Bug 760105 - Add argument to CommonUtils.encodeBase64URL for padding; r=rnewman

services/common/tests/unit/test_utils_encodeBase64URL.js

@@ -0,0 +1,27 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+Cu.import("resource://services-common/utils.js");
+
+function run_test() {
+  run_next_test();
+}
+
+add_test(function test_simple() {
+  let expected = {
+    hello: "aGVsbG8=",
+    "<>?": "PD4_",
+  };
+
+  for (let [k, v] in Iterator(expected)) {
+    do_check_eq(CommonUtils.encodeBase64URL(k), v);
+  }
+
+  run_next_test();
+});
+
+add_test(function test_no_padding() {
+  do_check_eq(CommonUtils.encodeBase64URL("hello", false), "aGVsbG8");
+
+  run_next_test();
+});

services/common/tests/unit/xpcshell.ini

@@ -7,6 +7,7 @@ tail =
 
 [test_utils_atob.js]
 [test_utils_encodeBase32.js]
+[test_utils_encodeBase64URL.js]
 [test_utils_json.js]
 [test_utils_makeURI.js]
 [test_utils_namedTimer.js]

services/common/utils.js

@@ -59,9 +59,21 @@ let CommonUtils = {
 
   /**
    * Encode byte string as base64URL (RFC 4648).
+   *
+   * @param bytes
+   *        (string) Raw byte string to encode.
+   * @param pad
+   *        (bool) Whether to include padding characters (=). Defaults
+   *        to true for historical reasons.
    */
-  encodeBase64URL: function encodeBase64URL(bytes) {
-    return btoa(bytes).replace("+", "-", "g").replace("/", "_", "g");
+  encodeBase64URL: function encodeBase64URL(bytes, pad=true) {
+    let s = btoa(bytes).replace("+", "-", "g").replace("/", "_", "g");
+
+    if (!pad) {
+      s = s.replace("=", "");
+    }
+
+    return s;
   },
 
   /**