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Re: [Cbor] 65-bit negatives, big nums conflict between CDE and dCBOR drafts?

Carsten Bormann <cabo@tzi.org> Sat, 06 April 2024 18:11 UTC

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From: Carsten Bormann <cabo@tzi.org>
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Date: Sat, 06 Apr 2024 20:10:52 +0200
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To: "lgl island-resort.com" <lgl@island-resort.com>
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Subject: Re: [Cbor] 65-bit negatives, big nums conflict between CDE and dCBOR drafts?
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Hi Laurence,

On 6. Apr 2024, at 19:47, lgl island-resort.com <lgl@island-resort.com> wrote:
> 
> 
>> On Apr 6, 2024, at 6:56 AM, Anders Rundgren <anders.rundgren.net@gmail.com> wrote:
>> 
>> Although I personally don't find the CBOR int/bignum arrangement ideal, this boat has (since long) already sailed and nobody died.
> 
> It looks to me that there is a new requirement in draft-ietf-cbor-cde-02 that isn’t in RFC 7049 (canonical CBOR) or RFC 8949 (Preferred Serialization and CDE). The requirement is that no value that can fit into an int64 or uint64 can be sent as a tag 3. That implies 65-bit negatives ints must be sent.

This is not a “new requirement” [1].

[1]: https://www.rfc-editor.org/rfc/rfc8949.html#section-3.4.3

Grüße, Carsten

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