[Freeipa-devel] [PATCH 556-557] Add option to disable setkeytab extended operations

[Alexander Bokovoy]

On Wed, 02 Dec 2015, Simo Sorce wrote:
>> >>>> We also have to fix the permission to change keytab, so that it uses
>> >>>> the new
>> >>>> style (https://fedorahosted.org/freeipa/ticket/5487). I would
>> >>>> actually make
>> >>>> this ticket and the ipa-sam ticket a blocker for this patch set.
>> >>>>
>> >>>> Otherwise you are actually introducing a switch that breaks FreeIPA
>> >>>> as some of
>> >>>> it's core server functions still use the old method.
>> >>>
>> >>> The point of this patchset is to introduce the switch early so that
>> >>> current server will support the off switch when newer servers down the
>> >>> road are ready to flip it. The defaults are still to allow these
>> >>> operations for services/hosts.
>> >>
>> >> I still do not get the logic about an early switch. Now, if switch is
>> >> turned
>> >> on, FreeIPA server breaks on several places. I would really rather
>> >> expect the
>> >> switch to be introduced when the server itself supports it. Then,
>> >> admin would
>> >> enable it when the clients are sufficiently updated and can use the
>> >> new method.
>> >>
>> >> Why would admin want to enable the switch early if it breaks FreeIPA
>> >> some of
>> >> the FreeIPA servers? Permission can be upgraded in newer version and get
>> >> replicated, that's fine. But ipa-sam would be still broken on this old
>> >> FreeIPA
>> >> server.
>> > Old server is not a problem here: ipa-sam only talks to the
>> > localhost-based server as we always use ldapi protocol. So if server is
>> > running old-behavior FreeIPA, ipa-sam on the same server will work
>> > against it.
>> >
>> > What I don't want to have is a situation where setkeytab is disabled and
>> > a new server obeys it but ipa-sam on this new server is not updated and
>> > will expectedly fail. We are not that forced to do the change right now
>> > in 4.3, given that the default will still be to keep setkeytab, thus we
>> > can wait with this patch until ipa-sam is fixed and then push both
>> > patches into the closest release, be it 4.3.x (x>=0) or whatever is the
>> > next one.
>> >
>>
>> +1, fixing ipa-sam would be then a release blocker for 4.3 which is not
>> desired.
>>
>> Also what about adding support for "ipaProtectedoperation check" for
>> user principals?
>>
>> I'm afraid that forbidding getting user principal might be regarded as a
>> regression which might cause that admins won't set DisableSetKeytab.
>
>One thing at a time.
>We have bugs open for all these things, but I see no reason not to add
>an *optional* setting just because some things break when it is turned
>on.
The problem is that current getkeytab extended operation has not enough
information to be a replacement for ipa-sam's use of setkeytab, as I've
found with your current patches. So adding an optional setting in the
hope that it will not be used in real life is a bit naive, but if people
activate it, whole trust setup will break. I still prefer to have the
patchset first be completed and then merged. There is no problem in
keeping it aside while functionality is being implemented, we can
trivially rebase.
-- 
/ Alexander Bokovoy