Bug#312312: woody->sarge upgrade updates ssh_host_key, but not ssh_host_key.pub

[Colin Watson <cjwatson@debian.org>]

On Mon, Jul 04, 2005 at 09:18:31PM +1000, Vincent.McIntyre@csiro.au wrote:
> Colin Watson wrote:
> > I think I know what this might be. To confirm, could you compare the
> > actual host key material?
> >
> >   ssh-keygen -l -f /etc/ssh/ssh_host_key
> >   ssh-keygen -l -f /old/etc/ssh/ssh_host_key
> >
> > I'm betting that they're the same.
> 
> yes, they are the same.
> I did an od -c of each and compared. There are only 4 bytes different,
> starting just after the root@hostname bit.
> 
> byte#    new  old
> 277      247  *
> 300      235  356
> 301      247  *
> 302      235  356
> (octal)
> 
> I want to say - unicode characters? But I don't get it.

It's almost certainly this:

check_idea_key() {
    #check for old host_key files using IDEA, which openssh does not support
        if [ -f /etc/ssh/ssh_host_key ] ; then
                if ssh-keygen -p -N '' -f /etc/ssh/ssh_host_key 2>&1 | \
                                grep -q 'unknown cipher' 2>/dev/null ; then
      mv /etc/ssh/ssh_host_key /etc/ssh/ssh_host_key.old
      mv /etc/ssh/ssh_host_key.pub /etc/ssh/ssh_host_key.pub.old
  fi
        fi
}

(ignoring the dreadful formatting)

I'll fix this to use a temporary file instead.

Cheers,

-- 
Colin Watson                                       [cjwatson@debian.org]