From 421f43dd8bd993eb88581e1b5011cc061ceb4fc8 Mon Sep 17 00:00:00 2001 From: fiaxh Date: Sun, 25 Apr 2021 19:49:10 +0200 Subject: Add support for OMEMO call encryption --- plugins/omemo/src/jingle/jet_omemo.vala | 82 +++++++++------------------------ 1 file changed, 23 insertions(+), 59 deletions(-) (limited to 'plugins/omemo/src/jingle') diff --git a/plugins/omemo/src/jingle/jet_omemo.vala b/plugins/omemo/src/jingle/jet_omemo.vala index 14307be2..afcdfcd6 100644 --- a/plugins/omemo/src/jingle/jet_omemo.vala +++ b/plugins/omemo/src/jingle/jet_omemo.vala @@ -7,18 +7,15 @@ using Xmpp; using Xmpp.Xep; namespace Dino.Plugins.JetOmemo { + private const string NS_URI = "urn:xmpp:jingle:jet-omemo:0"; private const string AES_128_GCM_URI = "urn:xmpp:ciphers:aes-128-gcm-nopadding"; + public class Module : XmppStreamModule, Jet.EnvelopEncoding { public static Xmpp.ModuleIdentity IDENTITY = new Xmpp.ModuleIdentity(NS_URI, "0396_jet_omemo"); - private Omemo.Plugin plugin; const uint KEY_SIZE = 16; const uint IV_SIZE = 12; - public Module(Omemo.Plugin plugin) { - this.plugin = plugin; - } - public override void attach(XmppStream stream) { if (stream.get_module(Jet.Module.IDENTITY) != null) { stream.get_module(ServiceDiscovery.Module.IDENTITY).add_feature(stream, NS_URI); @@ -44,71 +41,38 @@ public class Module : XmppStreamModule, Jet.EnvelopEncoding { } public Jet.TransportSecret decode_envolop(XmppStream stream, Jid local_full_jid, Jid peer_full_jid, StanzaNode security) throws Jingle.IqError { - Store store = stream.get_module(Omemo.StreamModule.IDENTITY).store; StanzaNode? encrypted = security.get_subnode("encrypted", Omemo.NS_URI); if (encrypted == null) throw new Jingle.IqError.BAD_REQUEST("Invalid JET-OMEMO envelop: missing encrypted element"); - StanzaNode? header = encrypted.get_subnode("header", Omemo.NS_URI); - if (header == null) throw new Jingle.IqError.BAD_REQUEST("Invalid JET-OMEMO envelop: missing header element"); - string? iv_node = header.get_deep_string_content("iv"); - if (header == null) throw new Jingle.IqError.BAD_REQUEST("Invalid JET-OMEMO envelop: missing iv element"); - uint8[] iv = Base64.decode((!)iv_node); - foreach (StanzaNode key_node in header.get_subnodes("key")) { - if (key_node.get_attribute_int("rid") == store.local_registration_id) { - string? key_node_content = key_node.get_string_content(); - - uint8[] key; - Address address = new Address(peer_full_jid.bare_jid.to_string(), header.get_attribute_int("sid")); - if (key_node.get_attribute_bool("prekey")) { - PreKeySignalMessage msg = Omemo.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 = Omemo.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 - - uint8[] authtag = null; - if (key.length >= 32) { - int authtaglength = key.length - 16; - authtag = new uint8[authtaglength]; - uint8[] new_key = new uint8[16]; - Memory.copy(authtag, (uint8*)key + 16, 16); - Memory.copy(new_key, key, 16); - key = new_key; - } - // TODO: authtag? - return new Jet.TransportSecret(key, iv); + + Xep.Omemo.OmemoDecryptor decryptor = stream.get_module(Xep.Omemo.OmemoDecryptor.IDENTITY); + + Xmpp.Xep.Omemo.ParsedData? data = decryptor.parse_node(encrypted); + if (data == null) throw new Jingle.IqError.BAD_REQUEST("Invalid JET-OMEMO envelop: bad encrypted element"); + + foreach (Bytes encr_key in data.our_potential_encrypted_keys.keys) { + data.is_prekey = data.our_potential_encrypted_keys[encr_key]; + data.encrypted_key = encr_key.get_data(); + + try { + uint8[] key = decryptor.decrypt_key(data, peer_full_jid.bare_jid); + return new Jet.TransportSecret(key, data.iv); + } catch (GLib.Error e) { + debug("Decrypting JET key from %s/%d failed: %s", peer_full_jid.bare_jid.to_string(), data.sid, e.message); } } throw new Jingle.IqError.NOT_ACCEPTABLE("Not encrypted for targeted device"); } public void encode_envelop(XmppStream stream, Jid local_full_jid, Jid peer_full_jid, Jet.SecurityParameters security_params, StanzaNode security) { - ArrayList accounts = plugin.app.stream_interactor.get_accounts(); Store store = stream.get_module(Omemo.StreamModule.IDENTITY).store; - Account? account = null; - foreach (Account compare in accounts) { - if (compare.bare_jid.equals_bare(local_full_jid)) { - account = compare; - break; - } - } - if (account == null) { - // TODO - critical("Sending from offline account %s", local_full_jid.to_string()); - } - StanzaNode header_node; - StanzaNode encrypted_node = new StanzaNode.build("encrypted", Omemo.NS_URI).add_self_xmlns() - .put_node(header_node = new StanzaNode.build("header", Omemo.NS_URI) - .put_attribute("sid", store.local_registration_id.to_string()) - .put_node(new StanzaNode.build("iv", Omemo.NS_URI) - .put_node(new StanzaNode.text(Base64.encode(security_params.secret.initialization_vector))))); + var encryption_data = new Xep.Omemo.EncryptionData(store.local_registration_id); + encryption_data.iv = security_params.secret.initialization_vector; + encryption_data.keytag = security_params.secret.transport_key; + Xep.Omemo.OmemoEncryptor encryptor = stream.get_module(Xep.Omemo.OmemoEncryptor.IDENTITY); + encryptor.encrypt_key_to_recipient(stream, encryption_data, peer_full_jid.bare_jid); - plugin.trust_manager.encrypt_key(header_node, security_params.secret.transport_key, local_full_jid.bare_jid, new ArrayList.wrap(new Jid[] {peer_full_jid.bare_jid}), stream, account); - security.put_node(encrypted_node); + security.put_node(encryption_data.get_encrypted_node()); } public override string get_ns() { return NS_URI; } -- cgit v1.2.3-54-g00ecf