ssh_userauth_publickey_auto - file name of the key being unlocked

[Václav Kubernát <sir.venceslas@xxxxxxxxx>]

Hello,
I'm trying to use ssh_userauth_publickey_auto to authenticate to an
SSH server. I posted a question on the bug tracker
(https://bugs.libssh.org/T217) asking if it was possible to specify a
callback for unlocking a key. I was able to set up the callback.
However, I found out that the prompt arg the callback gets only reads
"Passphrase". So, if I want to prompt the user for the password for
the key, the user doesn't know which key he is supposed to unlock. I
have already kind of solved the issue by reading and unlocking the key
myself, and injecting the callback's private data with the filename,
but that meant I had to reimplement most of the "auto" functionality
myself, which seems like a waste. The code can be seen here:
https://gerrit.cesnet.cz/c/CzechLight/netconf-cli/+/2286/16/src/cli-netconf.cpp#118.

What do you think? Is it possible for ssh_userauth_publickey_auto to
tell me which key it is currently unlocking via the callback? Or if
not, what approach would you suggest?

Thank you
Václav Kubernát