php过滤xss函数
 
 
<?php 
/**
* @过滤XSS（跨站脚本攻击）的函数
* @par $val 字符串参数，可能包含恶意的脚本代码如<script language="javascript">alert("hello world");</script>
* @return  处理后的字符串
* @Recoded By Androidyue
**/
function RemoveXSS($val) { 
   // remove all non-printable characters. CR(0a) and LF(0b) and TAB(9) are allowed 
   // this prevents some character re-spacing such as <java\0script> 
   // note that you have to handle splits with \n, \r, and \t later since they *are* allowed in some inputs 
   $val = preg_replace('/([\x00-\x08,\x0b-\x0c,\x0e-\x19])/', '', $val); 
 
   // straight replacements, the user should never need these since they're normal characters 
   // this prevents like <IMG SRC=@avascript:alert('XSS')> 
   $search = 'abcdefghijklmnopqrstuvwxyz';
   $search .= 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'; 
   $search .= '1234567890!@#$%^&*()';
   $search .= '~`";:?+/={}[]-_|\'\\';
   for ($i = 0; $i < strlen($search); $i++) {
      // ;? matches the ;, which is optional
      // 0{0,7} matches any padded zeros, which are optional and go up to 8 chars
 
      // @ @ search for the hex values
      $val = preg_replace('/(&#[xX]0{0,8}'.dechex(ord($search[$i])).';?)/i', $search[$i], $val); // with a ;
      // @ @ 0{0,7} matches '0' zero to seven times 
      $val = preg_replace('/(&#0{0,8}'.ord($search[$i]).';?)/', $search[$i], $val); // with a ;
   }
 
   // now the only remaining whitespace attacks are \t, \n, and \r
   $ra1 = Array('javascript', 'vbscript', 'expression', 'applet', 'meta', 'xml', 'blink', 'link', 'style', 'script', 'embed', 'object', 'iframe', 'frame', 'frameset', 'ilayer', 'layer', 'bgsound', 'title', 'base');
   $ra2 = Array('onabort', 'onactivate', 'onafterprint', 'onafterupdate', 'onbeforeactivate', 'onbeforecopy', 'onbeforecut', 'onbeforedeactivate', 'onbeforeeditfocus', 'onbeforepaste', 'onbeforeprint', 'onbeforeunload', 'onbeforeupdate', 'onblur', 'onbounce', 'oncellchange', 'onchange', 'onclick', 'oncontextmenu', 'oncontrolselect', 'oncopy', 'oncut', 'ondataavailable', 'ondatasetchanged', 'ondatasetcomplete', 'ondblclick', 'ondeactivate', 'ondrag', 'ondragend', 'ondragenter', 'ondragleave', 'ondragover', 'ondragstart', 'ondrop', 'onerror', 'onerrorupdate', 'onfilterchange', 'onfinish', 'onfocus', 'onfocusin', 'onfocusout', 'onhelp', 'onkeydown', 'onkeypress', 'onkeyup', 'onlayoutcomplete', 'onload', 'onlosecapture', 'onmousedown', 'onmouseenter', 'onmouseleave', 'onmousemove', 'onmouseout', 'onmouseover', 'onmouseup', 'onmousewheel', 'onmove', 'onmoveend', 'onmovestart', 'onpaste', 'onpropertychange', 'onreadystatechange', 'onreset', 'onresize', 'onresizeend', 'onresizestart', 'onrowenter', 'onrowexit', 'onrowsdelete', 'onrowsinserted', 'onscroll', 'onselect', 'onselectionchange', 'onselectstart', 'onstart', 'onstop', 'onsubmit', 'onunload');
   $ra = array_merge($ra1, $ra2);
 
   $found = true; // keep replacing as long as the previous round replaced something
   while ($found == true) {
      $val_before = $val;
      for ($i = 0; $i < sizeof($ra); $i++) {
         $pattern = '/';
         for ($j = 0; $j < strlen($ra[$i]); $j++) {
            if ($j > 0) {
               $pattern .= '('; 
               $pattern .= '(&#[xX]0{0,8}([9ab]);)';
               $pattern .= '|'; 
               $pattern .= '|(&#0{0,8}([9|10|13]);)';
               $pattern .= ')*';
            }
            $pattern .= $ra[$i][$j];
         }
         $pattern .= '/i'; 
         $replacement = substr($ra[$i], 0, 2).'<x>'.substr($ra[$i], 2); // add in <> to nerf the tag 
  $val = preg_replace($pattern, $replacement, $val); // filter out the hex tags 
         if ($val_before == $val) { 
            // no replacements were made, so exit the loop 
            $found = false; 
         } 
      } 
   } 
   return $val; 
}
//测试一下效果 www.2cto.com
//echo RemoveXSS("<script language='javascript'>alert('hello world');</script>") ;
?>
 
javascript过滤xss
 
javascript过滤xss只是一种防君子不防小人的方法，可以两种方式，第一种是将尖括号和引号转义掉，如下面大代码：
 
function(cont){
    cont = cont.replace(/&/g, '&');
    cont = cont.replace(/</g, '<').replace(/>/g, '>');
    cont = cont.replace(/\'/g, ''').replace(/\"/g, '"');
    return cont;
};
第二种是动态创建一个dom，然后将str作为innerText，之后动态的取innerHTML出来，就可以是经过转义的内容了，
注：感谢Jackmasa 指出问题，其实这里还是会有问题，详细见文章：《前端安全》
 
apache防止svn版本库被浏览
 
前几天炒的比较热的svn版本库被爆的问题，自己查了下找到了简单的解决apache的svn版本库被浏览方式，nginx也是类似的禁用.svn的浏览
 
apache禁用svn
 
<Directory ~ ".svn">
Order allow,deny
Deny from all
</Directory>
nginx禁用svn
 
location ~ /.svn/ {
deny all;
}