catch (Error e) { if (Plugin.DEBUG) print(@"Unexpected error while publishing bundle: $(e.message)\n"); } stream.get_module(IDENTITY).active_bundle_requests.remove(jid.bare_jid.to_string() + @":$(store.local_registration_id)"); } public static void publish_bundles(XmppStream stream, SignedPreKeyRecord signed_pre_key_record, IdentityKeyPair identity_key_pair, Set pre_key_records, int32 device_id) throws Error { ECKeyPair tmp; StanzaNode bundle = new StanzaNode.build("bundle", NS_URI) .add_self_xmlns() .put_node(new StanzaNode.build("signedPreKeyPublic", NS_URI) .put_attribute("signedPreKeyId", signed_pre_key_record.id.to_string()) .put_node(new StanzaNode.text(Base64.encode((tmp = signed_pre_key_record.key_pair).public.serialize())))) .put_node(new StanzaNode.build("signedPreKeySignature", NS_URI) .put_node(new StanzaNode.text(Base64.encode(signed_pre_key_record.signature)))) .put_node(new StanzaNode.build("identityKey", NS_URI) .put_node(new StanzaNode.text(Base64.encode(identity_key_pair.public.serialize())))); StanzaNode prekeys = new StanzaNode.build("prekeys", NS_URI); foreach (PreKeyRecord pre_key_record in pre_key_records) { prekeys.put_node(new StanzaNode.build("preKeyPublic", NS_URI) .put_attribute("preKeyId", pre_key_record.id.to_string()) .put_node(new StanzaNode.text(Base64.encode(pre_key_record.key_pair.public.serialize())))); } bundle.put_node(prekeys); stream.get_module(Pubsub.Module.IDENTITY).publish(stream, null, @"$NODE_BUNDLES:$device_id", @"$NODE_BUNDLES:$device_id", "1", bundle); } public override string get_ns() { return NS_URI; } public override string get_id() { return IDENTITY.id; } } public class ReceivedPipelineListener : StanzaListener { private const string[] after_actions_const = {"EXTRACT_MESSAGE_2"}; public override string action_group { get { return "ENCRYPT_BODY"; } } public override string[] after_actions { get { return after_actions_const; } } private Store store; public ReceivedPipelineListener(Store store) { this.store = store; } public override async bool run(XmppStream stream, MessageStanza message) { StanzaNode? _encrypted = message.stanza.get_subnode("encrypted", NS_URI); if (_encrypted == null || MessageFlag.get_flag(message) != null || message.from == null) return false; StanzaNode encrypted = (!)_encrypted; if (!Plugin.ensure_context()) return false; MessageFlag flag = new MessageFlag(); message.add_flag(flag); StanzaNode? _header = encrypted.get_subnode("header"); if (_header == null) return false; StanzaNode header = (!)_header; if (header.get_attribute_int("sid") <= 0) return false; foreach (StanzaNode key_node in header.get_subnodes("key")) { if (key_node.get_attribute_int("rid") == store.local_registration_id) { try { string? payload = encrypted.get_deep_string_content("payload"); string? iv_node = header.get_deep_string_content("iv"); string? key_node_content = key_node.get_string_content(); if (payload == null || iv_node == null || key_node_content == null) continue; uint8[] key; uint8[] ciphertext = Base64.decode((!)payload); uint8[] iv = Base64.decode((!)iv_node); Address address = new Address(message.from.bare_jid.to_string(), header.get_attribute_int("sid")); if (key_node.get_attribute_bool("prekey")) { PreKeySignalMessage msg = Plugin.get_context().deserialize_pre_key_signal_message(Base64.decode((!)key_node_content)); SessionCipher cipher = store.create_session_cipher(address); key = cipher.decrypt_pre_key_signal_message(msg); } else { SignalMessage msg = Plugin.get_context().deserialize_signal_message(Base64.decode((!)key_node_content)); SessionCipher cipher = store.create_session_cipher(address); key = cipher.decrypt_signal_message(msg); } address.device_id = 0; // TODO: Hack to have address obj live longer if (key.length >= 32) { int authtaglength = key.length - 16; uint8[] new_ciphertext = new uint8[ciphertext.length + authtaglength]; uint8[] new_key = new uint8[16]; Memory.copy(new_ciphertext, ciphertext, ciphertext.length); Memory.copy((uint8*)new_ciphertext + ciphertext.length, (uint8*)key + 16, authtaglength); Memory.copy(new_key, key, 16); ciphertext = new_ciphertext; key = new_key; } message.body = arr_to_str(aes_decrypt(Cipher.AES_GCM_NOPADDING, key, iv, ciphertext)); flag.decrypted = true; } catch (Error e) { if (Plugin.DEBUG) print(@"OMEMO: Signal error while decrypting message: $(e.message)\n"); } } } return false; } private string arr_to_str(uint8[] arr) { // null-terminate the array uint8[] rarr = new uint8[arr.length+1]; Memory.copy(rarr, arr, arr.length); return (string)rarr; } } }