link.php

<?php

require_once('inc.php');
$config = require('config.php');

if (file_exists('key.php'))
{
    $key = require('key.php');
    if ($key['current'] !== $_SERVER['QUERY_STRING'])
    {
        if ($key['previous'] === $_SERVER['QUERY_STRING'])
        {
            header('Location: ?' . $key['current']);
        }
        else if (!isset($_POST['passwd']))
        {
            echo '<form method="post"><input type="password" name="passwd" /></form>';
        }
        else if ($_POST['passwd'] !== $config['passwd'])
        {
            echo 'Wrong';
        }
        else
        {
            header('Location: ?' . $key['current']);
        }
        exit;
    }
}
else
{
}

mt_srand(microtime(true) * 1000);
$new = sha1(crypt(microtime(true) . mt_rand() . time() . mt_rand()));
file_put_contents('key.php', '<?php return ' . var_export(array(
    'current' => $new,
    'previous' => isset($key) ? $key['current'] : '',
), true) . ';');

echo '<label for="webhook">Webhook:</label> <input id="webhook" size="80" type="text" value="' . dirname($_SERVER['SCRIPT_URI']) . '/hook.php?' . $new . '" />';
//print_r($_SERVER);