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<?php
$socket = null;
$errno = 0;
$context = stream_context_create(array('ssl' => array('local_cert' => dirname(__FILE__).'/cert.pem', 'passphrase' => 'pass')));
for ($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, $context);
}
if (!$socket) {
die("could not start/bind the ftp server\n");
}
$pid = pcntl_fork();
if ($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, $ssl;
if (!empty($ssl)) {
if ($buf !== "AUTH TLS\r\n") {
fputs($s, "500 Syntax error, command unrecognized.\r\n");
dump_and_exit($buf);
}
fputs($s, "234 auth type accepted\r\n");
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 (!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 ($buf === "SYST\r\n") {
fputs($s, "215 UNIX Type: L8.\r\n");
} elseif ($buf === "QUIT\r\n") {
break;
} elseif (preg_match("~^CWD ([A-Za-z./]+)\r\n$~", $buf, $m)) {
change_dir($m[1]);
fputs($s, "250 CWD command successful.\r\n");
} else if(preg_match('/^USER /', $buf)) {
user_auth($buf);
} else {
fputs($s, "500 Syntax error, command unrecognized.\r\n");
dump_and_exit($buf);
}
}
fclose($s);
exit;
}
fclose($socket);
?>
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