Re: [Doh] Servers offering responses for domaines they are not responsible for

Eliot Lear <lear@cisco.com> Thu, 09 November 2017 10:46 UTC

Return-Path: <lear@cisco.com>
X-Original-To: doh@ietfa.amsl.com
Delivered-To: doh@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 1D01312F29A for <doh@ietfa.amsl.com>; Thu, 9 Nov 2017 02:46:53 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -14.501
X-Spam-Level:
X-Spam-Status: No, score=-14.501 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_HI=-5, SPF_PASS=-0.001, USER_IN_DEF_DKIM_WL=-7.5] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=cisco.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 RNyLxvM6lisp for <doh@ietfa.amsl.com>; Thu, 9 Nov 2017 02:46:51 -0800 (PST)
Received: from bgl-iport-4.cisco.com (bgl-iport-4.cisco.com [72.163.197.28]) (using TLSv1.2 with cipher DHE-RSA-SEED-SHA (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 1AE3312EC8E for <doh@ietf.org>; Thu, 9 Nov 2017 02:46:50 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=@cisco.com; l=3339; q=dns/txt; s=iport; t=1510224411; x=1511434011; h=subject:to:references:from:message-id:date:mime-version: in-reply-to; bh=62go2c3/zUmhSXR4nseesRnckjrPqoj3sm3qETOrZaI=; b=W5iu/VxftOvJbivsCAqIYOjbodzzjtaRRMpv5g9KIXWSwJgNnAbHUg1d +dnl9vnn1DPRxBzA29O+21+7Z1/0yUQKdbGABVT21zmOqTw5tv44WXWEQ 5Ug6mrUYHgL6O3VSLwol06AGm//n7p/oMWFIKoH97SCJFwICubxvnd8N+ U=;
X-Files: signature.asc : 481
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: A0COAAAOMQRa/xjFo0hcGQEBAQEBAQEBAQEBAQcBAQEBAYUGhCSKH3SQL5ZNghEHA4U7AoUmGAEBAQEBAQEBAWsohR4BAQEBAgEjZgsOCioCAlcGAQoCCAEBihcIqVOCJ4sVAQEBAQEBAQMBAQEBAQEBAQEBAQ4PgzCBNYQ4gi5TiCuCYwWSc48nhEOCI44Yi3mHP5YhgTkfOIFxNCEIHRWDLoRmOYxAAQEB
X-IronPort-AV: E=Sophos;i="5.44,369,1505779200"; d="asc'?scan'208";a="55909176"
Received: from vla196-nat.cisco.com (HELO bgl-core-4.cisco.com) ([72.163.197.24]) by bgl-iport-4.cisco.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 09 Nov 2017 10:46:48 +0000
Received: from [10.232.4.170] ([10.232.4.170]) by bgl-core-4.cisco.com (8.14.5/8.14.5) with ESMTP id vA9AklXi029962; Thu, 9 Nov 2017 10:46:48 GMT
To: Andrew Sullivan <ajs@anvilwalrusden.com>, doh@ietf.org
References: <16B93F04-FE24-4C61-94F3-87EF7707F10E@vpnc.org> <E304CB00-95E6-4868-B3C4-FDF4049F6492@mnot.net> <202fca9c-d9e3-7a11-3cc7-2cc61b59a84f@cisco.com> <20171106120714.jxhnxoc4b4kv6wtt@mx4.yitter.info>
From: Eliot Lear <lear@cisco.com>
Message-ID: <5d2b439b-c070-48a0-c36c-834582e15daf@cisco.com>
Date: Thu, 09 Nov 2017 16:16:37 +0530
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:52.0) Gecko/20100101 Thunderbird/52.4.0
MIME-Version: 1.0
In-Reply-To: <20171106120714.jxhnxoc4b4kv6wtt@mx4.yitter.info>
Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="usDfahooFfVo5CuGk2QDGTrAK0WLkEeGF"
Archived-At: <https://mailarchive.ietf.org/arch/msg/doh/AubIh6fm7rdKRvbpoW0WQfNERlI>
Subject: Re: [Doh] Servers offering responses for domaines they are not responsible for
X-BeenThere: doh@ietf.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: DNS Over HTTPS <doh.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/doh>, <mailto:doh-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/doh/>
List-Post: <mailto:doh@ietf.org>
List-Help: <mailto:doh-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/doh>, <mailto:doh-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 09 Nov 2017 10:46:53 -0000

Hi Andrew,


On 11/6/17 5:37 PM, Andrew Sullivan wrote:
> On Mon, Nov 06, 2017 at 08:25:17AM +0100, Eliot Lear wrote:
>> It is a *a* remedy, and could certainly be mentioned.  However,
>> precisely because of the warnings in that document, it probably
>> shouldn't be listed on its own as the sole recommended approach.
> It's the only thing we have that solves this problem today, however.
> If you want geo- or even (and more accurately) network-topologically
> sensitive answers to work, you need to know where the query originator
> was.  For years we used the network address of the resolver as a proxy
> for the location of the query originator, but in a world where
> resolvers may be quite distant from the query originator that doesn't
> work, and it doesn't matter whether the query travels via UDP port 53
> or some other mechanism.
>
> And indeed, given the DOH use case (which as we're currently
> discussing it is really just last hop), I'm not sure what the problem
> is.  This is directly analagous to a stub contacting a full service
> resolver, and that's exactly the problem the large authoritative DNS
> tricks have and that edns-client-subnet addresses.

Having thought about this a bit, what got me was this:

1.  I get the impression through my own experience that it doesn't seem
to be used (I see odd localizations that could have been avoided were it
so); and
2.  Given that, DOH can exacerbate the problem if the service is not
deployed as a CDN itself.

So I think Mark's right to out the remediation.  I just am wary that
it's enough.

Eliot



>
> Best regards,
>
> A
>