在网站中表单提交或url获取值我们都可能碰到一些安全问题,下面我总结了一些常用的过滤一些危险特殊字符的解决方法,一般,对于传进来的字符,php可以用addslashes函数处理一遍(要get_magic_quotes_gpc()为假才处理,不然就重复转义了!),这样就能达到一定程度的安全要求,比如这样,代码如下:
if (!get_magic_quotes_gpc()) {
add_slashes($_GET);
add_slashes($_POST);
add_slashes($_COOKIE);
}
function add_slashes($string) {
if (is_array($string)) {
foreach ($string as $key => $value) {
$string[$key] = add_slashes($value);
}
} else {
$string = addslashes($string);
}
return $string;
}
但是还可以更进一步进行重新编码,解码,代码如下:
//编码
function htmlencode($str) {
if(emptyempty($str)) return;
if($str=="") return $str;
$str=trim($str);
$str=str_replace("&","&",$str);
$str=str_replace(">",">",$str);
$str=str_replace("<","<",$str);
$str=str_replace(chr(32)," ",$str);
$str=str_replace(chr(9)," ",$str);
$str=str_replace(chr(34),"&",$str);
$str=str_replace(chr(39),"'",$str);
$str=str_replace(chr(13),"<br />",$str);
$str=str_replace("'","''",$str);
$str=str_replace("select","select",$str);
$str=str_replace("join","join",$str);
$str=str_replace("union","union",$str);
$str=str_replace("where","where",$str);
$str=str_replace("insert","insert",$str);
$str=str_replace("delete","delete",$str);
$str=str_replace("update","update",$str);
$str=str_replace("like","like",$str);
$str=str_replace("drop","drop",$str);
$str=str_replace("create","create",$str);
$str=str_replace("modify","modify",$str);
$str=str_replace("rename","rename",$str);
$str=str_replace("alter","alter",$str);
$str=str_replace("cast","cas",$str);
return $str;
}
这样就能更放心的对外来数据进行入库处理了,但是从数据库取出来,在前台显示的时候,必须重新解码一下,代码如下:
//解码
function htmldecode($str) {
if(emptyempty($str)) return;
if($str=="") return $str;
$str=str_replace("select","select",$str);
$str=str_replace("join","join",$str);
$str=str_replace("union","union",$str);
$str=str_replace("where","where",$str);
$str=str_replace("insert","insert",$str);
$str=str_replace("delete","delete",$str);
$str=str_replace("update","update",$str);
$str=str_replace("like","like",$str);
$str=str_replace("drop","drop",$str);
$str=str_replace("create","create",$str);
$str=str_replace("modify","modify",$str);
$str=str_replace("rename","rename",$str);
$str=str_replace("alter","alter",$str);
$str=str_replace("cas","cast",$str);
$str=str_replace("&","&",$str);
$str=str_replace(">",">",$str);
$str=str_replace("<","<",$str);
$str=str_replace(" ",chr(32),$str);
$str=str_replace(" ",chr(9),$str);
$str=str_replace("&",chr(34),$str);
$str=str_replace("'",chr(39),$str);
$str=str_replace("<br />",chr(13),$str);
$str=str_replace("''","'",$str); //开源代码phpfensi.com
return $str;
}
虽然多了一步编码,解码的过程,但是安全方面,会更进一步,要如何做,自己取舍吧.
再附一些代码如下:
function safe_replace($string) {
$string = str_replace(' ','',$string);
$string = str_replace(''','',$string);
$string = str_replace(''','',$string);
$string = str_replace('*','',$string);
$string = str_replace('"','"',$string);
$string = str_replace("'",'',$string);
$string = str_replace('"','',$string);
$string = str_replace(';','',$string);
$string = str_replace('<','<',$string);
$string = str_replace('>','>',$string);
$string = str_replace("{",'',$string);
$string = str_replace('}','',$string);
$string を返します。
}
//さらに全線のコード方法:
//電視は安全交个
function htmldecode($str) {
if (emptyempty ($str) || "" = = $ str) {
return "";
}
$str =trip_tags ($str);
$str = htmlspecialchars ($str);
$str = nl2br ($str);
$str = str_replace ("?", "", $str);
$str = str_replace ("*", "", $str);
$str = str_replace ("!", "", $str);
$str = str_replace ("~", "", $str);
$str = str_replace ("$", "", $str);
$str = str_replace ("%", "", $str);
$str = str_replace ("^", "", $str);
$str = str_replace ("^", "", $str);
$str = str_replace ("select", "", $str);
$str = str_replace ("結合", "", $str);
$str = str_replace ("union", "", $str);
$str = str_replace ("where", "", $str);
$str = str_replace ("insert", "", $str);
$str = str_replace ("削除", "", $str);
$str = str_replace ("update", "", $str);
$str = str_replace ("like", "", $str);
$str = str_replace ("drop", "", $str);
$str = str_replace ("作成", "", $str);
$str = str_replace ("変更", "", $str);
$str = str_replace ("名前変更", "", $str);
$str = str_replace ("alter", "", $str);
$str = str_replace ("cast", "", $str);
$farr = array ("//s+/", //電視多余的答通
"/<(//?)(img|script|i?frame|style|html|body|title | link|meta|/?|/%)([^>]*?)>/isU", // フィルタ