js-beautify/unpackers/javascriptobfuscator_unpacker.js

//
// simple unpacker/deobfuscator for scripts messed up with javascriptobfuscator.com
// written by Einar Lielmanis <einar@jsbeautifier.org>
//
// usage:
//
// if (JavascriptObfuscator.detect(some_string)) {
//     var unpacked = JavascriptObfuscator.unpack(some_string);
// }
// 
//

var JavascriptObfuscator = {
    detect: function (str) {
        return /^var _0x[a-f0-9]+ ?\= ?\[/.test(str);
    },

    unpack: function (str) {
        if (JavascriptObfuscator.detect(str)) {
            var matches = /var (_0x[a-f\d]+) ?\= ?\[(.*?)\];/.exec(str);
            if (matches) {
                var var_name = matches[1];
                var strings = JavascriptObfuscator._smart_split(matches[2]);
                var str = str.substring(matches[0].length);
                for (var k in strings) {
                    str = str.replace(new RegExp(var_name + '\\[' + k + '\\]', 'g'), 
                        JavascriptObfuscator._fix_quotes(JavascriptObfuscator._unescape(strings[k])));
                }
            }
        }
        return str;
    },

    _fix_quotes: function(str) {
        var matches = /^"(.*)"$/.exec(str);
        if (matches) {
            str = matches[1];
            str = "'" + str.replace(/'/g, "\\'") + "'";
        }
        return str;
    },

    _smart_split: function(str) {
        var strings = [];
        var pos = 0;
        while (pos < str.length) {
            if (str.charAt(pos) == '"') {
                // new word
                var word = '';
                pos += 1;
                while (pos < str.length) {
                    if (str.charAt(pos) == '"') {
                        break;
                    }
                    if (str.charAt(pos) == '\\') {
                        word += '\\';
                        pos++;
                    }
                    word += str.charAt(pos);
                    pos++;
                }
                strings.push('"' + word + '"');
            }
            pos += 1;
        }
        return strings;
    },


    _unescape: function (str) {
        // inefficient if used repeatedly or on small strings, but wonderful on single large chunk of text
        for (var i = 32; i < 128; i++) {
            str = str.replace(new RegExp('\\\\x' + i.toString(16), 'ig'), String.fromCharCode(i));
        }
        return str;
    },

    run_tests: function (sanity_test) {
        var t = sanity_test || new SanityTest();

        t.test_function(JavascriptObfuscator._smart_split, "JavascriptObfuscator._smart_split");
        t.expect('', []);
        t.expect('"a", "b"', ['"a"', '"b"']);
        t.expect('"aaa","bbbb"', ['"aaa"', '"bbbb"']);
        t.expect('"a", "b\\\""', ['"a"', '"b\\\""']);
        t.test_function(JavascriptObfuscator._unescape, 'JavascriptObfuscator._unescape');
        t.expect('\\x40', '@');
        t.expect('\\x10', '\\x10');
        t.expect('\\x1', '\\x1');
        t.expect("\\x61\\x62\\x22\\x63\\x64", 'ab"cd');
        t.test_function(JavascriptObfuscator.detect, 'JavascriptObfuscator.detect');
        t.expect('', false);
        t.expect('abcd', false);
        t.expect('var _0xaaaa', false);
        t.expect('var _0xaaaa = ["a", "b"]', true);
        t.expect('var _0xaaaa=["a", "b"]', true);
        t.expect('var _0x1234=["a","b"]', true);
        return t;
    }


}