/*
PROJECT: Javascript Based Base64 Encoding and Decoding Engine

DATE: 02/10/2004

AUTHOR: Adrian Bacon

DESCRIPTION:Encode and decode data to and from the Base64 format
in Javascript. This could be used to convert encrypted
data to text for submitting via http gets or posts or
for sending via email or other text only mediums.

COPYRIGHT: You are free to use this code as you see fit provided
that you send any changes or modifications back to me.
*/

//First things first, set up our array that we are going to use.
var keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" + //all caps
"abcdefghijklmnopqrstuvwxyz" + //all lowercase
"0123456789+/="; // all numbers plus +/=

//Heres the encode function
function encode64(inp)
{
	var out = ""; //This is the output
	var chr1, chr2, chr3 = ""; //These are the 3 bytes to be encoded
	var enc1, enc2, enc3, enc4 = ""; //These are the 4 encoded bytes
	var i = 0; //Position counter

	do { //Set up the loop here
		chr1 = inp.charCodeAt(i++); //Grab the first byte
		chr2 = inp.charCodeAt(i++); //Grab the second byte
		chr3 = inp.charCodeAt(i++); //Grab the third byte

		//Here is the actual base64 encode part.
		//There really is only one way to do it.
		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;
		}

		//Lets spit out the 4 encoded bytes
		out = out + keyStr.charAt(enc1) + keyStr.charAt(enc2) + keyStr.charAt(enc3) +
		keyStr.charAt(enc4);

		// OK, now clean out the variables used.
		chr1 = chr2 = chr3 = "";
		enc1 = enc2 = enc3 = enc4 = "";

	} while (i < inp.length); //And finish off the loop

	//Now return the encoded values.
	return out;
}

//Heres the decode function
function decode64(inp)
{
	var out = ""; //This is the output
	var chr1, chr2, chr3 = ""; //These are the 3 decoded bytes
	var enc1, enc2, enc3, enc4 = ""; //These are the 4 bytes to be decoded
	var i = 0; //Position counter

	// remove all characters that are not A-Z, a-z, 0-9, +, /, or =
	var base64test = /[^A-Za-z0-9\+\/\=]/g;

	if (base64test.exec(inp)) { //Do some error checking
		alert("There were invalid base64 characters in the input text.\n" +
		"Valid base64 characters are A-Z, a-z, 0-9, ?+?, ?/?, and ?=?\n" +
		"Expect errors in decoding.");
	}
	inp = inp.replace(/[^A-Za-z0-9\+\/\=]/g, "");

	do { //Here.s the decode loop.

		//Grab 4 bytes of encoded content.
		enc1 = keyStr.indexOf(inp.charAt(i++));
		enc2 = keyStr.indexOf(inp.charAt(i++));
		enc3 = keyStr.indexOf(inp.charAt(i++));
		enc4 = keyStr.indexOf(inp.charAt(i++));

		//Heres the decode part. There.s really only one way to do it.
		chr1 = (enc1 << 2) | (enc2 >> 4);
		chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
		chr3 = ((enc3 & 3) << 6) | enc4;

		//Start to output decoded content
		out = out + String.fromCharCode(chr1);

		if (enc3 != 64) {
			out = out + String.fromCharCode(chr2);
		}
		if (enc4 != 64) {
			out = out + String.fromCharCode(chr3);
		}

		//now clean out the variables used
		chr1 = chr2 = chr3 = "";
		enc1 = enc2 = enc3 = enc4 = "";

	} while (i < inp.length); //finish off the loop

	//Now return the decoded values.
	return out;
}

function disObfuscate(a, input) {
  var s = decode64(input);
  var n = 0;
  var t = "";
  for( var i = 0; i < s.length; i++) {
    n = s.charCodeAt(i);
    t += String.fromCharCode(n^(27+i));
  }
  a.innerHTML = t;
  a.href = "mailto:"+t;
  return t;  
}