Cannot export SSH public key

[Felix E. Klee]

On Fri, Jan 5, 2024 at 2:43 PM Werner Koch <wk at gnupg.org> wrote:
> That is right.  The ssh-agent protocol has no means to tell the
> ssh-agent or gpg-agent some important environment cariabales, like the
> current tty or DISPLAY.

Interesting, thanks for the look behind the scenes!

> I am so used to run the updatestartuptty that I don't even think about
> this. It is the first thing I do when I ssh into my laptop.

I have to do it twice, though, until it works. In my `~/.bashrc` I have:

    gpg-connect-agent updatestartuptty /bye

Right after logging in (auto login on Ubuntu / WSL 2), I get:

    gpg-connect-agent: no running gpg-agent - starting
    '/usr/bin/gpg-agent'
    gpg-connect-agent: waiting for the agent to come up ... (5s)
    gpg-connect-agent: connection to agent established

That looks good, but somehow it doesn’t work:

    $ ssh some_server
    sign_and_send_pubkey: signing failed for RSA "cardno:18 698 015"
    from agent: agent refused operation
    sign_and_send_pubkey: signing failed for RSA "(none)" from agent:
    agent refused operation
    felix at some_server: Permission denied (publickey).

After starting `tmux`, which runs `gpg-connect-agent` again, everything
works fine. I get the PIN entry dialog, and I can connect by SSH.

This is a non-issue, not really worth debugging. I start `tmux` every
time anyhow.