$salt, int $opslimit, int $memlimit, int $alg = null): string
{
    error_clear_last();
    if ($alg !== null) {
        $result = \sodium_crypto_pwhash($length, $password, $salt, $opslimit, $memlimit, $alg);
    } else {
        $result = \sodium_crypto_pwhash($length, $password, $salt, $opslimit, $memlimit);
    }
    if ($result === false) {
        throw SodiumException::createFromPhpError();
    }
    return $result;
}