Scp example requires -O flag with openssh 9.0

[neurosnap]

Greetings!

Love the library and everything you all are working towards!

openssh v9 just released which changes the default protocol for scp https://www.openssh.com/txt/release-9.0

The current scp example does not work unless specifying the -O flag.

It seems like anyone that wishes to implement an scp server now needs to support both: legacy scp and sftp.

I wanted to surface that potential issue here as well as ask a general question about implementation.

I'm probably going to start working on adding sftp support to scp but wondered if you all had any advice on how to best implement it? Happy to send whatever I come up with upstream.

Thanks!

[caarlos0]

definitely something to look into, thanks for reporting!

[caarlos0]

something to look at: https:/pkg/sftp

[neurosnap]

Happy to submit a PR, it's still a WIP, but we have a working version at pico.sh:

https://git.sr.ht/~erock/wish/tree/main/item/send/send.go#L11

[caarlos0]

ah, amazing @neurosnap , would be neat! Don't need to worry too much, I can finish what you started :)

thanks!

[dezren39]

found a 2024 url for picosh/send sftp: https:/picosh/send/blob/41432db245e0a519290e1e38442dc16cbc0fe802/send/sftp/sftp.go#L50

[caarlos0]

while I can't repro the original issue here, if you need sftp, you can do something like:

	s, err := wish.NewServer(
		wish.WithAddress(fmt.Sprintf("%s:%d", host, port)),
		wish.WithHostKeyPath(".ssh/term_info_ed25519"),
		func(s *ssh.Server) error {
			s.SubsystemHandlers = map[string]ssh.SubsystemHandler{
				"sftp": func(s ssh.Session) {
					log.Info("using sftp")
					srv, err := sftp.NewServer(s, sftp.WithServerWorkingDirectory("/tmp/dir"))
					if err != nil {
						wish.Fatalln(s, err)
					}
					if err := srv.Serve(); err == io.EOF {
						if err := srv.Close(); err != nil {
							wish.Fatalln(s, err)
						}
					} else if err != nil {
						wish.Fatalln(s, err)
					}
				},
			}
			return nil
		},
		wish.WithMiddleware(
			scp.Middleware(handler, handler),
		),
	)

[caarlos0]

also #224 should make it easier to do so:

https:/charmbracelet/wish/pull/224/files#diff-0e073cd2eec6b81539c170b0ce89175003229e8833999c3d39bb763cc668ba96