// Base64 code from Tyler Akins -- http://rumkin.com

Base64 = (function() {
    var keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

    function encode64(input) {
	    var output = '';
	    var chr1, chr2, chr3;
	    var enc1, enc2, enc3, enc4;
	    var i = 0;

	    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 += keyStr.charAt(enc1) + keyStr.charAt(enc2) + keyStr.charAt(enc3) + keyStr.charAt(enc4);
       }
       
       return output.toString();
    }

    function decode64(input) {
	    var output = '';
	    var chr1, chr2, chr3;
	    var enc1, enc2, enc3, enc4;
	    var i = 0;

	    // remove all characters that are not A-Z, a-z, 0-9, +, /, or =
	    input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");

	    while (i < input.length) {
		    enc1 = keyStr.indexOf(input.charAt(i++));
		    enc2 = keyStr.indexOf(input.charAt(i++));
		    enc3 = keyStr.indexOf(input.charAt(i++));
		    enc4 = keyStr.indexOf(input.charAt(i++));

		    chr1 = (enc1 << 2) | (enc2 >> 4);
		    chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
		    chr3 = ((enc3 & 3) << 6) | enc4;

		    output += String.fromCharCode(chr1);

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

	    return output;
    }

    return { encode: encode64, decode: decode64 };
})();