Re: [TLS] Feedback on draft-ietf-tls-tlsflags

[Yoav Nir <[e-mail]>]

> On 30 Jan 2020, at 22:08, Stephen Farrell <[e-mail]> wrote:
> 
> 
> 
> On 30/01/2020 17:57, Yoav Nir wrote:
>> Hi folks.
>> 
>> In case you’re not following GitHub, there was an issue with a brief
>> discussion ([1]) and a resulting pull request ([2]).
>> 
>> If there are no objections by late next week, I will merge the PR.
> 
> Allowing 2040 flags seems a bit mad and a possible
> foot-gun - with a specification required rule that
> could end up worse than the ciphersuites registry!
> 
> Given it's possible to define a tls_flags2 extension
> if this one runs out, I'd argue to constrain this to a
> much smaller number of flags - 63 should be plenty
> I'd say.
> 
> That said, it's not that huge a deal since I have
> a hard time seeing implementers even trying to code
> for 2040 flags and specification required is the
> same rule as for extensions.
> 
> Cheers,
> S.

The format allows 2040 bits. I think we should never define that many bits. I think we should never define even 60 bits. But I also think it should be left up to the TLS chairs and the IANA experts to serve as gatekeepers rather than tying their hands in the specification.