Re: New Deb 8 and no sshd access from other hosts

[David Wright <deblis@lionunicorn.co.uk>]

On Fri 25 Mar 2016 at 12:12:44 (-0500), Tom Browder wrote:
> I have installed Deb on my laptop and reused my old Deb 7 .ssh directory.
> 
> I can now ssh into the existing remote servers but cannot ssh into my
> laptop from them (as a normal user)--I always get asked for a
> password.  So the remote servers recognize my old Deb 7 keys, but
> apparently my laptop doesn't recognize the other servers' keys.
> 
> I have compared files:
> 
>   /etc/ssh/ssh_conf
>   /etc/ssh/sshd_conf
>   /etc/pam.d/ssh/sshd
> 
> between the laptop and the remote server and can see no significant
> difference for a normal user.
> 
> I can also see the host names in the .ssh/known_hosts file.  I do see
> that my laptop host's entries in the remote host's known_hosts are of
> type "EDCSA" while the remote host's entries in the laptop's
> known_hosts file are of type "RSA."
> 
> Can anyone suggest where to look next?

What you lost on your laptop is ~/.ssh/authorized_keys which would
have had the public keys from your ~/.ssh/ on each of the remote hosts.
You can write them back by typing
$ ssh-copy-id -i ~/.ssh/id_rsa.pub your-user-name@laptop
on each of the remote servers in turn.

Now, when you-on-the-remote-host try to contact the laptop with ssh,
the laptop will use the public key (that you just copied) to ascertain
that you-on-the-remote-host know the private key of the pair, and let
you in.

Cheers,
David.