Re: [Cbor] Deterministic CBOR as a possible DISPATCH item

[Carsten Bormann <[e-mail]>]

On 2023-03-05, at 13:59, Wolf McNally <[e-mail]> wrote:
> 
> Our view is that it’s good to be opinionated, and enforce good practices in APIs. 

Which is great, as long as the users of the API know that their application protocol is forced into this practice.
(Application protocol designers may not be aware of what you consider good practice.)

> Determinism is one such good practice when it comes to creating cryptographically enhanced documents.

Determinism is mostly unneeded in interchanged data items.
(It is needed for signing inputs, which are therefore best designed to make determinism inexpensive.)
It still is nice to have, e.g., for test scripts.

> Generally the size of encoded numeric values should not be semantically meaningful, so our codec does the work of selecting an unambiguous size for serialization.

Which is a good thing.  I was just pointing out that your “codec” does make some additional choices for the application.  Which again can be a good thing as long as application builders know this.
(I don’t know a lot of application protocols that would be broken by your choices, but that is mostly because I don’t know a lot of application protocols that actually need floating point numbers.  See for instance https://datatracker.ietf.org/doc/html/rfc8610#appendix-H, which would need some minor modification to accommodate the values 0.0 and 1.0.)

> If you haven’t seen it yet, I recommend the video we just published on our dCBOR implementations, which goes into a number of our design choices:

… will have a look when I find time…

Grüße, Carsten