2 files changed, 168 insertions, 0 deletions
diff --git a/main/src/plugins/omemo/jingle/jet_omemo.vala b/main/src/plugins/omemo/jingle/jet_omemo.vala
new file mode 100644
index 00000000..07d03f64
--- /dev/null
+++ b/main/src/plugins/omemo/jingle/jet_omemo.vala
@@ -0,0 +1,115 @@
+using Dino.Crypto;
+using Dino.Crypto.Omemo;
+using Dino;
+using Dino.Entities;
+using Gee;
+using Omemo;
+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");
+    const uint KEY_SIZE = 16;
+    const uint IV_SIZE = 12;
+
+    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);
+            stream.get_module(Jet.Module.IDENTITY).register_envelop_encoding(this);
+            stream.get_module(Jet.Module.IDENTITY).register_cipher(new AesGcmCipher(KEY_SIZE, IV_SIZE, AES_128_GCM_URI));
+        }
+    }
+
+    public override void detach(XmppStream stream) {
+        stream.get_module(ServiceDiscovery.Module.IDENTITY).remove_feature(stream, NS_URI);
+    }
+
+    public async bool is_available(XmppStream stream, Jid full_jid) {
+        bool? has_feature = yield stream.get_module(ServiceDiscovery.Module.IDENTITY).has_entity_feature(stream, full_jid, NS_URI);
+        if (has_feature == null || !(!)has_feature) {
+            return false;
+        }
+        return yield stream.get_module(Xep.Jet.Module.IDENTITY).is_available(stream, full_jid);
+    }
+
+    public string get_type_uri() {
+        return Omemo.NS_URI;
+    }
+
+    public Jet.TransportSecret decode_envolop(XmppStream stream, Jid local_full_jid, Jid peer_full_jid, StanzaNode security) throws Jingle.IqError {
+        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");
+
+        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) {
+        Store store = stream.get_module(Omemo.StreamModule.IDENTITY).store;
+
+        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);
+
+        security.put_node(encryption_data.get_encrypted_node());
+    }
+
+    public override string get_ns() { return NS_URI; }
+    public override string get_id() { return IDENTITY.id; }
+}
+
+public class AesGcmCipher : Jet.Cipher, Object {
+    private uint key_size;
+    private uint default_iv_size;
+    private string uri;
+    public AesGcmCipher(uint key_size, uint default_iv_size, string uri) {
+        this.key_size = key_size;
+        this.default_iv_size = default_iv_size;
+        this.uri = uri;
+    }
+    public string get_cipher_uri() {
+        return uri;
+    }
+    public Jet.TransportSecret generate_random_secret() {
+        uint8[] iv = new uint8[default_iv_size];
+        Crypto.randomize(iv);
+        uint8[] key = new uint8[key_size];
+        Crypto.randomize(key);
+        return new Jet.TransportSecret(key, iv);
+    }
+    public InputStream wrap_input_stream(InputStream input, Jet.TransportSecret secret) requires (secret.transport_key.length == key_size) {
+        SymmetricCipherDecryption cipher = create_symmetric_cipher_decryption("AES-GCM");
+        cipher.set_key(secret.transport_key);
+        cipher.set_iv(secret.initialization_vector);
+        return new ConverterInputStream(input, new SymmetricCipherDecrypter((owned) cipher, 16));
+    }
+    public OutputStream wrap_output_stream(OutputStream output, Jet.TransportSecret secret) requires (secret.transport_key.length == key_size) {
+        SymmetricCipherEncryption cipher = create_symmetric_cipher_encryption("AES-GCM");
+        cipher.set_key(secret.transport_key);
+        cipher.set_iv(secret.initialization_vector);
+        return new ConverterOutputStream(output, new SymmetricCipherEncrypter((owned) cipher, 16));
+    }
+}
+}
diff --git a/main/src/plugins/omemo/jingle/jingle_helper.vala b/main/src/plugins/omemo/jingle/jingle_helper.vala
new file mode 100644
index 00000000..ec6c0eca
--- /dev/null
+++ b/main/src/plugins/omemo/jingle/jingle_helper.vala
@@ -0,0 +1,53 @@
+using Dino.Entities;
+using Xmpp;
+
+namespace Dino.Plugins.JetOmemo {
+public class EncryptionHelper : JingleFileEncryptionHelper, Object {
+    private StreamInteractor stream_interactor;
+
+    public EncryptionHelper(StreamInteractor stream_interactor) {
+        this.stream_interactor = stream_interactor;
+    }
+
+    public bool can_transfer(Conversation conversation) {
+        return true;
+    }
+
+    public async bool can_encrypt(Conversation conversation, FileTransfer file_transfer, Jid? full_jid) {
+        XmppStream? stream = stream_interactor.get_stream(conversation.account);
+        if (stream == null) return false;
+
+        Gee.List<Jid>? resources = stream.get_flag(Presence.Flag.IDENTITY).get_resources(conversation.counterpart);
+        if (resources == null) return false;
+
+        if (full_jid == null) {
+            foreach (Jid test_jid in resources) {
+                if (yield stream.get_module(Module.IDENTITY).is_available(stream, test_jid)) {
+                    return true;
+                }
+            }
+        } else {
+            if (yield stream.get_module(Module.IDENTITY).is_available(stream, full_jid)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    public string? get_precondition_name(Conversation conversation, FileTransfer file_transfer) {
+        return Xep.Jet.NS_URI;
+    }
+
+    public Object? get_precondition_options(Conversation conversation, FileTransfer file_transfer) {
+        return new Xep.Jet.Options(Omemo.NS_URI, AES_128_GCM_URI);
+    }
+
+    public Encryption get_encryption(Xmpp.Xep.JingleFileTransfer.FileTransfer jingle_transfer) {
+        Xep.Jet.SecurityParameters? security = jingle_transfer.security as Xep.Jet.SecurityParameters;
+        if (security != null && security.encoding.get_type_uri() == Omemo.NS_URI) {
+            return Encryption.OMEMO;
+        }
+        return Encryption.NONE;
+    }
+}
+}