/*
|
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 MD5 = C_algo.MD5;
|
|
/**
|
* This key derivation function is meant to conform with EVP_BytesToKey.
|
* www.openssl.org/docs/crypto/EVP_BytesToKey.html
|
*/
|
var EvpKDF = C_algo.EvpKDF = Base.extend({
|
/**
|
* Configuration options.
|
*
|
* @property {number} keySize The key size in words to generate. Default: 4 (128 bits)
|
* @property {Hasher} hasher The hash algorithm to use. Default: MD5
|
* @property {number} iterations The number of iterations to perform. Default: 1
|
*/
|
cfg: Base.extend({
|
keySize: 128/32,
|
hasher: MD5,
|
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.EvpKDF.create();
|
* var kdf = CryptoJS.algo.EvpKDF.create({ keySize: 8 });
|
* var kdf = CryptoJS.algo.EvpKDF.create({ keySize: 8, iterations: 1000 });
|
*/
|
init: function (cfg) {
|
this.cfg = this.cfg.extend(cfg);
|
},
|
|
/**
|
* Derives a key from a password.
|
*
|
* @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 hasher
|
var hasher = cfg.hasher.create();
|
|
// Initial values
|
var derivedKey = WordArray.create();
|
|
// Shortcuts
|
var derivedKeyWords = derivedKey.words;
|
var keySize = cfg.keySize;
|
var iterations = cfg.iterations;
|
|
// Generate key
|
while (derivedKeyWords.length < keySize) {
|
if (block) {
|
hasher.update(block);
|
}
|
var block = hasher.update(password).finalize(salt);
|
hasher.reset();
|
|
// Iterations
|
for (var i = 1; i < iterations; i++) {
|
block = hasher.finalize(block);
|
hasher.reset();
|
}
|
|
derivedKey.concat(block);
|
}
|
derivedKey.sigBytes = keySize * 4;
|
|
return derivedKey;
|
}
|
});
|
|
/**
|
* Derives a key from a password.
|
*
|
* @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.EvpKDF(password, salt);
|
* var key = CryptoJS.EvpKDF(password, salt, { keySize: 8 });
|
* var key = CryptoJS.EvpKDF(password, salt, { keySize: 8, iterations: 1000 });
|
*/
|
C.EvpKDF = function (password, salt, cfg) {
|
return EvpKDF.create(cfg).compute(password, salt);
|
};
|
}());
|
