inc/libs/security_functions.php

   1 <?php
   2 /************************************************************************
   3  * MXChange v0.2.1                                    Start: 09/20/2005 *
   4  * ===============                              Last change: 09/20/2005 *
   5  *                                                                      *
   6  * -------------------------------------------------------------------- *
   7  * File              : security_functions.php                           *
   8  * -------------------------------------------------------------------- *
   9  * Short description : Secure all GET, POST and COOKIE data             *
  10  * -------------------------------------------------------------------- *
  11  * Kurzbeschreibung  : Alle GET, POST und COOKIE-Daten sichern          *
  12  * -------------------------------------------------------------------- *
  13  * $Revision::                                                        $ *
  14  * $Date::                                                            $ *
  15  * $Tag:: 0.2.1-FINAL                                                 $ *
  16  * $Author::                                                          $ *
  17  * Needs to be in all Files and every File needs "svn propset           *
  18  * svn:keywords Date Revision" (autoprobset!) at least!!!!!!            *
  19  * -------------------------------------------------------------------- *
  20  * Copyright (c) 2003 - 2008 by Roland Haeder                           *
  21  * For more information visit: http://www.mxchange.org                  *
  22  *                                                                      *
  23  * This program is free software; you can redistribute it and/or modify *
  24  * it under the terms of the GNU General Public License as published by *
  25  * the Free Software Foundation; either version 2 of the License, or    *
  26  * (at your option) any later version.                                  *
  27  *                                                                      *
  28  * This program is distributed in the hope that it will be useful,      *
  29  * but WITHOUT ANY WARRANTY; without even the implied warranty of       *
  30  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the        *
  31  * GNU General Public License for more details.                         *
  32  *                                                                      *
  33  * You should have received a copy of the GNU General Public License    *
  34  * along with this program; if not, write to the Free Software          *
  35  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,               *
  36  * MA  02110-1301  USA                                                  *
  37  ************************************************************************/
  38
  39 // Some security stuff...
  40 if (ereg(basename(__FILE__), $_SERVER['PHP_SELF'])) {
  41         $INC = substr(dirname(__FILE__), 0, strpos(dirname(__FILE__), '/inc') + 4) . '/security.php';
  42         require($INC);
  43 }
  44
  45 /**
  46  * Function to secure input strings
  47  *
  48  * @param       $str    The unsecured string
  49  * @param       $strip  Strip tags
  50  * @return      $str    A (hopefully) secured string against XSS and other bad things
  51  */
  52 function secureString ($str, $strip=true) {
  53         // Shall we strip HTML code?
  54         if ($strip) $str = strip_tags($str);
  55
  56         // Trim string
  57         $str = trim($str);
  58
  59         // Encode in entities
  60         $str = htmlentities($str, ENT_QUOTES);
  61         return $str;
  62 }
  63
  64 // Run only once this security check/exchange
  65 if (defined('__SECURITY')) return;
  66
  67 // Runtime/GPC quoting is off now...
  68 @set_magic_quotes_runtime(false);
  69 @ini_set('magic_quotes_gpc', false); // This may not work on some systems
  70
  71 // Check if important arrays are found and define them if missing
  72 if (!isset($_SERVER)) {
  73         global $_SERVER;
  74         $_SERVER = $GLOBALS['_SERVER'];
  75 }
  76
  77 if (!isset($_GET)) {
  78         global $_GET;
  79         $_GET = $GLOBALS['_GET'];
  80 }
  81
  82 if (!isset($_POST)) {
  83         global $_POST;
  84         $_POST = $GLOBALS['_POST'];
  85 }
  86
  87 // Include IP-Filter here
  88 //require("/usr/share/php/ipfilter.php");
  89
  90 // Generate arrays which holds the relevante chars to replace
  91 $GLOBALS['security_chars'] = array(
  92 // The chars we are looking for...
  93         'from' => array("{", "}", '/', '.', "'", "$", '(', ')', '{--', '--}', "%", ';', "[", "]", ':', "--"),
  94 // ... and we will replace to.
  95         'to'   => array(
  96                 "{OPEN_ANCHOR2}",
  97                 "{CLOSE_ANCHOR2}",
  98                 "{SLASH}",
  99                 "{DOT}",
 100                 "{QUOT}",
 101                 "{DOLLAR}",
 102                 "{OPEN_ANCHOR}",
 103                 "{CLOSE_ANCHOR}",
 104                 "{OPEN_TEMPLATE}",
 105                 "{CLOSE_TEMPLATE}",
 106                 "{PER}",
 107                 "{SEMI}",
 108                 "{OPEN_INDEX}",
 109                 "{CLOSE_INDEX}",
 110                 "{DBL_DOT}",
 111                 "{COMMENT}"
 112                 ),
 113                 );
 114
 115                 // Characters allowed in URLs
 116                 //
 117                 // Note: Do not replace 'to' with 'from' and vise-versa! When you do this all booked URLs will be
 118                 //       rejected because of the {SLASH}, {DOT} and all below listed items inside the URL.
 119                 $GLOBALS['url_chars'] = array(
 120                 // Search for these secured characters
 121         'to'   => array("{SLASH}", "{DOT}", "{PER}", "{DBL_DOT}", "{COMMENT}"),
 122                 // Replace with these characters
 123         'from' => array('/', '.', "%", ':', "--")
 124                 );
 125
 126                 // Overworked security part:
 127                 if (is_array($_GET)) {
 128                         foreach ($_GET as $seckey => $secvalue) {
 129                                 if (is_array($secvalue)) {
 130                                         // Throw arrays away...
 131                                         unset($_GET[$seckey]);
 132                                 } else {
 133                                         // Only variables are allowed (non-array) but we secure them all!
 134                                         foreach ($GLOBALS['security_chars']['from'] as $key => $char) {
 135                                                 // Pass all through
 136                                                 $_GET[$seckey] = str_replace($char  , $GLOBALS['security_chars']['to'][$key], $_GET[$seckey]);
 137                                         }
 138
 139                                         // Strip all other out
 140                                         $_GET[$seckey] = strip_tags($_GET[$seckey]);
 141                                 }
 142                         }
 143                 }
 144
 145                 if (basename($_SERVER['PHP_SELF']) != 'install.php') {
 146                         // And POST data
 147                         foreach ($_POST as $seckey => $secvalue) {
 148                                 if (!is_array($secvalue)) {
 149                                         // Only variables are allowed (non-array) to be secured...
 150                                         foreach ($GLOBALS['security_chars']['from'] as $key => $char) {
 151                                                 // Pass all through
 152                                                 $_POST[$seckey] = str_replace($char  , $GLOBALS['security_chars']['to'][$key], $_POST[$seckey]);
 153                                         }
 154
 155                                         // Strip all other out
 156                                         $_POST[$seckey] = strip_tags($_POST[$seckey]);
 157                                 }
 158                         }
 159                 }
 160
 161                 // Activate caching or transparent compressing when it is not already done
 162                 if (!defined('_OB_CACHING')) {
 163                         if (phpversion() >= '4.0.4pl1' && (strstr(getenv('HTTP_USER_AGENT'),'compatible') || (strstr(getenv('HTTP_USER_AGENT'), "Mozilla")))) {
 164                                 if ((extension_loaded('zlib')) && (function_exists('ob_start'))) {
 165                                         // Start caching
 166                                         define('_OB_CACHING', 'on');
 167                                         ob_start();
 168                                 } else {
 169                                         // Extension not loaded or required function is missing
 170                                         define('_OB_CACHING', '404');
 171                                 }
 172                         } else {
 173                                 // Old PHP version
 174                                 define('_OB_CACHING', 'old');
 175                         }
 176                 }
 177
 178                 // At last secure the $_SERVER['PHP_SELF'] element
 179                 $_SERVER['PHP_SELF'] = secureString($_SERVER['PHP_SELF']);
 180
 181                 // Split it up into path and filename
 182                 $SELF_DIR  = dirname($_SERVER['PHP_SELF']);
 183                 $SELF_FILE = basename($_SERVER['PHP_SELF']);
 184
 185                 // Check for a .php inside the $SELF_DIR...
 186                 while (ereg('.php', $SELF_DIR)) {
 187                         // Correct the dirname
 188                         $SELF_DIR = substr($SELF_DIR, 0, (strpos($SELF_DIR, '.php') + 4));
 189                         // Rewrite filename...
 190                         $SELF_FILE = basename($SELF_DIR);
 191                         // ... and dirname
 192                         $SELF_DIR = dirname($SELF_DIR);
 193                 }
 194
 195                 // Put both together again and let's pray it is secured now...
 196                 $_SERVER['PHP_SELF'] = $SELF_DIR.'/'.$SELF_FILE;
 197
 198                 // Remove uneccessary variables
 199                 unset($SELF_DIR);
 200                 unset($SELF_FILE);
 201
 202                 // Security system loaded...
 203                 define('__SECURITY', '1');
 204
 205                 //
 206                 ?>