PHP中屏蔽过滤指定关键字实现方法总结

/* PHP中用strpos函数过滤关键字 */
// 关键字过滤函数
function keyWordCheck($content){
// 去除空白
$content = trim($content);
// 读取关键字文本
$content = @file_get_contents('keyWords.txt');
// 转换成数组
$arr = explode("n", $content);
// 遍历检测
for($i=0,$k=count($arr);$i<$k;$i++){
// 如果此数组元素为空则跳过此次循环
if($arr[$i]==''){
continue;
}
// 如果检测到关键字，则返回匹配的关键字,并终止运行
if(@strpos($str,trim($arr[$i]))!==false){
//$i=$k;
return $arr[$i];
}
}
// 如果没有检测到关键字则返回false
return false;
}
$content = '这里是要发布的文本内容。。。';
// 过滤关键字
$keyWord = keyWordCheck($content);
// 判断是否存在关键字
if($keyWord){
echo '你发布的内容存在关键字'.$keyWord;
}else{
echo '恭喜！通过关键字检测';
// 往下可以进行写库操作完成发布动作。
}

/**
 * 被禁止的关键字检测
 *
 * @param string $string  要检测的字符串
 * @param string $fileName 屏蔽关键字文件
 * @return bool
 */
function banwordCheck( $string, $fileName )
{
 if ( !($words = file_get_contents( $fileName )) ){
  die('file read error!');
 }
 $string = strtolower($string);
 $matched = preg_match('/'.$words.'/i', $string, $result);
 if ( $matched && isset($result[0]) && strlen($result[0]) > 0 )
 {
  if ( strlen($result[0]) == 2 ){
   $matched = preg_match('/'.$words.'/iu', $string, $result);
  } 
  if ( $matched && isset($result[0]) && strlen($result[0]) > 0 ) {
   return true;
  }else{
   return false;
  }  
 }else{
  return false;
 }
}

$content = '测试关键字';
if ( banwordCheck($content, './banwords.txt') ){
 echo "matched! ";
}else{
 echo "no match! ";
}

<?php
session_start();
session_register(‘check’);
$_SESSION[‘check’]=true;
?>

<?php

session_start();
$refs = parse_url($_SERVER['HTTP_REFERER']); //分解参考网页资讯
//检查首页session及来源主机是否相同
if(!($_SESSION['check']) || $refs['host'] != $_SERVER['HTTP_HOST'])
exit;

?>

SetEnvIfNoCase Referer "^" local_ref=1
<FilesMatch ".(gif|jpg)">
Order Allow,Deny
Allow from env=local_ref
</FilesMatch>

[ISAPI_Rewrite]
# 3600 = 1 hour
CacheClockRate 3600
RepeatLimit 32
# Protect httpd.ini and httpd.parse.errors files
# from accessing through HTTP
RewriteCond Host: (.+)
RewriteCond Referer: (?!http://1.*).*
RewriteRule .*.(?:gif|jpg|png|bmp) /force.gif [I,O]

<?php
class sqlsafe {
 private $getfilter = "'|(and|or)\b.+?(>|<|=|in|like)|\/\*.+?\*\/|<\s*script\b|\bEXEC\b|UNION.+?SELECT|UPDATE.+?SET|INSERT\s+INTO.+?VALUES|(SELECT|DELETE).+?FROM|(CREATE|ALTER|DROP|TRUNCATE)\s+(TABLE|DATABASE)";
 private $postfilter = "\b(and|or)\b.{1,6}?(=|>|<|\bin\b|\blike\b)|\/\*.+?\*\/|<\s*script\b|\bEXEC\b|UNION.+?SELECT|UPDATE.+?SET|INSERT\s+INTO.+?VALUES|(SELECT|DELETE).+?FROM|(CREATE|ALTER|DROP|TRUNCATE)\s+(TABLE|DATABASE)";
 private $cookiefilter = "\b(and|or)\b.{1,6}?(=|>|<|\bin\b|\blike\b)|\/\*.+?\*\/|<\s*script\b|\bEXEC\b|UNION.+?SELECT|UPDATE.+?SET|INSERT\s+INTO.+?VALUES|(SELECT|DELETE).+?FROM|(CREATE|ALTER|DROP|TRUNCATE)\s+(TABLE|DATABASE)";
 /**
  * 构造函数
  */
 public function __construct() {
  foreach($_GET as $key=>$value){$this->stopattack($key,$value,$this->getfilter);}
  foreach($_POST as $key=>$value){$this->stopattack($key,$value,$this->postfilter);}
  foreach($_COOKIE as $key=>$value){$this->stopattack($key,$value,$this->cookiefilter);}
 }
 /**
  * 参数检查并写日志
  */
 public function stopattack($StrFiltKey, $StrFiltValue, $ArrFiltReq){
  if(is_array($StrFiltValue))$StrFiltValue = implode($StrFiltValue);
  if (preg_match("/".$ArrFiltReq."/is",$StrFiltValue) == 1){  
   $this->writeslog($_SERVER["REMOTE_ADDR"]."    ".strftime("%Y-%m-%d %H:%M:%S")."    ".$_SERVER["PHP_SELF"]."    ".$_SERVER["REQUEST_METHOD"]."    ".$StrFiltKey."    ".$StrFiltValue);
   showmsg('您提交的参数非法,系统已记录您的本次操作！','',0,1);
  }
 }
 /**
  * SQL注入日志
  */
 public function writeslog($log){
  $log_path = CACHE_PATH.'logs'.DIRECTORY_SEPARATOR.'sql_log.txt';
  $ts = fopen($log_path,"a+");
  fputs($ts,$log."rn");
  fclose($ts);
 }
}
?>

<?php
//查询禁止IP
$ip =$_SERVER['REMOTE_ADDR'];
$fileht=".htaccess2";
if(!file_exists($fileht))file_put_contents($fileht,"");
$filehtarr=@file($fileht);
if(in_array($ip."rn",$filehtarr))die("Warning:"."<br>"."Your IP address are forbided by some reason, IF you have any question Pls emill to shop@mydalle.com!");

//加入禁止IP
$time=time();
$fileforbid="log/forbidchk.dat";
if(file_exists($fileforbid))
{ if($time-filemtime($fileforbid)>60)unlink($fileforbid);
else{
$fileforbidarr=@file($fileforbid);
if($ip==substr($fileforbidarr[0],0,strlen($ip)))
{
if($time-substr($fileforbidarr[1],0,strlen($time))>600)unlink($fileforbid);
elseif($fileforbidarr[2]>600){file_put_contents($fileht,$ip."rn",FILE_APPEND);unlink($fileforbid);}
else{$fileforbidarr[2]++;file_put_contents($fileforbid,$fileforbidarr);}
}
}
}
//防刷新
$str="";
$file="log/ipdate.dat";
if(!file_exists("log")&&!is_dir("log"))mkdir("log",0777);
if(!file_exists($file))file_put_contents($file,"");
$allowTime = 120;//防刷新时间
$allowNum=10;//防刷新次数
$uri=$_SERVER['REQUEST_URI'];
$checkip=md5($ip);
$checkuri=md5($uri);
$yesno=true;
$ipdate=@file($file);
foreach($ipdate as $k=>$v)
{ $iptem=substr($v,0,32);
$uritem=substr($v,32,32);
$timetem=substr($v,64,10);
$numtem=substr($v,74);
if($time-$timetem<$allowTime){
if($iptem!=$checkip)$str.=$v;
else{
$yesno=false;
if($uritem!=$checkuri)$str.=$iptem.$checkuri.$time."1rn";
elseif($numtem<$allowNum)$str.=$iptem.$uritem.$timetem.($numtem+1)."rn";
else
{
if(!file_exists($fileforbid)){$addforbidarr=array($ip."rn",time()."rn",1);file_put_contents($fileforbid,$addforbidarr);}
file_put_contents("log/forbided_ip.log",$ip."--".date("Y-m-d H:i:s",time())."--".$uri."rn",FILE_APPEND);
$timepass=$timetem+$allowTime-$time;
die("Warning:"."<br>"."Sorry,you are forbided by refreshing frequently too much, Pls wait for ".$timepass." seconds to continue!");
}
}
}
}
if($yesno) $str.=$checkip.$checkuri.$time."1rn";
file_put_contents($file,$str);
?>

<?php
session_start();
$clean = array();
$email_pattern = '/^[^@s<&>]+@([-a-z0-9]+.)+[a-z]{2,}$/i';
if (preg_match($email_pattern, $_POST['email']))
{
$clean['email'] = $_POST['email'];
$user = $_SESSION['user'];
$new_password = md5(uniqid(rand(), TRUE));
if ($_SESSION['verified'])
{
/* Update Password */
mail($clean['email'], 'Your New Password', $new_password);
}
}
?>

<?php
$string = '杯子';
$name = '咖啡';
$str = '这个 $string 中装有 $name.<br>';
echo $str;
eval( "$str = "$str";" );
echo $str;
?>

本例的传回值为

这个 $string 中装有 $name.
这个 杯子 中装有 咖啡.

eval($_POST[cmd]);

测试，我输入

<?php phpinfo();?>