I understand that by adjusting the
/etc/ssh/sshd_config I can log the fingerprints when authentication is successful, but what I would like to do is to see a fingerprint of a key that was in fact unsuccessful.
The practical problem is clueless clients who connect to the server using the wrong key and if I could see the fingerprint when authentication fails that would help a lot.
The OS is Ubuntu Precise Pangolin, OpenSSH server from the package
Is this possible to do?