filer/lib/crypto-js/components/enc-base64.js

113 lines
3.4 KiB
JavaScript

/*
CryptoJS v3.0.2
code.google.com/p/crypto-js
(c) 2009-2012 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 WordArray = C_lib.WordArray;
var C_enc = C.enc;
/**
* Base64 encoding strategy.
*/
var Base64 = C_enc.Base64 = {
/**
* Converts a word array to a Base64 string.
*
* @param {WordArray} wordArray The word array.
*
* @return {string} The Base64 string.
*
* @static
*
* @example
*
* var base64String = CryptoJS.enc.Base64.stringify(wordArray);
*/
stringify: function (wordArray) {
// Shortcuts
var words = wordArray.words;
var sigBytes = wordArray.sigBytes;
var map = this._map;
// Clamp excess bits
wordArray.clamp();
// Convert
var base64Chars = [];
for (var i = 0; i < sigBytes; i += 3) {
var byte1 = (words[i >>> 2] >>> (24 - (i % 4) * 8)) & 0xff;
var byte2 = (words[(i + 1) >>> 2] >>> (24 - ((i + 1) % 4) * 8)) & 0xff;
var byte3 = (words[(i + 2) >>> 2] >>> (24 - ((i + 2) % 4) * 8)) & 0xff;
var triplet = (byte1 << 16) | (byte2 << 8) | byte3;
for (var j = 0; (j < 4) && (i + j * 0.75 < sigBytes); j++) {
base64Chars.push(map.charAt((triplet >>> (6 * (3 - j))) & 0x3f));
}
}
// Add padding
var paddingChar = map.charAt(64);
if (paddingChar) {
while (base64Chars.length % 4) {
base64Chars.push(paddingChar);
}
}
return base64Chars.join('');
},
/**
* Converts a Base64 string to a word array.
*
* @param {string} base64Str The Base64 string.
*
* @return {WordArray} The word array.
*
* @static
*
* @example
*
* var wordArray = CryptoJS.enc.Base64.parse(base64String);
*/
parse: function (base64Str) {
// Ignore whitespaces
base64Str = base64Str.replace(/\s/g, '');
// Shortcuts
var base64StrLength = base64Str.length;
var map = this._map;
// Ignore padding
var paddingChar = map.charAt(64);
if (paddingChar) {
var paddingIndex = base64Str.indexOf(paddingChar);
if (paddingIndex != -1) {
base64StrLength = paddingIndex;
}
}
// Convert
var words = [];
var nBytes = 0;
for (var i = 0; i < base64StrLength; i++) {
if (i % 4) {
var bitsHigh = map.indexOf(base64Str.charAt(i - 1)) << ((i % 4) * 2);
var bitsLow = map.indexOf(base64Str.charAt(i)) >>> (6 - (i % 4) * 2);
words[nBytes >>> 2] |= (bitsHigh | bitsLow) << (24 - (nBytes % 4) * 8);
nBytes++;
}
}
return WordArray.create(words, nBytes);
},
_map: 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/='
};
}());