[ZJCTF 2019]NiZhuanSiWei的深入解析

    <?php  
    $text = $_GET["text"];
    $file = $_GET["file"];
    $password = $_GET["password"];
    if(isset($text)&&(file_get_contents($text,'r')==="welcome to the zjctf")){
    echo "<br><h1>".file_get_contents($text,'r')."</h1></br>";
    if(preg_match("/flag/",$file)){
        echo "Not now!";
        exit(); 
    }else{
        include($file);  //useless.php
        $password = unserialize($password);
        echo $password;
    }
    }
    else{
    highlight_file(__FILE__);
    }
    ?>