整理php防注入和XSS攻击通用过滤

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<?php
//php防注入和XSS攻击通用过滤. 
//by qq:831937
$_GET     && SafeFilter($_GET);
$_POST    && SafeFilter($_POST);
$_COOKIE  && SafeFilter($_COOKIE);

function SafeFilter (&$arr) 
{

   $ra=Array('/([\x00-\x08,\x0b-\x0c,\x0e-\x19])/','/script/','/javascript/','/vbscript/','/expression/','/applet/','/meta/','/xml/','/blink/','/link/','/style/','/embed/','/object/','/frame/','/layer/','/title/','/bgsound/','/base/','/onload/','/onunload/','/onchange/','/onsubmit/','/onreset/','/onselect/','/onblur/','/onfocus/','/onabort/','/onkeydown/','/onkeypress/','/onkeyup/','/onclick/','/ondblclick/','/onmousedown/','/onmousemove/','/onmouseout/','/onmouseover/','/onmouseup/','/onunload/');

   if (is_array($arr))
   {
     foreach ($arr as $key => $value) 
     {
        if (!is_array($value))
        {
          if (!get_magic_quotes_gpc())             //不对magic_quotes_gpc转义过的字符使用addslashes(),避免双重转义。
          {
             $value  = addslashes($value);           //给单引号(')、双引号(")、反斜线(\)与 NUL(NULL 字符)加上反斜线转义
          }
          $value       = preg_replace($ra,'',$value);     //删除非打印字符,粗暴式过滤xss可疑字符串
          $arr[$key]     = htmlentities(strip_tags($value)); //去除 HTML 和 PHP 标记并转换为 HTML 实体
        }
        else
        {
          SafeFilter($arr[$key]);
        }
     }
   }
}
?>

所以得SQL语句如果有类似这样的写法:”select * from cdr where src
=”.$userId; 都要改成 $userId=mysql_real_escape_string($userId)

所以,htmlspecialchars函数更多的时候要加上第二个参数, 应该这样用:
htmlspecialchars($string,ENT_QUOTES).当然,如果需要不转化如何的引号,用htmlspecialchars($string,ENT_NOQUOTES).
另外, 尽量少用htmlentities,
在全部英文的时候htmlentities和htmlspecialchars没有区别,都可以达到目的.但是,中文情况下,
htmlentities却会转化所有的html代码,连同里面的它无法识别的中文字符也给转化了。
htmlentities和htmlspecialchars这两个函数对
‘之类的字符串支持不好,都不能转化,
所以用htmlentities和htmlspecialchars转化的字符串只能防止XSS攻击,不能防止SQL注入攻击.

mysql_real_escape_string()

例子

所有有打印的语句如echo,print等 在打印前都要使用htmlentities()
进行过滤,这样可以防止Xss,注意中文要写出htmlentities($name,ENT_NOQUOTES,GB2312)

function xss_clean($data){
 // Fix &entity\n;
 $data=str_replace(array('&','<','>'),array('&amp;','&lt;','&gt;'),$data);
 $data=preg_replace('/(*\w+)[\x00-\x20]+;/u','$1;',$data);
 $data=preg_replace('/(*[0-9A-F]+);*/iu','$1;',$data);
 $data=html_entity_decode($data,ENT_COMPAT,'UTF-8');
 // Remove any attribute starting with "on" or xmlns
 $data=preg_replace('#(<[^>]+?[\x00-\x20"\'])(?:on|xmlns)[^>]*+>#iu','$1>',$data);
 // Remove javascript: and vbscript: protocols
 $data=preg_replace('#([a-z]*)[\x00-\x20]*=[\x00-\x20]*([`\'"]*)[\x00-\x20]*j[\x00-\x20]*a[\x00-\x20]*v[\x00-\x20]*a[\x00-\x20]*s[\x00-\x20]*c[\x00-\x20]*r[\x00-\x20]*i[\x00-\x20]*p[\x00-\x20]*t[\x00-\x20]*:#iu','$1=$2nojavascript...',$data);
 $data=preg_replace('#([a-z]*)[\x00-\x20]*=([\'"]*)[\x00-\x20]*v[\x00-\x20]*b[\x00-\x20]*s[\x00-\x20]*c[\x00-\x20]*r[\x00-\x20]*i[\x00-\x20]*p[\x00-\x20]*t[\x00-\x20]*:#iu','$1=$2novbscript...',$data);
 $data=preg_replace('#([a-z]*)[\x00-\x20]*=([\'"]*)[\x00-\x20]*-moz-binding[\x00-\x20]*:#u','$1=$2nomozbinding...',$data);
 // Only works in IE: 
 $data=preg_replace('#(<[^>]+?)style[\x00-\x20]*=[\x00-\x20]*[`\'"]*.*?expression[\x00-\x20]*\([^>]*+>#i','$1>',$data);
 $data=preg_replace('#(<[^>]+?)style[\x00-\x20]*=[\x00-\x20]*[`\'"]*.*?behaviour[\x00-\x20]*\([^>]*+>#i','$1>',$data);
 $data=preg_replace('#(<[^>]+?)style[\x00-\x20]*=[\x00-\x20]*[`\'"]*.*?s[\x00-\x20]*c[\x00-\x20]*r[\x00-\x20]*i[\x00-\x20]*p[\x00-\x20]*t[\x00-\x20]*:*[^>]*+>#iu','$1>',$data);
 // Remove namespaced elements (we do not need them)
 $data=preg_replace('#</*\w+:\w[^>]*+>#i','',$data);
 do{// Remove really unwanted tags
 $old_data=$data;
 $data=preg_replace('#</*(?:applet|b(?:ase|gsound|link)|embed|frame(?:set)?|i(?:frame|layer)|l(?:ayer|ink)|meta|object|s(?:cript|tyle)|title|xml)[^>]*+>#i','',$data);
 }while($old_data!==$data);
 // we are done...
 return $data;
}

方法一,利用php htmlentities函数

方法三:

例子