Plink + sudo in emacs: connection without password

Question

I would like to modify a file on a remote server with emacs on a user I can only access through sudo su - username without a password.

I am currently able to modify files on my personal space on this server using:

C-x C-f /plink:me@server:/path/file

I read there that I could use the following to open a file as the other user:

C-x C-f /plink:me@server|sudo:other@server:/path/file

The problem is that using this syntax, emacs asks me for a password Password for /sudo:other@server: which I don't have.. giving an empty password does not work, neither does giving my user's password.

Is there a way to configure tramp to connect to this other user as sudo su - other would do without asking for a password?

PS: I am using emacs 28.1 on Windows 10.

Answer 1

You could specify a new Tramp method, derived from the sudo method:

(add-to-list 'tramp-methods
             `("mysudo"
               (tramp-login-program        "sudo")
               (tramp-login-args           (("su") ("-" "%u")))
               (tramp-remote-shell         ,tramp-default-remote-shell)
               (tramp-remote-shell-login   ("-l"))
               (tramp-remote-shell-args    ("-c"))
               (tramp-connection-timeout   10)
               (tramp-session-timeout      300)))

Then you can open a remote file like

C-x C-f /plink:me@server|mysudo:other@server:/path/file

Disclaimer: it is untested.