3 files changed, 199 insertions, 0 deletions
diff --git a/javascript/README.md b/javascript/README.md
index 5c2c96b..6ed9bbb 100644
--- a/javascript/README.md
+++ b/javascript/README.md
@@ -23,3 +23,20 @@ Example:
     bob_session.create_inbound(bob, bob_message);
     var plaintext = bob_session.decrypt(message_1.type, bob_message);
     bob.remove_one_time_keys(bob_session);
+
+
+Group chat:
+
+    var outbound_session = new Olm.OutboundGroupSession();
+    outbound_session.create();
+
+    // exchange these over a secure channel
+    var session_id = group_session.session_id();
+    var session_key = group_session.session_key();
+    var message_index = group_session.message_index();
+
+    var inbound_session = new Olm.InboundGroupSession();
+    inbound_session.create(message_index, session_key);
+
+    var ciphertext = outbound_session.encrypt("Hello");
+    var plaintext = inbound_session.decrypt(ciphertext);
diff --git a/javascript/olm_inbound_group_session.js b/javascript/olm_inbound_group_session.js
new file mode 100644
index 0000000..cfb557f
--- /dev/null
+++ b/javascript/olm_inbound_group_session.js
@@ -0,0 +1,78 @@
+function InboundGroupSession() {
+    var size = Module['_olm_inbound_group_session_size']();
+    this.buf = malloc(size);
+    this.ptr = Module['_olm_inbound_group_session'](this.buf);
+}
+
+function inbound_group_session_method(wrapped) {
+    return function() {
+        var result = wrapped.apply(this, arguments);
+        if (result === OLM_ERROR) {
+            var message = Pointer_stringify(
+                Module['_olm_inbound_group_session_last_error'](arguments[0])
+            );
+            throw new Error("OLM." + message);
+        }
+        return result;
+    }
+}
+
+InboundGroupSession.prototype['free'] = function() {
+    Module['_olm_clear_inbound_group_session'](this.ptr);
+    free(this.ptr);
+}
+
+InboundGroupSession.prototype['pickle'] = restore_stack(function(key) {
+    var key_array = array_from_string(key);
+    var pickle_length = inbound_group_session_method(
+        Module['_olm_pickle_inbound_group_session_length']
+    )(this.ptr);
+    var key_buffer = stack(key_array);
+    var pickle_buffer = stack(pickle_length);
+    inbound_group_session_method(Module['_olm_pickle_inbound_group_session'])(
+        this.ptr, key_buffer, key_array.length, pickle_buffer, pickle_length
+    );
+    return Pointer_stringify(pickle_buffer, pickle_length);
+});
+
+InboundGroupSession.prototype['unpickle'] = restore_stack(function(key, pickle) {
+    var key_array = array_from_string(key);
+    var key_buffer = stack(key_array);
+    var pickle_array = array_from_string(pickle);
+    var pickle_buffer = stack(pickle_array);
+    inbound_group_session_method(Module['_olm_unpickle_inbound_group_session'])(
+        this.ptr, key_buffer, key_array.length, pickle_buffer,
+        pickle_array.length
+    );
+});
+
+InboundGroupSession.prototype['create'] = restore_stack(function(message_index, session_key) {
+    var key_array = array_from_string(session_key);
+    var key_buffer = stack(key_array);
+
+    inbound_group_session_method(Module['_olm_init_inbound_group_session'])(
+        this.ptr, message_index, key_buffer, key_array.length
+    );
+});
+
+InboundGroupSession.prototype['decrypt'] = restore_stack(function(
+    message
+) {
+    var message_array = array_from_string(message);
+    var message_buffer = stack(message_array);
+    var max_plaintext_length = session_method(
+        Module['_olm_group_decrypt_max_plaintext_length']
+    )(this.ptr, message_buffer, message_array.length);
+    // caculating the length destroys the input buffer.
+    // So we copy the array to a new buffer
+    var message_buffer = stack(message_array);
+    var plaintext_buffer = stack(max_plaintext_length);
+    var plaintext_length = session_method(Module["_olm_group_decrypt"])(
+        this.ptr,
+        message_buffer, message.length,
+        plaintext_buffer, max_plaintext_length
+    );
+    return Pointer_stringify(plaintext_buffer, plaintext_length);
+});
+
+olm_exports['InboundGroupSession'] = InboundGroupSession;
diff --git a/javascript/olm_outbound_group_session.js b/javascript/olm_outbound_group_session.js
new file mode 100644
index 0000000..277a882
--- /dev/null
+++ b/javascript/olm_outbound_group_session.js
@@ -0,0 +1,104 @@
+
+function OutboundGroupSession() {
+    var size = Module['_olm_outbound_group_session_size']();
+    this.buf = malloc(size);
+    this.ptr = Module['_olm_outbound_group_session'](this.buf);
+}
+
+function outbound_group_session_method(wrapped) {
+    return function() {
+        var result = wrapped.apply(this, arguments);
+        if (result === OLM_ERROR) {
+            var message = Pointer_stringify(
+                Module['_olm_outbound_group_session_last_error'](arguments[0])
+            );
+            throw new Error("OLM." + message);
+        }
+        return result;
+    }
+}
+
+OutboundGroupSession.prototype['free'] = function() {
+    Module['_olm_clear_outbound_group_session'](this.ptr);
+    free(this.ptr);
+}
+
+OutboundGroupSession.prototype['pickle'] = restore_stack(function(key) {
+    var key_array = array_from_string(key);
+    var pickle_length = outbound_group_session_method(
+        Module['_olm_pickle_outbound_group_session_length']
+    )(this.ptr);
+    var key_buffer = stack(key_array);
+    var pickle_buffer = stack(pickle_length);
+    outbound_group_session_method(Module['_olm_pickle_outbound_group_session'])(
+        this.ptr, key_buffer, key_array.length, pickle_buffer, pickle_length
+    );
+    return Pointer_stringify(pickle_buffer, pickle_length);
+});
+
+OutboundGroupSession.prototype['unpickle'] = restore_stack(function(key, pickle) {
+    var key_array = array_from_string(key);
+    var key_buffer = stack(key_array);
+    var pickle_array = array_from_string(pickle);
+    var pickle_buffer = stack(pickle_array);
+    outbound_group_session_method(Module['_olm_unpickle_outbound_group_session'])(
+        this.ptr, key_buffer, key_array.length, pickle_buffer,
+        pickle_array.length
+    );
+});
+
+OutboundGroupSession.prototype['create'] = restore_stack(function(key) {
+    var random_length = session_method(
+        Module['_olm_init_outbound_group_session_random_length']
+    )(this.ptr);
+    var random = random_stack(random_length);
+    outbound_group_session_method(Module['_olm_init_outbound_group_session'])(
+        this.ptr, random, random_length
+    );
+});
+
+OutboundGroupSession.prototype['encrypt'] = restore_stack(function(plaintext) {
+    var plaintext_array = array_from_string(plaintext);
+    var message_length = outbound_group_session_method(
+        Module['_olm_group_encrypt_message_length']
+    )(this.ptr, plaintext_array.length);
+    var plaintext_buffer = stack(plaintext_array);
+    var message_buffer = stack(message_length);
+    outbound_group_session_method(Module['_olm_group_encrypt'])(
+        this.ptr,
+        plaintext_buffer, plaintext_array.length,
+        message_buffer, message_length
+    );
+    return Pointer_stringify(message_buffer, message_length);
+});
+
+OutboundGroupSession.prototype['session_id'] = restore_stack(function(key) {
+    var length = outbound_group_session_method(
+        Module['_olm_outbound_group_session_id_length']
+    )(this.ptr);
+    var session_id = stack(length);
+    outbound_group_session_method(Module['_olm_outbound_group_session_id'])(
+        this.ptr, session_id, length
+    );
+    return Pointer_stringify(session_id, length);
+});
+
+OutboundGroupSession.prototype['session_key'] = restore_stack(function(key) {
+    var key_length = outbound_group_session_method(
+        Module['_olm_outbound_group_session_key_length']
+    )(this.ptr);
+    var key = stack(key_length);
+    outbound_group_session_method(Module['_olm_outbound_group_session_key'])(
+        this.ptr, key, key_length
+    );
+    return Pointer_stringify(key, key_length);
+});
+
+OutboundGroupSession.prototype['message_index'] = function() {
+    var idx = outbound_group_session_method(
+        Module['_olm_outbound_group_session_message_index']
+    )(this.ptr);
+    return idx;
+};
+
+olm_exports['OutboundGroupSession'] = OutboundGroupSession;