<?php
/*
$Id$
This code is part of LDAP Account Manager (http://www.sourceforge.net/projects/lam)
Copyright (C) 2006 Roland Gruber
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/**
* This file includes functions to perform several security checks on each page load.
*
* @package lib
* @author Roland Gruber
*/
/** configuration options */
include_once('config.inc');
/** ldap connection */
include_once('ldap.inc');
// check client IP address
checkClientIP();
/**
* Starts a session and checks the environment.
* The script is stopped if one of the checks fail.
*/
function startSecureSession() {
// check if client IP is on the list of valid IPs
checkClientIP();
// start session
if (isset($_SESSION)) unset($_SESSION);
$sessionDir = substr(__FILE__, 0, strlen(__FILE__) - 17) . "/sess";
session_save_path($sessionDir);
@session_start();
// check session id
if (! isset($_SESSION["sec_session_id"]) || ($_SESSION["sec_session_id"] != session_id())) {
// session id is invalid
die();
}
// check if client IP has not changed
if (!isset($_SESSION["sec_client_ip"]) || ($_SESSION["sec_client_ip"] != $_SERVER['REMOTE_ADDR'])) {
// IP is invalid
die();
}
// check if session time has not expired
if (($_SESSION['sec_sessionTime'] + (60 * $_SESSION['cfgMain']->sessionTimeout)) > time()) {
// ok, update time
$_SESSION['sec_sessionTime'] = time();
}
else {
// session expired, logoff user
logoffAndBackToLoginPage();
}
}
/**
* Checks if the client's IP address is on the list of allowed IPs.
* The script is stopped if the host is not valid.
*
*/
function checkClientIP() {
$cfg = new CfgMain();
$allowedHosts = $cfg->allowedHosts;
// skip test if no hosts are defined
if ($allowedHosts == "") return;
$allowedHosts = explode(",", $allowedHosts);
$grantAccess = false;
for ($i = 0; $i < sizeof($allowedHosts); $i++) {
$host = $allowedHosts[$i];
$ipRegex = '^[0-9\\.\\*]+$';
if (!ereg($ipRegex, $host)) continue;
$hostRegex = str_replace(".", "\\.", $host);
$hostRegex = '^' . str_replace("*", ".*", $hostRegex) . '$';
$clientIP = $_SERVER['REMOTE_ADDR'];
if (ereg($hostRegex, $clientIP)) {
// client is allowed to access LAM
$grantAccess = true;
}
}
// stop script is client may not access LAM
if (!$grantAccess) die();
}
/**
* Logs off the user and displays the login page.
*
*/
function logoffAndBackToLoginPage() {
// log message
$ldapUser = $_SESSION['ldap']->decrypt_login();
logNewMessage(LOG_WARNING, 'Session of user ' . $ldapUser[0] . ' expired.');
// delete key and iv in cookie
if (function_exists('mcrypt_create_iv')) {
setcookie("Key", "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx", 0, "/");
setcookie("IV", "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx", 0, "/");
}
// close LDAP connection
@$_SESSION["ldap"]->destroy();
// link back to login page
$paths = array('./', '../', '../../', '../../../');
$page = 'login.php';
for ($i = 0; $i < sizeof($paths); $i++) {
if (file_exists($paths[$i] . $page)) {
$page = $paths[$i] . $page;
break;
}
}
$page .= "?expired=yes";
echo $_SESSION['header'];
echo "<title></title>\n";
echo "</head>\n";
echo "<body>\n";
// print JavaScript refresh
echo "<script type=\"text/javascript\">\n";
echo "top.location.href = \"" . $page . "\";\n";
echo "</script>\n";
// print link if refresh does not work
echo "<p>\n";
echo "<a target=\"_top\" href=\"" . $page . "\">" . _("Your session expired, click here to go back to the login page.") . "</a>\n";
echo "</p>\n";
echo "</body>\n";
echo "</html>\n";
// destroy session
session_destroy();
unset($_SESSION);
die();
}
/**
* Puts a new message in the log file.
*
* @param string $level log level (LOG_NOTICE, LOG_WARNING, LOG_ERR)
* @param string $message log message
*/
function logNewMessage($level, $message) {
$possibleLevels = array(LOG_NOTICE => 'NOTICE', LOG_WARNING => 'WARNING', LOG_ERR => 'ERROR');
if (!in_array($level, array_keys($possibleLevels))) StatusMessage('ERROR', 'Invalid log level!', $level);
if (isset($_SESSION['cfgMain'])) $cfg = $_SESSION['cfgMain'];
else $cfg = new CfgMain();
// check if logging is disabled
if ($cfg->logDestination == 'NONE') return;
// check if log level is high enough
elseif ($cfg->logLevel < $level) return;
// ok to log, build log message
$prefix = "LDAP Account Manager - " . $possibleLevels[$level] . ": ";
$message = $prefix . $message;
// Syslog logging
if ($cfg->logDestination == 'SYSLOG') {
syslog($level, $message);
}
// log to file
else {
touch($cfg->logDestination);
if (is_writable($cfg->logDestination)) {
$file = fopen($cfg->logDestination, 'a');
if ($file) {
fwrite($file, $message . "\n");
fclose($file);
}
}
else {
StatusMessage('ERROR', 'Unable to write to log file!', $cfg->logDestination);
}
}
}
?>