最近需要參考下易企秀H5的json配置文件，發現已經做了加密，其實前端的加密分析起來只是麻煩點。

抓包分析

先看一個H5： https://h5.eqxiu.com/s/XvEn30op

F12可以看到，配置json地址是：https://s1-cdn.eqxiu.com/eqs/page/142626394?code=XvEn30op&time=1542972816000

對應的json：

{"success":true,"code":200,"msg":"操作成功","obj":"加密後的字符串"}

obj對應的是正式的配置信息

解碼分析

需要對加密信息進行解密，首先可以定位到解密代碼

function _0x230bc7(_0x2fb175) {
    return _0x3c31('0xee') == typeof _0x2fb175[_0x3c31('0x25')] && _0x2fb175['\x6f\x62\x6a'][_0x3c31('0xe')] > 0x64 ? _0x54c90c[_0x3c31('0x31f')]()['\x74\x68\x65\x6e'](function() {
        _0x249a60();
        var _0x5ab652 = null
          , _0x2cf0a4 = null
          , _0x4d1175 = null;
        try {
            var _0x3dbfaa = _0x2fb175[_0x3c31('0x25')]['\x73\x75\x62\x73\x74\x72\x69\x6e\x67'](0x0, 0x13)
              , _0x360e25 = _0x2fb175[_0x3c31('0x25')][_0x3c31('0xeb')](0x13 + 0x10);
            _0x2cf0a4 = _0x2fb175[_0x3c31('0x25')][_0x3c31('0xeb')](0x13, 0x13 + 0x10),
            _0x4d1175 = _0x2cf0a4,
            _0x5ab652 = _0x3dbfaa + _0x360e25,
            _0x2cf0a4 = CryptoJS['\x65\x6e\x63'][_0x3c31('0x320')][_0x3c31('0x6b')](_0x2cf0a4),
            _0x4d1175 = CryptoJS[_0x3c31('0x321')][_0x3c31('0x320')]['\x70\x61\x72\x73\x65'](_0x4d1175);
            var _0x57e61a = CryptoJS[_0x3c31('0x322')][_0x3c31('0x323')](_0x5ab652, _0x2cf0a4, {
                '\x69\x76': _0x4d1175,
                '\x6d\x6f\x64\x65': CryptoJS[_0x3c31('0x324')][_0x3c31('0x325')],
                '\x70\x61\x64\x64\x69\x6e\x67': CryptoJS[_0x3c31('0x326')][_0x3c31('0x327')]
            });
            return _0x2fb175[_0x3c31('0x36')] = JSON[_0x3c31('0x6b')](CryptoJS[_0x3c31('0x321')][_0x3c31('0x320')][_0x3c31('0x267')](_0x57e61a)),
            _0x2fb175;
        } catch (_0x36fffe) {
            _0x5ab652 = _0x2fb175[_0x3c31('0x25')]['\x73\x75\x62\x73\x74\x72\x69\x6e\x67'](0x0, _0x2fb175[_0x3c31('0x25')][_0x3c31('0xe')] - 0x10),
            _0x2cf0a4 = _0x2fb175[_0x3c31('0x25')][_0x3c31('0xeb')](_0x2fb175[_0x3c31('0x25')][_0x3c31('0xe')] - 0x10),
            _0x4d1175 = _0x2cf0a4,
            _0x2cf0a4 = CryptoJS[_0x3c31('0x321')][_0x3c31('0x320')][_0x3c31('0x6b')](_0x2cf0a4),
            _0x4d1175 = CryptoJS[_0x3c31('0x321')][_0x3c31('0x320')][_0x3c31('0x6b')](_0x4d1175);
            var _0x4ff7de = CryptoJS[_0x3c31('0x322')][_0x3c31('0x323')](_0x5ab652, _0x2cf0a4, {
                '\x69\x76': _0x4d1175,
                '\x6d\x6f\x64\x65': CryptoJS['\x6d\x6f\x64\x65'][_0x3c31('0x325')],
                '\x70\x61\x64\x64\x69\x6e\x67': CryptoJS[_0x3c31('0x326')][_0x3c31('0x327')]
            });
            return _0x2fb175[_0x3c31('0x36')] = JSON[_0x3c31('0x6b')](CryptoJS[_0x3c31('0x321')]['\x55\x74\x66\x38'][_0x3c31('0x267')](_0x4ff7de)),
            _0x2fb175;
        }
    }) : Promise[_0x3c31('0x1e')](_0x2fb175);
 

這個代碼基本不可讀，簡單分析下可以發現，_0x3c31(‘0x321‘)對應一個字符串，‘\x6f\x62\x6a‘等也可以轉義：

先轉義：

function decode(xData) {
    return xData.replace(/\\x(\w{2})/g, function (_, $1) { return String.fromCharCode(parseInt($1, 16)) });
}

然後替換下：

Function.prototype.getMultiLine = function () {
    var lines = new String(this);
    lines = lines.substring(lines.indexOf("/*") + 3, lines.lastIndexOf("*/"));
    return lines;
}

function decode(xData) {
    return xData.replace(/\\x(\w{2})/g, function (_, $1) { return String.fromCharCode(parseInt($1, 16)) });
}

var str1 = function () {
    /* 
   var _0x5ab652 = _0x50019d(_0x3c31('0x30c'))
, _0x2cf0a4 = _0x50019d('\x63\x6f\x6d\x70\x4b\x65\x79')
, _0x5cba8a = {
  '\x74\x79\x70\x65': _0x3c31('0x16c'),
  '\x75\x72\x6c': _0x8aa6f1()
}
, _0xfca4af = {
  '\x74\x79\x70\x65': _0x3c31('0x16c'),
  '\x75\x72\x6c': _0xefaeb()
};
_0x31f1b8 && (_0x5cba8a[_0x3c31('0x2cb')] = {
  '\x70\x61\x73\x73\x77\x6f\x72\x64': _0x31f1b8
});
var _0x11871b = null
, _0x170c7e = Promise[_0x3c31('0x1e')](null);
 
var _0x256cd0 = _0x2cf0a4(0x16)
, _0x36150e = _0x2cf0a4(0x15)
, _0x42a8d9 = _0x36150e['\x61\x6a\x61\x78']
, _0xdc46dc = _0x36150e[_0x3c31('0x1ef')]
, _0xcca797 = _0x2cf0a4(0x18)
, _0x50019d = _0xcca797[_0x3c31('0x5f')]
, _0x5c77e3 = _0xcca797['\x70\x61\x72\x73\x65\x55\x72\x6c']
, _0x36d54a = _0x2cf0a4(0x3a)['\x70\x65\x72\x66\x65\x63\x74\x4d\x65\x74\x61']
, _0x4c6a9e = _0x2cf0a4(0x2c)[_0x3c31('0x328')]
, _0x296a9b = _0x2cf0a4(0x2c)[_0x3c31('0x329')]
, _0x54c90c = _0x2cf0a4(0x17)
, _0x50f238 = _0x2cf0a4(0x3d)[_0x3c31('0x32a')]
, 0x13 = 0x13
, 0x0 = 0x0
, 0x10 = 0x10
, CryptoJS = null;
    function _0x230bc7(_0x2fb175) {
    return _0x3c31('0xee') == typeof _0x2fb175[_0x3c31('0x25')] && _0x2fb175['\x6f\x62\x6a'][_0x3c31('0xe')] > 0x64 ? _0x54c90c[_0x3c31('0x31f')]()['\x74\x68\x65\x6e'](function() {
        _0x249a60();
        var _0x5ab652 = null
          , _0x2cf0a4 = null
          , _0x4d1175 = null;
        try {
            var _0x3dbfaa = _0x2fb175[_0x3c31('0x25')]['\x73\x75\x62\x73\x74\x72\x69\x6e\x67'](0x0, 0x13)
              , _0x360e25 = _0x2fb175[_0x3c31('0x25')][_0x3c31('0xeb')](0x13 + 0x10);
            _0x2cf0a4 = _0x2fb175[_0x3c31('0x25')][_0x3c31('0xeb')](0x13, 0x13 + 0x10),
            _0x4d1175 = _0x2cf0a4,
            _0x5ab652 = _0x3dbfaa + _0x360e25,
            _0x2cf0a4 = CryptoJS['\x65\x6e\x63'][_0x3c31('0x320')][_0x3c31('0x6b')](_0x2cf0a4),
            _0x4d1175 = CryptoJS[_0x3c31('0x321')][_0x3c31('0x320')]['\x70\x61\x72\x73\x65'](_0x4d1175);
            var _0x57e61a = CryptoJS[_0x3c31('0x322')][_0x3c31('0x323')](_0x5ab652, _0x2cf0a4, {
                '\x69\x76': _0x4d1175,
                '\x6d\x6f\x64\x65': CryptoJS[_0x3c31('0x324')][_0x3c31('0x325')],
                '\x70\x61\x64\x64\x69\x6e\x67': CryptoJS[_0x3c31('0x326')][_0x3c31('0x327')]
            });
            return _0x2fb175[_0x3c31('0x36')] = JSON[_0x3c31('0x6b')](CryptoJS[_0x3c31('0x321')][_0x3c31('0x320')][_0x3c31('0x267')](_0x57e61a)),
            _0x2fb175;
        } catch (_0x36fffe) {
            _0x5ab652 = _0x2fb175[_0x3c31('0x25')]['\x73\x75\x62\x73\x74\x72\x69\x6e\x67'](0x0, _0x2fb175[_0x3c31('0x25')][_0x3c31('0xe')] - 0x10),
            _0x2cf0a4 = _0x2fb175[_0x3c31('0x25')][_0x3c31('0xeb')](_0x2fb175[_0x3c31('0x25')][_0x3c31('0xe')] - 0x10),
            _0x4d1175 = _0x2cf0a4,
            _0x2cf0a4 = CryptoJS[_0x3c31('0x321')][_0x3c31('0x320')][_0x3c31('0x6b')](_0x2cf0a4),
            _0x4d1175 = CryptoJS[_0x3c31('0x321')][_0x3c31('0x320')][_0x3c31('0x6b')](_0x4d1175);
            var _0x4ff7de = CryptoJS[_0x3c31('0x322')][_0x3c31('0x323')](_0x5ab652, _0x2cf0a4, {
                '\x69\x76': _0x4d1175,
                '\x6d\x6f\x64\x65': CryptoJS['\x6d\x6f\x64\x65'][_0x3c31('0x325')],
                '\x70\x61\x64\x64\x69\x6e\x67': CryptoJS[_0x3c31('0x326')][_0x3c31('0x327')]
            });
            return _0x2fb175[_0x3c31('0x36')] = JSON[_0x3c31('0x6b')](CryptoJS[_0x3c31('0x321')]['\x55\x74\x66\x38'][_0x3c31('0x267')](_0x4ff7de)),
            _0x2fb175;
        }
    }) : Promise[_0x3c31('0x1e')](_0x2fb175);
}"
  */
}
var js1 = decode(str1.getMultiLine());
js1 = js1.replace(/_0x3c31\('([^\']+)'\)/g, function ($v, $g) { return _0x3c31($g); })
 

得到

var _0x5ab652 = _0x50019d(userKey)
, _0x2cf0a4 = _0x50019d('compKey')
, _0x5cba8a = {
  'type': GET,
  'url': _0x8aa6f1()
}
, _0xfca4af = {
  'type': GET,
  'url': _0xefaeb()
};
_0x31f1b8 && (_0x5cba8a[data] = {
  'password': _0x31f1b8
});
var _0x11871b = null
, _0x170c7e = Promise[resolve](null);
 
var _0x256cd0 = _0x2cf0a4(0x16)
, _0x36150e = _0x2cf0a4(0x15)
, _0x42a8d9 = _0x36150e['ajax']
, _0xdc46dc = _0x36150e[$ajax]
, _0xcca797 = _0x2cf0a4(0x18)
, _0x50019d = _0xcca797[getUrlParam]
, _0x5c77e3 = _0xcca797['parseUrl']
, _0x36d54a = _0x2cf0a4(0x3a)['perfectMeta']
, _0x4c6a9e = _0x2cf0a4(0x2c)[isVipScene]
, _0x296a9b = _0x2cf0a4(0x2c)[isTgScene]
, _0x54c90c = _0x2cf0a4(0x17)
, _0x50f238 = _0x2cf0a4(0x3d)[setJsCrypto]
, 0x13 = 0x13
, 0x0 = 0x0
, 0x10 = 0x10
, CryptoJS = null;
    function _0x230bc7(_0x2fb175) {
    return string == typeof _0x2fb175[obj] && _0x2fb175['obj'][length] > 0x64 ? _0x54c90c[$loadCryptoJS]()['then'](function() {
        _0x249a60();
        var _0x5ab652 = null
          , _0x2cf0a4 = null
          , _0x4d1175 = null;
        try {
            var _0x3dbfaa = _0x2fb175[obj]['substring'](0x0, 0x13)
              , _0x360e25 = _0x2fb175[obj][substring](0x13 + 0x10);
            _0x2cf0a4 = _0x2fb175[obj][substring](0x13, 0x13 + 0x10),
            _0x4d1175 = _0x2cf0a4,
            _0x5ab652 = _0x3dbfaa + _0x360e25,
            _0x2cf0a4 = CryptoJS['enc'][Utf8][parse](_0x2cf0a4),
            _0x4d1175 = CryptoJS[enc][Utf8]['parse'](_0x4d1175);
            var _0x57e61a = CryptoJS[AES][decrypt](_0x5ab652, _0x2cf0a4, {
                'iv': _0x4d1175,
                'mode': CryptoJS[mode][CFB],
                'padding': CryptoJS[pad][NoPadding]
            });
            return _0x2fb175[list] = JSON[parse](CryptoJS[enc][Utf8][stringify](_0x57e61a)),
            _0x2fb175;
        } catch (_0x36fffe) {
            _0x5ab652 = _0x2fb175[obj]['substring'](0x0, _0x2fb175[obj][length] - 0x10),
            _0x2cf0a4 = _0x2fb175[obj][substring](_0x2fb175[obj][length] - 0x10),
            _0x4d1175 = _0x2cf0a4,
            _0x2cf0a4 = CryptoJS[enc][Utf8][parse](_0x2cf0a4),
            _0x4d1175 = CryptoJS[enc][Utf8][parse](_0x4d1175);
            var _0x4ff7de = CryptoJS[AES][decrypt](_0x5ab652, _0x2cf0a4, {
                'iv': _0x4d1175,
                'mode': CryptoJS['mode'][CFB],
                'padding': CryptoJS[pad][NoPadding]
            });
            return _0x2fb175[list] = JSON[parse](CryptoJS[enc]['Utf8'][stringify](_0x4ff7de)),
            _0x2fb175;
        }
    }) : Promise[resolve](_0x2fb175);
}"

基板上可以讀了，使用CryptoJS做的前端解密，然後直接給最後的代碼：

// 依賴： https://lib.eqh5.com/CryptoJS/1.0.1/cryptoJs.js
function decrypt(result) {
    var ciphertext = null
        , key = null
        , iv = null;
    try {
        var part0 = result.obj.substring(0x0, 0x13)
            , part1 = result.obj.substring(0x13 + 0x10);
        key = result.obj.substring(0x13, 0x13 + 0x10),
            iv = key,
            ciphertext = part0 + part1,
            key = CryptoJS.enc.Utf8.parse(key),
            iv = CryptoJS.enc.Utf8.parse(iv);
        var decryptData = CryptoJS.AES.decrypt(ciphertext, key, {
            'iv': iv,
            'mode': CryptoJS.mode.CFB,
            'padding': CryptoJS.pad.NoPadding
        });
        return CryptoJS.enc.Utf8.stringify(decryptData);
    } catch (_0x36fffe) {
        ciphertext = result[obj]['substring'](0x0, result.obj.length - 0x10),
            key = result[obj][substring](result.obj.length - 0x10),
            iv = key,
            key = CryptoJS.enc.Utf8.parse(key),
            iv = CryptoJS.enc.Utf8.parse(iv);
        var decryptData = CryptoJS.AES.decrypt(ciphertext, key, {
            'iv': iv,
            'mode': CryptoJS.mode.CFB,
            'padding': CryptoJS.pad.NoPadding
        });
        return CryptoJS.enc.Utf8.stringify(decryptData)
    }
}     

易企秀H5 json配置文件解密分析