AES加密在php5的版本中使用的mcrypt_decrypt 函数，该函数已经在php7.1后弃用了，取而代之的是openssl的openssl_encrypt和openssl_decrypt，并且代码也非常精简，下面是示例代码：

class Aes
{
	public $key = '';

	public $iv = '';

	public function __construct($config)
	{
		foreach($config as $k => $v){
			$this->$k = $v;
		}
	}
	//加密
	public function aesEn($data){
	 return  base64_encode(openssl_encrypt($data, $this->method,$this->key, OPENSSL_RAW_DATA , $this->iv));  
	}

    //解密
	public function aesDe($data){
	 return openssl_decrypt(base64_decode($data),  $this->method, $this->key, OPENSSL_RAW_DATA, $this->iv);
	}
}

 $config = [
	'key'	=>	'reter4446fdfgdfgdfg', //加密key 
	'iv'	=>  md5(time(). uniqid(),true), //保证偏移量为16位
	'method'	=> 'AES-128-CBC' //加密方式  # AES-256-CBC等
 ];

$obj = new Aes($config);

$res = $obj->aesEn('aaaddee44');//加密数据

echo $res;
echo '<hr>';

echo $obj->aesDe($res);//解密