<?php

$socket = null;
$errno = 0;
$context = stream_context_create(array('ssl' => array('local_cert' => dirname(__FILE__).'/cert.pem')));

for ($i=0; $i<10 && !$socket; ++$i) {
	$port = rand(50000, 65535);

	$socket = @stream_socket_server("tcp://127.0.0.1:$port", $errno, $errstr, STREAM_SERVER_BIND|STREAM_SERVER_LISTEN, $context);
}
//set anther random port that is not the same as $port
do{
	$pasv_port = rand(50000, 65535);
}while($pasv_port == $port);

if (!$socket) {
	echo "$errstr ($errno)\n";
	die("could not start/bind the ftp server\n");
}

$pid = pcntl_fork();

function pasv_listen($action){
	global $pasv_port, $tmp_file;
	$tmp_file = 'nm2.php';
	$pid = pcntl_fork();
	if($pid === 0){
		$soc  = stream_socket_server("tcp://127.0.0.1:$pasv_port");
		$fs = stream_socket_accept($soc, 3);
		switch ($action) {
			case 'fget':
			case 'get':
			//listen for 3 seconds 3 seconds
			fputs($fs, "I am passive.\r\n");
			break;
			case 'put':
			file_put_contents($tmp_file,  stream_get_contents($fs));
			break;
			case 'list':
			fputs($fs, "drwxr-x---   3 owner  group      4096 Jul 12 12:16 .\r\n");
			fputs($fs, "drwxr-x---   3 owner  group      4096 Jul 12 12:16 ..\r\n");
			fputs($fs, "drwxr-x---   3 owner  group      4096 Jul 12 12:16 public_ftp\r\n");
			break;
			case 'list_null':
			fputs($fs, "\r\n");
			break;
		}
		fclose($fs);
		exit;
	}
}

if ($pid) {

	function dump_and_exit($buf)
	{
		var_dump($buf);
		fclose($GLOBALS['s']);
		exit;
	}

	function anonymous()
	{
		return $GLOBALS['user'] === 'anonymous';
	}

	/* quick&dirty realpath() like function */
	function change_dir($dir)
	{
		global $cwd;

		if ($dir[0] == '/') {
			$cwd = $dir;
			return;
		}

		$cwd = "$cwd/$dir";

		do {
			$old = $cwd;
			$cwd = preg_replace('@/?[^/]+/\.\.@', '', $cwd);
		} while ($old != $cwd);

		$cwd = strtr($cwd, array('//' => '/'));
		if (!$cwd) $cwd = '/';
	}

	$s = stream_socket_accept($socket);

	if (!$s) die("Error accepting a new connection\n");

	fputs($s, "220----- PHP FTP server 0.3 -----\r\n220 Service ready\r\n");
	$buf = fread($s, 2048);


	function user_auth($buf) {
		global $user, $s, $ssl, $bug37799;

		if (!empty($ssl)) {
			if ($buf !== "AUTH TLS\r\n") {
				fputs($s, "500 Syntax error, command unrecognized.\r\n");
				dump_and_exit($buf);
			}

			if (empty($bug37799)) {
				fputs($s, "234 auth type accepted\r\n");
			} else {
				fputs($s, "666 dummy\r\n");
				sleep(1);
				fputs($s, "666 bogus msg\r\n");
				exit;
			}

			if (!stream_socket_enable_crypto($s, true, STREAM_CRYPTO_METHOD_SSLv23_SERVER)) {
				die("SSLv23 handshake failed.\n");
			}

			if (!preg_match('/^PBSZ \d+\r\n$/', $buf = fread($s, 2048))) {
				fputs($s, "501 bogus data\r\n");
				dump_and_exit($buf);
			}

			fputs($s, "200 OK\r\n");
			$buf = fread($s, 2048);

			if ($buf !== "PROT P\r\n") {
				fputs($s, "504 Wrong protection.\r\n");
				dump_and_exit($buf);
			}

			fputs($s, "200 OK\r\n");

			$buf = fread($s, 2048);
		}

		if ($buf == "AUTH TLS\r\n") {
		   fputs($s, "500 not supported.\r\n");
		   return ;
		} else if (!preg_match('/^USER (\w+)\r\n$/', $buf, $m)) {
			fputs($s, "500 Syntax error, command unrecognized.\r\n");
			dump_and_exit($buf);
		}
		$user = $m[1];
		if ($user !== 'user' && $user !== 'anonymous') {
			fputs($s, "530 Not logged in.\r\n");
			fclose($s);
			exit;
		}

		if (anonymous()) {
			fputs($s, "230 Anonymous user logged in\r\n");

		} else {
			fputs($s, "331 User name ok, need password\r\n");

			if (!preg_match('/^PASS (\w+)\r\n$/', $buf = fread($s, 100), $m)) {
				fputs($s, "500 Syntax error, command unrecognized.\r\n");
				dump_and_exit($buf);
			}

			$pass = $m[1];
			if ($pass === 'pass') {
				fputs($s, "230 User logged in\r\n");
			} else {
				fputs($s, "530 Not logged in.\r\n");
				fclose($s);
				exit;
			}
		}
	}

	user_auth($buf);

	$cwd = '/';
	$num_bogus_cmds = 0;

	while($buf = fread($s, 4098)) {
		if (!empty($bogus)) {
			fputs($s, "502 Command not implemented (".$num_bogus_cmds++.").\r\n");

		} else if ($buf === "HELP\r\n") {
			fputs($s, "214-There is help available for the following commands:\r\n");
			fputs($s, " USER\r\n");
			fputs($s, " HELP\r\n");
			fputs($s, "214 end of list\r\n");

		} elseif ($buf === "HELP HELP\r\n") {
			fputs($s, "214 Syntax: HELP [<SP> <string>] <CRLF>\r\n");

		} elseif ($buf === "PWD\r\n") {
			fputs($s, "257 \"$cwd\" is current directory.\r\n");

		} elseif ($buf === "CDUP\r\n") {
			change_dir('..');
			fputs($s, "250 CDUP command successful.\r\n");

		} elseif ($buf === "SYST\r\n") {
			if (isset($bug27809)) {
				fputs($s, "215   OS/400 is the remote operating system. The TCP/IP version is \"V5R2M0\"\r\n");
			} elseif (isset($bug79100)) {
				// do nothing so test hits timeout
			} elseif (isset($bug80901)) {
				fputs($s, "\r\n" . str_repeat("*", 4096) . "\r\n");
			} else {
				fputs($s, "215 UNIX Type: L8.\r\n");
			}

		} elseif ($buf === "TYPE A\r\n") {
			$ascii = true;
			fputs($s, "200 OK\r\n");

		} elseif ($buf === "AUTH SSL\r\n") {
			$ascii = true;
			fputs($s, "500 not supported\r\n");

		} elseif ($buf === "TYPE I\r\n") {
			$ascii = false;
			fputs($s, "200 OK\r\n");

		} elseif ($buf === "QUIT\r\n") {
			break;

		} elseif (preg_match("~^PORT (\d+),(\d+),(\d+),(\d+),(\d+),(\d+)\r\n$~", $buf, $m)) {
			$host = "$m[1].$m[2].$m[3].$m[4]";
			$port = ((int)$m[5] << 8) + (int)$m[6];
			fputs($s, "200 OK.\r\n");

		} elseif (preg_match("~^STOR ([\w/.-]+)\r\n$~", $buf, $m)) {
			fputs($s, "150 File status okay; about to open data connection\r\n");

			if(empty($pasv))
			{
				if (!$fs = stream_socket_client("tcp://$host:$port")) {
					fputs($s, "425 Can't open data connection\r\n");
					continue;
				}

				$data = stream_get_contents($fs);
				$orig = file_get_contents(dirname(__FILE__).'/'.$m[1]);


				if (isset($ascii) && !$ascii && $orig === $data) {
					fputs($s, "226 Closing data Connection.\r\n");

				} elseif ((!empty($ascii) || isset($bug39583)) && $data === strtr($orig, array("\r\n" => "\n", "\r" => "\n", "\n" => "\r\n"))) {
					fputs($s, "226 Closing data Connection.\r\n");

				} else {
					var_dump($data);
					var_dump($orig);
					fputs($s, "552 Requested file action aborted.\r\n");
				}
				fclose($fs);
			}else{
				$data = file_get_contents('nm2.php');
				$orig = file_get_contents(dirname(__FILE__).'/'.$m[1]);
				if ( $orig === $data) {
					fputs($s, "226 Closing data Connection.\r\n");

				} else {
					var_dump($data);
					var_dump($orig);
					fputs($s, "552 Requested file action aborted.\r\n");
				}
			}

		} elseif (preg_match("~^APPE ([\w/.-]+)\r\n$~", $buf, $m)) {
			fputs($s, "150 File status okay; about to open data connection\r\n");

			if(empty($pasv))
			{
				if (!$fs = stream_socket_client("tcp://$host:$port")) {
					fputs($s, "425 Can't open data connection\r\n");
					continue;
				}

				$data = stream_get_contents($fs);
				file_put_contents(__DIR__.'/'.$m[1], $data, FILE_APPEND);
				fputs($s, "226 Closing data Connection.\r\n");
				fclose($fs);
			}else{
				$data = stream_get_contents($fs);
				file_put_contents(__DIR__.'/'.$m[1], $data, FILE_APPEND);
				fputs($s, "226 Closing data Connection.\r\n");
				fclose($fs);
			}

		}elseif (preg_match("~^CWD ([A-Za-z./]+)\r\n$~", $buf, $m)) {
			if (isset($bug77680)) {
				fputs($s, "550 Directory change to $m[1] failed: file does not exist\r\n");
				var_dump($buf);
			} else {
				change_dir($m[1]);
				fputs($s, "250 CWD command successful.\r\n");
			}

		} elseif (preg_match("~^NLST(?: ([A-Za-z./]+))?\r\n$~", $buf, $m)) {

			if (isset($m[1]) && (($m[1] === 'bogusdir') || ($m[1] === '/bogusdir'))) {
				fputs($s, "250 $m[1]: No such file or directory\r\n");
				continue;
			}

			// there are some servers that don't open the ftp-data socket if there's nothing to send
			if (isset($bug39458) && isset($m[1]) && $m[1] === 'emptydir') {
				fputs($s, "226 Transfer complete.\r\n");
				continue;
			}

			if (empty($pasv)) {
				fputs($s, "150 File status okay; about to open data connection\r\n");
				if (!$fs = stream_socket_client("tcp://$host:$port")) {
					fputs($s, "425 Can't open data connection\r\n");
					continue;
				}
			} else {
				fputs($s, "125 Data connection already open; transfer starting.\r\n");
				$fs=$pasvs;
			}


			if ((!empty($ssl)) && (!stream_socket_enable_crypto($pasvs, true, STREAM_CRYPTO_METHOD_SSLv23_SERVER))) {
				die("SSLv23 handshake failed.\n");
			}

			if (empty($m[1]) || $m[1] !== 'emptydir') {
				fputs($fs, "file1\r\nfile1\r\nfile\nb0rk\r\n");
			}

			fputs($s, "226 Closing data Connection.\r\n");
			fclose($fs);

		} elseif (preg_match("~^MKD ([A-Za-z./]+)\r\n$~", $buf, $m)) {
			if (isset($bug7216)) {
				fputs($s, "257 OK.\r\n");
			} else {
				if (isset($bug77680)) {
					var_dump($buf);
				}
				fputs($s, "257 \"/path/to/ftproot$cwd$m[1]\" created.\r\n");
			}

		} elseif (preg_match('/^USER /', $buf)) {
			user_auth($buf);

		} elseif (preg_match('/^MDTM ([\w\h]+)/', $buf, $matches)) {
			switch ($matches [1]){
				case "A":
				fputs($s, "213 19980615100045.014\r\n");
				break;
				case "B":
				fputs($s, "213 19980615100045.014\r\n");
				break;
				case "C":
				fputs($s, "213 19980705132316\r\n");
				break;
				case "19990929043300 File6":
				fputs($s, "213 19991005213102\r\n");
				break;
				default :
				fputs($s, "550 No file named \"{$matches [1]}\"\r\n");
				break;
			}
		}elseif (preg_match('/^RETR ([\/]*[\w\h]+)/', $buf, $matches)) {
			if(!empty($pasv)){
				;
			}
			else if (!$fs = stream_socket_client("tcp://$host:$port")) {
				fputs($s, "425 Can't open data connection\r\n");
				continue;
			}

			switch($matches[1]){

				case "pasv":
					fputs($s, "150 File status okay; about to open data connection.\r\n");
					//the data connection is handled in another forked process
					// called from outside this while loop
					fputs($s, "226 Closing data Connection.\r\n");
					break;
				case "a story":
					fputs($s, "150 File status okay; about to open data connection.\r\n");
					fputs($fs, "For sale: baby shoes, never worn.\r\n");
					fputs($s, "226 Closing data Connection.\r\n");
					break;
				case "binary data":
					fputs($s, "150 File status okay; about to open data connection.\r\n");
					$transfer_type = $ascii? 'ASCII' : 'BINARY' ;
					fputs($fs, $transfer_type."Foo\0Bar\r\n");
					fputs($s, "226 Closing data Connection.\r\n");
					break;
				case "fget":
					fputs($s, "150 File status okay; about to open data connection.\r\n");
					$transfer_type = $ascii? 'ASCII' : 'BINARY' ;
					fputs($fs, $transfer_type."FooBar\r\n");
					fputs($s, "226 Closing data Connection.\r\n");
					break;
				case "fgetresume":
					fputs($s, "150 File status okay; about to open data connection.\r\n");
					$transfer_type = $ascii? 'ASCII' : 'BINARY' ;
					fputs($fs, "Bar\r\n");
					fputs($s, "226 Closing data Connection.\r\n");
					break;
				case "fget_large":
					fputs($s, "150 File status okay; about to open data connection.\r\n");
					$transfer_type = $ascii? 'ASCII' : 'BINARY' ;
					if ($GLOBALS['rest_pos'] == '5368709119') {
						fputs($fs, "X");
					} else {
						fputs($fs, "Y");
					}
					fputs($s, "226 Closing data Connection.\r\n");
					break;
				case "mediumfile":
					fputs($s, "150 File status okay; about to open data connection.\r\n");
					for($i = 0; $i < 150; $i++){
						fputs($fs, "This is line $i of the test data.\n");
					}
					fputs($s, "226 Closing data Connection.\r\n");
					break;
				case "/bug73457":
					fputs($s, "150 File status okay; about to open data connection.\r\n");
					break;

				default:
					fputs($s, "550 {$matches[1]}: No such file or directory \r\n");
					break;
			}
			if(isset($fs))
				fclose($fs);


		}elseif (preg_match('/^PASV/', $buf, $matches)) {
			$pasv=true;
			$host = "127.0.0.1";
			$i=0;

			if (empty($bug73457)) {
				do {
					if (!empty($ssl)) {
						$soc = @stream_socket_server("tcp://127.0.0.1:$pasv_port", $errno, $errstr, STREAM_SERVER_BIND|STREAM_SERVER_LISTEN, $context);
					} else {
						$soc = @stream_socket_server("tcp://127.0.0.1:$pasv_port");
					}
					/* Could bind port, Try another port */
					if (!$soc) {
						$pasv_port = rand(50000, 65535);
					}
					$i++;
				} while ($i<10 && !$soc);

				if (!$soc) {
					echo "$errstr ($errno)\n";
					die("could not bind passive port\n");
				}
			} else {
				$pasv_port=1234;
			}

			$p2 = $pasv_port % ((int) 1 << 8);
			$p1 = ($pasv_port-$p2)/((int) 1 << 8);
			fputs($s, "227 Entering Passive Mode. (127,0,0,1,{$p1},{$p2})\r\n");

            if (empty($bug73457)) {
                $pasvs = stream_socket_accept($soc,10);
            }

		} elseif (preg_match('/^EPSV/', $buf, $matches)) {
			fputs($s, "550 Extended passsive mode not supported.\r\n");
		} elseif (preg_match('/^SITE EXEC/', $buf, $matches)) {
			fputs($s, "200 OK\r\n");

		} elseif (preg_match('/^RMD/', $buf, $matches)) {
			fputs($s, "250 OK\r\n");

		} elseif (preg_match('/^SITE CHMOD/', $buf, $matches)) {
			fputs($s, "200 OK\r\n");

		} elseif (preg_match('/^DELE ([\w\h]+)/', $buf, $matches)) {
			if (isset($matches[1]) && in_array($matches[1], ['file1', "file\nb0rk"])){
				fputs($s, "250 Delete successful\r\n");
			} else {
				fputs($s, "550 No such file or directory\r\n");
			}
		} elseif (preg_match('/^ALLO (\d+)/', $buf, $matches)) {
			fputs($s, "200 " . $matches[1] . " bytes allocated\r\n");

		}elseif (preg_match('/^LIST www\//', $buf, $matches)) {
			fputs($s, "226 Transfer complete\r\n");

		}elseif (preg_match('/^LIST no_exists\//', $buf, $matches)) {
			fputs($s, "425 Error establishing connection\r\n");

		}elseif (preg_match('/^REST (\d+)/', $buf, $matches)) {
			$GLOBALS['rest_pos'] = $matches[1];
			fputs($s, "350 OK\r\n");
		}elseif (preg_match('/^SIZE largefile/', $buf)) {
			fputs($s, "213 5368709120\r\n");
		}elseif (preg_match('/^RNFR existing_file/', $buf, $matches)) {
			fputs($s, "350 File or directory exists, ready for destination name\r\n");
		}elseif (preg_match('/^RNFR nonexisting_file/', $buf, $matches)) {
			fputs($s, "550 No such file or directory\r\n");
		}elseif (preg_match('/^RNTO nonexisting_file/', $buf, $matches)) {
			fputs($s, "250 Rename successful\r\n");
		}elseif (preg_match('/^MLSD no_exists\//', $buf, $matches)) {
			fputs($s, "425 Error establishing connection\r\n");
		}elseif (preg_match("~^MLSD(?: ([A-Za-z./]+))?\r\n$~", $buf, $m)) {

			if(isset($m[1]) && (($m[1] === 'bogusdir') || ($m[1] === '/bogusdir'))) {
				fputs($s, "250 $m[1]: No such file or directory\r\n");
				continue;
			}

			// there are some servers that don't open the ftp-data socket if there's nothing to send
			if(isset($bug39458) && isset($m[1]) && $m[1] === 'emptydir') {
				fputs($s, "226 Transfer complete.\r\n");
				continue;
			}

			if(empty($pasv)) {
				fputs($s, "150 File status okay; about to open data connection\r\n");
				if(!$fs = stream_socket_client("tcp://$host:$port")) {
					fputs($s, "425 Can't open data connection\r\n");
					continue;
				}
			} else {
				fputs($s, "125 Data connection already open; transfer starting.\r\n");
				$fs = $pasvs;
			}

			if((!empty($ssl)) && (!stream_socket_enable_crypto($pasvs, TRUE, STREAM_CRYPTO_METHOD_SSLv23_SERVER))) {
				die("SSLv23 handshake failed.\n");
			}

			if(empty($m[1]) || $m[1] !== 'emptydir') {
				fputs($fs, "modify=20170127230002;perm=flcdmpe;type=cdir;unique=811U4340002;UNIX.group=33;UNIX.mode=0755;UNIX.owner=33; .\r\n");
				fputs($fs, "modify=20170127230002;perm=flcdmpe;type=pdir;unique=811U4340002;UNIX.group=33;UNIX.mode=0755;UNIX.owner=33; ..\r\n");
				fputs($fs, "modify=20170126121225;perm=adfrw;size=4729;type=file;unique=811U4340CB9;UNIX.group=33;UNIX.mode=0644;UNIX.owner=33; foobar\r\n");
				fputs($fs, "fact=val=ue;empty=; path;name\r\n");
				fputs($fs, "no_space\r\n");
				fputs($fs, "no_semi pathname\r\n");
				fputs($fs, "no_eq; pathname\r\n");
			}

			fputs($s, "226 Closing data Connection.\r\n");
			fclose($fs);
		}elseif (preg_match('/^SIZE \/bug73457/', $buf)) {
			fputs($s, "213 10\r\n");
		}elseif (preg_match("/^SITE/", $buf)) {
			fputs($s, "500 Syntax error, command unrecognized.\r\n");
		}else {
			dump_and_exit($buf);
		}
	}
	fclose($s);
	exit;
}

fclose($socket);
?>
