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 /**
  23  * SkeletonKey is view controller for generating secure passwords.
  24  *
  25  * @param {HTMLDocument} doc The document on which to operate.
  26  */
  27 var SkeletonKey = SkeletonKey || function(doc) {
  28   this._master = doc.getElementById('master');
  29   this._sitekey = doc.getElementById('sitekey');
  30   this._username = doc.getElementById('username');
  31   this._password = doc.getElementById('password');
  32   this._generateButton = doc.getElementById('generate');
  33   this._init();
  34 };
  35
  36 /**
  37  * The number of iterations to perform in PBKDF2.
  38  * @const {int}
  39  */
  40 SkeletonKey.prototype.ITERATIONS = 1000;
  41 /**
  42  * The size of the key, in bytes.
  43  * @const {int}
  44  */
  45 SkeletonKey.prototype.KEYSIZE = 256/32;
  46
  47 /**
  48  * The minimum length of a password.
  49  * @const {int}
  50  */
  51 SkeletonKey.prototype.MIN_LENGTH = 6;
  52
  53 /**
  54  * Initializes event handlers for the page.
  55  * @private
  56  */
  57 SkeletonKey.prototype._init = function() {
  58   this._generateButton.onclick = this._onGenerate.bind(this);
  59 };
  60
  61 /**
  62  * Event handler for generating a new password.
  63  * @param {Event} e
  64  * @private
  65  */
  66 SkeletonKey.prototype._onGenerate = function(e) {
  67   var salt = this._username.value + '@' + this._sitekey.value;
  68
  69   // |key| is a WordArray of 32-bit words.
  70   var key = CryptoJS.PBKDF2(this._master.value, salt,
  71       {keySize: this.KEYSIZE, iterations: this.ITERATIONS});
  72   var hexString = key.toString();
  73   hexString = this._capitalizeKey(hexString);
  74   this._password.value = hexString;
  75 };
  76
  77 /**
  78  * Takes a HEX string and returns a mixed-case string.
  79  * @param {string} key
  80  * @return string
  81  * @private
  82  */
  83 SkeletonKey.prototype._capitalizeKey = function(key) {
  84   // |key| is too long for a decent password, so try and use the second half of
  85   // it as the basis for capitalizing the key.
  86   var capsSource = null;
  87   var keyLength = key.length;
  88   if (keyLength / 2 <= this.MIN_LENGTH) {
  89     capsSouce = key.substr(0, keyLength - this.MIN_LENGTH);
  90   } else {
  91     capsSource = key.substr(keyLength / 2);
  92   }
  93
  94   if (!capsSource || capsSource.length < 1) {
  95     return key;
  96   }
  97
  98   key = key.substr(0, capsSource.length);
  99   var capsSourceLength = capsSource.length;
 100
 101   var j = 0;
 102   var newKey = "";
 103   for (var i = 0; i < key.length; i++) {
 104     var c = key.charCodeAt(i);
 105     // If this is not a lowercase letter or there's no more source, skip.
 106     if (c < 0x61 || c > 0x7A || j >= capsSourceLength) {
 107       newKey += key[i];
 108       continue;
 109     }
 110
 111     var makeCap = capsSource.charCodeAt(j++) % 2;
 112     if (makeCap)
 113       newKey += String.fromCharCode(c - 0x20);
 114     else
 115       newKey += key[i];
 116   }
 117
 118   return newKey;
 119 };