XSS安全处理

Security.class.php文件

 <?php
 class Security {

     public $filename_bad_chars =    array(
         '../', '<!--', '-->', '<', '>',
         "'", '"', '&', '$', '#',
         '{', '}', '[', ']', '=',
         ';', '?', '%20', '%22',
         '%3c',        // <
         '%253c',    // <
         '%3e',        // >
         '%0e',        // >
         '%28',        // (
         '%29',        // )
         '%2528',    // (
         '%26',        // &
         '%24',        // $
         '%3f',        // ?
         '%3b',        // ;
         '%3d'        // =
     );
     protected $_xss_hash =    '';
     protected $_never_allowed_str =    array(
         'document.cookie'    => '[removed]',
         'document.write'    => '[removed]',
         '.parentNode'        => '[removed]',
         '.innerHTML'        => '[removed]',
         '-moz-binding'        => '[removed]',
         '<!--'                => '&lt;!--',
         '-->'                => '--&gt;',
         '<![CDATA['            => '&lt;![CDATA[',
         '<comment>'            => '&lt;comment&gt;'
     );
     protected $_never_allowed_regex = array(
         'javascript\s*:',
         '(document|(document\.)?window)\.(location|on\w*)',
         'expression\s*(\(|&\#40;)', // CSS and IE
         'vbscript\s*:', // IE, surprise!
         'Redirect\s+302',
         "([\"'])?data\s*:[^\\1]*?base64[^\\1]*?,[^\\1]*?\\1?"
     );

     public function gprc_xss(){
         if($_POST)$_POST             = $this->xss_clean($_POST);
         if($_GET)$_GET               = $this->xss_clean($_GET);
         if($_COOKIE)$_COOKIE         = $this->xss_clean($_COOKIE);
         if($_REQUEST)$_REQUEST       = $this->xss_clean($_REQUEST);
     }

     public function remove_invisible_characters($str, $url_encoded = TRUE){
             $non_displayables = array();
             if ($url_encoded)  {
                 $non_displayables[] = '/%0[0-8bcef]/';    // url encoded 00-08, 11, 12, 14, 15
                 $non_displayables[] = '/%1[0-9a-f]/';    // url encoded 16-31
             }
             $non_displayables[] = '/[\x00-\x08\x0B\x0C\x0E-\x1F\x7F]+/S';    // 00-08, 11, 12, 14-31, 127
             do {
                 $str = preg_replace($non_displayables, '', $str, -1, $count);
             }
             while ($count);
             return $str;
     }

     public function xss_clean($str, $is_image = FALSE){
         if (is_array($str)){
             while (list($key) = each($str)){
                 $str[$key] = $this->xss_clean($str[$key]);
             }
             return $str;
         }
         $str = $this->_validate_entities($this->remove_invisible_characters($str));
         $str = rawurldecode($str);
         $str = preg_replace_callback("/[a-z]+=([\'\"]).*?\\1/si", array($this, '_convert_attribute'), $str);
         $str = preg_replace_callback('/<\w+.*/si', array($this, '_decode_entity'), $str);
         $str = $this->remove_invisible_characters($str);
         $str = str_replace("\t", ' ', $str);
         $converted_string = $str;
         $str = $this->_do_never_allowed($str);
         if ($is_image === TRUE){
             $str = preg_replace('/<\?(php)/i', '&lt;?\\1', $str);
         }else    {
             $str = str_replace(array('<?', '?'.'>'), array('&lt;?', '?&gt;'), $str);
         }
         $words = array(
             'javascript', 'expression', 'vbscript', 'script', 'base64',
             'applet', 'alert', 'document', 'write', 'cookie', 'window'
         );
         foreach ($words as $word){
             $word = implode('\s*', str_split($word)).'\s*';
             $str = preg_replace_callback('#('.substr($word, 0, -3).')(\W)#is', array($this, '_compact_exploded_words'), $str);
         }
         do{
             $original = $str;
             if (preg_match('/<a/i', $str))$str = preg_replace_callback('#<a\s+([^>]*?)(?:>|$)#si', array($this, '_js_link_removal'), $str);
             if (preg_match('/<img/i', $str))$str = preg_replace_callback('#<img\s+([^>]*?)(?:\s?/?>|$)#si', array($this, '_js_img_removal'), $str);
             if (preg_match('/script|xss/i', $str))$str = preg_replace('#</*(?:script|xss).*?>#si', '[removed]', $str);
         }
         while ($original !== $str);
         unset($original);
         $str = $this->_remove_evil_attributes($str, $is_image);
         $naughty = 'alert|applet|audio|basefont|base|behavior|bgsound|blink|body|embed|expression|form|frameset|frame|head|html|ilayer|iframe|input|isindex|layer|link|meta|object|plaintext|style|script|textarea|title|video|xml|xss';
         $str = preg_replace_callback('#<(/*\s*)('.$naughty.')([^><]*)([><]*)#is', array($this, '_sanitize_naughty_html'), $str);
         $str = preg_replace('#(alert|cmd|passthru|eval|exec|expression|system|fopen|fsockopen|file|file_get_contents|readfile|unlink)(\s*)\((.*?)\)#si',    '\\1\\2(\\3)',    $str);
         $str = $this->_do_never_allowed($str);
         if ($is_image === TRUE)return ($str === $converted_string);
         return $str;
     }

     public function xss_hash(){
         if ($this->_xss_hash === '')$this->_xss_hash = md5(uniqid(mt_rand()));
         return $this->_xss_hash;
     }

     public function entity_decode($str, $charset = NULL){
         if (strpos($str, '&') === FALSE)return $str;
         if (empty($charset))$charset = 'utf-8';

         do{
             $matches = $matches1 = 0;
             $str = preg_replace('~(&#x0*[0-9a-f]{2,5});?~iS', '$1;', $str, -1, $matches);
             $str = preg_replace('~(&#\d{2,4});?~S', '$1;', $str, -1, $matches1);
             $str = html_entity_decode($str, ENT_COMPAT, $charset);
         }
         while ($matches OR $matches1);
         return $str;
     }

     public function sanitize_filename($str, $relative_path = FALSE){
         $bad = $this->filename_bad_chars;
         if ( ! $relative_path){
             $bad[] = './';
             $bad[] = '/';
         }
         $str = $this->remove_invisible_characters($str, FALSE);
         do{
             $old = $str;
             $str = str_replace($bad, '', $str);
         }while ($old !== $str);
         return stripslashes($str);
     }

     public function strip_image_tags($str){
         return preg_replace(array('#<img[\s/]+.*?src\s*=\s*["\'](.+?)["\'].*?\>#', '#<img[\s/]+.*?src\s*=\s*(.+?).*?\>#'), '\\1', $str);
     }

     protected function _compact_exploded_words($matches){
         return preg_replace('/\s+/s', '', $matches[1]).$matches[2];
     }

     protected function _remove_evil_attributes($str, $is_image){
         $evil_attributes = array('style', 'xmlns', 'formaction');
         if ($is_image === TRUE)unset($evil_attributes[array_search('xmlns', $evil_attributes)]);

         do {
             $count = 0;
             $attribs = array();
             preg_match_all('/('.implode('|', $evil_attributes).')\s*=\s*(\042|\047)([^\\2]*?)(\\2)/is', $str, $matches, PREG_SET_ORDER);
             foreach ($matches as $attr){
                 $attribs[] = preg_quote($attr[0], '/');
             }
             preg_match_all('/('.implode('|', $evil_attributes).')\s*=\s*([^\s>]*)/is', $str, $matches, PREG_SET_ORDER);
             foreach ($matches as $attr){
                 $attribs[] = preg_quote($attr[0], '/');
             }
             if (count($attribs) > 0)$str = preg_replace('/(<?)(\/?[^><]+?)([^A-Za-z<>\-])(.*?)('.implode('|', $attribs).')(.*?)([\s><]?)([><]*)/i', '$1$2 $4$6$7$8', $str, -1, $count);
         }
         while ($count);
         return $str;
     }

     protected function _sanitize_naughty_html($matches)    {
         return '&lt;'.$matches[1].$matches[2].$matches[3].str_replace(array('>', '<'), array('&gt;', '&lt;'), $matches[4]);
     }

     protected function _js_link_removal($match){
         return str_replace($match[1],
                     preg_replace('#href=.*?(?:alert\(|alert&\#40;|javascript:|livescript:|mocha:|charset=|window\.|document\.|\.cookie|<script|<xss|data\s*:)#si',
                             '',    $this->_filter_attributes(str_replace(array('<', '>'), '', $match[1]))    ),$match[0]);
     }

     protected function _js_img_removal($match){
         return str_replace($match[1],
                     preg_replace('#src=.*?(?:alert\(|alert&\#40;|javascript:|livescript:|mocha:|charset=|window\.|document\.|\.cookie|<script|<xss|base64\s*,)#si',
                             '',$this->_filter_attributes(str_replace(array('<', '>'), '', $match[1]))
                     ),
                     $match[0]);
     }

     protected function _convert_attribute($match){
         return str_replace(array('>', '<', '\\'), array('&gt;', '&lt;', '\\\\'), $match[0]);
     }

     protected function _filter_attributes($str){
         $out = '';
         if (preg_match_all('#\s*[a-z\-]+\s*=\s*(\042|\047)([^\\1]*?)\\1#is', $str, $matches)){
             foreach ($matches[0] as $match){
                 $out .= preg_replace('#/\*.*?\*/#s', '', $match);
             }
         }
         return $out;
     }

     protected function _decode_entity($match){
         return $this->entity_decode($match[0], strtoupper('utf-8'));
     }

     protected function _validate_entities($str){
         $str = preg_replace('|\&([a-z\_0-9\-]+)\=([a-z\_0-9\-]+)|i', $this->xss_hash().'\\1=\\2', $str);
         $str = preg_replace('#(&\#?[0-9a-z]{2,})([\x00-\x20])*;?#i', '\\1;\\2', $str);
         $str = preg_replace('#(&\#x?)([0-9A-F]+);?#i', '\\1\\2;', $str);
         return str_replace($this->xss_hash(), '&', $str);
     }

     protected function _do_never_allowed($str){
         $str = str_replace(array_keys($this->_never_allowed_str), $this->_never_allowed_str, $str);
         foreach ($this->_never_allowed_regex as $regex){
             $str = preg_replace('#'.$regex.'#is', '[removed]', $str);
         }
         return $str;
     }
     /**
      * @desc: 暂时不用
      * */
     public function gprc_sql(){
         if(!get_magic_quotes_gpc()) {
             if($_POST)    $_POST      =  $this->daddslashes($_POST);
             if($_GET)     $_GET       =  $this->daddslashes($_GET);
             if($_COOKIE)  $_COOKIE    =  $this->daddslashes($_COOKIE);
             if($_REQUEST) $_REQUEST   =  $this->daddslashes($_REQUEST);
         }
     }

     public function daddslashes($string){
         if(!is_array($string)) return addslashes($string);
         foreach($string as $key => $val) $string[$key] =  $this->daddslashes($val);
         return $string;
     }
 }

调用方式:

$SEC = new Security();
$SEC->gprc_xss();
$SEC = NULL;