<html>
<head>
<!-- This stuff in the header has nothing to do with the level -->
<link rel="stylesheet" type="text/css" href="http://natas.labs.overthewire.org/css/level.css">
<link rel="stylesheet" href="http://natas.labs.overthewire.org/css/jquery-ui.css" />
<link rel="stylesheet" href="http://natas.labs.overthewire.org/css/wechall.css" />
<script src="http://natas.labs.overthewire.org/js/jquery-1.9.1.js"></script>
<script src="http://natas.labs.overthewire.org/js/jquery-ui.js"></script>
<script src=http://natas.labs.overthewire.org/js/wechall-data.js></script><script src="http://natas.labs.overthewire.org/js/wechall.js"></script>
<script>var wechallinfo = { "level": "natas12", "pass": "<censored>" };</script></head>
<body>
<h1>natas12</h1>
<div id="content">
<?php

function genRandomString() {
    
$length 10;
    
$characters "0123456789abcdefghijklmnopqrstuvwxyz";
    
$string "";

    for (
$p 0$p $length$p++) {
        
$string .= $characters[mt_rand(0strlen($characters)-1)];
    }

    return 
$string;
}

function 
makeRandomPath($dir$ext) {
    do {
    
$path $dir."/".genRandomString().".".$ext;
    } while(
file_exists($path));
    return 
$path;
}

function 
makeRandomPathFromFilename($dir$fn) {
    
$ext pathinfo($fnPATHINFO_EXTENSION);
    return 
makeRandomPath($dir$ext);
}

if(
array_key_exists("filename"$_POST)) {
    
$target_path makeRandomPathFromFilename("upload"$_POST["filename"]);


        if(
filesize($_FILES['uploadedfile']['tmp_name']) > 1000) {
        echo 
"File is too big";
    } else {
        if(
move_uploaded_file($_FILES['uploadedfile']['tmp_name'], $target_path)) {
            echo 
"The file <a href=\"$target_path\">$target_path</a> has been uploaded";
        } else{
            echo 
"There was an error uploading the file, please try again!";
        }
    }
} else {
?>

<form enctype="multipart/form-data" action="index.php" method="POST">
<input type="hidden" name="MAX_FILE_SIZE" value="1000" />
<input type="hidden" name="filename" value="<?php print genRandomString(); ?>.jpg" />
Choose a JPEG to upload (max 1KB):<br/>
<input name="uploadedfile" type="file" /><br />
<input type="submit" value="Upload File" />
</form>
<?php ?>
<div id="viewsource"><a href="index-source.html">View sourcecode</a></div>
</div>
</body>
</html>