手游解密 mobile game decrypt

lua解密，cocos2dx引擎，xxtea加密，另有一层自定义加密。因为手游会更新，所以希望能给我一个类似XXTEADecrypt（[login to view URL]）的工具，或者教会我怎么做工具。可以的话顺带图片解密。 need luac to lua. a mobile game made by cocos2dx engine. lua files were encrypted by xxtea, with an additional unkown encrypt(i guess). Considering the updates of future contents of this mobile game, i hope i can get some kind of tools like [login to view URL] that may help in the future. the key and signment already known but i dont know whether it was changed at present. Also all image files' decryption would be appreciated.