Re: [Webpush] Last-minute Review of Webpush Encryption

Martin Thomson <martin.thomson@gmail.com> Tue, 04 July 2017 04:34 UTC

Return-Path: <martin.thomson@gmail.com>
X-Original-To: webpush@ietfa.amsl.com
Delivered-To: webpush@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 75516131652 for <webpush@ietfa.amsl.com>; Mon, 3 Jul 2017 21:34:54 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.7
X-Spam-Level:
X-Spam-Status: No, score=-2.7 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_LOW=-0.7, SPF_PASS=-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 VJNV_-J6ZoSx for <webpush@ietfa.amsl.com>; Mon, 3 Jul 2017 21:34:52 -0700 (PDT)
Received: from mail-lf0-x230.google.com (mail-lf0-x230.google.com [IPv6:2a00:1450:4010:c07::230]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 5711C13147B for <webpush@ietf.org>; Mon, 3 Jul 2017 21:34:52 -0700 (PDT)
Received: by mail-lf0-x230.google.com with SMTP id t72so2373852lff.1 for <webpush@ietf.org>; Mon, 03 Jul 2017 21:34:52 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=ru4bhixjW25yQFXTWpBi/mk4h8UBjpcF4zdslKGZ6jA=; b=UmB6K/FxfITwgki6F7fNpWtxAwRmQ+b0W/KwQLjW2m3VNmXubc/ag/ozlf+EkXDCkm iI+1cAD4w57jKMLNZmo3/tijbehlxTyh4KNoEUuHk5cZHMsWyAGCdoc5PaPxWVYKIC2G YJGEUngndYVlNVuVuxFgXS65wG4dT96/Z+lCmVzSnnqcKOphDmpR1F0c2deFzLyRJfkN wBBX1ahu+Tyd4OFFNcuPFM3bQ3rYVU8N/nAD/1ZpSTCBDGyRh13M1Z+1lU5zuOwQKjJ+ SeLv58G/WgcV2uohQ3ShgRbrJZs1XobE1fGE6JNnbrviPIKriQqqHTAtfxc3OCEB/DrM H7xw==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=ru4bhixjW25yQFXTWpBi/mk4h8UBjpcF4zdslKGZ6jA=; b=OmhIXx7AHOWDhhgyF+fMe6DPOWyy4FHZ6Yi2NraK3NEiXIt6hdFlMcorxUEkZJHYRH neVySK8bHZuNgigO++PbJ+uvopEdTuwTUVsTZmVFknpDTkYJBChV1qhEm3+OugojQeFx JjE8v0ISc+VIZ2aK/S7UrQh+q95VAi97nZE85OveeItjgvZNzhOqkzppWe+CRQgZPQ0l b3VMDqfe0AwAecxpByuFuqnH0MVs7x/4x9cPlJ6VbB5FkNi/0xMNGni5Q+0TupJVVLds uYYkBWlG5Vv52i5UQfhnHiF0rc+P+QNySUtPGUxvrxxTTDxEloZJjptBrO8mJt6aWlZf q7Gg==
X-Gm-Message-State: AIVw1107yBHeSMbvoJONRuw//BbhwSs9horfWzHdMDK/fciDJltsNyQp OrOgQQyH+5k2xBdwMMb/9aswVrqBwSNYA4Q=
X-Received: by 10.25.206.203 with SMTP id e194mr4374756lfg.43.1499142890638; Mon, 03 Jul 2017 21:34:50 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.46.69.84 with HTTP; Mon, 3 Jul 2017 21:34:50 -0700 (PDT)
In-Reply-To: <00c1c3f6-7492-aca6-ee24-54041e35ccc7@outer-planes.net>
References: <00c1c3f6-7492-aca6-ee24-54041e35ccc7@outer-planes.net>
From: Martin Thomson <martin.thomson@gmail.com>
Date: Tue, 04 Jul 2017 14:34:50 +1000
Message-ID: <CABkgnnWs9q_nHQ5UwyE93PT3EAy_V0FrdSXJehO65g6KJEQiBQ@mail.gmail.com>
To: "Matthew A. Miller" <linuxwolf+ietf@outer-planes.net>
Cc: "webpush@ietf.org" <webpush@ietf.org>
Content-Type: text/plain; charset="UTF-8"
Archived-At: <https://mailarchive.ietf.org/arch/msg/webpush/j91ciRYvu6H1KrIO_YMPyisc5Tg>
Subject: Re: [Webpush] Last-minute Review of Webpush Encryption
X-BeenThere: webpush@ietf.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: Discussion of potential IETF work on a web push protocol <webpush.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/webpush>, <mailto:webpush-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/webpush/>
List-Post: <mailto:webpush@ietf.org>
List-Help: <mailto:webpush-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/webpush>, <mailto:webpush-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 04 Jul 2017 04:34:54 -0000

On 4 July 2017 at 02:23, Matthew A. Miller
<linuxwolf+ietf@outer-planes.net> wrote:
> In Section 3.4 "Encryption Summary", I think it adds clarity to
> explicitly stating the "L" inputs for the two final HKDFs.  I've
> submitted PR #12 to that effect.

I see your point, and I agree that this could be clearer, but I didn't
really like the unused variables.  See
https://github.com/webpush-wg/webpush-encryption/pull/13, which you
already approved :)

> More concerning is that "keyid" is expected to be the "raw" ECDH public
> key, which is almost certainly not a UTF-8 encoded string; this bends
> the SHOULD in draft-ietf-httpbis-encryption-encoding.  It needs to be
> called out more explicitly than I see so far, but I don't have any
> specific text to start with.

I think that a note will help, yes.
https://github.com/webpush-wg/webpush-encryption/pull/14