<?php

    // ---- CONFIGURATION -------------------------------

    define('DB_HOST', '********');
    define('DB_USERNAME', '*******');
    define('DB_PASSWORD', '********');
    define('DB_NAME', '********');
    define('DB_TABLE', 'authme');

    // ---- PASSWORD COMPARISON FUNCTION ----------------

    function passwordCompare($rawHash, $password)
    {
        $parts = explode('$', $rawHash);

        if (count($parts) === 4)
        {
            $hash = hash('sha256', $password);
            $hash = hash('sha256', $hash . $parts[2]);

            return $hash === $parts[3];
        }

        return FALSE;
    }

    // --------------------------------------------------

    header('Content-Type: text/plain');

    $username = isset($_POST['username']) ? $_POST['username'] : NULL;
    $password = isset($_POST['password']) ? $_POST['password'] : NULL;

    if (empty($username) || empty($password))
    {
        die('false:EMPTY_REQUEST');
    }

    try
    {
        $database = new PDO('mysql:dbname=' . DB_NAME . ';host=' . DB_HOST, DB_USERNAME, DB_PASSWORD);
    }
    catch (PDOException $e)
    {
        die('false:ERROR_DATABASE_CONNECT');
    }

    $statement = $database->prepare('SELECT password FROM ' . DB_TABLE . ' WHERE username = :username');
    $state = $statement->execute(array('username' => $username));

    if ($state === FALSE)
    {
        die('false:ERROR_DATABASE_QUERY');
    }

    $result = $statement->fetchAll(PDO::FETCH_ASSOC);

    if ($result === FALSE)
    {
        die('false:ERROR_DATABASE_FETCH');
    }

    if (count($result) === 0)
    {
        die('false');
    }

    if (passwordCompare($result[0]['password'], $password) === TRUE)
    {
        die('true');
    }

    die('false');
?>