function checkPasswd($passwd, $user) {
    $authenticated = false;

    if($fh = fopen('passwd.txt', 'r')) {
        while(!feof($fh)) {
            $line = trim(fgets($fh));
            $account = explode(':', $line);

            if(count($account) == 2) {
                list($username, $password) = $account;

                if($username == $user && $password == $passwd) {
                    $authenticated = true;
                }
            }
        }

        fclose($fh);
    }

    return $authenticated;
}