Re: [Id-event] Thread: Clarifying use of sub and iss in SET tokens

[William Denniss <[e-mail]>]

If JWT had a "typ" field all along, this entire discussion could be
avoided, but it's too late for that now. I believe that this was actually
the founding reason behind standardizing SET, introducing the "events"
claim. At least, to avoid the 3+ versions of event-on-JWT that were in
discussion at the time.

As with all security considerations people can not follow them and have bad
things happen.

Doesn't suggesting that unrelated systems not issue tokens sharing the same
iss/aud namespace make sense here as a mitigation though?  To me that's
better and more scalable than every spec removing some required claim from
the other specs (e.g. mandating that people can't use "sub").


On Wed, Mar 1, 2017 at 3:54 PM, Marius Scurtescu <[e-mail]>
wrote:

> We also talked about adding another claim that defines the type or purpose
> of the JWT ("access token", "SET", etc). In a way it is the only sane
> option, but it is not addressing existing implementations. Asking
> implementors to "be careful" is asking for trouble IMO, especially because
> systems evolve by incrementally adding functionality.
>
> Marius
>
> On Wed, Mar 1, 2017 at 12:44 PM, William Denniss <[e-mail]>
> wrote:
>
>> OK so perhaps the "URI" thing is overly restrictive.
>>
>> I guess the security consideration I'm recommending here is that you
>> shouldn't have multiple systems that issue JWTs with the same iss/aud
>> tuple, except when those systems are tightly coupled (as is the case with
>> Connect & Logout).
>>
>> If a shared issuer is used, then URI-based namespacing is *one* way to
>> avoid this, but there are others.
>>
>> I'm trying to avoid the need for SET to "break" possible use in access
>> tokens (one of the stated goals in the original post) – I think having
>> advice like this can avoid normative language that changes, and overly
>> complicates SET.
>>
>> _______________________________________________
>> Id-event mailing list
>> [e-mail]
>> https://www.ietf.org/mailman/listinfo/id-event
>>
>>
>