if err != nil {
		logger.Fatal(fmt.Errorf("invalid arguments passed, private key file is not accessible: %v", err), "unable to start SFTP server")
	}

	private, err := ssh.ParsePrivateKey(privateBytes)
	if err != nil {
		logger.Fatal(fmt.Errorf("invalid arguments passed, private key file is not parseable: %v", err), "unable to start SFTP server")
	}

	if userCaKeyFile != "" {

			return nil, errors.New("kms: no KMS server endpoint provided")
		}
		endpoints, err := expandEndpoints(rawEndpoint)
		if err != nil {
			return nil, err
		}

		key, err := mtls.ParsePrivateKey(env.Get(EnvKMSAPIKey, ""))
		if err != nil {
			return nil, err
		}

		var rootCAs *x509.CertPool
		if opts != nil && opts.CADir != "" {
			rootCAs, err = certs.GetRootCAs(opts.CADir)