github.com/jincm/wesharechain@v0.0.0-20210122032815-1537409ce26a/app/lib/crypto1/pbkdf2/pbkdf2.js (about)

     1  /*!
     2   * Crypto-JS v1.1.0
     3   * http://code.google.com/p/crypto-js/
     4   * Copyright (c) 2009, Jeff Mott. All rights reserved.
     5   * http://code.google.com/p/crypto-js/wiki/License
     6   */
     7  (function(){
     8  
     9  // Shortcut
    10  var util = Crypto.util;
    11  
    12  Crypto.PBKDF2 = function (password, salt, keylen, options) {
    13  
    14  	// Defaults
    15  	var hasher = options && options.hasher || Crypto.SHA1,
    16  	    iterations = options && options.iterations || 1;
    17  
    18  	// Pseudo-random function
    19  	function PRF(password, salt) {
    20  		return Crypto.HMAC(hasher, salt, password, { asBytes: true });
    21  	}
    22  
    23  	// Generate key
    24  	var derivedKeyBytes = [],
    25  	    blockindex = 1;
    26  	while (derivedKeyBytes.length < keylen) {
    27  
    28  		var block = PRF(password, salt + util.bytesToString(
    29  		                                 util.wordsToBytes([blockindex])));
    30  
    31  		for (var u = block, i = 1; i < iterations; i++) {
    32  			u = PRF(password, util.bytesToString(u));
    33  			for (var j = 0; j < block.length; j++) block[j] ^= u[j];
    34  		}
    35  
    36  		derivedKeyBytes = derivedKeyBytes.concat(block);
    37  		blockindex++;
    38  
    39  	}
    40  
    41  	// Truncate excess bytes
    42  	derivedKeyBytes.length = keylen;
    43  
    44  	return options && options.asBytes ? derivedKeyBytes :
    45  	       options && options.asString ? util.bytesToString(derivedKeyBytes) :
    46  	       util.bytesToHex(derivedKeyBytes);
    47  
    48  };
    49  
    50  })();