GCrypto 对AES与XXTEA的简单封装 详细说明参见http://www.ghost233.me/gcrypto-%E5%AF%B9aes%E4%B8%8Exxtea%E7%9A%84%E7%AE%80%E5%8D%95%E5%B0%81%E8%A3%85/