FIDO U2F component extension

chrome/browser/resources/cryptotoken/b64.js

+// Copyright (c) 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// WebSafeBase64Escape and Unescape.
+// mschilder@google.com
+function B64_encode(bytes, opt_length) {
+  if (!opt_length) opt_length = bytes.length;
+  var b64out =
+      'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_';
+  var result = '';
+  var shift = 0;
+  var accu = 0;
+  var input_index = 0;
+  while (opt_length--) {
+    accu <<= 8;
+    accu |= bytes[input_index++];
+    shift += 8;
+    while (shift >= 6) {
+      var i = (accu >> (shift - 6)) & 63;
+      result += b64out.charAt(i);
+      shift -= 6;
+    }
+  }
+  if (shift) {
+    accu <<= 8;
+    shift += 8;
+    var i = (accu >> (shift - 6)) & 63;
+    result += b64out.charAt(i);
+  }
+  return result;
+}
+
+// Normal base64 encode; not websafe, including padding.
+function base64_encode(bytes, opt_length) {
+  if (!opt_length) opt_length = bytes.length;
+  var b64out =
+      'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
+  var result = '';
+  var shift = 0;
+  var accu = 0;
+  var input_index = 0;
+  while (opt_length--) {
+    accu <<= 8;
+    accu |= bytes[input_index++];
+    shift += 8;
+    while (shift >= 6) {
+      var i = (accu >> (shift - 6)) & 63;
+      result += b64out.charAt(i);
+      shift -= 6;
+    }
+  }
+  if (shift) {
+    accu <<= 8;
+    shift += 8;
+    var i = (accu >> (shift - 6)) & 63;
+    result += b64out.charAt(i);
+  }
+  while (result.length % 4) result += '=';
+  return result;
+}
+
+var B64_inmap =
+[
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 63, 0, 0,
+ 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 0, 0, 0, 0, 0, 0,
+  0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
+ 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 0, 0, 0, 0, 64,
+  0, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41,
+ 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 0, 0, 0, 0, 0
+];
+
+function B64_decode(string) {
+  var bytes = [];
+  var accu = 0;
+  var shift = 0;
+  for (var i = 0; i < string.length; ++i) {
+    var c = string.charCodeAt(i);
+    if (c < 32 || c > 127 || !B64_inmap[c - 32]) return [];
+    accu <<= 6;
+    accu |= (B64_inmap[c - 32] - 1);
+    shift += 6;
+    if (shift >= 8) {
+      bytes.push((accu >> (shift - 8)) & 255);
+      shift -= 8;
+    }
+  }
+  return bytes;
+}