crypto-js/enc-base64.js

;(function (root, factory) {
	if (typeof exports === "object") {
		// CommonJS
		module.exports = exports = factory(require("./core"));
	}
	else if (typeof define === "function" && define.amd) {
		// AMD
		define(["./core"], factory);
	}
	else {
		// Global (browser)
		factory(root.CryptoJS);
	}
}(this, function (CryptoJS) {

	(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) {
	            // Shortcuts
	            var base64StrLength = base64Str.length;
	            var map = this._map;
	            var reverseMap = this._reverseMap;

	            if (!reverseMap) {
	                    reverseMap = this._reverseMap = [];
	                    for (var j = 0; j < map.length; j++) {
	                        reverseMap[map.charCodeAt(j)] = j;
	                    }
	            }

	            // Ignore padding
	            var paddingChar = map.charAt(64);
	            if (paddingChar) {
	                var paddingIndex = base64Str.indexOf(paddingChar);
	                if (paddingIndex !== -1) {
	                    base64StrLength = paddingIndex;
	                }
	            }

	            // Convert
	            return parseLoop(base64Str, base64StrLength, reverseMap);

	        },

	        _map: 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/='
	    };

	    function parseLoop(base64Str, base64StrLength, reverseMap) {
	      var words = [];
	      var nBytes = 0;
	      for (var i = 0; i < base64StrLength; i++) {
	          if (i % 4) {
	              var bits1 = reverseMap[base64Str.charCodeAt(i - 1)] << ((i % 4) * 2);
	              var bits2 = reverseMap[base64Str.charCodeAt(i)] >>> (6 - (i % 4) * 2);
	              words[nBytes >>> 2] |= (bits1 | bits2) << (24 - (nBytes % 4) * 8);
	              nBytes++;
	          }
	      }
	      return WordArray.create(words, nBytes);
	    }
	}());


	return CryptoJS.enc.Base64;

}));