Re: [MLS] Proposal: Proposals (was: Laziness)

Stephen Farrell <stephen.farrell@cs.tcd.ie> Fri, 23 August 2019 11:26 UTC

Return-Path: <stephen.farrell@cs.tcd.ie>
X-Original-To: mls@ietfa.amsl.com
Delivered-To: mls@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 39669120811 for <mls@ietfa.amsl.com>; Fri, 23 Aug 2019 04:26:42 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -4.299
X-Spam-Level:
X-Spam-Status: No, score=-4.299 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=cs.tcd.ie
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 0xSpseUtV3rQ for <mls@ietfa.amsl.com>; Fri, 23 Aug 2019 04:26:40 -0700 (PDT)
Received: from mercury.scss.tcd.ie (mercury.scss.tcd.ie [134.226.56.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id BE6D41200B2 for <mls@ietf.org>; Fri, 23 Aug 2019 04:26:39 -0700 (PDT)
Received: from localhost (localhost [127.0.0.1]) by mercury.scss.tcd.ie (Postfix) with ESMTP id ED90ABE24; Fri, 23 Aug 2019 12:26:34 +0100 (IST)
Received: from mercury.scss.tcd.ie ([127.0.0.1]) by localhost (mercury.scss.tcd.ie [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 8lGhLbHGm7Mg; Fri, 23 Aug 2019 12:26:34 +0100 (IST)
Received: from [134.226.36.93] (unknown [134.226.36.93]) by mercury.scss.tcd.ie (Postfix) with ESMTPSA id 8AD69BE20; Fri, 23 Aug 2019 12:26:34 +0100 (IST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cs.tcd.ie; s=mail; t=1566559594; bh=+j7c130MeehhDT29HH55Y9g2gKbiKSJuZ6Ybt/nW6/E=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=b7urtukGFjtw8Y2SbugSo47zHxN1aMZ5xzC9nEsYwylXaBBDPmvE8R3gibzsJCxbl d0nvkgkyXr/Ue3rGTJuixfdGzQ7+dPs7v2jX33FfypnvELJY3ulYZ2r+/fWvqUPT+j K017VW9Z1jHrS/jIsrB8ili7F3s0tzafGCxCOawA=
To: Raphael Robert <raphael@wire.com>
Cc: Richard Barnes <rlb@ipv.sx>, Messaging Layer Security WG <mls@ietf.org>
References: <CAL02cgSbgkYyMcm=w8+oF+R5GBKaaofV3_x_VF0rMc0jWhs+Kg@mail.gmail.com> <f9634330-93bb-df46-a37c-bdf19359c2e0@cs.tcd.ie> <AE4D69D4-F7BA-490C-887E-A557BAC656FC@wire.com>
From: Stephen Farrell <stephen.farrell@cs.tcd.ie>
Openpgp: id=5BB5A6EA5765D2C5863CAE275AB2FAF17B172BEA; url=
Autocrypt: addr=stephen.farrell@cs.tcd.ie; prefer-encrypt=mutual; keydata= mQINBFo9UDIBEADUH4ZPcUnX5WWRWO4kEkHea5Y5eEvZjSwe/YA+G0nrTuOU9nemCP5PMvmh 5Cg8gBTyWyN4Z2+O25p9Tja5zUb+vPMWYvOtokRrp46yhFZOmiS5b6kTq0IqYzsEv5HI58S+ QtaFq978CRa4xH9Gi9u4yzUmT03QNIGDXE37honcAM4MOEtEgvw4fVhVWJuyy3w//0F2tzKr EMjmL5VGuD/Q9+G/7abuXiYNNd9ZFjv4625AUWwy+pAh4EKzS1FE7BOZp9daMu9MUQmDqtZU bUv0Q+DnQAB/4tNncejJPz0p2z3MWCp5iSwHiQvytYgatMp34a50l6CWqa13n6vY8VcPlIqO Vz+7L+WiVfxLbeVqBwV+4uL9to9zLF9IyUvl94lCxpscR2kgRgpM6A5LylRDkR6E0oudFnJg b097ZaNyuY1ETghVB5Uir1GCYChs8NUNumTHXiOkuzk+Gs4DAHx/a78YxBolKHi+esLH8r2k 4LyM2lp5FmBKjG7cGcpBGmWavACYEa7rwAadg4uBx9SHMV5i33vDXQUZcmW0vslQ2Is02NMK 7uB7E7HlVE1IM1zNkVTYYGkKreU8DVQu8qNOtPVE/CdaCJ/pbXoYeHz2B1Nvbl9tlyWxn5Xi HzFPJleXc0ksb9SkJokAfwTSZzTxeQPER8la5lsEEPbU/cDTcwARAQABtDJTdGVwaGVuIEZh cnJlbGwgKDIwMTcpIDxzdGVwaGVuLmZhcnJlbGxAY3MudGNkLmllPokCQAQTAQgAKgIbAwUJ CZQmAAULCQgHAgYVCAkKCwIEFgIDAQIeAQIXgAUCWj6jdwIZAQAKCRBasvrxexcr6o7QD/9m x9DPJetmW794RXmNTrbTJ44zc/tJbcLdRBh0KBn9OW/EaAqjDmgNJeCMyJTKr1ywaps8HGUN hLEVkc14NUpgi4/Zkrbi3DmTp25OHj6wXBS5qVMyVynTMEIjOfeFFyxG+48od+Xn7qg6LT7G rHeNf+z/r0v9+8eZ1Ip63kshQDGhhpmRMKu4Ws9ZvTW2ACXkkTFaSGYJj3yIP4R6IgwBYGMz DXFX6nS4LA1s3pcPNxOgrvCyb60AiJZTLcOk/rRrpZtXB1XQc23ZZmrlTkl2HaThL6w3YKdi Ti1NbuMeOxZqtXcUshII45sANm4HuWNTiRh93Bn5bN6ddjgsaXEZBKUBuUaPBl7gQiQJcAlS 3MmGgVS4ZoX8+VaPGpXdQVFyBMRFlOKOC5XJESt7wY0RE2C8PFm+5eywSO/P1fkl9whkMgml 3OEuIQiP2ehRt/HVLMHkoM9CPQ7t6UwdrXrvX+vBZykav8x9U9M6KTgfsXytxUl6Vx5lPMLi 2/Jrsz6Mzh/IVZa3xjhq1OLFSI/tT2ji4FkJDQbO+yYUDhcuqfakDmtWLMxecZsY6O58A/95 8Qni6Xeq+Nh7zJ7wNcQOMoDGj+24di2TX1cKLzdDMWFaWzlNP5dB5VMwS9Wqj1Z6TzKjGjru q8soqohwb2CK9B3wzFg0Bs1iBI+2RuFnxLkCDQRaPVAyARAA+g3R0HzGr/Dl34Y07XqGqzq5 SU0nXIu9u8Ynsxj7gR5qb3HgUWYEWrHW2jHOByXnvkffucf5yzwrsvw8Q8iI8CFHiTYHPpey 4yPVn6R0w/FOMcY70eTIu/k6EEFDlDbs09DtKcrsT9bmN0XoRxITlXwWTufYqUnmS+YkAuk+ TLCtUin7OdaS2uU6Ata3PLQSeM2ZsUQMmYmHPwB9rmf+q2I005AJ9Q1SPQ2KNg/8xOGxo13S VuaSqYRQdpV93RuCOzg4vuXtR+gP0KQrus/P2ZCEPvU9cXF/2MIhXgOz207lv3iE2zGyNXld /n8spvWk+0bH5Zqd9Wcba/rGcBhmX9NKKDARZqjkv/zVEP1X97w1HsNYeUFNcg2lk9zQKb4v l1jx/Uz8ukzH2QNhU4R39dbF/4AwWuSVkGW6bTxHJqGs6YimbfdQqxTzmqFwz3JP0OtXX5q/ 6D4pHwcmJwEiDNzsBLl6skPSQ0Xyq3pua/qAP8MVm+YxCxJQITqZ8qjDLzoe7s9X6FLLC/DA L9kxl5saVSfDbuI3usH/emdtn0NA9/M7nfgih92zD92sl1yQXHT6BDa8xW1j+RU4P+E0wyd7 zgB2UeYgrp2IIcfG+xX2uFG5MJQ/nYfBoiALb0+dQHNHDtFnNGY3Oe8z1M9c5aDG3/s29QbJ +w7hEKKo9YMAEQEAAYkCJQQYAQgADwUCWj1QMgIbDAUJCZQmAAAKCRBasvrxexcr6qwvD/9b Rek3kfN8Q+jGrKl8qwY8HC5s4mhdDJZI/JP2FImf5J2+d5/e8UJ4fcsT79E0/FqX3Z9wZr6h sofPqLh1/YzDsYkZDHTYSGrlWGP/I5kXwUmFnBZHzM3WGrL3S7ZmCYMdudhykxXXjq7M6Do1 oxM8JofrXGtwBTLv5wfvvygJouVCVe87Ge7mCeY5vey1eUi4zSSF1zPpR6gg64w2g4TXM5qt SwkZVOv1g475LsGlYWRuJV8TA67yp1zJI7HkNqCo8KyHX0DPOh9c+Sd9ZX4aqKfqH9HIpnCL AYEgj7vofeix7gM3kQQmwynqq32bQGQBrKJEYp2vfeO30VsVx4dzuuiC5lyjUccVmw5D72J0 FlGrfEm0kw6D1qwyBg0SAMqamKN6XDdjhNAtXIaoA2UMZK/vZGGUKbqTgDdk0fnzOyb2zvXK CiPFKqIPAqKaDHg0JHdGI3KpQdRNLLzgx083EqEc6IAwWA6jSz+6lZDV6XDgF0lYqAYIkg3+ 6OUXUv6plMlwSHquiOc/MQXHfgUP5//Ra5JuiuyCj954FD+MBKIj8eWROfnzyEnBplVHGSDI ZLzL3pvV14dcsoajdeIH45i8DxnVm64BvEFHtLNlnliMrLOrk4shfmWyUqNlzilXN2BTFVFH 4MrnagFdcFnWYp1JPh96ZKjiqBwMv/H0kw==
Message-ID: <9d3f0d93-4f69-bb71-9951-f3007820b14d@cs.tcd.ie>
Date: Fri, 23 Aug 2019 12:26:30 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0
MIME-Version: 1.0
In-Reply-To: <AE4D69D4-F7BA-490C-887E-A557BAC656FC@wire.com>
Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="33W6FSYqMFGHcawR8z2j6R3YFnGUJvCvq"
Archived-At: <https://mailarchive.ietf.org/arch/msg/mls/lAxIqkyhs_cATzNqz-9nGbn42y0>
Subject: Re: [MLS] Proposal: Proposals (was: Laziness)
X-BeenThere: mls@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Messaging Layer Security <mls.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/mls>, <mailto:mls-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/mls/>
List-Post: <mailto:mls@ietf.org>
List-Help: <mailto:mls-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/mls>, <mailto:mls-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 23 Aug 2019 11:26:42 -0000

Hiya,

On 23/08/2019 11:24, Raphael Robert wrote:
> Right now, Add and Remove handshake messages have to be signed by an
> existing member of the group. There is no way for the server to make
> any changes to the group membership.

Thanks. As you note in your other mail, that seems a
bit concerning, from a potentially ghostly point of
view. My initial reaction (again with the "benefit"
of not having kept up to date with the drafts:-) is
that a service using MLS could put itself in a position
to do the same thing within the application layer if
necessary, so it'd seem better for it not to be a
feature of the MLS protocol.

I've no opinion on the general idea of proposals, my
concern is only really about a non-member of the group
(the server or anyone else) being able to control
group membership like that, for what I guess would
effectively be all applications using MLS.

Cheers,
S.

> 
>> On 23 Aug 2019, at 11:08, Stephen Farrell
>> <stephen.farrell@cs.tcd.ie>; wrote:
>> 
>> Signed PGP part
>> 
>> Sorry for not following mls in detail but can you explain how:
>> 
>> On 22/08/2019 23:16, Richard Barnes wrote:
>>> 2. Allow some flavor of server-initiated Add and Remove
>> 
>> ...compares to the status quo ante?
>> 
>> Thanks, S. <0x5AB2FAF17B172BEA.asc>
>> 
>> 
> 
>