/* 防sql注入,xss攻击 (1)*/
function actionClean($str)
{
    $str=trim($str);
    $str=strip_tags($str);
    $str=stripslashes($str);
    $str=addslashes($str);
    $str=rawurldecode($str);
    $str=quotemeta($str);
    $str=htmlspecialchars($str);
    //去除特殊字符
    $str=preg_replace("/\/|\~|\!|\@|\#|\\$|\%|\^|\&|\*|\(|\)|\_|\+|\{|\}|\:|\<|\>|\", "" , $str);
    $str=preg_replace("/\s/", "", $str);//去除空格、换行符、制表符
    return $str;
}
//防止sql注入。xss攻击(1)
public function actionFilterArr($arr)
{
    if(is_array($arr)){
      foreach($arr as $k => $v){
        $arr[$k] = $this->actionFilterWords($v);
      }
    }else{
      $arr = $this->actionFilterWords($arr);
    }
    return $arr;
}
//防止xss攻击
public function actionFilterWords($str)
{
    $farr = array(
      "/<(\\/",
      "/(<[^>]*)on[a-zA-Z]+\s*=([^>]*>)/isU",
      "/select|insert|update|delete|drop|\'|\/\*|\*|\+|\-|\"|\.\.\/|\.\/|union|into|load_file|outfile|dump/is"
    );
    $str = preg_replace($farr,'',$str);
    return $str;
}
//防止sql注入,xss攻击(2)
public function post_check($post) {
   if(!get_magic_quotes_gpc()) {
     foreach($post as $key=>$val){
       $post[$key] = addslashes($val);
     }
    }
   foreach($post as $key=>$val){
    //把"_"过滤掉
    $post[$key] = str_replace("_", "\_", $val);
    //把"%"过滤掉
    $post[$key] = str_replace("%", "\%", $val); //sql注入
    $post[$key] = nl2br($val);
    //转换html
    $post[$key] = htmlspecialchars($val); //xss攻击
   }
   return $post;
}

//防止sql
$post=$this->post_check($_POST);
//var_dump($post);die;
$u_name=trim($post['u_name']);
$pwd=trim($post['pwd']);
if(empty($u_name)||empty($pwd))
{
  exit('字段不能非空');
}
$u_name=$this->actionFilterArr($u_name);
$pwd=$this->actionFilterArr($pwd);
//防止sql注入，xss攻击
$u_name=$this->actionClean(Yii::$app->request->post('u_name'));
$pwd=$this->actionClean(Yii::$app->request->post('pwd'));
$email=$this->actionClean(Yii::$app->request->post('email'));
//防止csrf攻击
$session=Yii::$app->session;
$csrf_token=md5(uniqid(rand(),TRUE));
$session->set('token',$csrf_token);
$session->set('token',time());
//接收数据
if($_POST)
{
  if(empty($session->get('token')) && $session->get('token')!=Yii::$app->request->post('token') && (time()-$session->get('token_time'))>30){
    exit('csrf攻击');
  }
  //防止sql
  .....

//关闭csrf
piblic $enableCsrfValidation = false;