B64 - EncoDeco

b64.js

function B64(c) {
   if (c == 63) return 47;
   else if (c == 62) return 43;
   else if (c >= 52) return c - 4;
   else if (c >= 26) return c + 71; 
   else return c + 65;
}

function B10(c) {
  if (c == 47) return 63;
  else if (c == 43) return 62;
  else if (c >= 97) return c - 71;
  else if (c >= 65) return c - 65;
  else return c + 4;
}

String.prototype.toBase64 = function() {
  var bits = this.split('').reduce(function(carry, char) { carry += ('00000000' + (char.charCodeAt()>>>0).toString(2)).substr(-8); return carry; }, '');
  var enc = ''; for (var i = 0; i < Math.ceil(bits.length / 6); i++) enc += String.fromCharCode(B64(parseInt(bits.substr(i*6, 6),2))); return enc;
};

String.prototype.fromBase64 = function() {
  var bits = this.split('').reduce(function(carry, char) { carry += ('00000000' + (B10(char.charCodeAt())>>>0).toString(2)).substr(-6); return carry; }, '');
  var enc = ''; for (var i = 0; i < Math.ceil(bits.length / 8); i++) enc += String.fromCharCode(parseInt(bits.substr(i*8, 8),2)); return enc;
};