[cifs-protocol] [EXTERNAL] [MS-SFU] Clarify the new NonForwardableDelegation flag - TrackingID#2107090040004014

[Isaac Boukris]

On Tue, Jul 27, 2021 at 3:43 PM Isaac Boukris <iboukris at gmail.com> wrote:
>
> I've run a couple of tests, it looks like the behavior did change
> significantly, as now any service with an empty
> msDS-AllowedToDelegateTo list is treated as TrustedToAuthForDelegation
> and gets forwardable tickets with S4U2Self, on the other hand when the
> new NonForwardableDelegation is enabled (set to 0..), then the
> evidence ticket is required to be forwardable even in RBCD.
>
> Please confirm and update the documentation accordingly, especially
> for the cross-realm RBCD case which I suppose would also require
> forwardable tickets and the other realm is trusted for that.

Looking at the updated doc again, I can see that the S4U2Self change
is already documented in MS-SFU 3.2.5.1.2, but not the S4U2Proxy part
in 3.2.5.2.3, assuming we only need to document the
NonForwardableDelegation enabled behavior (which I understand will be
the default), then I guess we can remove the 'UserAccountControl'
check and simply say that: if the service ticket in the
additional-tickets field is not set to forwardable then the KDC MUST
return KRB-ERR-BADOPTION ..

Thanks