Being Cellfish

<?php

// This a copy taken 2008-08-21 from http://siphon9.net/loune/f/ntlm.php.txt to make sure the code is not lost.
// For more information see:
// http://blogs.msdn.com/cellfish/archive/2008/08/26/getting-the-logged-on-windows-user-in-your-apache-server.aspx

// NTLM specs http://davenport.sourceforge.net/ntlm.html

$headers = apache_request_headers();

if (!isset($headers['Authorization'])){
	header('HTTP/1.1 401 Unauthorized');
	header('WWW-Authenticate: NTLM');
	exit;
}

$auth = $headers['Authorization'];

if (substr($auth,0,5) == 'NTLM ') {
	$msg = base64_decode(substr($auth, 5));
	if (substr($msg, 0, 8) != "NTLMSSP\x00")
		die('error header not recognised');

	if ($msg[8] == "\x01") {
		$msg2 = "NTLMSSP\x00\x02"."\x00\x00\x00\x00". // target name len/alloc
			"\x00\x00\x00\x00". // target name offset
			"\x01\x02\x81\x01". // flags
			"\x00\x00\x00\x00\x00\x00\x00\x00". // challenge
			"\x00\x00\x00\x00\x00\x00\x00\x00". // context
			"\x00\x00\x00\x00\x30\x00\x00\x00"; // target info len/alloc/offset

		header('HTTP/1.1 401 Unauthorized');
		header('WWW-Authenticate: NTLM '.trim(base64_encode($msg2)));
		exit;
	}
	else if ($msg[8] == "\x03") {
		function get_msg_str($msg, $start, $unicode = true) {
			$len = (ord($msg[$start+1]) * 256) + ord($msg[$start]);
			$off = (ord($msg[$start+5]) * 256) + ord($msg[$start+4]);
			if ($unicode)
				return str_replace("\0", '', substr($msg, $off, $len));
			else
				return substr($msg, $off, $len);
		}
		$user = get_msg_str($msg, 36);
		$domain = get_msg_str($msg, 28);
		$workstation = get_msg_str($msg, 44);


		print "You are $user from $workstation.$domain";
	}
}

?>