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 {
  37         $INC = substr(dirname(__FILE__), 0, strpos(dirname(__FILE__), "/inc") + 4) . "/security.php";
  38         require($INC);
  39 }
  40
  41 /**
  42  * Function to secure input strings
  43  *
  44  * @param       $str    The unsecured string
  45  * @return      $str    A (hopefully) secured string against HTML and other things
  46  */
  47 function secureString ($str) {
  48         $str = trim(strip_tags($str));
  49         $str = htmlentities($str, ENT_QUOTES);
  50         return $str;
  51 }
  52
  53 // Run only once this security check/exchange
  54 if (defined('__SECURITY')) return;
  55
  56 // Fatal messages goes here
  57 global $FATAL;
  58 $FATAL = array();
  59
  60 // Runtime quoting is off now...
  61 set_magic_quotes_runtime(false);
  62
  63 // Check if important arrays are found and define them if missing
  64 if (!isset($_SERVER))
  65 {
  66         global $_SERVER;
  67         $_SERVER = $GLOBALS['_SERVER'];
  68 }
  69 if (!isset($_GET))
  70 {
  71         global $_GET;
  72         $_GET = $GLOBALS['_GET'];
  73 }
  74 if (!isset($_POST))
  75 {
  76         global $_POST;
  77         $_POST = $GLOBALS['_POST'];
  78 }
  79 if (!isset($_COOKIE))
  80 {
  81         global $_COOKIE;
  82         $_COOKIE = $GLOBALS['_COOKIE'];
  83 }
  84
  85 // Include IP-Filter here
  86 //require("/usr/share/php/ipfilter.php");
  87
  88 // Generate arrays which holds the relevante chars to replace
  89 global $SEC_CHARS, $URL_CHARS;
  90 $SEC_CHARS = array(
  91         // The chars we are looking for...
  92         'from' => array("{", "}", "/", ".", "'", "$", "(", ")", '{--', '--}', "%", ";", "[", "]", ":", "--"),
  93         // ... and we will replace to.
  94         'to'   => array(
  95                 "{OPEN_ANCHOR2}",
  96                 "{CLOSE_ANCHOR2}",
  97                 "{SLASH}",
  98                 "{DOT}",
  99                 '{QUOT}',
 100                 "{DOLLAR}",
 101                 "{OPEN_ANCHOR}",
 102                 "{CLOSE_ANCHOR}",
 103                 "{OPEN_TEMPLATE}",
 104                 "{CLOSE_TEMPLATE}",
 105                 "{PER}",
 106                 "{SEMI}",
 107                 "{OPEN_INDEX}",
 108                 "{CLOSE_INDEX}",
 109                 "{DBL_DOT}",
 110                 "{COMMENT}"
 111         ),
 112 );
 113
 114 // Characters allowed in URLs
 115 //
 116 // Note: Do not replace 'to' with 'from' and vise-versa! When you do this all booked URLs will be
 117 //       rejected because of the {SLASH}, {DOT} and all below listed items inside the URL.
 118 $URL_CHARS = array(
 119         // Search for these secured characters
 120         'to'   => array("{SLASH}", "{DOT}", "{PER}", "{DBL_DOT}", "{COMMENT}"),
 121         // Replace with these characters
 122         'from' => array("/", ".", "%", ":", "--")
 123 );
 124
 125 // Overworked security part:
 126 if (is_array($_GET)) {
 127         foreach ($_GET as $seckey=>$secvalue)
 128         {
 129                 if (is_array($secvalue))
 130                 {
 131                         // Throw arrays away...
 132                         unset($_GET[$seckey]);
 133                 }
 134                  else
 135                 {
 136                         // Only variables are allowed (non-array) but we secure them all!
 137                         foreach ($SEC_CHARS['from'] as $key=>$char)
 138                         {
 139                                 // Pass all through
 140                                 $_GET[$seckey] = str_replace($char  , $SEC_CHARS['to'][$key], $_GET[$seckey]);
 141                         }
 142
 143                         // Strip all other out
 144                         $_GET[$seckey] = strip_tags($_GET[$seckey]);
 145                 }
 146         }
 147 }
 148
 149 if (basename($_SERVER['PHP_SELF']) != "install.php")
 150 {
 151         // And POST data
 152         foreach ($_POST as $seckey=>$secvalue)
 153         {
 154                 if (!is_array($secvalue))
 155                 {
 156                         // Only variables are allowed (non-array) to be secured...
 157                         foreach ($SEC_CHARS['from'] as $key=>$char)
 158                         {
 159                                 // Pass all through
 160                                 $_POST[$seckey] = str_replace($char  , $SEC_CHARS['to'][$key], $_POST[$seckey]);
 161                         }
 162
 163                         // Strip all other out
 164                         $_POST[$seckey] = strip_tags($_POST[$seckey]);
 165                 }
 166         }
 167
 168         // ... and finally cookies
 169         foreach ($_COOKIE as $seckey=>$secvalue)
 170         {
 171                 if (is_array($secvalue))
 172                 {
 173                         // Throw arrays away...
 174                         unset($_COOKIE[$seckey]);
 175                 }
 176                  else
 177                 {
 178                         // Only variables are allowed (non-array) but we secure them all!
 179                         foreach ($SEC_CHARS['from'] as $key=>$char)
 180                         {
 181                                 // Pass all through
 182                                 $_COOKIE[$seckey] = str_replace($char  , $SEC_CHARS['to'][$key], $_COOKIE[$seckey]);
 183                         }
 184
 185                         // Strip all other out
 186                         $_COOKIE[$seckey] = strip_tags($_COOKIE[$seckey]);
 187                 }
 188         }
 189 }
 190
 191 // Activate caching or transparent compressing when it is not already done
 192 if (!defined('_OB_CACHING'))
 193 {
 194         if (phpversion() >= '4.0.4pl1' && (strstr(getenv('HTTP_USER_AGENT'),'compatible') || (strstr(getenv('HTTP_USER_AGENT'), "Mozilla"))))
 195         {
 196                 if ((extension_loaded('zlib')) && (function_exists('ob_start')))
 197                 {
 198                         // Start caching
 199                         define('_OB_CACHING', "on");
 200                         ob_start();
 201                 }
 202                  else
 203                 {
 204                         // Extension not loaded or required function is missing
 205                         define('_OB_CACHING', "404");
 206                 }
 207         }
 208          else
 209         {
 210                 // Old PHP version
 211                 define('_OB_CACHING', "old");
 212         }
 213 }
 214
 215 // At last secure the $_SERVER['PHP_SELF'] element
 216 $_SERVER['PHP_SELF'] = secureString($_SERVER['PHP_SELF']);
 217
 218 // Split it up into path and filename
 219 $SELF_DIR  = dirname($_SERVER['PHP_SELF']);
 220 $SELF_FILE = basename($_SERVER['PHP_SELF']);
 221
 222 // Check for a .php inside the $SELF_DIR...
 223 while (ereg(".php", $SELF_DIR))
 224 {
 225         // Correct the dirname
 226         $SELF_DIR = substr($SELF_DIR, 0, (strpos($SELF_DIR, ".php") + 4));
 227         // Rewrite filename...
 228         $SELF_FILE = basename($SELF_DIR);
 229         // ... and dirname
 230         $SELF_DIR = dirname($SELF_DIR);
 231 }
 232
 233 // Put both together again and let's pray it is secured now...
 234 $_SERVER['PHP_SELF'] = $SELF_DIR."/".$SELF_FILE;
 235
 236 // Remove uneccessary variables
 237 unset($SELF_DIR);
 238 unset($SELF_FILE);
 239
 240 // Security system loaded...
 241 define('__SECURITY', "1");
 242
 243 //
 244 ?>