Re: [quicwg/base-drafts] introduce a version alias mechanism (#2573)

Mike Bishop <notifications@github.com> Fri, 19 April 2019 19:47 UTC

Return-Path: <noreply@github.com>
X-Original-To: quic-issues@ietfa.amsl.com
Delivered-To: quic-issues@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id AAAE11200B1 for <quic-issues@ietfa.amsl.com>; Fri, 19 Apr 2019 12:47:48 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -8.001
X-Spam-Level:
X-Spam-Status: No, score=-8.001 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HTML_MESSAGE=0.001, MAILING_LIST_MULTI=-1, RCVD_IN_DNSWL_HI=-5, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=github.com
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id XbCm1AnFQ_Q8 for <quic-issues@ietfa.amsl.com>; Fri, 19 Apr 2019 12:47:46 -0700 (PDT)
Received: from out-1.smtp.github.com (out-1.smtp.github.com [192.30.252.192]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 896AB1203A2 for <quic-issues@ietf.org>; Fri, 19 Apr 2019 12:47:46 -0700 (PDT)
Date: Fri, 19 Apr 2019 12:47:45 -0700
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=github.com; s=pf2014; t=1555703265; bh=wLumfKPAdIOskKKgoPpUH1NXgIfsNwapDlJdnuzQiLg=; h=Date:From:Reply-To:To:Cc:In-Reply-To:References:Subject:List-ID: List-Archive:List-Post:List-Unsubscribe:From; b=hp6IJGOqtDWylKSpdySUFxCmS1khxnwr3ZvXbOy/5yrEwFGJyQsl2h97rkFIVtL7y 6cKZxK2XvTJtzQAiXIWiJcwmBeO2J5cUYHcn/+p9Sl8wByXHNkBaA0httIkVVqdN/y fx7nIlSeTqaxn+whMqrRitL2cmgscjfBHBenolpM=
From: Mike Bishop <notifications@github.com>
Reply-To: quicwg/base-drafts <reply+AFTOJK63RRUB5A44Z54F6DN2Y5MGDEVBNHHBS6WUXE@reply.github.com>
To: quicwg/base-drafts <base-drafts@noreply.github.com>
Cc: Subscribed <subscribed@noreply.github.com>
Message-ID: <quicwg/base-drafts/pull/2573/review/228806243@github.com>
In-Reply-To: <quicwg/base-drafts/pull/2573@github.com>
References: <quicwg/base-drafts/pull/2573@github.com>
Subject: Re: [quicwg/base-drafts] introduce a version alias mechanism (#2573)
Mime-Version: 1.0
Content-Type: multipart/alternative; boundary="--==_mimepart_5cba25e1bd87a_70733f8a328cd95c16845a"; charset="UTF-8"
Content-Transfer-Encoding: 7bit
Precedence: list
X-GitHub-Sender: MikeBishop
X-GitHub-Recipient: quic-issues
X-GitHub-Reason: subscribed
X-Auto-Response-Suppress: All
X-GitHub-Recipient-Address: quic-issues@ietf.org
Archived-At: <https://mailarchive.ietf.org/arch/msg/quic-issues/nuhXW7zv5CW93eOjjSBWEmoqRAA>
X-BeenThere: quic-issues@ietf.org
X-Mailman-Version: 2.1.29
List-Id: Notification list for GitHub issues related to the QUIC WG <quic-issues.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/quic-issues>, <mailto:quic-issues-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/quic-issues/>
List-Post: <mailto:quic-issues@ietf.org>
List-Help: <mailto:quic-issues-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/quic-issues>, <mailto:quic-issues-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 19 Apr 2019 19:47:49 -0000

MikeBishop commented on this pull request.



> @@ -3251,12 +3251,17 @@ using for private experimentation on the GitHub wiki at
 In order to avoid ossification of the version number defined by this draft,
 servers announce a list of version numbers that they interpret as aliases for
 the version number used in this draft. Alias versions MUST NOT be a reserved
-version. Servers SHOULD send at least one version alias, and SHOULD frequently
-change the value that they announce. Each version alias contains a lifetime,
-which indicates how long the server will accept this version alias. It also
-contains an initial salt, which is used instead of the initial salt as defined
-in section 5.2 of {{QUIC-TLS}}. The list of version aliases is sent in the
-server's Transport Parameters (see {{transport-parameter-definitions}}).
+version. A server MUST NOT advertise an alias version number for a version that
+it actually supports. If the server advertises an alias version number that the
+client actually supports, the client MUST assume the server doesn't support
+that version and ignore the alias.

I don't know that the client has to ignore the alias, per se -- it just needs to be cognizant of what the interpretation of that version will be on that server.  On the other hand, if there's a possibility that the server might acquire support for that version between flights (server upgrade case), perhaps it's better that the client just avoids it entirely after all.

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/quicwg/base-drafts/pull/2573#pullrequestreview-228806243