From: Peter van der Stok <stokc...@bbhmail.nl> Sent: Monday, July 9, 2018 1:01 AM To: Jim Schaad <i...@augustcellars.com> Cc: consulta...@vanderstok.org; draft-ietf-ace-coap-...@ietf.org; 'ace' <ace@ietf.org> Subject: Re: [Ace] Review draft-ietf-ace-coap-est * In section 4.1 I have a question about what you are using for payload content encoding. Part of this might just be a question of how you plan to move from ASN.1 to CBOR at some point in the future. I think that it would necessitate doing new media-types in that event. You appear to be doing a CBOR bstr wrapping on the ASN.1 encoding payload. I don't believe that there is any reason for doing this. I would expect that the payload would be the ASN.1 w/o any ASN.1. It is highly possible that I am just mis-reading what the text says and this is what you say. <pvds> What I wanted to do, and did not express very well. Keep the ASN.1 structure of the payload; (re-using code) Use straight binary coding instead of the base64-encoded (30% payload reduction) Wrap the binary in a CBOR major type 2 h'xxx' notation. (compatibility with multipart) Not sure if this needs a new media type, the http content-coding and transfer-coding registries were not very helpful. </pvds> [JLS] I do not believe that the wrapping of content with the CBOR binary text wrapping is needed at this point. If that is needed for the multi-part wrapping, then it is the job of the multi-part wrapping to deal with this problem. Multipart needs to be able to say I have a multipart of <plain text, json> neither of which are CBOR objects. Therefor there is no reason for you to use a CBOR wrapper for this and not just use the binary value. <pvds> You are right of course, the CBOR wrapping is not needed outside the multipart media type. However, CBOR wrapping for all payloads, reduces the choices when decoding the payload; They all start the same. And it adds 2-3 bytes on many. </pvds> [JLS] I don’t follow this at all. How I read this statement is I have a binary value and I need to look at the content type to figure out what ASN.1 structure it is and decode it. This is very hard. So I am going to change this to I need to look at the content type to figure out that I have a CBOR bstring value. It is easy to remove the CBOR bstring value. I now have a binary value and I need to look at the content type to figure out what ASN.1 structure it is and decode it. This is somehow easier.
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