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anima-wg / constrained-voucher

This is a repo for the IETF Internet Draft about constrained vouchers in CBOR
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Is application/voucher-cose+cbor a correct name? #264

Closed EskoDijk closed 11 months ago

EskoDijk commented 1 year ago

Alternative would be: application/voucher-cbor+cose

to signal that it is a Voucher in CBOR format, with a wrapping of COSE around it ("+cose"). Or should it be application/voucher-cose+cbor ?

thomas-fossati commented 1 year ago

If you wanted to do application/voucher-cbor+cose you'd need to define and register +cose in the SSS registry because it's not there yet.

EskoDijk commented 1 year ago

Thanks @thomas-fossati, I see now the RFC 6838 guidance on this. The suffix behind the '+' ought to be an already-registered encoding standard. And here the '+cbor' makes sense, as the underlying syntax of the (outer) COSE object is itself also plain CBOR -- besides being COSE.

Adding +cose to the SSS registry would give some complications maybe; for some reason the COSE RFC did not register this.

EskoDijk commented 1 year ago

The +cose suffix has been requested now, see email thread: https://mailarchive.ietf.org/arch/msg/cose/Qb9W7ouloS__x7WyiN_AUsH4kXc/

EskoDijk commented 1 year ago

If this registration proceeds, then we may change our media type to either one of application/voucher+cose application/voucher-cbor+cose

EskoDijk commented 1 year ago

No input received from media-types WG, next step in process is to send the request to IANA per email. (Checking with mcr who will send the email and if not already sent.)

EskoDijk commented 1 year ago

Discussion in media-types list was resolved (after filing an IANA request), conclusion is that we need to do the registration template inside a document - which should be this I-D I think. With that, the registration can be processed.

Because "COSE" already implies the payload is CBOR (wrapped inside the COSE in a single byte string) the media type can become application/voucher+cose . The added -cbor would be redundant in the name. The element voucher on its own formally doesn't need a format designator, because only the following parts must be parsable in isolation:

and both of these are fully clear in their encoding and meaning. If the COSE would be stripped off, then it would require another media type like either application/cbor or a more specific one (e.g. application/voucher-cbor) but the latter would need to be defined in RFC8366-bis.

EskoDijk commented 1 year ago

@thomas-fossati FYI I've now linked a PR to request the registration: https://github.com/anima-wg/constrained-voucher/pull/277