I have a CentOS 8 server set up with a few users with SSH keys, and I haven't had any problems logging in with any of the users as of a few days ago. (Password authentication is disabled, so is root login.)
I go to log in today using PuTTY and WinSCP and get a chilling:
Server refused our key
This happens for ALL users.
sshd seems to be functioning obviously since it gets up to the point of refusing a key. When I dig through the logs I see:
Server offered these authentication methods: publickey,gssapi-keyex,gssapi-with-mic
This indicates that
sshd seems to be operating normally.
I tried logging in using keys loaded in Pageant, and I also tried bypassing Pageant and loading the keys directly in PuTTY and WinSCP, the key is still refused. And yes, it's the correct key, and it hasn't changed.
I happen to have a backup application running so I am able to see what changes to the files may have taken place on the server. I can confirm that the
.ssh/authorized_keys files have not been modified. Nor has
sshd_config, which I downloaded and looked at.
The last time I logged in was a few days ago and I did a
dnf update, but I don't see how that can affect any of this.
Any ideas what may be causing this?