mit-krb5 and heimdal binaries

Rowland Penny rpenny at
Sun Mar 19 17:10:33 UTC 2023

On 19/03/2023 16:52, Alexander Bokovoy wrote:
> On su, 19 maalis 2023, Rowland Penny via samba-technical wrote:
>> On 19/03/2023 10:29, ronnie sahlberg wrote:
>>> On Sun, 19 Mar 2023 at 19:15, Rowland Penny via samba-technical
>>> <samba-technical at> wrote:
>>>> On 19/03/2023 09:05, Alexander Bokovoy wrote:
>>>>> On su, 19 maalis 2023, Rowland Penny via samba-technical wrote:
>>>>>> On 19/03/2023 08:07, Alexander Bokovoy wrote:
>>>>>>> On su, 19 maalis 2023, Rowland Penny via samba-technical wrote:
>>>>>>>> On 19/03/2023 07:29, Alexander Bokovoy via samba-technical wrote:
>>>>>>>>> Hi,
>>>>>>>>> On su, 19 maalis 2023, Michael Tokarev via samba-technical wrote:
>>>>>>>>>> Hi!
>>>>>>>>>> I already asked a similar question before, but it keeps popping up in different
>>>>>>>>>> contexts and forms, and the more I use samba myself, the more often it comes to
>>>>>>>>>> me too, especially in context of using various security tokens for auth.  And the
>>>>>>>>>> more I think about all this, the more sane it looks to me.
>>>>>>>>>> The thing is: mit-krb5 has much better user-level support than heimdal. But samba
>>>>>>>>>> does not fully support mit-krb5 as an active directory domain controller.  The
>>>>>>>>>> AD-DC thing is server-side.
>>>>>>>>>> I can think of providing two builds of samba for a distribution (eg debian/ubuntu), -
>>>>>>>>>> one implementing whole ad-dc, as a complete thing, using their own set of libs,
>>>>>>>>>> linked with heimdal. And a usual set of more client-side packages, with their own
>>>>>>>>>> libraries, built against mit-krb5.  Or maybe some other combination also has its
>>>>>>>>>> right to be, - for example, smbclient built with mit-krb5, the rest is heimdal.
>>>>>>>>>> An essential part of this is that the two sets (built against mit-krb5 and heimdal)
>>>>>>>>>> do not share any internal libraries, each has its own libraries. This way, there's
>>>>>>>>>> no "mix" of differently built samba, each build uses only its own libs, so there's
>>>>>>>>>> no clash here.  They share the same smb.conf though.
>>>>>>>>>> So far, I've seen requests to build two versions of the server (again, with mit-krb5
>>>>>>>>>> and with heimdal), - and I faced the same issues too.  This is because a regular AD
>>>>>>>>>> member server is also good to have mit-krb5 support to integrate nicely into the auth
>>>>>>>>>> infrastructure. While for ad-dc, it is less often used as "end-user" server.
>>>>>>>>>> So I can think of a separate samba-ad-dc binary package providing whole samba suite
>>>>>>>>>> built against heimdal (maybe without smbclient and some other minor things), and
>>>>>>>>>> samba "file server" binary package providing regular server not suitable to use as
>>>>>>>>>> an ad-dc, but conflicting with samba-ad-dc, so it is not possible to install one
>>>>>>>>>> together with another.
>>>>>>>>>> This approach also has another good side effect, to discourage usage of samba-ad-dc
>>>>>>>>>> as a regular file server.
>>>>>>>>>> Or maybe the whole thing is moot now, and we just can provide regular samba built
>>>>>>>>>> against mit-krb5 to work as a good AD-DC?  That would be the best solution IMHO.
>>>>>>>>> I would be against a blended build against both MIT Kerberos and Heimdal
>>>>>>>>> Kerberos in a distribution. It is not going to bring you anything good,
>>>>>>>>> support wise.
>>>>>>>>> Andreas and I have submitted a talk to SambaXP about MIT
>>>>>>>>> Kerberos/Heimdal Kerberos-based Samba AD DC configurations, where they
>>>>>>>>> stand against each other and what are perspectives. In short, both have
>>>>>>>>> unique features that do not exist in the other variant and both are
>>>>>>>>> close to being production-ready. We want to change the status for MIT
>>>>>>>>> Kerberos-based build from experimental to production. Effectively,
>>>>>>>>> actual decision for a version shipped in a particular distribution would
>>>>>>>>> need to be made by that distribution, of course.
>>>>>>>> I do not think this is a good idea, Samba should use one or the other, not
>>>>>>>> both. If you do use both, to a certain extent you will nearly double the
>>>>>>>> support required.
>>>>>>> I did say exactly that: I am against blended build. Not sure what made
>>>>>>> you think otherwise.
>>>>>>>>> Distributions need to take into account security releases, as Rowland
>>>>>>>>> has pointed out as well. However, from my Fedora and RHEL experience,
>>>>>>>>> this is not a problem with MIT Kerberos -- certainly not more than with
>>>>>>>>> Heimdal. It is pretty much a coordination question and I believe we have
>>>>>>>>> very good coordination on that front with MIT Kerberos and distribution
>>>>>>>>> maintainers.
>>>>>>>> That is strange, from what Andrew wrote, he appears to think the opposite.
>>>>>>> I am one of developers and one of maintainers for both Samba and MIT
>>>>>>> Kerberos in Fedora and RHEL (as well as few other relevant projects). I
>>>>>>> personally see no issues with MIT Kerberos upstream collaboration.
>>>>>>> Things get discussed and fixed when needed, contributions get accepted.
>>>>>>> Our willingness to move Samba AD/MIT support from experimental forward
>>>>>>> to supported is based on that factor as well.
>>>>>>>>> If I was in Samba AD support for production deployments, I'd probably
>>>>>>>>> go with deploying DCs in a containerized image way to isolate completely
>>>>>>>>> from the rest of the OS. There are few images already that provide this
>>>>>>>>> setup: [1] was presented at SambaXP by Michael Adam and other folks now
>>>>>>>>> from IBM Storage, [2] is older and also active one.
>>>>>>>>> [1]
>>>>>>>>> [2]
>>>>>>>> I personally have no axe to grind over the matter, I do not care which kdc
>>>>>>>> is used, just as long as it is only one, if only from the support point of
>>>>>>>> view.
>>>>>>>> I also only say that using MIT is experimental because other wiser (at least
>>>>>>>> I hope they are wiser than me) people say it is, if this changes then so be
>>>>>>>> it.
>>>>>>>> I still do not think it is a good idea for a distro to provide two versions
>>>>>>>> of Samba, one using Heimdal and the other using MIT.
>>>>>>> Yep. However, tools we have in most distributions allow to provide more
>>>>>>> flexibility. It all needs maintainers, though. Without maintainers there
>>>>>>> is just an illusion that someone could depend on a package that is in
>>>>>>> reality not supported well -- whether it is built with a single scenario
>>>>>>> in mind or set up to handle multiple approaches.
>>>>>> Alexander, as I said, I do not have an axe to grind in this, if Samba
>>>>>> decides to move to MIT, then so be it. You however, do have  an axe to
>>>>>> grind, you work for red-hat, who are on record as saying that there will
>>>>>> never be an AD DC on RHEL. Are you now saying that, if Samba moves to MIT,
>>>>>> there will be ?
>>>>> I don't say that. What I said is that I am responsible for both Fedora
>>>>> and RHEL. Fedora does provide Samba AD DC already for several years,
>>>>> using MIT Kerberos backend. That's what I stand behind and will continue
>>>>> to support.
>>>> Yes, Fedora has provided an AD DC for sometime, but it could be honest
>>>> about it and say:
>>>> A) Samba has marked the use of MIT as experimental, so you shouldn't use
>>>> this in production (even if you think they could be)
>>> The normal way these things are resolved is to ask why it is
>>> experimental and what need to be done
>>> to make it production quality.
>>> No one wants to do this work and this is the core of the issue.
>> Even if I wanted to do this work, I couldn't, I cannot write 'C'.
>> There is a Samba wikipage that gives reasons why MIT is experimental. One of
>> the reasons was removed, even though the bug is still open.
>>>> B) RHEL will never provide an AD DC
>>> Ask RHEL why? and then address the issues raised. Once the issues are
>>> resolved ask the people to re-evaluate.
>> I do not have to ask RHEL why, it is blatantly obvious, they want you to use
>> their 'not quite an AD DC' freeipa instead and I doubt that anything a
>> single person says is going to change that.
> This is simply an opinion of yours, which I do not share. However, I
> hope the point of this thread is not to spend time in issuing fireballs
> against each other.

No, I am just stating things as I see them, others may see them 
differently, as is their right.

> gives the official
> answer and as one of several people from Samba Team who were involved
> into that discussion, 

I don't remember this being discussed by the general Samba team, it 
sounds more like this discussion involved people employed by red-hat who 
also happened to be members of the Samba team.

> I should say that the reasoning still stands.
> Whatever we as developers might think about supporting at a scale,
> our estimations are too optimistic given the complexity we have to deal
> with in the case of large Active Directory deployments.

To me, this sounds like a commercial decision, a decision that only 
people actively involved the company could make, it is not something 
that anyone outside the company could be involved in.
However, it still stands that red-hat will never (never say never) have 
an AD DC available for RHEL.

This is not something that I (or any other individual) am likely to 
change, so I will not try.

> I hope we as a team will continue working on Samba AD support for both
> MIT Kerberos and Heimdal as long as there is a real interest in
> supporting both upstream. The focus of the industry has long been moving
> away from traditional enterprise directory services, yet there is a
> value in Kerberos that is still there and is not replaced by anything
> else.

I hope we will continue to support Samba in all its aspects (with the 
exception of SMBv1).


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