checkSession()

Complexity

Conditions	46
Paths	> 20000

Size

Total Lines	109
Code Lines	56

Duplication

Lines	0
Ratio	0 %

Importance

Changes

0

<?php
function checkSession($type = 'post', $from_action = '', $is_fatal = true)
{
	global $context, $sc, $modSettings, $boardurl;

	// Is it in as $_POST['sc']?
	if ($type == 'post')
	{
		$check = isset($_POST[$_SESSION['session_var']]) ? $_POST[$_SESSION['session_var']] : (empty($modSettings['strictSessionCheck']) && isset($_POST['sc']) ? $_POST['sc'] : null);
		if ($check !== $sc)
			$error = 'session_timeout';
	}

	// How about $_GET['sesc']?
	elseif ($type == 'get')
	{
		$check = isset($_GET[$_SESSION['session_var']]) ? $_GET[$_SESSION['session_var']] : (empty($modSettings['strictSessionCheck']) && isset($_GET['sesc']) ? $_GET['sesc'] : null);
		if ($check !== $sc)
			$error = 'session_verify_fail';
	}

	// Or can it be in either?
	elseif ($type == 'request')
	{
		$check = isset($_GET[$_SESSION['session_var']]) ? $_GET[$_SESSION['session_var']] : (empty($modSettings['strictSessionCheck']) && isset($_GET['sesc']) ? $_GET['sesc'] : (isset($_POST[$_SESSION['session_var']]) ? $_POST[$_SESSION['session_var']] : (empty($modSettings['strictSessionCheck']) && isset($_POST['sc']) ? $_POST['sc'] : null)));

		if ($check !== $sc)
			$error = 'session_verify_fail';
	}

	// Verify that they aren't changing user agents on us - that could be bad.
	if ((!isset($_SESSION['USER_AGENT']) || $_SESSION['USER_AGENT'] != $_SERVER['HTTP_USER_AGENT']) && empty($modSettings['disableCheckUA']))
		$error = 'session_verify_fail';

	// Make sure a page with session check requirement is not being prefetched.
	if (isset($_SERVER['HTTP_X_MOZ']) && $_SERVER['HTTP_X_MOZ'] == 'prefetch')
	{
		ob_end_clean();
		send_http_status(403);
		die;

Using exit here is not recommended.

	}

	// Check the referring site - it should be the same server at least!
	if (isset($_SESSION['request_referer']))
		$referrer = $_SESSION['request_referer'];
	else
		$referrer = isset($_SERVER['HTTP_REFERER']) ? @parse_url($_SERVER['HTTP_REFERER']) : array();

	// Check the refer but if we have CORS enabled and it came from a trusted source, we can skip this check.
	if (!empty($referrer['host']) && (empty($modSettings['allow_cors']) || empty($context['valid_cors_found']) || !in_array($context['valid_cors_found'], array('same', 'subdomain'))))
	{
		if (strpos($_SERVER['HTTP_HOST'], ':') !== false)
			$real_host = substr($_SERVER['HTTP_HOST'], 0, strpos($_SERVER['HTTP_HOST'], ':'));
		else
			$real_host = $_SERVER['HTTP_HOST'];

		$parsed_url = parse_iri($boardurl);

		// Are global cookies on?  If so, let's check them ;).
		if (!empty($modSettings['globalCookies']))
		{
			if (preg_match('~(?:[^\.]+\.)?([^\.]{3,}\..+)\z~i', $parsed_url['host'], $parts) == 1)
				$parsed_url['host'] = $parts[1];

			if (preg_match('~(?:[^\.]+\.)?([^\.]{3,}\..+)\z~i', $referrer['host'], $parts) == 1)
				$referrer['host'] = $parts[1];

			if (preg_match('~(?:[^\.]+\.)?([^\.]{3,}\..+)\z~i', $real_host, $parts) == 1)
				$real_host = $parts[1];
		}

		// Okay: referrer must either match parsed_url or real_host.
		if (isset($parsed_url['host']) && strtolower($referrer['host']) != strtolower($parsed_url['host']) && strtolower($referrer['host']) != strtolower($real_host))
		{
			$error = 'verify_url_fail';
			$log_error = true;
		}
	}

	// Well, first of all, if a from_action is specified you'd better have an old_url.
	if (!empty($from_action) && (!isset($_SESSION['old_url']) || preg_match('~[?;&]action=' . $from_action . '([;&]|$)~', $_SESSION['old_url']) == 0))
	{
		$error = 'verify_url_fail';
		$log_error = true;
	}

	if (strtolower($_SERVER['HTTP_USER_AGENT']) == 'hacker')
		fatal_error('Sound the alarm!  It\'s a hacker!  Close the castle gates!!', false);

	// Everything is ok, return an empty string.
	if (!isset($error))
		return '';
	// A session error occurred, show the error.
	elseif ($is_fatal)
	{
		if (isset($_GET['xml']))
		{
			ob_end_clean();
			send_http_status(403, 'Forbidden - Session timeout');
			die;

Using exit here is not recommended.

		}
		else
			fatal_lang_error($error, isset($log_error) ? 'user' : false);
	}
	// A session error occurred, return the error to the calling function.
	else
		return $error;

	// We really should never fall through here, for very important reasons.  Let's make sure.
	die('No direct access...');

Using exit here is not recommended.

}
?>