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  *                                                                      *
  14  * -------------------------------------------------------------------- *
  15  * Copyright (c) 2003 - 2008 by Roland Haeder                           *
  16  * For more information visit: http://www.mxchange.org                  *
  17  *                                                                      *
  18  * This program is free software; you can redistribute it and/or modify *
  19  * it under the terms of the GNU General Public License as published by *
  20  * the Free Software Foundation; either version 2 of the License, or    *
  21  * (at your option) any later version.                                  *
  22  *                                                                      *
  23  * This program is distributed in the hope that it will be useful,      *
  24  * but WITHOUT ANY WARRANTY; without even the implied warranty of       *
  25  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the        *
  26  * GNU General Public License for more details.                         *
  27  *                                                                      *
  28  * You should have received a copy of the GNU General Public License    *
  29  * along with this program; if not, write to the Free Software          *
  30  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,               *
  31  * MA  02110-1301  USA                                                  *
  32  ************************************************************************/
  33
  34 // Some security stuff...
  35 if (ereg(basename(__FILE__), $_SERVER['PHP_SELF'])) {
  36         $INC = substr(dirname(__FILE__), 0, strpos(dirname(__FILE__), "/inc") + 4) . "/security.php";
  37         require($INC);
  38 }
  39
  40 /**
  41  * Function to secure input strings
  42  *
  43  * @param       $str    The unsecured string
  44  * @return      $str    A (hopefully) secured string against XSS and other bad things
  45  */
  46 function secureString ($str) {
  47         $str = trim(strip_tags($str));
  48         $str = htmlentities($str, ENT_QUOTES);
  49         return $str;
  50 }
  51
  52 // Run only once this security check/exchange
  53 if (defined('__SECURITY')) return;
  54
  55 // Fatal messages goes here
  56 global $FATAL;
  57 $FATAL = array();
  58
  59 // Runtime/GPC quoting is off now...
  60 @set_magic_quotes_runtime(false);
  61 @ini_set('magic_quotes_gpc', false); // This may not work on some systems
  62
  63 // Check if important arrays are found and define them if missing
  64 if (!isset($_SERVER)) {
  65         global $_SERVER;
  66         $_SERVER = $GLOBALS['_SERVER'];
  67 }
  68
  69 if (!isset($_GET)) {
  70         global $_GET;
  71         $_GET = $GLOBALS['_GET'];
  72 }
  73
  74 if (!isset($_POST)) {
  75         global $_POST;
  76         $_POST = $GLOBALS['_POST'];
  77 }
  78
  79 if (!isset($_COOKIE)) {
  80         global $_COOKIE;
  81         $_COOKIE = $GLOBALS['_COOKIE'];
  82 }
  83
  84 // Include IP-Filter here
  85 //require("/usr/share/php/ipfilter.php");
  86
  87 // Generate arrays which holds the relevante chars to replace
  88 global $SEC_CHARS, $URL_CHARS;
  89 $SEC_CHARS = array(
  90         // The chars we are looking for...
  91         'from' => array("{", "}", "/", ".", "'", "$", "(", ")", '{--', '--}', "%", ";", "[", "]", ":", "--"),
  92         // ... and we will replace to.
  93         'to'   => array(
  94                 "{OPEN_ANCHOR2}",
  95                 "{CLOSE_ANCHOR2}",
  96                 "{SLASH}",
  97                 "{DOT}",
  98                 '{QUOT}',
  99                 "{DOLLAR}",
 100                 "{OPEN_ANCHOR}",
 101                 "{CLOSE_ANCHOR}",
 102                 "{OPEN_TEMPLATE}",
 103                 "{CLOSE_TEMPLATE}",
 104                 "{PER}",
 105                 "{SEMI}",
 106                 "{OPEN_INDEX}",
 107                 "{CLOSE_INDEX}",
 108                 "{DBL_DOT}",
 109                 "{COMMENT}"
 110         ),
 111 );
 112
 113 // Characters allowed in URLs
 114 //
 115 // Note: Do not replace 'to' with 'from' and vise-versa! When you do this all booked URLs will be
 116 //       rejected because of the {SLASH}, {DOT} and all below listed items inside the URL.
 117 $URL_CHARS = array(
 118         // Search for these secured characters
 119         'to'   => array("{SLASH}", "{DOT}", "{PER}", "{DBL_DOT}", "{COMMENT}"),
 120         // Replace with these characters
 121         'from' => array("/", ".", "%", ":", "--")
 122 );
 123
 124 // Overworked security part:
 125 if (is_array($_GET)) {
 126         foreach ($_GET as $seckey=>$secvalue) {
 127                 if (is_array($secvalue)) {
 128                         // Throw arrays away...
 129                         unset($_GET[$seckey]);
 130                 } else {
 131                         // Only variables are allowed (non-array) but we secure them all!
 132                         foreach ($SEC_CHARS['from'] as $key=>$char) {
 133                                 // Pass all through
 134                                 $_GET[$seckey] = str_replace($char  , $SEC_CHARS['to'][$key], $_GET[$seckey]);
 135                         }
 136
 137                         // Strip all other out
 138                         $_GET[$seckey] = strip_tags($_GET[$seckey]);
 139                 }
 140         }
 141 }
 142
 143 if (basename($_SERVER['PHP_SELF']) != "install.php") {
 144         // And POST data
 145         foreach ($_POST as $seckey=>$secvalue) {
 146                 if (!is_array($secvalue)) {
 147                         // Only variables are allowed (non-array) to be secured...
 148                         foreach ($SEC_CHARS['from'] as $key=>$char) {
 149                                 // Pass all through
 150                                 $_POST[$seckey] = str_replace($char  , $SEC_CHARS['to'][$key], $_POST[$seckey]);
 151                         }
 152
 153                         // Strip all other out
 154                         $_POST[$seckey] = strip_tags($_POST[$seckey]);
 155                 }
 156         }
 157
 158         // ... and finally cookies
 159         foreach ($_COOKIE as $seckey=>$secvalue) {
 160                 if (is_array($secvalue)) {
 161                         // Throw arrays away...
 162                         unset($_COOKIE[$seckey]);
 163                 } else {
 164                         // Only variables are allowed (non-array) but we secure them all!
 165                         foreach ($SEC_CHARS['from'] as $key=>$char) {
 166                                 // Pass all through
 167                                 $_COOKIE[$seckey] = str_replace($char  , $SEC_CHARS['to'][$key], $_COOKIE[$seckey]);
 168                         }
 169
 170                         // Strip all other out
 171                         $_COOKIE[$seckey] = strip_tags($_COOKIE[$seckey]);
 172                 }
 173         }
 174 }
 175
 176 // Activate caching or transparent compressing when it is not already done
 177 if (!defined('_OB_CACHING')) {
 178         if (phpversion() >= '4.0.4pl1' && (strstr(getenv('HTTP_USER_AGENT'),'compatible') || (strstr(getenv('HTTP_USER_AGENT'), "Mozilla")))) {
 179                 if ((extension_loaded('zlib')) && (function_exists('ob_start'))) {
 180                         // Start caching
 181                         define('_OB_CACHING', "on");
 182                         ob_start();
 183                 } else {
 184                         // Extension not loaded or required function is missing
 185                         define('_OB_CACHING', "404");
 186                 }
 187         } else {
 188                 // Old PHP version
 189                 define('_OB_CACHING', "old");
 190         }
 191 }
 192
 193 // At last secure the $_SERVER['PHP_SELF'] element
 194 $_SERVER['PHP_SELF'] = secureString($_SERVER['PHP_SELF']);
 195
 196 // Split it up into path and filename
 197 $SELF_DIR  = dirname($_SERVER['PHP_SELF']);
 198 $SELF_FILE = basename($_SERVER['PHP_SELF']);
 199
 200 // Check for a .php inside the $SELF_DIR...
 201 while (ereg(".php", $SELF_DIR)) {
 202         // Correct the dirname
 203         $SELF_DIR = substr($SELF_DIR, 0, (strpos($SELF_DIR, ".php") + 4));
 204         // Rewrite filename...
 205         $SELF_FILE = basename($SELF_DIR);
 206         // ... and dirname
 207         $SELF_DIR = dirname($SELF_DIR);
 208 }
 209
 210 // Put both together again and let's pray it is secured now...
 211 $_SERVER['PHP_SELF'] = $SELF_DIR."/".$SELF_FILE;
 212
 213 // Remove uneccessary variables
 214 unset($SELF_DIR);
 215 unset($SELF_FILE);
 216
 217 // Security system loaded...
 218 define('__SECURITY', "1");
 219
 220 //
 221 ?>