Re: [Stox] Stephen Farrell's IESG feedback on draft-ietf-stox-core

Peter Saint-Andre <stpeter@stpeter.im> Mon, 10 February 2014 22:52 UTC

Return-Path: <stpeter@stpeter.im>
X-Original-To: stox@ietfa.amsl.com
Delivered-To: stox@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 8A01F1A08A8; Mon, 10 Feb 2014 14:52:34 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.45
X-Spam-Level:
X-Spam-Status: No, score=-2.45 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RP_MATCHES_RCVD=-0.548, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001] autolearn=ham
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 JnXoVvwH4QVE; Mon, 10 Feb 2014 14:52:29 -0800 (PST)
Received: from stpeter.im (mailhost.stpeter.im [207.210.219.225]) by ietfa.amsl.com (Postfix) with ESMTP id 6BF601A08AA; Mon, 10 Feb 2014 14:52:12 -0800 (PST)
Received: from aither.local (unknown [24.8.129.242]) (Authenticated sender: stpeter) by stpeter.im (Postfix) with ESMTPSA id F2536403BB; Mon, 10 Feb 2014 15:52:11 -0700 (MST)
Message-ID: <52F9581B.9060008@stpeter.im>
Date: Mon, 10 Feb 2014 15:52:11 -0700
From: Peter Saint-Andre <stpeter@stpeter.im>
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:24.0) Gecko/20100101 Thunderbird/24.3.0
MIME-Version: 1.0
To: Stephen Farrell <stephen.farrell@cs.tcd.ie>, The IESG <iesg@ietf.org>
References: <52F91953.8010604@stpeter.im> <52F950B2.2050107@cs.tcd.ie>
In-Reply-To: <52F950B2.2050107@cs.tcd.ie>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Cc: stox@ietf.org
Subject: Re: [Stox] Stephen Farrell's IESG feedback on draft-ietf-stox-core
X-BeenThere: stox@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: SIP-TO-XMPP Working Group discussion list <stox.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/stox>, <mailto:stox-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/stox/>
List-Post: <mailto:stox@ietf.org>
List-Help: <mailto:stox-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/stox>, <mailto:stox-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 10 Feb 2014 22:52:34 -0000

On 2/10/14, 3:20 PM, Stephen Farrell wrote:
>
> Hi Peter,
>
> On 02/10/2014 06:24 PM, Peter Saint-Andre wrote:
>> ( + STOX WG since one of the issues might deserve broader discussion )
>>
>> Hi Stephen, thanks for your review:
>>
>> https://datatracker.ietf.org/doc/draft-ietf-stox-core/ballot/
>>
>> You wrote in part:
>>
>>     - I wondered why you didn't just say that (D)TLS SHOULD
>>     be used/supported between gateways. Given that all the
>>     relevant bits of code are likely to support that, wouldn't
>>     it be a good thing?
>>
>> Yes, that seems eminently reasonable.
>
> Just to be clear - the above is the only DISCUSS point.

Yep.

>>     - Has anyone thought about confusability in the name
>>     mappings? I expected to see a bit of text in the
>>     security considerations but didn't see it.
>>
>> Confusion is always possible. :-) Were you thinking about confusable
>> characters from Unicode, or something else?
>
> Right. Maybe its all there already and I just didn't see
> if in the mapping stuff, or maybe not. I'm not sure.

Section 10.5 of draft-ietf-precis-framework has some very nice text 
about visually similar characters. We could borrow from that.

>>     - It seems a shame to not be able to gateway when the To is
>>     a sips URI at all but I understand that some loss of
>>     security is inevitable for cases like this. Is there any
>>     work planned for an update that would allow gatewaying for
>>     such cases, e.g. if the 1st XMPP server is the one to which
>>     the user is connected and the user is connected using
>>     XMPP/TLS?
>>
>> Hmm. I cannot say that I am aware of planning for updates to provide
>> more secure gatewaying, although folks active in the STOX WG might be
>> thinking along those lines.
>>
>> Depending on the deployment architecture, I think there are cases where
>> it is *possible* to TLS-protect all the hops. For instance, if
>> sip.example.org has a direct server-to-server connection to
>> xmpp.example.com (no intermediate hops) and both organizations agree to
>> force the use of TLS for client connections (e.g., via SLA), then I
>> suppose that sip.example.com could honor 'sips' URIs when sending
>> traffic to xmpp.example.com. However, such an arrangement is rare enough
>> right now that I don't know if it is worth mentioning.
>
> Fair enough. I can see that detecting that you (probably) have
> all (D)TLS hops might be tricky and error prone.

That's how I see it.

Oh, and we at least need to mention DTLS for the UDP cases, though (see 
Section 5 of draft-ietf-stox-core).

Peter

-- 
Peter Saint-Andre
https://stpeter.im/