/**

     *

     * @param string $string 需要加密的字符串

     * @param string $key 密钥

     * @return string

     */

    public static function encrypts($string, $key)

    {

        $key = substr(openssl_digest(openssl_digest($key, 'sha1', true), 'sha1', true), 0, 16);

        // openssl_encrypt 加密不同Mcrypt，对秘钥长度要求，超出16加密结果不变

        $data = openssl_encrypt($string, 'AES-128-ECB', $key, OPENSSL_RAW_DATA);

        $encrypted = strtolower(bin2hex($data));

        return $encrypted;

    }   

/**

     * @param string $string 需要解密的字符串

     * @param string $key 密钥

     * @return string

     */

    public static function decrypts($string, $key)

    {

        $key = substr(openssl_digest(openssl_digest($key, 'sha1', true), 'sha1', true), 0, 16);

        $decrypted = openssl_decrypt(hex2bin($string), 'AES-128-ECB', $key, OPENSSL_RAW_DATA);

        return $decrypted;

    }