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Re: [TLS] Spencer Dawkins' No Objection on draft-ietf-tls-tls13-26: (with COMMENT)

Martin Thomson <martin.thomson@gmail.com> Thu, 08 March 2018 23:32 UTC

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From: Martin Thomson <martin.thomson@gmail.com>
Date: Fri, 09 Mar 2018 10:32:48 +1100
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To: Eric Rescorla <ekr@rtfm.com>
Cc: Spencer Dawkins <spencerdawkins.ietf@gmail.com>, "<tls@ietf.org>" <tls@ietf.org>, draft-ietf-tls-tls13@ietf.org, The IESG <iesg@ietf.org>, tls-chairs <tls-chairs@ietf.org>
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Subject: Re: [TLS] Spencer Dawkins' No Objection on draft-ietf-tls-tls13-26: (with COMMENT)
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On Fri, Mar 9, 2018 at 12:10 AM, Eric Rescorla <ekr@rtfm.com> wrote:
>> I wondered why
>>
>>    Newer
>>    clients or servers, when communicating with newer peers, SHOULD
>>    negotiate the most preferred common parameters.
>>
>> was not a MUST.
>
>
> Ugh, this is actually not even a normative statement, It's just a statement
> of
> what the protocol is supposed to do. Good catch!

Drop the SHOULD, yeah.  Is it worth noting that it's the server's
preference that wins?  As in:

   Newer clients or servers, when communicating with newer peers,
negotiate the common parameters most preferred by the server.

Or is that too constraining?

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