[Openid-specs-ab] Obtaining claims without requiring additional round trips

Sat Nov 5 22:51:03 UTC 2011

John,

I am not sure if I understood your point.
So, Mike's requirement is for the user attributes to be returned from Token
Endpoint as I understand.
Then why "A viable design some people might want tis to send the claim
requests in a signed JWT to the user-info endpoint." would work?

The requirement for id_token to be short is when the client wants to stuff
it to the cookie directly.
If the client is sophisticated enough (and we are talking about
sophisticated client that can handle crypto itself here), it may as well
extract a portion of id_token and put it in the cookie. We have to weight
if "short id_token" requirement is more important than "access_token
compatibility (i.e., opaque)" requirement.

If we were to use access_token as the carrier for the userinfo, then client
should have the way to tell it, and the server should have a way to publish
its capability. In fact, the server may publish two endpoints: the legacy
token endpoint and JWT token endpoint. The later essentially is a UserInfo
endpoint that can interpret the "code".

Mike,

I have a question. Are you talking about the case for the code flow or
implicit flow?

=nat

On Sun, Nov 6, 2011 at 4:05 AM, John Bradley <ve7jtb at ve7jtb.com> wrote:

> Keeping the id_token small is a requirement.  I don't want to start
> stuffing user attributes in it beyond the user_id.
>
> Another issue is that some IdP may not want to have all of the user
> attributes available at both the token endpoint and the authorization
> server.
>
> A viable design some people might want tis to send the claim requests in a
> signed JWT to the user-info endpoint.
>
> Not all JWT access tokens will contain claim values.
>
> If we make this the default then clients need to check in discovery if
> they shouldn't sniff the token.
> I suppose if the IdP is not publishing a user-info endpoint that could be
> a hint, but not definitive.
>
> To avoid having the basic client do crypto we would need to use the code
> flow.  That way the id_token and access token come from a trusted endpoint
> and can just be base64 decoded.
>
> I think people who are attaching additional scopes to the access token
> won't use it and will want the opaque token.
>
> One way around that was somehing I had in mind with an earlier draft.
> The decoded access token has distributed claims in it.  You could just
> make the aditional scopes distributed claims, that has the advantage of
> providing a endpoint URL for the access token, and multiple access tokens.
> that was rejected and not being OAuth like at the time.
>
> Unfortunately I won't make the Monday call.
>
> John B.
>
> On 2011-11-05, at 3:30 PM, Nat Sakimura wrote:
>
> So, one possible "another way" would be to have an option to include more
> user info in the id_token.
> That way, we can keep the "opaqueness" requirement for the access_token
> intact and still accomodate the need for being able to access claims
> without a second call.
>
> That actually is how it was done in earlier drafts.
>
> =nat
>
> On Sun, Nov 6, 2011 at 1:39 AM, Mike Jones <Michael.Jones at microsoft.com>wrote:
>
>>  As discussed during the working group call on Thursday, I received
>> feedback on the current Connect design from a key Microsoft product
>> architect based upon his product’s use cases.  The high-order bit in his
>> feedback was that he needs RPs to be able to access claims without making a
>> second call to Check ID or UserInfo endpoints.  Per the discussion on the
>> call, the requirement to be able to access claims without additional round
>> trips seems entirely reasonable and is motivated by real user-interface
>> latency concerns.****
>>
>> ** **
>>
>> To accomplish this, all claims would be carried in JWT tokens, which
>> would then be directly used by the RPs.  This conflicts with the current
>> design decision that the access token is opaque and that UserInfo claims
>> can only be retrieved by making a second call to the UserInfo endpoint.  I
>> propose that we change that decision before declaring implementer’s drafts.
>> ****
>>
>> ** **
>>
>> Specifically, I would require that, in the normal case, the access token
>> is a JWT containing the UserInfo claims (just like the ID Token is a JWT
>> containing the logged-in session claims).  If we decide that it’s important
>> to allow some implementations to use a different token format, that should
>> be the exception, not the default.  In that exceptional case, those IdPs
>> must declare in their discovery information that UserInfo claims must be
>> retrieved from the UserInfo endpoint, and cannot be directly accessed
>> within a JWT access token.****
>>
>> ** **
>>
>> I’d promised on the call to write up this proposed change.  This is that
>> write-up.  We’ll discuss this on the Monday call.****
>>
>> ** **
>>
>>                                                             Best wishes,*
>> ***
>>
>>                                                             -- Mike****
>>
>> ** **
>>
>> P.S.  Coincidentally, I also independently received essentially the same
>> feedback from a different product architect yesterday, based upon his
>> review of the specs.****
>>
>> ** **
>>
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>>
>>
>
>
> --
> Nat Sakimura (=nat)
> Chairman, OpenID Foundation
> http://nat.sakimura.org/
> @_nat_en
>
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>

-- 
Nat Sakimura (=nat)
Chairman, OpenID Foundation
http://nat.sakimura.org/
@_nat_en
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