jwee-base64.js

//////////////////////////////////////////////////////////////////////////
// JWee JavaScript Framework & Toolkit 
// Copyright (c) 2010 AUTHORS (jweeframework@gmail.com)
// Licensed under the MIT and GPL (for now). 
// http://www.jwee.org
//////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////

wee.base64 = {
	
	
	decode: function(data) {

		 var b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
		 var o1, o2, o3, h1, h2, h3, h4, bits, i = 0, ac = 0, dec = "", tmp_arr = [];
	
		 if (!data) {
			  return data;
		 }
	
		 data += '';
	
		 do {  // unpack four hexets into three octets using index points in b64
			  h1 = b64.indexOf(data.charAt(i++));
			  h2 = b64.indexOf(data.charAt(i++));
			  h3 = b64.indexOf(data.charAt(i++));
			  h4 = b64.indexOf(data.charAt(i++));
	
			  bits = h1<<18 | h2<<12 | h3<<6 | h4;
	
			  o1 = bits>>16 & 0xff;
			  o2 = bits>>8 & 0xff;
			  o3 = bits & 0xff;
	
			  if (h3 == 64) {
					tmp_arr[ac++] = String.fromCharCode(o1);
			  } else if (h4 == 64) {
					tmp_arr[ac++] = String.fromCharCode(o1, o2);
			  } else {
					tmp_arr[ac++] = String.fromCharCode(o1, o2, o3);
			  }
		 } while (i < data.length);
	
		 dec = tmp_arr.join('');
//		 dec = this.utf8_decode(dec);
	
		 return dec;
	},

	encode: 
		function(data) {
			  
		 var b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
		 var o1, o2, o3, h1, h2, h3, h4, bits, i = 0, ac = 0, enc="", tmp_arr = [];
	
		 if (!data) {
			  return data;
		 }
	
		 data = this.utf8_encode(data+'');
		 
		 do { // pack three octets into four hexets
			  o1 = data.charCodeAt(i++);
			  o2 = data.charCodeAt(i++);
			  o3 = data.charCodeAt(i++);
	
			  bits = o1<<16 | o2<<8 | o3;
	
			  h1 = bits>>18 & 0x3f;
			  h2 = bits>>12 & 0x3f;
			  h3 = bits>>6 & 0x3f;
			  h4 = bits & 0x3f;
	
			  // use hexets to index into b64, and append result to encoded string
			  tmp_arr[ac++] = b64.charAt(h1) + b64.charAt(h2) + b64.charAt(h3) + b64.charAt(h4);
		 } while (i < data.length);
		 
		 enc = tmp_arr.join('');
		 
		 switch (data.length % 3) {
			  case 1:
					enc = enc.slice(0, -2) + '==';
			  break;
			  case 2:
					enc = enc.slice(0, -1) + '=';
			  break;
		 }
	
		 return enc;
	}
	
};