php aes

/**
 * aes
 *
 */
class aes{
    private $key = "wt@36";
    private $iv         = "8401948501850295"; //只能是16字节
 
    /**
     * 
     * @param unknown_type $key
     * @param string $iv   16 length
     */
    function __construct($key,$iv=null){
        $this->key = $key;
        if (!empty($iv)){
         $this->iv = $iv;
        }
    }
 
    /**
     * 加密
     * @param string $value
     * @return string
     */
    function encrypt($value){
     return bin2hex(mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $this->key, $value, MCRYPT_MODE_CBC,$this->iv));
    }
    
    /*
     * AES解密
    */
    function decrypt($value){
     return mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $this->key, pack("H*",$value),MCRYPT_MODE_CBC, $this->iv);
    }
}