加密
$data='加密数据';
$encrypted=base64_encode($data);
$key=md5($key);
$res=openssl_encrypt($encrypted, 'aes-256-ecb',$key,1,substr( 0, 16));
解密
$encrypted=base64_decode( $res);
$key=md5($key);
$res=openssl_decrypt($encrypted, 'aes-256-ecb',$key,1,substr( 0, 16));