Re: Digests: deprecating parameters?

Lucas Pardue <lucaspardue.24.7@gmail.com> Tue, 18 August 2020 13:19 UTC

Return-Path: <ietf-http-wg-request+bounce-httpbisa-archive-bis2juki=lists.ie@listhub.w3.org>
X-Original-To: ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com
Delivered-To: ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id A0E643A09D3 for <ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com>; Tue, 18 Aug 2020 06:19:42 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.996
X-Spam-Level:
X-Spam-Status: No, score=-2.996 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HEADER_FROM_DIFFERENT_DOMAINS=0.001, HTML_MESSAGE=0.001, MAILING_LIST_MULTI=-1, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.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 p2G14VS9EwnJ for <ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com>; Tue, 18 Aug 2020 06:19:40 -0700 (PDT)
Received: from lyra.w3.org (lyra.w3.org [128.30.52.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 5FF213A09D4 for <httpbisa-archive-bis2Juki@lists.ietf.org>; Tue, 18 Aug 2020 06:19:40 -0700 (PDT)
Received: from lists by lyra.w3.org with local (Exim 4.92) (envelope-from <ietf-http-wg-request@listhub.w3.org>) id 1k81Ti-0000Fx-Qa for ietf-http-wg-dist@listhub.w3.org; Tue, 18 Aug 2020 13:16:39 +0000
Resent-Date: Tue, 18 Aug 2020 13:16:38 +0000
Resent-Message-Id: <E1k81Ti-0000Fx-Qa@lyra.w3.org>
Received: from mimas.w3.org ([128.30.52.79]) by lyra.w3.org with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from <lucaspardue.24.7@gmail.com>) id 1k81Th-0000F6-OI for ietf-http-wg@listhub.w3.org; Tue, 18 Aug 2020 13:16:37 +0000
Received: from mail-ej1-x643.google.com ([2a00:1450:4864:20::643]) by mimas.w3.org with esmtps (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from <lucaspardue.24.7@gmail.com>) id 1k81Tg-0000yu-1h for ietf-http-wg@w3.org; Tue, 18 Aug 2020 13:16:37 +0000
Received: by mail-ej1-x643.google.com with SMTP id bo3so21983193ejb.11 for <ietf-http-wg@w3.org>; Tue, 18 Aug 2020 06:16:35 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Zmhc9Qb+LOsrDY7NQOWUJMvti+KO5YdgYZ35bvpXbmE=; b=WKiK+lnYvucIXq2vbm5keJ1x+l9QABjWxPxH9Sm5q4bAPAyK+yb3mwoqZDY3EHPDLj FvNduRqCxF+lG2OSY6ecI5uOuJG0OZyi15j1m1Xj7mXx/5D+rKc/PHtTqH/E951R+HBH sUr+YgopnMY3fRnrA3yyLbZtvN0BN/Hwwi+u2yz8cw0eZiNjakBnG+N16RQGlZ4TcebJ mrxY83twjfdVGP1k8iOvt4S7AzhItmIWwf8Lnc/3j6PxPF5ceva+FiUZtHT7sXBZBp7B 4OKUnECysGOre+DtBPHi4y/Swkxj29GUE/T/bt15CmuoKb3BfCO1x5Nxn9hGn78tHSQo J0mA==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Zmhc9Qb+LOsrDY7NQOWUJMvti+KO5YdgYZ35bvpXbmE=; b=eXyxmz7zE1jBthdD/MIqY4aS1wxJITqIFaCvi+IhBpayOLOJNskkhG+IwKQKhk8Ryl 4piRQe7fvZdQGdWpIFNltKp9PO1aHJGF1eisoVbRp4+tdURAi3MoDLVvDR1XAIQOr2jR CiUOHXOQaLN0KKPpXUC5Jn/UJE2oYqN6La3QA7mP7zO2SeEpr7WiWZrRdevjINnpxavx paS0zuEEtK9rGnP2NGwBjiAaZ9cRQypahLIoWLMNZvzOLl7zcYjz40ilgkr/vcF1Aonb JR9zGOPkKUXllvHGO4VEYR25zQlm3S+wN++kXS2nNoSD1mFZ9Tiq5dAW3cYuQ6VWOK4J 7ZQA==
X-Gm-Message-State: AOAM5323+WyMix6cz2lVXkpY7+5wE60zE4+JIuswLfMd4Vydp3woOYQh DjZaRak8QlckCG+hzXq2dWEIHV41kCXIOgGxbe4iTe7UgKs=
X-Google-Smtp-Source: ABdhPJw4sOFNPubXEqdAP4grlYCKayrVDZarANdpxGX/4msqCOvAixiKl1kCrcLjXIPKTF2g0O18Pt89hAx1CBjQ6QM=
X-Received: by 2002:a17:906:15c2:: with SMTP id l2mr19876324ejd.112.1597756584759; Tue, 18 Aug 2020 06:16:24 -0700 (PDT)
MIME-Version: 1.0
References: <CALGR9oYCU2b3wiTFV8uNO37opK0XMgq_=D0sTyZVw8kVuKG+4g@mail.gmail.com> <c71669f6-bb90-1952-7ca4-2db42a64fe55@treenet.co.nz>
In-Reply-To: <c71669f6-bb90-1952-7ca4-2db42a64fe55@treenet.co.nz>
From: Lucas Pardue <lucaspardue.24.7@gmail.com>
Date: Tue, 18 Aug 2020 14:16:12 +0100
Message-ID: <CALGR9oZizHnvk2MmM4VacSw-YOnXM8OnC0=Mwm8UuaN9pO6=1A@mail.gmail.com>
To: Amos Jeffries <squid3@treenet.co.nz>
Cc: HTTP Working Group <ietf-http-wg@w3.org>, Roberto Polli <robipolli@gmail.com>
Content-Type: multipart/alternative; boundary="000000000000ac174e05ad26b167"
Received-SPF: pass client-ip=2a00:1450:4864:20::643; envelope-from=lucaspardue.24.7@gmail.com; helo=mail-ej1-x643.google.com
X-W3C-Hub-Spam-Status: No, score=-7.8
X-W3C-Hub-Spam-Report: BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, W3C_AA=-1, W3C_IRA=-1, W3C_IRR=-3, W3C_WL=-1
X-W3C-Scan-Sig: mimas.w3.org 1k81Tg-0000yu-1h b04a52be19b1cb1e7819d85fd00a9754
X-Original-To: ietf-http-wg@w3.org
Subject: Re: Digests: deprecating parameters?
Archived-At: <https://www.w3.org/mid/CALGR9oZizHnvk2MmM4VacSw-YOnXM8OnC0=Mwm8UuaN9pO6=1A@mail.gmail.com>
Resent-From: ietf-http-wg@w3.org
X-Mailing-List: <ietf-http-wg@w3.org> archive/latest/37932
X-Loop: ietf-http-wg@w3.org
Resent-Sender: ietf-http-wg-request@w3.org
Precedence: list
List-Id: <ietf-http-wg.w3.org>
List-Help: <https://www.w3.org/Mail/>
List-Post: <mailto:ietf-http-wg@w3.org>
List-Unsubscribe: <mailto:ietf-http-wg-request@w3.org?subject=unsubscribe>

Hey Amos,

On Tue, Aug 18, 2020 at 1:42 PM Amos Jeffries <squid3@treenet.co.nz> wrote:

> On 18/08/20 9:49 pm, Lucas Pardue wrote:
> > Hello folks,
> >
> > We're wondering what the group might think about deprecating the Digest
> > parameters. Please respond for or against the idea, either here or on
> > the GitHub issue https://github.com/httpwg/http-extensions/issues/850
> >
> > _Background_
> > While updating the Digests spec we've found somewhat of a gap when it
> > comes to "parameters". These are mentioned in RFC 3230:
> >
> > |For some algorithms, one or more parameters may be supplied.
> > digest-algorithm = token The BNF for "parameter" is as is used in RFC
> > 2616 [4]. All digest- algorithm values are case-insensitive.|
> >
> > It seems wrong to define parameters as part of the algorithm, so we
> > started on a PR to fix things up.
>
> I do not see any indication in RFC 3230 that the parameters have to be
> defined with the algorithm. There could be a specification which defines
> a parameter which is relevant to all algorithms but is optional. Eg a
> "q=" or "charset=" parameters.
>
> Such a parameter may be *sent* on some algorithms entries, but not on
> others depending on the sender implementation.
>
> So IMO, that particular line of argument against parameters is not a
> valid one.
>

This is probably where the gap leads to interpretation, and maybe I
misinterpreted things.

I think the terminology is the annoying thing here, since digest is a tuple
of algorithm and computed value. The BNF in 3230 doesn't make it super
clear where a parameter would be expressed. For instance, is it reasonable
to assume that the intended digest parameter delimiter was ';'? I do agree
with your "global parameter" concept, which could apply to all digests
independent of the algorithm used.

I think this would be a good time to refer to the structured headers
> document as a syntax basis
> <https://tools.ietf.org/html/draft-ietf-httpbis-header-structure>.
>
> That documents the possible existence of parameters even when they are
> not specifically defined by the header document (eg RFC 3230). Which
> allows dropping the mention of them from RFC 3230 successor document
> without formally deprecating or requiring any implementation changes.
>

That sounds reasonable, especially given the previous point. Does that work
for others?

Cheers,
Lucas