PHP各种过滤字符函数
复制代码 代码如下:
<?php
/**
* 安全过滤函数
*
* @param $string
* @return string
*/
function safe_replace($string) {
$string = str_replace("%20","",$string);
$string = str_replace("%27","",$string);
$string = str_replace("%2527","",$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);
return $string;
}
?>
<?php
/**
* 返回经addslashes处理过的字符串或数组
* @param $string 需要处理的字符串或数组
* @return mixed
*/
function new_addslashes($string) {
if(!is_array($string)) return addslashes($string);
foreach($string as $key => $val) $string[$key] = new_addslashes($val);
return $string;
}
?>
<?php
//对请求的字符串进行安全处理
/*
$safestep
0 为不处理，
1 为禁止不安全HTML内容(javascript等)，
2 完全禁止HTML内容，并替换部份不安全字符串（如：eval(、union、CONCAT(、--、等）
*/
function StringSafe($str, $safestep=-1){
$safestep = ($safestep > -1) ? $safestep : 1;
if($safestep == 1){
$str = preg_replace("#script:#i", "ｓｃｒｉｐｔ：", $str);
$str = preg_replace("#<[/]{0,1}(link|meta|ifr|fra|scr)[^>]*>#isU", "", $str);
$str = preg_replace("#[ ]{1,}#", " ", $str);
return $str;
}else if($safestep == 2){
$str = addslashes(htmlspecialchars(stripslashes($str)));
$str = preg_replace("#eval#i", "ｅｖａｌ", $str);
$str = preg_replace("#union#i", "ｕｎｉｏｎ", $str);
$str = preg_replace("#concat#i", "ｃｏｎｃａｔ", $str);
$str = preg_replace("#--#", "－－", $str);
$str = preg_replace("#[ ]{1,}#", " ", $str);
return $str;
}else{
return $str;
}
}
?>
<?php
/**
+----------------------------------------------------------
* 输出安全的html，用于过滤危险代码
+----------------------------------------------------------
* @access public
+----------------------------------------------------------
* @param string $text 要处理的字符串
* @param mixed $tags 允许的标签列表，如 table|td|th|td
+----------------------------------------------------------
* @return string
+----------------------------------------------------------
*/
static public function safeHtml($text, $tags = null)
{
$text = trim($text);
//完全过滤注释
$text = preg_replace("/<!--?.*-->/","",$text);
//完全过滤动态代码
$text = preg_replace("/<?|?".">/","",$text);
//完全过滤js
$text = preg_replace("/<script?.*/script>/","",$text);
$text = str_replace("[","[",$text);
$text = str_replace("]","]",$text);
$text = str_replace("|","|",$text);
//过滤换行符
$text = preg_replace("/ ? /","",$text);
//br
$text = preg_replace("/<br(s/)?".">/i","[br]",$text);
$text = preg_replace("/([br]s*){10,}/i","[br]",$text);
//过滤危险的属性，如：过滤on事件lang js
while(preg_match("/(<[^><]+)(lang|on|action|background|codebase|dynsrc|lowsrc)[^><]+/i",$text,$mat)){
$text=str_replace($mat[0],$mat[1],$text);
}
while(preg_match("/(<[^><]+)(window.|javascript:|js:|about:|file:|document.|vbs:|cookie)([^><]*)/i",$text,$mat)){
$text=str_replace($mat[0],$mat[1].$mat[3],$text);
}
if( empty($allowTags) ) { $allowTags = self::$htmlTags["allow"]; }
//允许的HTML标签
$text = preg_replace("/<(".$allowTags.")( [^><[]]*)>/i","[12]",$text);
//过滤多余html
if ( empty($banTag) ) { $banTag = self::$htmlTags["ban"]; }
$text = preg_replace("/</?(".$banTag.")[^><]*>/i","",$text);
//过滤合法的html标签
while(preg_match("/<([a-z]+)[^><[]]*>[^><]*</1>/i",$text,$mat)){
$text=str_replace($mat[0],str_replace(">","]",str_replace("<","[",$mat[0])),$text);
}
//转换引号
while(preg_match("/([[^[]]*=s*)("|")([^2=[]]+)2([^[]]*])/i",$text,$mat)){
$text=str_replace($mat[0],$mat[1]."|".$mat[3]."|".$mat[4],$text);
}
//空属性转换
$text = str_replace("""","||",$text);
$text = str_replace("""","||",$text);
//过滤错误的单个引号
while(preg_match("/[[^[]]*("|")[^[]]*]/i",$text,$mat)){
$text=str_replace($mat[0],str_replace($mat[1],"",$mat[0]),$text);
}
//转换其它所有不合法的 < >
$text = str_replace("<","<",$text);
$text = str_replace(">",">",$text);
$text = str_replace(""",""",$text);
//反转换
$text = str_replace("[","<",$text);
$text = str_replace("]",">",$text);
$text = str_replace("|",""",$text);
//过滤多余空格
$text = str_replace(" "," ",$text);
return $text;
}
?>
<?php
function RemoveXSS($val) {
// remove all non-printable characters. CR(0a) and LF(0b) and TAB(9) are allowed
// this prevents some character re-spacing such as <javascript>
// note that you have to handle splits with , , and 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
$val = preg_replace("/(�{0,8}".ord($search[$i]).";?)/", $search[$i], $val); // with a ;
}
// now the only remaining whitespace attacks are , , and
$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 .= "|(�{0,8}([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;
}
?>
