Method WriteFile

easyssh.go:484–540

WriteFile reads size bytes from the reader and writes them to a file on the remote machine

(reader io.Reader, size int64, etargetFile string)

// WriteFile reads size bytes from the reader and writes them to a file on the remote machine
func (ssh_conf *MakeConfig) WriteFile(reader io.Reader, size int64, etargetFile string) error {
	targetFile := filepath.Base(etargetFile)
	// Reject characters that would either inject extra SCP control records
	// (\n, \r) or terminate the filename field early (\x00). The remote-side
	// scp command is invoked through the user's shell, so etargetFile is
	// single-quoted below to neutralise shell metacharacters.
	if strings.ContainsAny(etargetFile, "\x00\n\r") || strings.ContainsAny(targetFile, "\x00\n\r") {
		return ErrInvalidTargetFile
	}

	session, client, err := ssh_conf.Connect()
	if err != nil {
		return err
	}
	defer func() { _ = client.Close() }()
	defer func() { _ = session.Close() }()

	w, err := session.StdinPipe()
	if err != nil {
		return err
	}

	copyF := func() error {
		_, err := fmt.Fprintln(w, "C0644", size, targetFile)
		if err != nil {
			return err
		}

		if size > 0 {
			_, err = io.Copy(w, reader)
			if err != nil {
				return err
			}
		}

		_, err = fmt.Fprint(w, "\x00")
		if err != nil {
			return err
		}

		return nil
	}

	copyErrC := make(chan error, 1)
	go func() {
		defer func() { _ = w.Close() }()
		copyErrC <- copyF()
	}()

	err = session.Run("scp -tr " + shellQuote(etargetFile))
	if err != nil {
		return err
	}

	err = <-copyErrC
	return err
}