source: branches/1.2/workflow/js/jscode/base64.js @ 1349

// This code was written by Tyler Akins and has been placed in the
// public domain. It would be nice if you left this header intact.
// Base64 code from Tyler Akins -- http://rumkin.com

keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

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

        do {
                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 = output + keyStr.charAt(enc1) + keyStr.charAt(enc2) +
                keyStr.charAt(enc3) + keyStr.charAt(enc4);
        } while (i < input.length);
        return output;
}

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, "");

        do {
                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 = output + String.fromCharCode(chr1);

                if (enc3 != 64) {
                        output = output + String.fromCharCode(chr2);
                }
                if (enc4 != 64) {
                        output = output + String.fromCharCode(chr3);
                }
        } while (i < input.length);

        return output;
}