OpenSSH Key replacement

[der.hans]

Am 14. Mai, 2008 schwätzte koder so:

> After upgrading my OpenSSH and ancillary files using the Ubuntu update I
> can no longer use sftp to logon between my desktop and laptop both
> located inside of my DSL router.
>
>
> It worked yesterday, in fact I just learned to use it yesterday before
> updating. Now I get:
>
> koder at delta-dawn:~$ sftp koder at 198.162.1.101
> Connecting to 198.162.1.101...
> ssh: connect to host 198.162.1.101 port 22: Connection refused
> Couldn't read packet: Connection reset by peer
> koder at delta-dawn:~$ ssh 198.162.1.101
> ssh: connect to host 198.162.1.101 port 22: Connection refused

Looks like the ssh service didn't restart.

> The Ubuntu notice said that the update would automatically update the
> keys in installation after asking my permission. It did not ask.

ls -l /etc/ssh/ssh_host*

Are those dates from when you ran the update?

Are they older than Sep 2006?

If they're older than Sep 2006 there was nothing to update.

> I ran the ssh-vulnkey tool as sudo. It did not return anything except a
> new prompt.

Did you run with -a?

> The notices says to check my keys by looking in various listed files.
> What am I looking for?

http://www.ubuntu.com/usn/usn-612-2

Also check all of your known_hosts files. If host keys have changed, you
need to change their entries in all the known_hosts files for clients that
connect.

> Can I just delete the contents of the files, or the files themselves to
> start clean?
>
> I looked in the /etc/ssh folder and found the 'moduli' file but am not
> sure what to do with it.
>
> Is that any documentation on this?

The bug reports have documentation, but I haven't found anything that will
answer all questions or adequately explain why some things need to be
done.

ciao,

der.hans
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