[Openid-specs-ab] Spec call notes 23-Feb-15

Brian Campbell bcampbell at pingidentity.com
Wed Feb 25 18:18:29 UTC 2015


For what it's worth, the back-channel stuff we did with logout flipped
things around. The clients/RPs we were dealing with are stateless on the
server side with respect to individual sessions, which renders a
back-channel logout request from OP to RP pretty much useless. We have the
OP maintain a lightweight session revocation list and RPs can poll it
periodically at their discretion. I'm not suggesting that that model be
standardized but just offering a data point on one approach that was taken.

I might humbly suggest that back-channel logout is not something that
should be standardized at the SSO protocol layer like Connect. It strikes
me as more of the kind of thing that'd be useful as the account level and
more of a "shared signals" or deprovisiniong kind of thing.



On Tue, Feb 24, 2015 at 5:18 AM, John Bradley <ve7jtb at ve7jtb.com> wrote:

> I don’t actualy think we need a signed token in the front channel.
>
> I am talking about using a signed token in the back channel, but that is
> quite different, as all of the session information needs to be derived from
> the token as the RP has no session cooke.
>
> In the front channel there are two issues.
>
> 1 what account to sign out if there is more than one logged in from the IdP
> 2 is this from the IdP or a cross site request forgery.
>
> 1 could be solved by including the subject or a session identifier.
> 2 The sid alone should be sufficient to stop a XSRF unless the id_token
> has leaked.
>
> If you send the sid then you probably don’t need to send the sub. (That is
> where I thought we were going)
>
> I think trying to OAuth protect  the clients endpoint with a bearer token
> might be an advanced option, but that would need to be in a query parameter
> to be sent from a image tag.
> Is setting up a way for clients to provision a AS with a AT per subject
> worth while.   If it is one AT for all subjects then it leaks right away
> and is no real good to prevent xsrf.
>
> Modifying the authorization request to include a token is possible, but I
> am not sure how necessary.
>
> John B.
>
> On Feb 24, 2015, at 1:38 AM, Torsten Lodderstedt <torsten at lodderstedt.net>
> wrote:
>
> I don't understand why you want to invite a new token concept for the
> logout. First there was a sid. The sid alone is not enough (if the same
> value is used among RPs in the same session), therefore you need to
> introduce an audience and a digital signature. This is getting more complex
> with every iteration.
>
> From a conceptual perspective, the challenge we are facing is the OP wants
> to send a request to a protected resource (logout endpoint at the RP).
> Sounds familiar? Yes, because this is classic OAuth with the OP taking the
> role of the client.
>
> I would therefore suggest to let the RP register the token it wants to get
> its logout endpoint invoked with. One could also use RFC 6750 mechanisms
> (or even pop) to carry the token in the actual logout request. The
> advantage of this design: this token is opaque to the OP. There is no need
> to specify it. The token design and how to identify the respective session
> at the RP is at the RP's discretion. It could just be a reference to its
> session database. It also could be a JWT.
>
> kind regards,
> Torsten.
>
> Am 24. Februar 2015 03:45:34 MEZ, schrieb John Bradley <ve7jtb at ve7jtb.com
> >:
>
>> My point was not that audience was not needed, but rather that it could
>> be a different audience to differentiate between the login and sign out
>> tokens.
>> That WAY the sign out tokens would not be accepted as login tokens.   eg
>> the logout_uri rather than the client_id as a posable example.
>>
>> John B.
>>
>> On Feb 23, 2015, at 6:32 PM, Mike Jones <Michael.Jones at microsoft.com>
>> wrote:
>>
>> Spec call notes 23-Feb-15
>>
>>
>> Nat Sakimura
>>
>> Mike Jones
>>
>> Brian Campbell
>>
>> Edmund Jay
>>
>> John Bradley
>>
>>
>> Agenda
>>
>>                Use of Pragma: no-cache in Form Post Response Mode
>>
>>                Logout
>>
>>                Certification
>>
>>
>> Use of Pragma: no-cache in Form Post Response Mode
>>
>>                Brian believes the only change needed is to remove the
>> "Pragma: no-cache"
>>
>>                He believes that "Cache-Control: no-store" also performs a
>> "Cache-Control: no-cache"
>>
>>                               Mike will confirm this
>>
>>                Then Mike will make the change and update the blog post
>>
>>                Later in the call, Brian pointed out that we should have
>> normative text about not caching the result
>>
>>                               He will propose a sentence to add
>>
>>
>> Logout
>>
>>                When using the Session ID on the front channel, you're
>> only picking from among those that are live in the browser
>>
>>                An alternative to putting "sid" and "iss" as query
>> parameters is to them in a JWT
>>
>>                               But it should not be a legal ID Token, so
>> perhaps shouldn't have a subject
>>
>>                               John pointed out that we should at least
>> consider whether an audience would be needed
>>
>>                John will be working on a back channel logout spec also
>> using the Session ID
>>
>>                               We should try to have these be as close to
>> one another as reasonably possible
>>
>>                               He's on his way to Barcelona for MWC, so
>> this may not happen for a bit
>>
>>                People agreed that the differentiation between image and
>> iframe GETs must happen at registration time
>>
>>                The query parameters still need to be reviewed
>>
>>
>> Certification
>>
>>                Roland now has testing up on the Symantec hosts
>>
>>                A team member of Roland's created an OP self-registration
>> page at https://op.certification.openid.net:60000/
>>
>>                               When you select dynamic configuration, the
>> answer to the first question is the issuer path (this isn't obvious)
>>
>>                               Mike will file some bugs on clarifying how
>> the tool works
>>
>>                People doing testing should migrate over to the official
>> server
>>
>>                This also means that Roland can now also put up the RP
>> tests
>>
>>                Breno should be getting back to us within a week or so on
>> how long it will take them to create a conforming implementation
>>
>> _______________________________________________
>> Openid-specs-ab mailing list
>> Openid-specs-ab at lists.openid.net
>> http://lists.openid.net/mailman/listinfo/openid-specs-ab
>>
>>
>>
>> ------------------------------
>>
>> Openid-specs-ab mailing list
>> Openid-specs-ab at lists.openid.net
>> http://lists.openid.net/mailman/listinfo/openid-specs-ab
>>
>>
> --
> Diese Nachricht wurde von meinem Android-Mobiltelefon mit K-9 Mail
> gesendet.
>
>
>
> _______________________________________________
> Openid-specs-ab mailing list
> Openid-specs-ab at lists.openid.net
> http://lists.openid.net/mailman/listinfo/openid-specs-ab
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openid.net/pipermail/openid-specs-ab/attachments/20150225/347d4419/attachment-0001.html>


More information about the Openid-specs-ab mailing list