[solved] Re: No login with Debian 12 ssh client, ssh-rsa key, Debian 8 sshd

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

the following line in ~/.ssh/config did the trick:

  PubkeyAcceptedAlgorithms +ssh-rsa

This lets ssh -v report:

  debug1: Offering public key: /home/.../.ssh/id_rsa RSA SHA256:...
  debug1: Server accepts key: /home/.../.ssh/id_rsa RSA SHA256:...
  Authenticated to ... ([...]:22) using "publickey".

and leads to a shell session on the Debian 8 machine.

So the mere message
  debug1: Offering public key: /home/.../.ssh/id_rsa RSA SHA256:...
does not mean that RSA would be acceptable on the client side.
It would be nice if the refusal message would be somewhat clearer than
  debug1: send_pubkey_test: no mutual signature algorithm


I wrote:
> > The ssh-rsa key was generated by Debian 10. man ssh-keygen of buster
> > says the default of option -b with RSA was 2048.
> > (Does anybody know how to analyze a key file in regard to such
> > parameters ?)

Michael Kjörling wrote:
> $ ssh-keygen -l -f $pubkeyfile

Says "2048 SHA256:... ...@... (RSA)".
(Now that i know the right option, i can suddenly see it in the man page.)


Have a nice day :)

Thomas