1 files changed, 74 insertions, 0 deletions
diff --git a/remote/shared/ChallengeHeaderParser.sys.mjs b/remote/shared/ChallengeHeaderParser.sys.mjs
new file mode 100644
index 0000000000..7cb73a4146
--- /dev/null
+++ b/remote/shared/ChallengeHeaderParser.sys.mjs
@@ -0,0 +1,74 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Parse the parameter in a name/value pair and remove quotes.
+ *
+ * @param {string} paramValue
+ *     A string representing a challenge parameter.
+ *
+ * @returns {object}
+ *     An object with name and value string properties.
+ */
+function parseChallengeParameter(paramValue) {
+  const [name, value] = paramValue.split("=");
+  return { name, value: value?.replace(/["']/g, "") };
+}
+
+/**
+ * Simple parser for authenticate (WWW-Authenticate or Proxy-Authenticate)
+ * headers.
+ *
+ * Bug 1857847: Replace with Necko's ChallengeParser once exposed to JS.
+ *
+ * @param {string} headerValue
+ *     The value of an authenticate header.
+ *
+ * @returns {Array<object>}
+ *     Array of challenge objects containing two properties:
+ *     - {string} scheme: The scheme for the challenge
+ *     - {Array<object>} params: Array of { name, value } objects representing
+ *       all the parameters of the challenge.
+ */
+export function parseChallengeHeader(headerValue) {
+  const challenges = [];
+  const parts = headerValue.split(",").map(part => part.trim());
+
+  let scheme = null;
+  let params = [];
+
+  const schemeRegex = /^(\w+)(?:\s+(.*))?$/;
+  for (const part of parts) {
+    const matches = part.match(schemeRegex);
+    if (matches !== null) {
+      // This is a new scheme.
+      if (scheme !== null) {
+        // If we have a challenge recorded, add it to the array.
+        challenges.push({ scheme, params });
+      }
+
+      // Reset the state for a new scheme.
+      scheme = matches[1];
+      params = [];
+      if (matches[2]) {
+        params.push(parseChallengeParameter(matches[2]));
+      }
+    } else {
+      if (scheme === null) {
+        // A scheme should always be found before parameters, this header
+        // probably needs a more careful parsing solution.
+        return [];
+      }
+
+      params.push(parseChallengeParameter(part));
+    }
+  }
+
+  if (scheme !== null) {
+    // If we have a challenge recorded, add it to the array.
+    challenges.push({ scheme, params });
+  }
+
+  return challenges;
+}