diff options
Diffstat (limited to 'plugins/omemo/src/dtls_srtp_verification_draft.vala')
| -rw-r--r-- | plugins/omemo/src/dtls_srtp_verification_draft.vala | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/plugins/omemo/src/dtls_srtp_verification_draft.vala b/plugins/omemo/src/dtls_srtp_verification_draft.vala new file mode 100644 index 00000000..e2441670 --- /dev/null +++ b/plugins/omemo/src/dtls_srtp_verification_draft.vala @@ -0,0 +1,195 @@ +using Signal; +using Gee; +using Xmpp; + +namespace Dino.Plugins.Omemo.DtlsSrtpVerificationDraft { + public const string NS_URI = "http://gultsch.de/xmpp/drafts/omemo/dlts-srtp-verification"; + + public class StreamModule : XmppStreamModule { + + public static Xmpp.ModuleIdentity<StreamModule> IDENTITY = new Xmpp.ModuleIdentity<StreamModule>(NS_URI, "dtls_srtp_omemo_verification_draft"); + + private VerificationSendListener send_listener = new VerificationSendListener(); + private HashMap<string, int> device_id_by_jingle_sid = new HashMap<string, int>(); + private HashMap<string, Gee.List<string>> content_names_by_jingle_sid = new HashMap<string, Gee.List<string>>(); + + private void on_preprocess_incoming_iq_set_get(XmppStream stream, Xmpp.Iq.Stanza iq) { + if (iq.type_ != Iq.Stanza.TYPE_SET) return; + + Gee.List<StanzaNode> content_nodes = iq.stanza.get_deep_subnodes(Xep.Jingle.NS_URI + ":jingle", Xep.Jingle.NS_URI + ":content"); + if (content_nodes.size == 0) return; + + string? jingle_sid = iq.stanza.get_deep_attribute(Xep.Jingle.NS_URI + ":jingle", "sid"); + if (jingle_sid == null) return; + + Xep.Omemo.OmemoDecryptor decryptor = stream.get_module(Xep.Omemo.OmemoDecryptor.IDENTITY); + + foreach (StanzaNode content_node in content_nodes) { + string? content_name = content_node.get_attribute("name"); + if (content_name == null) continue; + StanzaNode? transport_node = content_node.get_subnode("transport", Xep.JingleIceUdp.NS_URI); + if (transport_node == null) continue; + StanzaNode? fingerprint_node = transport_node.get_subnode("fingerprint", NS_URI); + if (fingerprint_node == null) continue; + StanzaNode? encrypted_node = fingerprint_node.get_subnode("encrypted", Omemo.NS_URI); + if (encrypted_node == null) continue; + + Xep.Omemo.ParsedData? parsed_data = decryptor.parse_node(encrypted_node); + if (parsed_data == null || parsed_data.ciphertext == null) continue; + + if (device_id_by_jingle_sid.has_key(jingle_sid) && device_id_by_jingle_sid[jingle_sid] != parsed_data.sid) { + warning("Expected DTLS fingerprint to be OMEMO encrypted from %s %d, but it was from %d", iq.from.to_string(), device_id_by_jingle_sid[jingle_sid], parsed_data.sid); + } + + foreach (Bytes encr_key in parsed_data.our_potential_encrypted_keys.keys) { + parsed_data.is_prekey = parsed_data.our_potential_encrypted_keys[encr_key]; + parsed_data.encrypted_key = encr_key.get_data(); + + try { + uint8[] key = decryptor.decrypt_key(parsed_data, iq.from.bare_jid); + string cleartext = decryptor.decrypt(parsed_data.ciphertext, key, parsed_data.iv); + + StanzaNode new_fingerprint_node = new StanzaNode.build("fingerprint", Xep.JingleIceUdp.DTLS_NS_URI).add_self_xmlns() + .put_node(new StanzaNode.text(cleartext)); + string? hash_attr = fingerprint_node.get_attribute("hash", NS_URI); + string? setup_attr = fingerprint_node.get_attribute("setup", NS_URI); + if (hash_attr != null) new_fingerprint_node.put_attribute("hash", hash_attr); + if (setup_attr != null) new_fingerprint_node.put_attribute("setup", setup_attr); + transport_node.put_node(new_fingerprint_node); + + device_id_by_jingle_sid[jingle_sid] = parsed_data.sid; + if (!content_names_by_jingle_sid.has_key(content_name)) { + content_names_by_jingle_sid[content_name] = new ArrayList<string>(); + } + content_names_by_jingle_sid[content_name].add(content_name); + + stream.get_flag(Xep.Jingle.Flag.IDENTITY).get_session.begin(jingle_sid, (_, res) => { + Xep.Jingle.Session? session = stream.get_flag(Xep.Jingle.Flag.IDENTITY).get_session.end(res); + if (session != null) print(@"$(session.contents_map.has_key(content_name))\n"); + if (session == null || !session.contents_map.has_key(content_name)) return; + var encryption = new OmemoContentEncryption() { encryption_ns=NS_URI, encryption_name="OMEMO", our_key=new uint8[0], peer_key=new uint8[0], peer_device_id=device_id_by_jingle_sid[jingle_sid] }; + session.contents_map[content_name].encryptions[NS_URI] = encryption; + + if (iq.stanza.get_deep_attribute(Xep.Jingle.NS_URI + ":jingle", "action") == "session-accept") { + session.additional_content_add_incoming.connect(on_content_add_received); + } + }); + + break; + } catch (Error e) { + debug("Decrypting message from %s/%d failed: %s", iq.from.bare_jid.to_string(), parsed_data.sid, e.message); + } + } + } + } + + private void on_preprocess_outgoing_iq_set_get(XmppStream stream, Xmpp.Iq.Stanza iq) { + if (iq.type_ != Iq.Stanza.TYPE_SET) return; + + StanzaNode? jingle_node = iq.stanza.get_subnode("jingle", Xep.Jingle.NS_URI); + if (jingle_node == null) return; + + string? sid = jingle_node.get_attribute("sid", Xep.Jingle.NS_URI); + if (sid == null || !device_id_by_jingle_sid.has_key(sid)) return; + + Gee.List<StanzaNode> content_nodes = jingle_node.get_subnodes("content", Xep.Jingle.NS_URI); + if (content_nodes.size == 0) return; + + foreach (StanzaNode content_node in content_nodes) { + StanzaNode? transport_node = content_node.get_subnode("transport", Xep.JingleIceUdp.NS_URI); + if (transport_node == null) continue; + StanzaNode? fingerprint_node = transport_node.get_subnode("fingerprint", Xep.JingleIceUdp.DTLS_NS_URI); + if (fingerprint_node == null) continue; + string fingerprint = fingerprint_node.get_deep_string_content(); + + Xep.Omemo.OmemoEncryptor encryptor = stream.get_module(Xep.Omemo.OmemoEncryptor.IDENTITY); + Xep.Omemo.EncryptionData enc_data = encryptor.encrypt_plaintext(fingerprint); + encryptor.encrypt_key(enc_data, iq.to.bare_jid, device_id_by_jingle_sid[sid]); + + StanzaNode new_fingerprint_node = new StanzaNode.build("fingerprint", NS_URI).add_self_xmlns().put_node(enc_data.get_encrypted_node()); + string? hash_attr = fingerprint_node.get_attribute("hash", Xep.JingleIceUdp.DTLS_NS_URI); + string? setup_attr = fingerprint_node.get_attribute("setup", Xep.JingleIceUdp.DTLS_NS_URI); + if (hash_attr != null) new_fingerprint_node.put_attribute("hash", hash_attr); + if (setup_attr != null) new_fingerprint_node.put_attribute("setup", setup_attr); + transport_node.put_node(new_fingerprint_node); + + transport_node.sub_nodes.remove(fingerprint_node); + } + } + + private void on_message_received(XmppStream stream, Xmpp.MessageStanza message) { + StanzaNode? proceed_node = message.stanza.get_subnode("proceed", Xep.JingleMessageInitiation.NS_URI); + if (proceed_node == null) return; + + string? jingle_sid = proceed_node.get_attribute("id"); + if (jingle_sid == null) return; + + StanzaNode? device_node = proceed_node.get_subnode("device", NS_URI); + if (device_node == null) return; + + int device_id = device_node.get_attribute_int("id", -1); + if (device_id == -1) return; + + device_id_by_jingle_sid[jingle_sid] = device_id; + } + + private void on_session_initiate_received(XmppStream stream, Xep.Jingle.Session session) { + if (device_id_by_jingle_sid.has_key(session.sid)) { + foreach (Xep.Jingle.Content content in session.contents) { + on_content_add_received(stream, content); + } + } + session.additional_content_add_incoming.connect(on_content_add_received); + } + + private void on_content_add_received(XmppStream stream, Xep.Jingle.Content content) { + if (!content_names_by_jingle_sid.has_key(content.session.sid) || content_names_by_jingle_sid[content.session.sid].contains(content.content_name)) { + var encryption = new OmemoContentEncryption() { encryption_ns=NS_URI, encryption_name="OMEMO", our_key=new uint8[0], peer_key=new uint8[0], peer_device_id=device_id_by_jingle_sid[content.session.sid] }; + content.encryptions[encryption.encryption_ns] = encryption; + } + } + + public override void attach(XmppStream stream) { + stream.get_module(Xmpp.MessageModule.IDENTITY).received_message.connect(on_message_received); + stream.get_module(Xmpp.MessageModule.IDENTITY).send_pipeline.connect(send_listener); + stream.get_module(Xmpp.Iq.Module.IDENTITY).preprocess_incoming_iq_set_get.connect(on_preprocess_incoming_iq_set_get); + stream.get_module(Xmpp.Iq.Module.IDENTITY).preprocess_outgoing_iq_set_get.connect(on_preprocess_outgoing_iq_set_get); + stream.get_module(Xep.Jingle.Module.IDENTITY).session_initiate_received.connect(on_session_initiate_received); + } + + public override void detach(XmppStream stream) { + stream.get_module(Xmpp.MessageModule.IDENTITY).received_message.disconnect(on_message_received); + stream.get_module(Xmpp.MessageModule.IDENTITY).send_pipeline.disconnect(send_listener); + stream.get_module(Xmpp.Iq.Module.IDENTITY).preprocess_incoming_iq_set_get.disconnect(on_preprocess_incoming_iq_set_get); + stream.get_module(Xmpp.Iq.Module.IDENTITY).preprocess_outgoing_iq_set_get.disconnect(on_preprocess_outgoing_iq_set_get); + stream.get_module(Xep.Jingle.Module.IDENTITY).session_initiate_received.disconnect(on_session_initiate_received); + } + + public override string get_ns() { return NS_URI; } + + public override string get_id() { return IDENTITY.id; } + } + + public class VerificationSendListener : StanzaListener<MessageStanza> { + + private const string[] after_actions_const = {}; + + public override string action_group { get { return "REWRITE_NODES"; } } + public override string[] after_actions { get { return after_actions_const; } } + + public override async bool run(XmppStream stream, MessageStanza message) { + StanzaNode? proceed_node = message.stanza.get_subnode("proceed", Xep.JingleMessageInitiation.NS_URI); + if (proceed_node == null) return false; + + StanzaNode device_node = new StanzaNode.build("device", NS_URI).add_self_xmlns() + .put_attribute("id", stream.get_module(Omemo.StreamModule.IDENTITY).store.local_registration_id.to_string()); + proceed_node.put_node(device_node); + return false; + } + } + + public class OmemoContentEncryption : Xep.Jingle.ContentEncryption { + public int peer_device_id { get; set; } + } +} + |