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/**
 *
 *  Base64 encode / decode
 *  http://www.webtoolkit.info/
 *
 **/

var Base64 = Base64 || {};

(function (base64) {
    "use strict";

    var _keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
        _utf8_encode = function (string) { // private method for UTF-8 encoding
            string = string.replace(/\r\n/g, "\n");
            var utftext = "";

            for (var n = 0; n < string.length; n++) {

                var c = string.charCodeAt(n);

                if (c < 128) {
                    utftext += String.fromCharCode(c);
                }
                else if ((c > 127) && (c < 2048)) {
                    utftext += String.fromCharCode((c >> 6) | 192);
                    utftext += String.fromCharCode((c & 63) | 128);
                }
                else {
                    utftext += String.fromCharCode((c >> 12) | 224);
                    utftext += String.fromCharCode(((c >> 6) & 63) | 128);
                    utftext += String.fromCharCode((c & 63) | 128);
                }

            }

            return utftext;
        },
        _utf8_decode = function (utftext) { // private method for UTF-8 decoding
            var string = "";
            var i = 0;
            var c1 = 0,
                c2 = 0,
                c3 = 0;

            while (i < utftext.length) {

                c1 = utftext.charCodeAt(i);

                if (c1 < 128) {
                    string += String.fromCharCode(c1);
                    i++;
                }
                else if ((c1 > 191) && (c1 < 224)) {
                    c2 = utftext.charCodeAt(i + 1);
                    string += String.fromCharCode(((c1 & 31) << 6) | (c2 & 63));
                    i += 2;
                }
                else {
                    c2 = utftext.charCodeAt(i + 1);
                    c3 = utftext.charCodeAt(i + 2);
                    string += String.fromCharCode(((c1 & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
                    i += 3;
                }

            }

            return string;
        };

    // public method for encoding
    base64.encode = function (input) {
        var output = "";
        var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
        var i = 0;

        input = _utf8_encode(input);

        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 = output +
                _keyStr.charAt(enc1) + _keyStr.charAt(enc2) +
                _keyStr.charAt(enc3) + _keyStr.charAt(enc4);

        }

        return output;
    };

    // public method for decoding
    base64.decode = function (input) {
        var output = "";
        var chr1, chr2, chr3;
        var enc1, enc2, enc3, enc4;
        var i = 0;

        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 = output + String.fromCharCode(chr1);

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

        }

        output = _utf8_decode(output);

        return output;

    };

})(Base64);
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