On Jan 9, 2013, at 3:05 PM, Torsten Lodderstedt 
<[email protected]<mailto:[email protected]>> wrote:

Hi Justin,

Am 09.01.2013 um 20:35 schrieb Justin Richer 
<[email protected]<mailto:[email protected]>>:

Thanks for the review, answers inline:
why is there a need for both scope and audience? I would assume the scope of 
the authorization request is typically turned into an audience of an access 
token.

You can have an audience of a single server that has multiple scopes, or a 
single scope that's across multiple servers. Scope is an explicit construct in 
OAuth2, and while it is sometimes used for audience restriction purposes, they 
really are independent. Note that both of these are optional in the response -- 
if the AS has no notion of audience restriction in its stored token metadata, 
then it just doesn't return the "audience" field.

You are making an interesting point here. To differentiate the resource server 
and the permissions of a particular at this server makes a lot of sense. BUT: 
the authorization request does not allow the client to specify both in separate 
parameters. Instead both must be folded into a single "scope" parameter. If I 
got your example correctly, the scope of the request would be

scope=myserver:read

whereas the results of the introspection would be

scope=read
audience=myserver

It's probably the different semantics of scope that confused me.

No, sorry if I was unclear: scope is scope, no different semantics. In this 
example case, you'd ask for scope=myserver:read and get back 
scope=myserver:read. I'm not suggesting that these be split up. Since the AS in 
this case knows that there's an audience, so it can return audience=myserver as 
well. The fact that it knows this through the scope mechanism is entirely 
system-dependent.

I agree that the lack of a method for specifying audience does make returning 
this field a little odd for simple OAuth deployments, but since audience 
restriction is a big part of clustered and enterprise deployments (in my 
personal experience), then it's something very useful to have the server return.




Generally, wouldn't it be simpler (spec-wise) to just return a JWT instead of 
inventing another set of JSON elements?

What would be the utility in returning a JWT? The RS/client making the call 
isn't going to take these results and present them elsewhere, so I don't want 
to give the impression that it's a token. (This, incidentally, is one of the 
main problems I have with the Ping introspection approach, which uses the Token 
Endpoint and invents a "token type" as its return value.) Also, the resource 
server would have to parse the JWT instead of raw JSON, the latter of which is 
easier and far more common. Besides, I'd have to invent new claims for things 
like "valid" and "scopes" and what not, so I'd be extending JWT anyway.

So while I think it's far preferable to use an actual JSON object, I'd be fine 
with re-using JWT claim names in the response if people prefer that. I tried to 
just use the expanded text since size constraints are not an issue outside of a 
JWT, so "issued_at" instead of "iat".

Finally, note that this is *not* the same as the old OIDC CheckId endpoint 
which merely parsed and unwrapped the data inside the token itself. This 
mechanism works just as well with an unstructured token as input since the AS 
can store all of the token's metadata, like expiration, separately and use the 
token's value as a lookup key.

I probably didn't describe well what I meant. I would suggest to return a JWT 
claim set from the introspection endpoint. That way one could use the same 
claims (e.g. iat instead of issued_at) for structured and handle-based tokens. 
So the logic operating on the token data could be the same.


OK, I follow you now. I'd be fine with re-using the JWT claim names and 
extending the namespace with the OAuth-specific parameters, like scope, that 
make sense here.

 -- Justin

regards,
Torsten.


 -- Justin

Am 09.01.2013 um 20:10 schrieb Justin Richer 
<[email protected]<mailto:[email protected]>>:

Updated the introspection draft with feedback from the UMA WG, who have 
incorporated it into their latest revision of UMA.

I would like this document to become a working group item.

 -- Justin


-------- Original Message --------
Subject:        New Version Notification for 
draft-richer-oauth-introspection-01.txt
Date:   Tue, 8 Jan 2013 14:48:47 -0800
From:   <[email protected]><mailto:[email protected]>
To:     <[email protected]><mailto:[email protected]>



A new version of I-D, draft-richer-oauth-introspection-01.txt
has been successfully submitted by Justin Richer and posted to the
IETF repository.

Filename:        draft-richer-oauth-introspection
Revision:        01
Title:           OAuth Token Introspection
Creation date:   2013-01-08
WG ID:           Individual Submission
Number of pages: 6
URL:             
http://www.ietf.org/internet-drafts/draft-richer-oauth-introspection-01.txt
Status:          
http://datatracker.ietf.org/doc/draft-richer-oauth-introspection
Htmlized:        http://tools.ietf.org/html/draft-richer-oauth-introspection-01
Diff:            
http://www.ietf.org/rfcdiff?url2=draft-richer-oauth-introspection-01

Abstract:
   This specification defines a method for a client or protected
   resource to query an OAuth authorization server to determine meta-
   information about an OAuth token.





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