[Freeipa-users] About Windows client
Dmitri Pal
dpal at redhat.com
Mon Mar 24 00:05:25 UTC 2014
On 03/23/2014 06:59 PM, Nordgren, Bryce L -FS wrote:
>
> I’m not, in general, in favor of solutions which promiscuously sling
> Kerberos passwords around the net. JpGina + Kerberos authenticating
> directly off of IPA would be the way to go, I think.
>
> Presumably Dimitri’s statement about the user being “foreign” and
> having limited access to windows services would apply equally well to
> a user with a SID from a foreign domain in a large Kerberos
> federation. This, and the uncertainty concerning what type of
> directory service the foreign KDC is paired with, is probably
> responsible for keeping Kerberos-based federations small.
>
If you have a SID you can tell Windows what t odo with it and how to
resolve it to name. If you do not have one you can't do anything if you
accessing elements of the Windows infra.
> That being said, the collaboration use case (not to mention “home
> networks”) is what makes “foreign” logins interesting. There’s hardly
> anything in common between two collaboration projects, so it’s hard to
> define far-reaching policies (i.e., you’re not missing out on much).
> Most all authorization decisions are delegated out to some project
> member responsible for the server/asset. Constructing authorization
> sets having members defined by text based principals makes a certain
> amount of sense. Hence the LDAP “member” attribute in RFC4519.
>
Collaboration can be in different ways. It all depends on the use case.
It can be OpenID, SAML, Kerberos, etc. There are different technologies
and they suit better different use cases.
> What would really be cool is the “inverse” of gluu or openam. Kerberos
> preauthentication data which allows the KDC to authenticate off of an
> OpenID Connect, SAML, or LDAP authentication source, caching the
> provided password and provisioning a Kerberos principal. Future AS
> exchanges would start out as “normal” Kerberos. Sort of like migration
> mode does now. If the KDC could then signal IPA that a new principal
> was provisioned, IPA could allocate and harmonize an SID and a UID for
> the principal in the domain.
>
It is already to some extend possible. It is called "constrained
delegation". The problem is that the gateway that would do such protocol
conversion would be able to impersonate any user in the Kerberos realm.
This is not the best but since it is being asked we are looking into it.
There is a project called Ipsilon
https://git.fedorahosted.org/git/ipsilon that is building the way of
federating different applications via SAML but in future it might be
extended to the workflows you are talking about here though I am not
sure I met these use cases in practice. Can you please share under what
circumstances such "inversion" would actually be needed?
> Poof. Console logins for Windows (pGina) and Linux (sssd) using IPA
> backed by your google account. That just eliminated 98% of the
> external accounts you would have had to create and manage.
>
Your Google account does not use Kerberos that means that your password
goes over the wire. The whole point of Kerberos that password does not
go the wire.
That being said modern Kerberos server and client support OTP
preauthentication method. This method can be used (abused) to proxy to
any RADIUS server including the one provided by Google. So if you use
Google 2FA then it becomes more interesting. You can extually try it now
with the latest upstream bits. It is not 100% complete but good enough
to give it a try.
We are also working with MIT to make sure that one can use IPA with
Kerberos password + HOTP/TOTP token. Then instead of sending the
authentication to the external entity (RADIUS server) the token code
would be processed by IPA, but to make is more secure and not send the
password over the wire together with OTP, KDC and client need to support
authentication sets. It is a feature that we will be looking to have in
a 1.14 Kerberos release.
> Food for thought.
>
> Bryce
>
> *From:*freeipa-users-bounces at redhat.com
> [mailto:freeipa-users-bounces at redhat.com] *On Behalf Of *Dmitri Pal
> *Sent:* Saturday, March 22, 2014 5:55 PM
> *To:* Will Sheldon
> *Cc:* freeipa-users at redhat.com
> *Subject:* Re: [Freeipa-users] About Windows client
>
> On 03/22/2014 05:47 PM, Will Sheldon wrote:
>
> I’d be curious to see how well a solution that combines pGina using
> RADIUS against some middleware like the Gluu server (www.gluu.org
> <http://www.gluu.org>) backed by IPA would work.
>
>
> This is not an interesting scenario. This would would probably work
> right now but the machine would still not know who the user is because
> it will not know user SID so he would be foreign and no Windows
> policies would apply to him. I suspect such user would have no or very
> limited read only access to Windows resources because all Windows ACLs
> are based on knowing the user SIDs and SIDs of the groups the user is
> a member of.
> The value of native IdM integration would be to get user SID and SIDs
> of the groups from IdM and then get the right kerberos ticket(s) for
> Windows resources using cross realm kerberos trusts and put these
> tickets into the right place so that windows system can use them
> automatically when user navigates to the corresponding resource.
> Something like this.
>
>
> It strikes me that getting domain federation between IPA and Gluu
> would tick a lot of boxes as it seems to offer a host of
> authentication and accounting interfaces including oAuth, SAML, OpenID
> and of course RADIUS.
>
>
> Kind regards,
>
> Will Sheldon
> +1.778-689-1244
>
> On Saturday, March 22, 2014 at 2:17 PM, Dmitri Pal wrote:
>
> On 03/22/2014 01:18 PM, Arthur wrote:
>
> Dmitri Pal wrote:
>
> On 03/20/2014 11:15 PM, Arthur Faizullin wrote:
>
> HI!
>
> I've got some thoughts on 4-th point: there is a
> http://pgina.org/
>
> pgina
>
> project, may be them are able to do such thing.
>
> Yes pgina is one of the options.
>
> Someone would have to take it and integrate with MIT
> Kerberos for
>
> Windows if it is not already doing so.
>
> But I suspect that it would be more a project in itself
> that would
>
> leverage code from MIT and may be pgina to integrate
> different parts.
>
> The biggest part figuring out the domain affiliation. I
> mean the use
>
> cases like this:
>
> a) The system is domainless but user authentictaes with
> user name and
>
> password against IPA
>
> b) The system is domainless but user authentictaes with
> user name and
>
> OTP against IPA
>
> c) The system is in an AD domain trusted by IdM domain but
> user
>
> authenticates with user name and password against IPA
> because he is
>
> in IdM domain.
>
> d) The system is in an AD domain trusted by IdM domain but
> user
>
> authenticates with user name and password against IPA
> because he is
>
> in IdM domain.
>
> More to research. We can help with guidance if someone
> wants to run
>
> with it.
>
> Thanks
>
> Dmitri
>
> 20.02.2014 04:23, Dmitri Pal пишет:
>
> Hello,
>
> I want to summarize our position regarding joining
> Windows systems
>
> into IPA.
>
> 1) If you already have AD we recommend using this
> system with AD and
>
> using trusts between AD and IPA.
>
> 2) If you do not have AD then use Samba 4 instead
> of it. It would be
>
> great when Samba 4 grows capability to establish
> trusts. Right now it
>
> can't but there is an effort going on. If you are
> interested - please
>
> contribute.
>
> 3) If neither of the two options work for you you
> can configure
>
> Windows system to work directly with IPA as
> described on the wiki. It
>
> is an option of last resort because IPA does not
> provide the services
>
> windows client expects. If this is good enough for
> you, fine by us.
>
> 4) Build a native Windows client (cred provider)
> for IPA using latest
>
> Kerberos. IMO this would be really useful if
> someone does that because
>
> we will not build this ourselves. With the native
> OTP support in IPA
>
> it becomes a real business opportunity to provide
> a native 2FA inside
>
> enterprise across multiple platforms. But please
> do it open source way
>
> otherwise we would not recommend you ;-)
>
> _______________________________________________
>
> Freeipa-users mailing list
>
> Freeipa-users at redhat.com <mailto:Freeipa-users at redhat.com>
>
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>
> My friend agreed to try. He is C# programmer. But the problem
> that has
>
> low knowledge about kerberos, GSSAPI, and I could not told him
> what is
>
> wrong with current pgina's ldap plugin.
>
> He does not want to subscribe to freeipa mail-lists, so may be
> I shall
>
> give him your (Dmitri) e-mail?
>
> He speaks russian :)
>
> List is really the way to develop open source software
> collaboratively.
>
> This is what we are doing here.
>
> We can agree that the communication about the topic will be
> prefixed in
>
> such a way that he can create a filter so that he would get only
> mails
>
> that match the filter.
>
> Would that work?
>
> I am not sure that I would be able to provide all the support. We
> are a
>
> community here and we have different roles and angles. Working
> with just
>
> one person would not fly, sorry.
>
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>
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>
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>
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>
> --
>
> Thank you,
>
> Dmitri Pal
>
> Sr. Engineering Manager for IdM portfolio
>
> Red Hat Inc.
>
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>
>
>
> --
> Thank you,
> Dmitri Pal
>
> Sr. Engineering Manager for IdM portfolio
> Red Hat Inc.
>
>
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Thank you,
Dmitri Pal
Sr. Engineering Manager for IdM portfolio
Red Hat Inc.
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