Re: [OAUTH-WG] Simpilfying use of assertions when requesting an access token

[David Recordon <[e-mail]>]

One of the things I really liked about WRAP (which we've largely preserved
in 2.0) is more specific flows for the different use cases. I generally
don't think that we should make this anymore generic than it already is. I
do think that merging the assertion type into the grant type parameter is
the right decision for the assertion use cases.


On Fri, Sep 10, 2010 at 12:37 AM, David Waite
<[e-mail]>wrote:

> I think combining the grant_type and assertion_type together is a great
> idea. However, I have recently been wondering if it would be a good idea to
> unify all the access grants to use the same parameters.
>
> For instance, you could have the parameters:
>
>        grant_type - the type of access grant (of course)
>        grant_qualifier - an identifier or URI associated with the grant
>        grant_value - the data (such as an opaque or secret value) used for
> a particular type of access grant
>
> So for the grant types mentioned below, you would have:
>
>        password:
>                a grant_qualifier of the user identifier, and a grant_value
> of their password
>
>        client_credentials:
>                a grant_qualifier of the client identifier, and a
> grant_value of the shared secret
>
>        refresh_token:
>                no grant_qualifier, a grant_value of the refresh token
>
>        authorization_code:
>                a grant_qualifier of the callback URI used to return the
> authorization code to the client, and a grant_value of the actual code
>
>        <SAML assertion extension URI>:
>                no grant_qualifier, a grant_value of the assertion as a
> string
>
> This would seem to have the following benefits:
>        - A number of query parameters defined to be used only in cases of a
> particular grant_type value would be eliminated
>        - The qualifier/value would provide a guideline for structuring new
> grant types
>        - The "grant_" prefix for the parameters could provide a logical
> grouping for any additional parameters, if a new grant type required more
> than the qualifier/value pair above.
>
> I must admit however, I had difficulty figuring out how to phrase
> 'qualifier' so that it would apply to a callback URI. I think it makes sense
> in that an authorization code is issued against and only valid for a
> specific callback URI, but would understand if this came off feeling like
> overloading that parameter.
>
> -David Waite
>
> On Sep 2, 2010, at 3:11 PM, Eran Hammer-Lahav wrote:
>
> > I would like to make this change in -11:
> >
> > Instead of the current user of the ‘assertion’ grant type –
> >
> >   POST /token HTTP/1.1
> >   Host: server.example.com
> >   Content-Type: application/x-www-form-urlencoded
> >
> >   grant_type=assertion&
> >   assertion_type=urn%3Aoasis%3Anames%3Atc%3ASAML%3A2.0%3Aassertion&
> >   assertion=PHNhbWxwOl[...omitted for brevity...]ZT4%3D
> >
> > Drop the ‘assertion’ grant type and put the assertion type directly in
> the grant_type parameter:
> >
> >   POST /token HTTP/1.1
> >   Host: server.example.com
> >   Content-Type: application/x-www-form-urlencoded
> >
> >   grant_type=urn%3Aoasis%3Anames%3Atc%3ASAML%3A2.0%3Aassertion&
> >   assertion=PHNhbWxwOl[...omitted for brevity...]ZT4%3D
> >
> > In other words, the grant_type parameter value will be defined as:
> >
> > -          authorization_code
> > -          password
> > -          client_credentials
> > -          refresh_token
> > -          an abolute URI (extensions)
> >
> > I considered turning all the values into URIs but found it to be
> counter-intuitive. The practice of using “official” short names and
> extension URIs is well established and is already the general architecture
> used here. This just makes it cleaner.
> >
> > I ran this idea by Brian Campbell and Chuck Mortimore who are generally
> supportive of the idea.
> >
> > Any objections?
> >
> > EHL
> >
> > _______________________________________________
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>
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