PHP利用str_replace防注入的方法-php手册-PHP中文網

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PHP利用str_replace防注入的方法

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Jun 13, 2016 am 09:31 AM

phpreplacestr

PHP各种过滤字符函数

复制代码代码如下:

       /**
    * 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('    $string = str_replace('>','>',$string);
    $string = str_replace("{",'',$string);
    $string = str_replace('}','',$string);
    $string = str_replace('','',$string);
    return $string;
    }
    ?>

        /**
    * 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;
    }
    ?>

        //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("#]*>#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;
    }
    }
    ?>

/**
 +----------------------------------------------------------
 * 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
 $text = preg_replace('/<script>/','',$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; } ?></script>