Re: [Cbor] Review of draft-ietf-cbor-packed-02

Carsten Bormann <cabo@tzi.org> Mon, 15 March 2021 20:33 UTC

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From: Carsten Bormann <cabo@tzi.org>
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Date: Mon, 15 Mar 2021 21:33:46 +0100
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To: Russ Housley <housley@vigilsec.com>
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Subject: Re: [Cbor] Review of draft-ietf-cbor-packed-02
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On 2021-03-15, at 19:40, Russ Housley <housley@vigilsec.com> wrote:
> 
> I felt this point of divergence from the original design goal needed explicit discussion.
> 
> I'm not sure what the right answer might be.  Maybe some preamble to say that a named table is needed for successfully recovering the entire content. In the current document, this context is assumed.

I added to PR#2:

>  * By the application environment, e.g., a media type.  These can
>    define tables that amount to a static dictionary that can be used in
>    a CBOR data item for this application environment.
> +  Note that, without this information, a data item that uses such a
> +  static dictionary can be decoded at the CBOR level, but not fully
> +  unpacked.
> +  The table setup mechanisms provided by this document are defined in
> +  such a way that an unpacker can at least recognize if this is the
> +  case.
>  
>  * By one or more tags enclosing the packed content.
[…]

I’m not sure that this fully addresses your comment, but I agree that it is important to make this point.

Grüße, Carsten