Re: [COSE] Assigning CBOR tags to key structures

There is a content type that was defined.  This can be used for the same purpose by including a content type in the protected properties.  This allows for identification of the content before doing the decryption.

jim

> -----Original Message-----
> From: Renzo Navas [mailto:renzoefra@gmail.com]
> Sent: Friday, April 7, 2017 1:34 AM
> To: cose <cose@ietf.org>
> Cc: Carsten Bormann <cabo@tzi.org>; Jim Schaad <ietf@augustcellars.com>
> Subject: Re: [COSE] Assigning CBOR tags to key structures
> 
> Hi all!
> Sorry to revive this 1 and half year old topic.
> 
> In the end we finally have no CBOR Tag for COSE_Key and COSE_KeySet, I
> could not find at IANA (nor on the cose rev 24 document) :( Was it discarded
> at the end, why? or there is a chance to still get the tag at IANA?
> 
> Regards !
> 
> Renzo
> 
> 
> ------------
> 
> PS: some more details of why this can be useful follow:
> 
> More details on the Use Case: transporting a symmetric key with COSE_Key , it
> has to be protected, so wrapped on an Encrypt0 message (Tag 16); Would be
> nice have a tag to identify that the payload is a Cose_key object; it is true at
> the moment I can design the app to always expect a keyobjet as the payload of
> an encrypt0 ... ; but I'm cutting flexibility, or we can design a custom cbor
> structure, but we are loosing on interoperability.
> I have a coap server, with limited ram, and I have actually size only for for two
> coap resources, so I can see I will have to overload some functionality of this
> resource, particularly this is a sort of "/authz-info" ace resource, that I will use
> to do authenticated key establishment (oauth pop token provisioning), and
> other stuff, so probably quite overloaded.
> 
> 
> 
> 
> On Sun, Oct 11, 2015 at 8:22 PM, Jim Schaad <ietf@augustcellars.com>
> wrote:
> > As a general rule, this makes sense to me.
> >
> > Jim
> >
> >
> >> -----Original Message-----
> >> From: Carsten Bormann [mailto:cabo@tzi.org]
> >> Sent: Sunday, October 11, 2015 2:32 AM
> >> To: Jim Schaad <ietf@augustcellars.com>
> >> Cc: cose@ietf.org
> >> Subject: Re: [COSE] Assigning CBOR tags to key structures
> >>
> >> I'd propose this rule:
> >> If there is a media type, there should be a CBOR tag for those
> >> environments that don't benefit from media types.
> >> (And generally vice versa, unless we are using CBOR tags in other
> >> than top-level
> >> positions.)
> >>
> >> Grüße, Carsten
> >>
> >>
> >> Jim Schaad wrote:
> >> > I am currently working on the IANA text for doing assignment of
> >> > CBOR tags in COSE.
> >> >
> >> > There is a possibility to request tags for the KEY and KEY_SET maps
> >> > in the document.  At the present time I have not done this.  Can
> >> > anybody see a reason for asking for tags on these two elements
> >> > other than
> >> completeness?
> >> > I.e. does anybody have a place where it would make sense to use the
> >> > pre-defined tags rather than knowing either a key or key set is in
> >> > this location (it is possible to distinguish between the two items
> >> > based on the an array vs map tag.)
> >> >
> >> >
> >> > Jim
> >> >
> >> >
> >> > _______________________________________________
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> >> > COSE@ietf.org
> >> > https://www.ietf.org/mailman/listinfo/cose
> >> >
> >
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