// we automatically make FTP also run under TLS mode.
	if globalIsTLS && tlsPrivateKey == "" && tlsPublicCert == "" {
		tlsPrivateKey = getPrivateKeyFile()
		tlsPublicCert = getPublicCertFile()
	}

	tls := tlsPrivateKey != "" && tlsPublicCert != ""

	if forceTLS && !tls {

	if !isFile(getPublicCertFile()) || !isFile(getPrivateKeyFile()) {
		return nil, nil, false, nil
	}

	if x509Certs, err = config.ParsePublicCertFile(getPublicCertFile()); err != nil {
		return nil, nil, false, err
	}

	manager, err = certs.NewManager(GlobalContext, getPublicCertFile(), getPrivateKeyFile(), config.LoadX509KeyPair)
	if err != nil {