diff options
Diffstat (limited to 'plugins/omemo/src/trust_manager.vala')
| -rw-r--r-- | plugins/omemo/src/trust_manager.vala | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/plugins/omemo/src/trust_manager.vala b/plugins/omemo/src/trust_manager.vala new file mode 100644 index 00000000..8f6e9017 --- /dev/null +++ b/plugins/omemo/src/trust_manager.vala @@ -0,0 +1,253 @@ +using Dino.Entities; +using Gee; +using Xmpp; +using Signal; +using Qlite; + +namespace Dino.Plugins.Omemo { + +public class TrustManager { + + private StreamInteractor stream_interactor; + private Database db; + private ReceivedMessageListener received_message_listener; + + public TrustManager(StreamInteractor stream_interactor, Database db) { + this.stream_interactor = stream_interactor; + this.db = db; + + received_message_listener = new ReceivedMessageListener(stream_interactor, db); + stream_interactor.get_module(MessageProcessor.IDENTITY).received_pipeline.connect(received_message_listener); + } + + public void set_blind_trust(Account account, Jid jid, bool blind_trust) { + int identity_id = db.identity.get_id(account.id); + if (identity_id < 0) return; + db.trust.update() + .with(db.trust.identity_id, "=", identity_id) + .with(db.trust.address_name, "=", jid.bare_jid.to_string()) + .set(db.trust.blind_trust, blind_trust).perform(); + } + + public void set_device_trust(Account account, Jid jid, int device_id, Database.IdentityMetaTable.TrustLevel trust_level) { + int identity_id = db.identity.get_id(account.id); + db.identity_meta.update() + .with(db.identity_meta.identity_id, "=", identity_id) + .with(db.identity_meta.address_name, "=", jid.bare_jid.to_string()) + .with(db.identity_meta.device_id, "=", device_id) + .set(db.identity_meta.trust_level, trust_level).perform(); + } + + private StanzaNode create_encrypted_key(uint8[] key, Address address, Store store) 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 EncryptState encrypt(MessageStanza message, Jid self_jid, Gee.List<Jid> recipients, XmppStream stream, Account account) { + EncryptState status = new EncryptState(); + if (!Plugin.ensure_context()) return status; + if (message.to == null) return status; + + StreamModule module = stream.get_module(StreamModule.IDENTITY); + + try { + //Check we have the bundles and device lists needed to send the message + if (!is_known_address(account, self_jid)) return status; + status.own_list = true; + status.own_devices = get_trusted_devices(account, self_jid).size; + status.other_waiting_lists = 0; + status.other_devices = 0; + foreach (Jid recipient in recipients) { + if (!is_known_address(account, recipient)) { + status.other_waiting_lists++; + } + if (status.other_waiting_lists > 0) return status; + status.other_devices += get_trusted_devices(account, recipient).size; + } + if (status.own_devices == 0 || status.other_devices == 0) return status; + + //Create a key and use it to encrypt the message + 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", module.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)))); + + //Encrypt the key for each recipient's device individually + Address address = new Address(message.to.bare_jid.to_string(), 0); + foreach (Jid recipient in recipients) { + foreach(int32 device_id in get_trusted_devices(account, recipient)) { + if (module.is_ignored_device(recipient, device_id)) { + status.other_lost++; + continue; + } + try { + address.name = recipient.bare_jid.to_string(); + address.device_id = (int) device_id; + StanzaNode key_node = create_encrypted_key(key, address, module.store); + 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 get_trusted_devices(account, self_jid)) { + if (module.is_ignored_device(self_jid, device_id)) { + status.own_lost++; + continue; + } + if (device_id != module.store.local_registration_id) { + address.device_id = (int) device_id; + try { + StanzaNode key_node = create_encrypted_key(key, address, module.store); + 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 bool is_known_address(Account account, Jid jid) { + int identity_id = db.identity.get_id(account.id); + if (identity_id < 0) return false; + return db.identity_meta.with_address(identity_id, jid.to_string()).count() > 0; + } + + public Gee.List<int32> get_trusted_devices(Account account, Jid jid) { + Gee.List<int32> devices = new ArrayList<int32>(); + int identity_id = db.identity.get_id(account.id); + if (identity_id < 0) return devices; + foreach (Row device in db.identity_meta.get_trusted_devices(identity_id, jid.bare_jid.to_string())) { + if(device[db.identity_meta.trust_level] != Database.IdentityMetaTable.TrustLevel.UNKNOWN || device[db.identity_meta.identity_key_public_base64] == null) + devices.add(device[db.identity_meta.device_id]); + } + return devices; + } + + private class ReceivedMessageListener : MessageListener { + public string[] after_actions_const = new string[]{ }; + public override string action_group { get { return "DECRYPT"; } } + public override string[] after_actions { get { return after_actions_const; } } + + private StreamInteractor stream_interactor; + private Database db; + + public ReceivedMessageListener(StreamInteractor stream_interactor, Database db) { + this.stream_interactor = stream_interactor; + this.db = db; + } + + public override async bool run(Entities.Message message, Xmpp.MessageStanza stanza, Conversation conversation) { + Store store = stream_interactor.module_manager.get_module(conversation.account, StreamModule.IDENTITY).store; + + StanzaNode? _encrypted = stanza.stanza.get_subnode("encrypted", NS_URI); + if (_encrypted == null || MessageFlag.get_flag(stanza) != null || stanza.from == null) return false; + StanzaNode encrypted = (!)_encrypted; + if (!Plugin.ensure_context()) return false; + MessageFlag flag = new MessageFlag(); + stanza.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); + Jid jid = stanza.from; + if (conversation.type_ == Conversation.Type.GROUPCHAT) { + jid = stream_interactor.get_module(MucManager.IDENTITY).get_real_jid(jid, conversation.account); + } + + Address address = new Address(jid.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; + + int identity_id = db.identity.get_id(conversation.account.id); + if (identity_id < 0) return false; + + Database.IdentityMetaTable.TrustLevel trust_level = (Database.IdentityMetaTable.TrustLevel) db.identity_meta.get_device(identity_id, jid.bare_jid.to_string(), header.get_attribute_int("sid"))[db.identity_meta.trust_level]; + if (trust_level == Database.IdentityMetaTable.TrustLevel.UNTRUSTED) { + message.body = _("OMEMO message from a rejected device"); + message.marked = Message.Marked.WONTSEND; + } + if (trust_level == Database.IdentityMetaTable.TrustLevel.UNKNOWN) { + message.body = _("OMEMO message from an unknown device: ")+message.body; + message.marked = Message.Marked.WONTSEND; + } + } 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; + } + } +} + +} |