Allow to run SSHd in Installer (12.2 patch)

[Ben RUBSON]

Thank you Ruben & Rodney for your interest into this.

Of course your solution works Rodney but is not really convenient trough a remote console.
What my patch tends to fix :)

Fingers crossed !

Ben

> On 12 Mar 2020, at 19:29, Rodney W. Grimes <freebsd-rwg at gndrsh.dnsmgr.net> wrote:
> 
> I have been starting sshd from install media since 5.4 or so,
> here is my current method that should work on 11, 12 and 13:
> 
> # This version for FreeBSD 11.0R, works for 12.0 too
> 
> mkdir /tmp/ssh
> cp -p /etc/ssh/sshd_config /tmp/ssh
> echo 'PermitRootLogin yes' >> /tmp/ssh/sshd_config
> echo 'AllowGroups wheel' >> /tmp/ssh/sshd_config
> echo 'PermitEmptyPasswords yes' >> /tmp/ssh/sshd_config
> echo 'HostKey /tmp/ssh/ssh_host_rsa_key' >> /tmp/ssh/sshd_config
> echo 'HostKey /tmp/ssh/ssh_host_dsa_key' >> /tmp/ssh/sshd_config
> echo 'UsePAM no' >> /tmp/ssh/sshd_config
> echo 'PasswordAuthentication yes' >> /tmp/ssh/sshd_config
> 
> ssh-keygen -t rsa -f /tmp/ssh/ssh_host_rsa_key -N ''
> ssh-keygen -t dsa -f /tmp/ssh/ssh_host_dsa_key -N ''
> 
> /usr/sbin/sshd -f /tmp/ssh/sshd_config
> 
> For those that "need" this feature today :-)  Just drop to
> a shell after booting from install media, run the above
> commands, and you can get in.  BEWARE, passwordless root login enabled!
> 
>> Hi Ben,
>> 
>> I'm not a FreeBSD developer (so not your targeted audience) but would 
>> very much like to see this land in a release!
>> 
>> Kind regards,
>> 
>> Ruben
>> 
>> On 3/10/20 4:07 PM, Ben RUBSON wrote:
>> 
>>>> On 2 Mar 2020, at 13:09, Ben RUBSON <ben.rubson at gmx.com> wrote:
>>>> 
>>>> Hi,
>>>> 
>>>> I've done some work to allow to connect to FreeBSD installer through SSH.
>>>> It can be useful for example if we have specific tasks to perform before installation, such as disks configuration etc...
>>>> Working through a SSH connection is much more convenient than in front of a console.
>>>> FreeBSD installer can then also be used as a rescue disk.
>>>> 
>>>> To achieve this, I've modified FreeBSD installer, so that after having installed SSHd, if performs following configuration modifications :
>>>> - generate host keys into /var/ssh (as default /etc/ssh is not writable) ;
>>>> - only allow keys authentication ;
>>>> - allow root authentication ;
>>>> - read authorized_keys file from /var/ssh (as default homedirs are not writable).
>>>> 
>>>> SSHd can then be started thanks to the installer shell : service sshd start
>>>> And a public key put into for example /var/ssh-keys/root/authorized_keys, thanks to fetch or whatever.
>>>> 
>>>> Work is here :
>>>> https://github.com/freebsd/freebsd/pull/156
>>>> Rather simple, and ready to be merged.
>>>> 
>>>> This job is more than 2 years old, I would then really be glad if we could see this in 12.2 installation ISOs.
>>>> It would prevent me from having to modify the new ISO files to implement this patch.
>>> 
>>> Any thoughts ? :)
>>> 
>>> Thank you very much !
>>> 
>>> Ben