Re: [DNSOP] Multi Provider DNSSEC Models

Shumon Huque <shuque@gmail.com> Wed, 21 March 2018 08:35 UTC

Return-Path: <shuque@gmail.com>
X-Original-To: dnsop@ietfa.amsl.com
Delivered-To: dnsop@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id A8AC2126D05 for <dnsop@ietfa.amsl.com>; Wed, 21 Mar 2018 01:35:57 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.698
X-Spam-Level:
X-Spam-Status: No, score=-2.698 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, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_LOW=-0.7, 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 AdAToWIlCgn4 for <dnsop@ietfa.amsl.com>; Wed, 21 Mar 2018 01:35:55 -0700 (PDT)
Received: from mail-io0-x22b.google.com (mail-io0-x22b.google.com [IPv6:2607:f8b0:4001:c06::22b]) (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 91809120724 for <dnsop@ietf.org>; Wed, 21 Mar 2018 01:35:55 -0700 (PDT)
Received: by mail-io0-x22b.google.com with SMTP id r18so5664707ioa.1 for <dnsop@ietf.org>; Wed, 21 Mar 2018 01:35:55 -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=SeTG+OsTW4YEQHjC1IPkVrvRr+Z45jAzwDtC14D6owE=; b=kINhSvJLwPBzD9KwlXcnShPNgXHQJTtKAAZtlhLBQBtRFS8tR/0F5P6CwCw2evFU16 WrHR4TKPUJziB9I44aEdJWO4qC6zUTG2dTQa/erfmiU131Pv0MJhnA97koDTkfhHPirw tvmUHV0577h0D7K0q9N31qjFmjLF/59wII/LQ6c/tGeo0nhl34QAO+XQj/PoOCG3wgxg X56NhxESLl9niKrq40nIv6yyWDtA+jBly4X+OC5ir1p/3xWHAdm+9RnxENrpmj7X+usC y+MxA1z0YvftJVRxh1J/YHtd/kRWTvtohQwFJ+y5rkpsm1WTXzW14tm4TfB7MfsoNsuJ sb2w==
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=SeTG+OsTW4YEQHjC1IPkVrvRr+Z45jAzwDtC14D6owE=; b=c1X9Z9DANNNbJ1m8oHxb8LKLjS8H0PrRyan/P3xQs2KMpAFiDHFJEKhJO0ShWbHT17 0zz/carZgd5k9jwzNAGZP6bC4Nt3gs8JEE3yKf54Hi8CwLZa7g0x3J58P6fuCNw8flN6 KEjUvKcaqkcuaMEjxb+QKIS7PLrv3SGqDS0GcdgX03CY6a/GYRl13M6jY1AoNFHZFmWq y0c1dQ8MJO6n8g/30WZQsUTf5OY2QiUUfW8twI6soZw6Zvmmw4buKYDd9FmzONizf6CP gQjueCRE2ByxdDdvIAteYxpFPexPP8uV2iOufSCmep+k7SVRHxxAss6pWXqyNg1jIitn UA2g==
X-Gm-Message-State: AElRT7GXAR65b+wgISPeQekYQwR2hijl+zbVnVmILIJdG5AGEKc/VwRG 1y5MY5GfmF8ZU12gkZrSDK5A7zJ/5l8ztTuPSpo=
X-Google-Smtp-Source: AG47ELs+8zx/bzR1cLGXeAGJIGTvgCdjItz0RL4HrCnJDUX3fnVmWSFf2LFJTYOIEKtd3bQpQSis8ePgZ3XF2mHTg+c=
X-Received: by 10.107.53.146 with SMTP id k18mr21155992ioo.292.1521621354796; Wed, 21 Mar 2018 01:35:54 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.79.203.9 with HTTP; Wed, 21 Mar 2018 01:35:54 -0700 (PDT)
In-Reply-To: <DFCE50F5-2385-4512-BF9F-1266C0DA4D6E@dotat.at>
References: <CAHPuVdVi5C3nyVuG2aiLefN7eFPOx+GnOCxU40iio_Gn0oQ8qA@mail.gmail.com> <DFCE50F5-2385-4512-BF9F-1266C0DA4D6E@dotat.at>
From: Shumon Huque <shuque@gmail.com>
Date: Wed, 21 Mar 2018 08:35:54 +0000
Message-ID: <CAHPuVdXy+oYgQEUoHoxN7W1BnuCoa+opHbQ9tbLZX2xDj2xoZg@mail.gmail.com>
To: Tony Finch <dot@dotat.at>
Cc: "dnsop@ietf.org WG" <dnsop@ietf.org>
Content-Type: multipart/alternative; boundary="001a114491d255dbb50567e81493"
Archived-At: <https://mailarchive.ietf.org/arch/msg/dnsop/ijwuWYb-pA9GeC03v4Q6v34H2Hk>
Subject: Re: [DNSOP] Multi Provider DNSSEC Models
X-BeenThere: dnsop@ietf.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: IETF DNSOP WG mailing list <dnsop.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/dnsop>, <mailto:dnsop-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/dnsop/>
List-Post: <mailto:dnsop@ietf.org>
List-Help: <mailto:dnsop-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/dnsop>, <mailto:dnsop-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 21 Mar 2018 08:35:58 -0000

On Wed, Mar 21, 2018 at 12:38 AM, Tony Finch <dot@dotat.at>; wrote:

>
> On 20 Mar 2018, at 11:50, Shumon Huque <shuque@gmail.com>; wrote:
>
> We've posted a new draft on Multi Provider DNSSEC models,
> which we're planning to discuss at Thursday's DNSOP session.
>
> https://tools.ietf.org/html/draft-huque-dnsop-multi-provider-dnssec-02
>
>
> I have read through it, and it looks pretty good, though I think you are
> burying the lede.
>
> The first time I looked through I missed the clever parts, and thought to
> myself that half of the models described in section 2 would make people
> very sad. But section 4 on resolver behaviour explains the cleverness that
> avoids making people sad (sharing public keys), so I looked through the
> model descriptions more carefully and saw that they do in fact mention the
> trick.
>

Thanks for the review.


> To fix this misunderstanding, the introductory paragraphs in section 2.2
> need to explain your cleverness a lot more explicitly. eg this sentence:
>
>
> *   A key requirement here is to manage the contents of the DNSKEY and DS
>    RRset in such a way that validating resolvers always have a viable
>    path to authenticate the DNSSEC signature chain no matter which
>    provider they query and obtain responses from.*
>
>
> Yeah, validation has to work, I know, now tell me the clever trick up
> front otherwise I might not realise there is one!
>

Ok, the missing part of the up-front description is that each provider has
to import the zone signing (public) keys of the other provider(s) into its
DNSKEY RRset. I can add this and elaborate some more.

By the way, I would not characterize this as a "trick", but rather a fairly
obvious key provisioning step that is needed to make the multi-provider
signing configuration work.

But I agree that this might not obvious to everyone if they haven't thought
through the details. Actually, I added the resolver behavior section, after
I needed to explain more clearly how this worked to a colleague.

Shumon.