base64.js

/**
 * Refactored variant in order to properly encapsulate private/protected 
 * methods within a functional scope and make things look a lot cleaner 
 * and lintier for greater good. 
 *
 * @voodootikigod
 */

 
/**
 *
 *  Base64 encode / decode
 *  Adapted from: http://www.webtoolkit.info/
 *
 **/

var Base64 = (function() {
 
  // private property
  var _keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

  // private method for UTF-8 encoding
  var _utf8_encode = function (string) {
    string = string.replace(/\r\n/g,"\n");
    var utftext = "";
    for (var n = 0; n < string.length; n++) {
      var c = string.charCodeAt(n);
      if (c < 128) {
        utftext += String.fromCharCode(c);
      }
      else if((c > 127) && (c < 2048)) {
        utftext += String.fromCharCode((c >> 6) | 192);
        utftext += String.fromCharCode((c & 63) | 128);
      }
      else {
        utftext += String.fromCharCode((c >> 12) | 224);
        utftext += String.fromCharCode(((c >> 6) & 63) | 128);
        utftext += String.fromCharCode((c & 63) | 128);
      }
    }
    return utftext;
  };
 
  // private method for UTF-8 decoding
  var _utf8_decode = function (utftext) {
    var string = "";
    var i = 0;
    var c = c1 = c2 = 0;
    while ( i < utftext.length ) {
      c = utftext.charCodeAt(i);
      if (c < 128) {
        string += String.fromCharCode(c);
        i++;
      }
      else if((c > 191) && (c < 224)) {
        c2 = utftext.charCodeAt(i+1);
        string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
        i += 2;
      }
      else {
        c2 = utftext.charCodeAt(i+1);
        c3 = utftext.charCodeAt(i+2);
        string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
        i += 3;
      }
    }
    return string;
  };


  return {
    encode : function (input) {
      var output = "";
      var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
      var i = 0;
 
      input = _utf8_encode(input);
 
      while (i < input.length) {
 
        chr1 = input.charCodeAt(i++);
        chr2 = input.charCodeAt(i++);
        chr3 = input.charCodeAt(i++);
 
        enc1 = chr1 >> 2;
        enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
        enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
        enc4 = chr3 & 63;
 
        if (isNaN(chr2)) {
          enc3 = enc4 = 64;
        } else if (isNaN(chr3)) {
          enc4 = 64;
        }
 
        output = output +
        _keyStr.charAt(enc1) + _keyStr.charAt(enc2) +
        _keyStr.charAt(enc3) + _keyStr.charAt(enc4);
 
      }
 
      return output;
    },
 
    // public method for decoding
    decode : function (input) {
      var output = "";
      var chr1, chr2, chr3;
      var enc1, enc2, enc3, enc4;
      var i = 0;
 
      input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
 
      while (i < input.length) {
 
        enc1 = this._keyStr.indexOf(input.charAt(i++));
        enc2 = this._keyStr.indexOf(input.charAt(i++));
        enc3 = this._keyStr.indexOf(input.charAt(i++));
        enc4 = this._keyStr.indexOf(input.charAt(i++));
 
        chr1 = (enc1 << 2) | (enc2 >> 4);
        chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
        chr3 = ((enc3 & 3) << 6) | enc4;
 
        output = output + String.fromCharCode(chr1);
 
        if (enc3 != 64) {
          output = output + String.fromCharCode(chr2);
        }
        if (enc4 != 64) {
          output = output + String.fromCharCode(chr3);
        }
 
      }
 
      output = exports.base64._utf8_decode(output);
 
      return output;
 
    }
  }
})()

exports.encode = Base64.encode;
exports.decode = Base64.decode;