core.js

   1 /* Copyright (c) 2012 Robert Sesek <http://robert.sesek.com>
   2  *
   3  * Permission is hereby granted, free of charge, to any person obtaining a copy
   4  * of this software and associated documentation files (the "Software"), to
   5  * deal in the Software without restriction, including without limitation the
   6  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
   7  * sell copies of the Software, and to permit persons to whom the Software is
   8  * furnished to do so, subject to the following conditions:
   9  *
  10  * The above copyright notice and this permission notice shall be included in
  11  * all copies or substantial portions of the Software.
  12  *
  13  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  14  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  15  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  16  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  17  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  18  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  19  * DEALINGS IN THE SOFTWARE.
  20  */
  21
  22 (function main() {
  23   if (typeof chrome !== 'undefined') {
  24     // TODO: load the extension JS
  25   } else {
  26     // TODO: load the hosted JS
  27   }
  28
  29   document.addEventListener('DOMContentLoaded', function() {
  30     var controller = new SkeletonKey(document);
  31   });
  32 })();
  33
  34 /**
  35  * SkeletonKey is view controller for generating secure passwords.
  36  *
  37  * @param {HTMLDocument} doc The document on which to operate.
  38  */
  39 var SkeletonKey = SkeletonKey || function(doc) {
  40   this._master = doc.getElementById('master');
  41   this._sitekey = doc.getElementById('sitekey');
  42   this._username = doc.getElementById('username');
  43   this._password = doc.getElementById('password');
  44   this._generateButton = doc.getElementById('generate');
  45   this._init();
  46 };
  47
  48 /**
  49  * The number of iterations to perform in PBKDF2.
  50  * @const {int}
  51  */
  52 SkeletonKey.prototype.ITERATIONS = 1000;
  53 /**
  54  * The size of the key, in bytes.
  55  * @const {int}
  56  */
  57 SkeletonKey.prototype.KEYSIZE = 256/32;
  58
  59 /**
  60  * The minimum length of a password.
  61  * @const {int}
  62  */
  63 SkeletonKey.prototype.MIN_LENGTH = 6;
  64
  65 /**
  66  * Initializes event handlers for the page.
  67  * @private
  68  */
  69 SkeletonKey.prototype._init = function() {
  70   this._generateButton.onclick = this._onGenerate.bind(this);
  71 };
  72
  73 /**
  74  * Event handler for generating a new password.
  75  * @param {Event} e
  76  * @private
  77  */
  78 SkeletonKey.prototype._onGenerate = function(e) {
  79   var salt = this._username.value + '@' + this._sitekey.value;
  80
  81   // |key| is a WordArray of 32-bit words.
  82   var key = CryptoJS.PBKDF2(this._master.value, salt,
  83       {keySize: this.KEYSIZE, iterations: this.ITERATIONS});
  84   var hexString = key.toString();
  85   hexString = this._capitalizeKey(hexString);
  86   this._password.value = hexString;
  87   this._password.focus();
  88   this._password.select();
  89 };
  90
  91 /**
  92  * Takes a HEX string and returns a mixed-case string.
  93  * @param {string} key
  94  * @return string
  95  * @private
  96  */
  97 SkeletonKey.prototype._capitalizeKey = function(key) {
  98   // |key| is too long for a decent password, so try and use the second half of
  99   // it as the basis for capitalizing the key.
 100   var capsSource = null;
 101   var keyLength = key.length;
 102   if (keyLength / 2 <= this.MIN_LENGTH) {
 103     capsSouce = key.substr(0, keyLength - this.MIN_LENGTH);
 104   } else {
 105     capsSource = key.substr(keyLength / 2);
 106   }
 107
 108   if (!capsSource || capsSource.length < 1) {
 109     return key;
 110   }
 111
 112   key = key.substr(0, capsSource.length);
 113   var capsSourceLength = capsSource.length;
 114
 115   var j = 0;
 116   var newKey = "";
 117   for (var i = 0; i < key.length; i++) {
 118     var c = key.charCodeAt(i);
 119     // If this is not a lowercase letter or there's no more source, skip.
 120     if (c < 0x61 || c > 0x7A || j >= capsSourceLength) {
 121       newKey += key[i];
 122       continue;
 123     }
 124
 125     var makeCap = capsSource.charCodeAt(j++) % 2;
 126     if (makeCap)
 127       newKey += String.fromCharCode(c - 0x20);
 128     else
 129       newKey += key[i];
 130   }
 131
 132   return newKey;
 133 };