Re: #612: Adopting pull #644

BTW, for reviewing, I use:
  https://github.com/http2/http2-spec/pull/644/files
... selecting the "split" view and turning off "Show notes".

YMMV.


> On 21 Nov 2014, at 6:05 pm, Martin Thomson <martin.thomson@gmail.com> wrote:
> 
> tl;dr: new PR:
> On 20 November 2014 15:47, Mark Nottingham <mnot@mnot.net> wrote:
>> What do people thing about changing this text:
>> 
>> """
>> A deployment of HTTP/2 over TLS 1.2 MUST NOT use any of the cipher suites that are only be used with cipher suites that are listed in <xref target="BadCipherSuites"/>
>> """
>> 
>> to a SHOULD NOT?
> 
> I've prepared the draft with a SHOULD.  And noted the risks...
> 
> On 20 November 2014 15:50, Mark Nottingham <mnot@mnot.net> wrote:
>> On 18 Nov 2014, at 7:36 pm, Yoav Nir <ynir.ietf@gmail.com> wrote:
>>> Regardless, unlike MAY and MUST, you can’t just use “SHOULD” and “SHOULD NOT” in a document. They require an explanation of why you should not, and under what circumstances your are allowed to do that something that your should not do.
>> 
> [...]
>>> So, if we agree with you, we need to complete the sentence, “HTTP/2.0 clients and server SHOULD NOT use ciphers from this list unless …”
>> 
>> "... unless the server is deployed to communicate with a known population of clients, or is willing to accept that some clients will refuse to communicate with it."
> 
> I've not chosen that precise form (it's clunky without the connection
> error being introduced).  But I think that I've framed it in a way
> that should avoid a DISCUSS target.
> 
>>> Finally, we should say something about why we need this functionality: endpoints typically will support both HTTP/1.1 and HTTP/2, and TLS does not allow either endpoint to restrict the list of negotiated cipher suites based on the ALPN negotiated protocol (i.e. ALPN just allows the client to send a list of protocol identifiers, not identifiers + cipher suites).
>> 
>> I think that's good editorial input for Martin.
> 
> Text to that effect has been in the document for ages, though it was
> removed in the PR.  I'll try to find a way to have it return in some
> fashion.
> 
> ...I've also tried to fix some wording contortions around the TLS
> 1.2/1.3+ split here.

--
Mark Nottingham   https://www.mnot.net/

Received on Friday, 21 November 2014 07:16:21 UTC