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/*
CryptoJS v3.1.2
code.google.com/p/crypto-js
(c) 2009-2013 by Jeff Mott. All rights reserved.
code.google.com/p/crypto-js/wiki/License
*/
(function () {
// Shortcuts
var C = CryptoJS;
var C_lib = C.lib;
var Base = C_lib.Base;
var WordArray = C_lib.WordArray;
var C_algo = C.algo;
var SHA1 = C_algo.SHA1;
var HMAC = C_algo.HMAC;
/**
* Password-Based Key Derivation Function 2 algorithm.
*/
var PBKDF2 = C_algo.PBKDF2 = Base.extend({
/**
* Configuration options.
*
* @property {number} keySize The key size in words to generate. Default: 4 (128 bits)
* @property {Hasher} hasher The hasher to use. Default: SHA1
* @property {number} iterations The number of iterations to perform. Default: 1
*/
cfg: Base.extend({
keySize: 128/32,
hasher: SHA1,
iterations: 1
}),
/**
* Initializes a newly created key derivation function.
*
* @param {Object} cfg (Optional) The configuration options to use for the derivation.
*
* @example
*
* var kdf = CryptoJS.algo.PBKDF2.create();
* var kdf = CryptoJS.algo.PBKDF2.create({ keySize: 8 });
* var kdf = CryptoJS.algo.PBKDF2.create({ keySize: 8, iterations: 1000 });
*/
init: function (cfg) {
this.cfg = this.cfg.extend(cfg);
},
/**
* Computes the Password-Based Key Derivation Function 2.
*
* @param {WordArray|string} password The password.
* @param {WordArray|string} salt A salt.
*
* @return {WordArray} The derived key.
*
* @example
*
* var key = kdf.compute(password, salt);
*/
compute: function (password, salt) {
// Shortcut
var cfg = this.cfg;
// Init HMAC
var hmac = HMAC.create(cfg.hasher, password);
// Initial values
var derivedKey = WordArray.create();
var blockIndex = WordArray.create([0x00000001]);
// Shortcuts
var derivedKeyWords = derivedKey.words;
var blockIndexWords = blockIndex.words;
var keySize = cfg.keySize;
var iterations = cfg.iterations;
// Generate key
while (derivedKeyWords.length < keySize) {
var block = hmac.update(salt).finalize(blockIndex);
hmac.reset();
// Shortcuts
var blockWords = block.words;
var blockWordsLength = blockWords.length;
// Iterations
var intermediate = block;
for (var i = 1; i < iterations; i++) {
intermediate = hmac.finalize(intermediate);
hmac.reset();
// Shortcut
var intermediateWords = intermediate.words;
// XOR intermediate with block
for (var j = 0; j < blockWordsLength; j++) {
blockWords[j] ^= intermediateWords[j];
}
}
derivedKey.concat(block);
blockIndexWords[0]++;
}
derivedKey.sigBytes = keySize * 4;
return derivedKey;
}
});
/**
* Computes the Password-Based Key Derivation Function 2.
*
* @param {WordArray|string} password The password.
* @param {WordArray|string} salt A salt.
* @param {Object} cfg (Optional) The configuration options to use for this computation.
*
* @return {WordArray} The derived key.
*
* @static
*
* @example
*
* var key = CryptoJS.PBKDF2(password, salt);
* var key = CryptoJS.PBKDF2(password, salt, { keySize: 8 });
* var key = CryptoJS.PBKDF2(password, salt, { keySize: 8, iterations: 1000 });
*/
C.PBKDF2 = function (password, salt, cfg) {
return PBKDF2.create(cfg).compute(password, salt);
};
}());
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