Re: [Tls-reg-review] Adopting tls-flags

[Christopher Wood <[e-mail]>]

On Sat, Mar 20, 2021, at 9:57 PM, Yoav Nir wrote:
> You mean add the cross_sni_resumption value to the tlsflags draft?  

I don't think that was the suggestion. I understand the proposal to be:

1. tls-flags owns the registry and its initial contents, and it's initially empty empty.
2. cross-sni-resumption defines the first registry value for tls-flags, with value 8.

Did I misunderstand? If not, would that work?

Best,
Chris

> Sure. We can do that, if we’re sure that the cross-sni-resumption draft 
> is getting approved in this form.  I don’t think there has been a WGLC 
> for it yet.
> 
> Also, section 4.1 of the TLSFLAGS draft has this advice:
> 
> 4.1.  Guidance for IANA Experts
> 
>    This extension allows up to 2040 flags.  However, they are not all
>    the same, because the length of the extension is determined by the
>    highest set bit.
> 
>    We would like to allocate the flags in such a way that the typical
>    extension is as short as possible.  The scenario we want to guard
>    against is that in a few years some extension is defined that all
>    implementations need to support and that is assigned a high number
>    because all of the lower numbers have already been allocated.  An
>    example of such an extension is the Renegotiation Indication
>    Extension defined in [RFC5746].
> 
>    For this reason, the IANA experts should allocate the flags as
>    follows:
> 
>    o  Flags 0-7 are reserved for documents coming out of the TLS working
>       group with a specific request to assign a low number.
> 
>    o  Flags 8-31 are for standards-track documents that the experts
>       believe will see wide adoption among either all users of TLS or a
>       significant group of TLS users.  For example, an extension that
>       will be used by all web clients or all smart objects.
> 
>    o  Flags 32-63 are for other documents, including experimental, that
>       are likely to see significant adoption.
> 
>    o  Flags 64-79 are not to be allocated.  They are for reserved for
>       private use.
> 
>    o  Flags 80-2039 can be used for temporary allocation in experiments,
>       for flags that are likely to see use only in very specific
>       environments, for national and corporate extensions, and as
>       overflow, in case one of the previous categories has been
>       exhausted.
> 
> 
> So IMO this is more fitting to receive the number 8 rather than the 
> number 1. That is, unless the WG wants to make the case that this flag 
> extension is going to be present in most ClientHello messages from now 
> on.
> 
> Yoav
> 
> > On 19 Mar 2021, at 22:38, Benjamin Kaduk <[e-mail]> wrote:
> > 
> > The draft that creates the registry owns the initial registry contents
> > until the registry itself is created.
> > 
> > So, just put the value in the draft's source, and try to avoid re-using a
> > number for different things during the draft's time as a draft.
> > 
> > -Ben
> > 
> > On Fri, Mar 19, 2021 at 01:26:10PM -0700, Christopher Wood wrote:
> >> + tls-reg-review
> >> 
> >> Good question! Since this is a new registry, I don't see any problem with grabbing 1 to populate it. The registry experts may have a better answer though.
> >> 
> >> Best,
> >> Chris
> >> 
> >> On Thu, Mar 18, 2021, at 5:06 PM, Victor Vasiliev wrote:
> >>> Do I actually get to just use 1, or do I need to ask you to do the 
> >>> early allocation process?
> >>> 
> >>> On Tue, Mar 16, 2021 at 9:50 PM Christopher Wood <[e-mail]> wrote:
> >>>> Friendly bump!
> >>>> 
> >>>> On Mon, Mar 1, 2021, at 7:52 AM, Christopher Wood wrote:
> >>>>> Hi Victor,
> >>>>> 
> >>>>> On Mon, Mar 1, 2021, at 7:39 AM, Victor Vasiliev wrote:
> >>>>>> Hi Chris,
> >>>>>> 
> >>>>>> This makes sense.  I will update the draft some time after the upcoming 
> >>>>>> IETF.  Do you want to just add a codepoint reserved for cross-domain 
> >>>>>> resumption into the draft, or how does that work?
> >>>>> 
> >>>>> Good question. I suspect your draft would just add, in the IANA 
> >>>>> considerations section, something like this:
> >>>>> 
> >>>>> ~~~
> >>>>> This document requests that IANA create a new entry in "TLS Flags" 
> >>>>> registry with the following parameters:
> >>>>> 
> >>>>> - Value: 1
> >>>>> - Flag Name: "cross_sni_resumption" (or whatever you want to name it)
> >>>>> - Message: NewSessionTicket
> >>>>> - Recommended: Y
> >>>>> - Reference: This document
> >>>>> ~~~
> >>>>> 
> >>>>> (See https://tools.ietf.org/html/draft-ietf-tls-tlsflags-04#section-4)
> >>>>> 
> >>>>>> 
> >>>>>> (sorry for late response, just noticed the part about the draft  submission deadline)
> >>>>> 
> >>>>> No problem!
> >>>>> 
> >>>>> Best,
> >>>>> Chris
> >>>>> 
> >> 
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