[Ace] WGLC comments on draft-ietf-ace-oauth-authz and draft-ietf-ace-params

Ludwig Seitz <ludwig.seitz@ri.se> Fri, 23 November 2018 10:31 UTC

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From: Ludwig Seitz <ludwig.seitz@ri.se>
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Subject: [Ace] WGLC comments on draft-ietf-ace-oauth-authz and draft-ietf-ace-params
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Hello ACE,

I have now addressed all WGLC comments (Jim Schaad's, Mike Jones' and 
Stefanie Gerdes') except for this one:

"Do we need to write something about how a RS should handle the presence 
of multiple tokens for the same client? Perhaps a security consideration?

I see two options:

1. Multiple tokens complement themselves i.e. if token A gives you right 
R1 and token B right R2 then you have R1+R2.

2. The newer token always overwrites the old one, which means if you 
want to extend your access rights as a client, when you already have A 
-> R1 you need to ask the AS for B*->R1+R2.
(see https://github.com/ace-wg/ace-oauth/issues/147).

AFAIK the common usage in OAuth is option 2, however Jim has pointed out 
use cases for option 1 and refers to it in

Jim has expressed a preference for 1. while Olaf has (in the Jabber at 
IETF 103) expressed a preference for 2.

I would need some guidance from the WG on how to proceed here.


Ludwig Seitz, PhD
Security Lab, RISE
Phone +46(0)70-349 92 51