weibo/lib/base64.js

Weibo SDK, base on node. Now support weibo, tqq, tsohu, twitter and github.

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

// support atob and btoa native method in browser

(function () {

var Base64 = {
 
  // private property
  _keyStr : "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
 
  // public method for encoding
  encode: function (input) {
    var output = "";
    var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
    var i = 0;
 
    input = Base64._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 +
      this._keyStr.charAt(enc1) + this._keyStr.charAt(enc2) +
      this._keyStr.charAt(enc3) + this._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 = Base64._utf8_decode(output);
 
    return output;
 
  },
 
  // private method for UTF-8 encoding
  _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
  _utf8_decode : function (utftext) {
    var string = "";
    var i = 0;
    var c = 0, c1 = 0, 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;
  },
  /**
   * A str encode and decode use on phpwind
   * 
   * e.g.: var my_key = 'awejfosjdlxldfjlsdfwerwljxoasldf!@##@'
   *  // encode
   *  var encode_str = Base64.strcode('fawave发威', my_key);
   *  // decode
   *  var source_str = Base64.strcode(encode_str, my_key, true)
   * 
   * @param {String} str
   * @param {String} key
   * @param {Boolen} decode, default is `false`
   * @return {String} encode or decode string
   * @api public
   */
  strcode: function (str, key, decode) {
      var keybuffer = this.utf8_encode(key);
      var key_length = keybuffer.length;
      var buffer = null, encoding = 'base64';
      if(decode) {
        buffer = this.decode(str);
      } else {
        buffer = this.utf8_encode(str);
      }
      var buf = '';
      for (var i = 0, len = buffer.length; i < len; i++) {
        var k = i % key_length;
        buf += String.fromCharCode(buffer.charCodeAt(i) ^ keybuffer.charCodeAt(k));
      }
      if (decode) {
        return this.utf8_decode(buffer);
      } else {
        return this.encode(buffer);
      }
  }
};

Base64.utf8_encode = Base64._utf8_encode;
Base64.utf8_decode = Base64._utf8_decode;

var root = this; // window on browser
if (typeof module === 'undefined') {
  root.weibo = root.weibo || {};
  root.weibo.base64 = Base64;
} else {
  module.exports = Base64;
}

})();