[Freeipa-users] subjectAlternitiveName for webservice

Thu Mar 12 14:54:36 UTC 2015

Matt . wrote:
> Hi,
> 
> Security wise I can understand that.
> 
> Yes I have read about that... but that would let me use the
> loadbalancer to connect ? I was not sure if the SAN would "connect" as
> "other" host.

Kerberos through a load balancer can be a problem. Is this what you're
worried about?

rob

> 
> 2015-03-12 15:07 GMT+01:00 Rob Crittenden <rcritten at redhat.com>:
>> Matt . wrote:
>>> Hi Guys,
>>>
>>> Is Rob able to look at this ? I hope he has some sparetime as I'm
>>> kinda stuck with this issue.
>>
>> Wildcard certs are not supported.
>>
>> You can request a SAN with certmonger using -D <FQDN>. That will work
>> with IPA 4.x for sure, maybe 3.3.5.
>>
>> rob
>>
>>>
>>> Thanks!
>>>
>>>
>>>
>>> 2015-03-08 12:30 GMT+01:00 Matt . <yamakasi.014 at gmail.com>:
>>>> I'm reviewing some things.
>>>>
>>>> When I'm using a loadbalancer, which I prefer in this setup I need to
>>>> have the same certificates on both servers. Maybe a wildcard for my
>>>> domain could do instead of having only both fqdn's of the servers
>>>> including the loadbalancer's fqdn.
>>>>
>>>> But the question remains, how?
>>>>
>>>>
>>>>
>>>> 2015-03-07 10:37 GMT+01:00 Matt . <yamakasi.014 at gmail.com>:
>>>>> Hi,
>>>>>
>>>>> I will balance with IP persistance so I think there won't be any
>>>>> mixing as long as that "used" server is online.
>>>>>
>>>>> 2015-03-06 19:16 GMT+01:00 Dmitri Pal <dpal at redhat.com>:
>>>>>> On 03/06/2015 11:05 AM, Matt . wrote:
>>>>>>>
>>>>>>> OK, understood.
>>>>>>>
>>>>>>> But when a webservice does execute a command (from scripting) to a SVR
>>>>>>> record and the first is not reacable, would it try to do it again or
>>>>>>> will handle DNS this in front of it ?
>>>>>>>
>>>>>>> I do a kinit against an IPA server using a keytab after I first
>>>>>>> checked if the user was able to auth himself using his ldap
>>>>>>> credentials, if so, this kinit exec is fired and I do some CURL stuff
>>>>>>> to the IPA server.
>>>>>>>
>>>>>>> That's why I wanted a loadbalancer, the loadbalancer sees if a server
>>>>>>> is down and doesn't even try to direct any of the commands to it...
>>>>>>> I'm not sure if the SRV will handle this well when doing these command
>>>>>>> from PHP for an example. Building in extra checks in front could be
>>>>>>> done but it not ideal as a loadbalancer can handle such things much
>>>>>>> better.
>>>>>>
>>>>>>
>>>>>> OK, this makes things much more clear. Thanks for the explanation.
>>>>>> Rob. What is our failover logic for API?
>>>>>>
>>>>>> For CLI we use a negotiation and then we store a cookie so as long as the
>>>>>> whole conversation goes to the same server you should be fine. I do not
>>>>>> think you need to re-encrypt the traffic at load balancer and thus have a
>>>>>> cert there then if you can enforce the use of the same server in this case.
>>>>>>
>>>>>> The issue I anticipate is with Kerberos. I think you should not load balance
>>>>>> the Kerberos traffic, only the API commands starting with the negotiation.
>>>>>>
>>>>>> Rob does that make sense for you?
>>>>>>
>>>>>>
>>>>>>>
>>>>>>> Thanks!
>>>>>>>
>>>>>>> Cheers,
>>>>>>>
>>>>>>> Matt
>>>>>>>
>>>>>>> 2015-03-06 16:41 GMT+01:00 Dmitri Pal <dpal at redhat.com>:
>>>>>>>>
>>>>>>>> On 03/06/2015 10:24 AM, Matt . wrote:
>>>>>>>>>
>>>>>>>>> Hi,
>>>>>>>>>
>>>>>>>>> I'm really bound to a loadbalancer, as it's HA setup of loadbalancers,
>>>>>>>>> SRV won't fit here sorry to say.
>>>>>>>>>
>>>>>>>>> I auth users, so their keytab should be the same between two masters I
>>>>>>>>> believe ?
>>>>>>>>
>>>>>>>>
>>>>>>>> Each entity in Kerberos exchange has its own identity and key.
>>>>>>>> If you send a ticket that is destined to service A instead to service B
>>>>>>>> it
>>>>>>>> would not work unless they share the same keys and identity. Sharinf same
>>>>>>>> keys and identities between the servers just would not work with IPA.
>>>>>>>> Keep in mind that IPA clients and server need to work and fail over if
>>>>>>>> you
>>>>>>>> do not have any load balancers and this is the common case. You are
>>>>>>>> trying
>>>>>>>> to add one where it is really not needed creating overhead for yourself.
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>> In that case... I need to add the altnames to the certs, but I'm not
>>>>>>>>> 100% there in step 6
>>>>>>>>>
>>>>>>>>> Thanks again!
>>>>>>>>>
>>>>>>>>> Cheers,
>>>>>>>>>
>>>>>>>>> Matthijs
>>>>>>>>>
>>>>>>>>> 2015-03-06 16:16 GMT+01:00 Petr Spacek <pspacek at redhat.com>:
>>>>>>>>>>
>>>>>>>>>> On 6.3.2015 15:39, Matt . wrote:
>>>>>>>>>>>
>>>>>>>>>>> I have 2 IPA servers where I kinit to and post to the api using
>>>>>>>>>>> curl/json.
>>>>>>>>>>
>>>>>>>>>> If we are talking purely about scripting, you can use IPA Python API.
>>>>>>>>>> It
>>>>>>>>>> will
>>>>>>>>>> handle fail over for you even without any load balancer. That would be
>>>>>>>>>> easiest
>>>>>>>>>> way.
>>>>>>>>>>
>>>>>>>>>>> As I need redundancy and don't want to have it script managed, but one
>>>>>>>>>>> central point where I can tal to I use a loadbalancer.
>>>>>>>>>>
>>>>>>>>>> Well, if you can control clients then the easiest and most universal
>>>>>>>>>> way
>>>>>>>>>> is to
>>>>>>>>>> use DNS SRV records and add failover logic to clients. That solution
>>>>>>>>>> works
>>>>>>>>>> even when servers are geographically distributed/in different networks
>>>>>>>>>> and
>>>>>>>>>> does not have single point of failure (the load balancer).
>>>>>>>>>>
>>>>>>>>>>> As I connect to the loadbalancer using DNAT, so the client IP is known
>>>>>>>>>>> on the IPA server because this is needed for the http service
>>>>>>>>>>> principals I need to add the loadbalancer hostname to my IPA server
>>>>>>>>>>> and make it as an ALT name to it's Certificate.
>>>>>>>>>>>
>>>>>>>>>>> As the users are the same on both servers I would asume i can use a
>>>>>>>>>>> keytab for a user against both servers from my clients.
>>>>>>>>>>
>>>>>>>>>> I'm talking about keytabs on the FreeIPA servers - services running on
>>>>>>>>>> IPA
>>>>>>>>>> server have their own keytabs too. Every service on every server has
>>>>>>>>>> own
>>>>>>>>>> keytab with different key.
>>>>>>>>>>
>>>>>>>>>> You need to talk with Simo or some other Kerberos guru about
>>>>>>>>>> possibility
>>>>>>>>>> of
>>>>>>>>>> sharing keytabs between IPA services.
>>>>>>>>>>
>>>>>>>>>>> Does this make it more clear ?
>>>>>>>>>>
>>>>>>>>>> I'm still not sure if you want to have human users too or just API
>>>>>>>>>> clients.
>>>>>>>>>>
>>>>>>>>>> Petr^2 Spacek
>>>>>>>>>>
>>>>>>>>>>> 2015-03-06 15:31 GMT+01:00 Petr Spacek <pspacek at redhat.com>:
>>>>>>>>>>>>
>>>>>>>>>>>> On 6.3.2015 15:13, Matt . wrote:
>>>>>>>>>>>>>
>>>>>>>>>>>>> Hi,
>>>>>>>>>>>>>
>>>>>>>>>>>>> But as the user is the same, I could use the same keytab for each
>>>>>>>>>>>>> ipa
>>>>>>>>>>>>> server ?
>>>>>>>>>>>>>
>>>>>>>>>>>>> I need to use the API indeed, so need to issue the http service.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Any other options ?
>>>>>>>>>>>>
>>>>>>>>>>>> I do not really understand your use case. Could you describe it in
>>>>>>>>>>>> detail, please?
>>>>>>>>>>>>
>>>>>>>>>>>> Petr^2 Spacek
>>>>>>>>>>>>
>>>>>>>>>>>>> 2015-03-06 14:24 GMT+01:00 Petr Spacek <pspacek at redhat.com>:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> On 6.3.2015 14:08, Martin Kosek wrote:
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> I'm figuring out how to regenerate the webserver certificates so I
>>>>>>>>>>>>>>> can
>>>>>>>>>>>>>>> use a loadbalancer in front of my ipa servers.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Are you talking about FreeIPA web interface? It is technically
>>>>>>>>>>>>>> possible to use
>>>>>>>>>>>>>> load-balancer but it will be really hacky. You would have to solve
>>>>>>>>>>>>>> certificates and also distribute shared keytabs and so on.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> I would recommend you to use "something" which issues HTTP redirect
>>>>>>>>>>>>>> to ipa
>>>>>>>>>>>>>> server 1/2/3/4/5 according to current state instead of using
>>>>>>>>>>>>>> classical load
>>>>>>>>>>>>>> balancer on the network level. Normal HTTP redirect will not force
>>>>>>>>>>>>>> you to mess
>>>>>>>>>>>>>> with certs and keytabs.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> --
>>>>>>>>>>>>>> Petr^2 Spacek
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> --
>>>>>>>>>> Petr Spacek  @  Red Hat
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> --
>>>>>>>> Thank you,
>>>>>>>> Dmitri Pal
>>>>>>>>
>>>>>>>> Sr. Engineering Manager IdM portfolio
>>>>>>>> Red Hat, Inc.
>>>>>>>>
>>>>>>>>
>>>>>>>> --
>>>>>>>> Manage your subscription for the Freeipa-users mailing list:
>>>>>>>> https://www.redhat.com/mailman/listinfo/freeipa-users
>>>>>>>> Go to http://freeipa.org for more info on the project
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Thank you,
>>>>>> Dmitri Pal
>>>>>>
>>>>>> Sr. Engineering Manager IdM portfolio
>>>>>> Red Hat, Inc.
>>>>>>
>>>>>> --
>>>>>> Manage your subscription for the Freeipa-users mailing list:
>>>>>> https://www.redhat.com/mailman/listinfo/freeipa-users
>>>>>> Go to http://freeipa.org for more info on the project
>>