[Samba] Auth based on user + host

[daniel vena]

Hello - I feel like hosts equiv could have solved this scenario, but
as that's been removed I'm looking for options.

What I want to do is have an account without a password that is only
allowed to access shares when connecting from a specific host.  In
this case, localhost.  Is that possible anymore?

The only solution I've been able to come up with would involve
duplicating each share, with the passwordless account as an invalid
user in the public share and hosts allow in the duplicated share the
account is allowed to access - which I can only see becoming extremely
cumbersome.

I realise the danger in passwordless accounts, this is a very secluded
system (private network).

Thanks for any assistance you can offer!