Add Passkeys Support

Closes gh-13305

javascript/lib/abort-controller.js

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2002-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+"use strict";
+
+const holder = {
+  controller: new AbortController(),
+};
+
+/**
+ * Returns a new AbortSignal to be used in the options for the registration and authentication ceremonies.
+ * Aborts the existing AbortController if it exists, cancelling any existing ceremony.
+ *
+ * The authentication ceremony, when triggered with conditional mediation, shows a non-modal
+ * interaction. If the user does not interact with the non-modal dialog, the existing ceremony MUST
+ * be cancelled before initiating a new one, hence the need for a singleton AbortController.
+ *
+ * @returns {AbortSignal} a new, non-aborted AbortSignal
+ */
+function newSignal() {
+  if (!!holder.controller) {
+    holder.controller.abort("Initiating new WebAuthN ceremony, cancelling current ceremony");
+  }
+  holder.controller = new AbortController();
+  return holder.controller.signal;
+}
+
+export default {
+  newSignal,
+};