if (!window.atob) {

  var tableStr = ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/;

  var table = tableStr.split();



  window.atob = function (base64) {

    if (/(=[^=]+|={3,})$/.test(base64)) throw new Error(String contains an invalid character);

    base64 = base64.replace(/=/g, );

    var n = base64.length & 3;

    if (n === 1) throw new Error(String contains an invalid character);

    for (var i = 0, j = 0, len = base64.length / 4, bin = []; i < len; ++i) {

      var a = tableStr.indexOf(base64[j++] || A), b = tableStr.indexOf(base64[j++] || A);

      var c = tableStr.indexOf(base64[j++] || A), d = tableStr.indexOf(base64[j++] || A);

      if ((a | b | c | d) < 0) throw new Error(String contains an invalid character);

      bin[bin.length] = ((a << 2) | (b >> 4)) & 255;

      bin[bin.length] = ((b << 4) | (c >> 2)) & 255;

      bin[bin.length] = ((c << 6) | d) & 255;

    };

    return String.fromCharCode.apply(null, bin).substr(0, bin.length + n - 4);

  };



  window.btoa = function (bin) {

    for (var i = 0, j = 0, len = bin.length / 3, base64 = []; i < len; ++i) {

      var a = bin.charCodeAt(j++), b = bin.charCodeAt(j++), c = bin.charCodeAt(j++);

      if ((a | b | c) > 255) throw new Error(String contains an invalid character);

      base64[base64.length] = table[a >> 2] + table[((a << 4) & 63) | (b >> 4)] +

                              (isNaN(b) ? = : table[((b << 2) & 63) | (c >> 6)]) +

                              (isNaN(b + c) ? = : table[c & 63]);

    }

    return base64.join();

  };



}



function hexToBase64(str) {

  return btoa(String.fromCharCode.apply(null,

    str.replace(/r|n/g, ).replace(/([da-fA-F]{2}) ?/g, 0x$1 ).replace(/ +$/, ).split( ))

  );

}



function base64ToHex(str) {

  for (var i = 0, bin = atob(str.replace(/[ rn]+$/, )), hex = []; i < bin.length; ++i) {

    var tmp = bin.charCodeAt(i).toString(16);

    if (tmp.length === 1) tmp = 0 + tmp;

    hex[hex.length] = tmp;

  }

  return hex.join( );

}