1 files changed, 103 insertions, 0 deletions
diff --git a/javascript/olm_inbound_group_session.js b/javascript/olm_inbound_group_session.js
new file mode 100644
index 0000000..6058233
--- /dev/null
+++ b/javascript/olm_inbound_group_session.js
@@ -0,0 +1,103 @@
+/* The 'length' argument to Pointer_stringify doesn't work if the input includes
+ * characters >= 128; we therefore need to add a NULL character to all of our
+ * strings. This acts as a symbolic constant to help show what we're doing.
+ */
+var NULL_BYTE_PADDING_LENGTH = 1;
+
+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 + NULL_BYTE_PADDING_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);
+});
+
+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(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, 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 = inbound_group_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 + NULL_BYTE_PADDING_LENGTH);
+    var plaintext_length = inbound_group_session_method(Module["_olm_group_decrypt"])(
+        this.ptr,
+        message_buffer, message_array.length,
+        plaintext_buffer, max_plaintext_length
+    );
+
+    // Pointer_stringify requires a null-terminated argument (the optional
+    // 'len' argument doesn't work for UTF-8 data).
+    Module['setValue'](
+        plaintext_buffer+plaintext_length,
+        0, "i8"
+    );
+
+    return Pointer_stringify(plaintext_buffer);
+});
+
+InboundGroupSession.prototype['session_id'] = restore_stack(function() {
+    var length = inbound_group_session_method(
+        Module['_olm_inbound_group_session_id_length']
+    )(this.ptr);
+    var session_id = stack(length + NULL_BYTE_PADDING_LENGTH);
+    inbound_group_session_method(Module['_olm_inbound_group_session_id'])(
+        this.ptr, session_id, length
+    );
+    return Pointer_stringify(session_id);
+});
+
+olm_exports['InboundGroupSession'] = InboundGroupSession;