[OpenAFS] Borderline offtopic: OpenAFS as ~ for Samba AD?

[Jeffrey Altman]

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On 2/15/2020 5:09 PM, M=C3=A5ns Nilsson wrote:
>> You only would create a system:authuser@smab4.realm group and then
>> create <user>@samb4.realm entries if you were treating the two sets of=

>> identifies as unique.
>=20
> My first impression is that this is something one does only if there is=
 no other
> way. Keeping accounts as similar across the board seems a bit easiser,
> if doable. Here it is so, so we'll stick to that.

Originally there was no cross-realm (aka cross-cell in Transarc AFS
lingo).  The fact that Kerberos v4 principals contained a realm didn't
matter because the realm would be stripped when looking up the identity
in the protection service.

Later on cross-realm was created for Kerberos v4.  To ensure that names
from EXAMPLE.COM weren't mistaken for identities from EXAMPLE.NET the
realm is only stripped for the local authentication realm.

It is safe to treat more than one realm as a local authentication realm
provided that there is a guarantee that all principals from both realms
always represent the same entity.  It that is not true, then using
cross-realm identities is required.

An alternative approach would be to add support for entity aliasing to
the protection service.  The protocol extensions to do so were
standardized nine years ago but no implementation was ever developed for
OpenAFS.

I believe in your scenario, treating both realms as local is sufficient.

Jeffrey Altman





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