Add support for OMEMO call encryption

1 files changed, 23 insertions, 59 deletions

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<Module> IDENTITY = new Xmpp.ModuleIdentity<Module>(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<Account> 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<Jid>.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; }