Re: [dns-privacy] [Ext] Re: ADoT requirements for authentication?

Ben Schwartz <bemasc@google.com> Tue, 29 October 2019 16:54 UTC

Return-Path: <bemasc@google.com>
X-Original-To: dns-privacy@ietfa.amsl.com
Delivered-To: dns-privacy@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id C072E120058 for <dns-privacy@ietfa.amsl.com>; Tue, 29 Oct 2019 09:54:13 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -17.499
X-Spam-Level:
X-Spam-Status: No, score=-17.499 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIMWL_WL_MED=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, ENV_AND_HDR_SPF_MATCH=-0.5, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001, USER_IN_DEF_DKIM_WL=-7.5, USER_IN_DEF_SPF_WL=-7.5] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=google.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 KMObfq_a2rWp for <dns-privacy@ietfa.amsl.com>; Tue, 29 Oct 2019 09:54:11 -0700 (PDT)
Received: from mail-il1-x12d.google.com (mail-il1-x12d.google.com [IPv6:2607:f8b0:4864:20::12d]) (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 BAD80120018 for <dns-privacy@ietf.org>; Tue, 29 Oct 2019 09:54:11 -0700 (PDT)
Received: by mail-il1-x12d.google.com with SMTP id z10so11944103ilo.8 for <dns-privacy@ietf.org>; Tue, 29 Oct 2019 09:54:11 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=DB3QC7Y2EuM9oFmnwS7yP1+pNmklJkKhzG2OR5zxhR0=; b=X4vDtqt1JVwE8U7iLF26K5+Uw4Q5x4zpU/ZZX1oHaOGPM7cJIPzyiZ+c0LI0PENMjU s6uRGDvPqI8ro0QJ0Duxvd4p0lW/tVmLE4cY1bhUAbonnuAepVbTM3mf/aDEXAZmd/GT cJ1+xw+05RhEbYO5HQxOSURuneyQii3XC9kDnBM6F+WFlVTbsAknTxouYvW5hZeFB6HH OtgCtkOL/KLU5752mciQ0ZczmPJIqVg/BUdP9BQ52wQX8Q6/ntAzGafv7+luQbPu6YsG Nn0zvaLhS17dWVZAr5QUKOYVaIDkPyKD7sXoKgEOO4cJeqKfa3V/LDUEeQ+naexCWcMh TWwA==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=DB3QC7Y2EuM9oFmnwS7yP1+pNmklJkKhzG2OR5zxhR0=; b=hKtzeDgeYjJOXjdD37jFS1I28prY3Bi4XEHP2MOavNzvBMOa0+s+lZh//vpanRPzeP PxWX18nXGxX9dIR2FAeMwD5q9wbD/M0pTza3pYVxTkHTMauNpolilOQxgZXrgSpn3hlD Yf4Jsxg42rzDMtlqvXdVkTycSG84ffHB+l7NRzluH8LluHE32p6mxBu0gPEaZOVVF9QB jE98ovc4vGNLxITcuopKRNsyGlB93PpY63LZBwZ++I3kx63It+t4Fj8+B4c+Kt7ZQS21 ZmZO5QXJBhk+LK/h4UP6XpFsRZzsMrSc4XeNK6Du0ikmrDcyv9Xmcf+aI6/H81BgerHQ 181g==
X-Gm-Message-State: APjAAAXO/sxwEwSH2nUF/rSnep0haW+LZuzw5jmBnzTx/6Of4a/PFt5U z+T0Tj8lPpUl0UToAoqugCM1g8dPelaBzFIgUJy8Rw==
X-Google-Smtp-Source: APXvYqyPJf+EpXIcTbElHL7kdogEy4J56g0vR6MlPa2BobUuhYqMpzbFF8rJfzeE33OW7gmXs8UXk8cAlDffY50r95U=
X-Received: by 2002:a92:4a06:: with SMTP id m6mr23717399ilf.153.1572368050596; Tue, 29 Oct 2019 09:54:10 -0700 (PDT)
MIME-Version: 1.0
References: <943e3973-f6a7-9f6e-a66a-33aff835bd5e@innovationslab.net> <503df6fb-b653-476f-055f-15c1a668ba36@innovationslab.net> <5fe86408-35a8-16ea-d22a-9c6c4a681057@icann.org> <CA+9kkMBZUPfWov6B+pgLYuFmZh10dTzwF2PdKs5Vozzssqvzjw@mail.gmail.com> <edf53c16-3be9-786c-dcb1-0edc9fd9711c@icann.org> <CA+9kkMC5ynqK+8QO==5Pi_9edjTkJJ3yLHBHqJFOox8fi1_8HQ@mail.gmail.com>
In-Reply-To: <CA+9kkMC5ynqK+8QO==5Pi_9edjTkJJ3yLHBHqJFOox8fi1_8HQ@mail.gmail.com>
From: Ben Schwartz <bemasc@google.com>
Date: Tue, 29 Oct 2019 12:53:59 -0400
Message-ID: <CAHbrMsAAvadukzifKEj9eEWB91aDjmnu775F_YdtBaUHrHwDDQ@mail.gmail.com>
To: Ted Hardie <ted.ietf@gmail.com>
Cc: Paul Hoffman <paul.hoffman@icann.org>, "dns-privacy@ietf.org" <dns-privacy@ietf.org>
Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg="sha-256"; boundary="000000000000266f6705960f7704"
Archived-At: <https://mailarchive.ietf.org/arch/msg/dns-privacy/lEe1xB8qL8BFu5WbyOhPDwl9Fnw>
Subject: Re: [dns-privacy] [Ext] Re: ADoT requirements for authentication?
X-BeenThere: dns-privacy@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: <dns-privacy.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/dns-privacy>, <mailto:dns-privacy-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/dns-privacy/>
List-Post: <mailto:dns-privacy@ietf.org>
List-Help: <mailto:dns-privacy-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/dns-privacy>, <mailto:dns-privacy-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 29 Oct 2019 16:54:14 -0000

FWIW, my expectation has been that ADoT would use TLSA-like authentication,
with no trust anchors other than DNSSEC (and nothing resembling the WebPKI).

On Tue, Oct 29, 2019 at 12:01 PM Ted Hardie <ted.ietf@gmail.com> wrote:

> Hi Paul,
>
> On Tue, Oct 29, 2019 at 8:27 AM Paul Hoffman <paul.hoffman@icann.org>
> wrote:
>
>> On 10/29/19 8:02 AM, Ted Hardie wrote:
>> > To be sure I understand you correctly, in the second case, the
>> connection would be made to some IP address (e.g. NASA's 198.116.4.181).
>> The recursive resolver logs the details of the certificate, but it
>> continues with the connection even if the CA NASA uses for the certificate
>> is not known to the resolver?  What does it do in the face of other
>> certificate errors like expired certificates or certificates presenting a
>> different name?
>>
>> It continues. This is exactly how opportunistic encryption is defined.
>>
>>
> Just to be clear, it's my experience that accepting self-signed
> certificates from peers does not equate to accepting certificate errors.
> The situation in which you set up a connection to n.n.n.n and get a self
> signed certificate saying "example.com" and when you set up a connection
> to n.n.n.n expecting "example.com" and get a cert back for
> "accident.example" are pretty distinguishable. I would expect some
> configurations to accept the first without issue; I find accepting the
> second deeply odd.
>
>
>> > I have to say that I'm pretty surprised by the idea that TLS in this
>> context should behave any differently than TLS in application layer
>> contexts, and I'm a little concerned about having configuration options for
>> this that amount to "ignore errors of types $FOO".
>>
>> TLS in application layers can specify that opportunistic encryption, yes?
>>
>>
> I think you are using "opportunistic encryption" to mean something
> different from what I mean by it.  What I mean by it is "use it when you
> can, even if you don't know in advance you can".  Testing for DoT before
> using a DNS resolver on UDP 53 and using it if you find it is
> "opportunistic encryption", for example.
>
>
>> >  Accepting self-signed certificates is a known configuration, so I get
>> that, but if someone has configured roots of trust, accepting other
>> certificates outside the roots of trust in the configuration is pretty odd
>> practice.
>>
>> Do you feel that there is a requirement that all recursive resolvers use
>> the same set of trust anchors?
>
>
> No.
>
>
>> If not, and if you are against the use of opportunistic encryption in
>> this case,
>
>
> See above.  I don't think I'm against opportunistic encryption.  I think
> I'm against starting to exchange traffic over a TLS connection with an
> identifiable error.  There are degrees there, obviously.  Some folks would
> say an expired but correct certificate should be logged but accepted, but a
> flat out "wrong name presented" would likely get different treatment.
>
> who will decide what set of trust anchors all resolvers in all
>> jurisdictions will use?
>>
>>
> Everyone will decide who they accept?  That's how the WebPKI works, for
> all its shuffling glory, and with ACME/Let's Encrypt it has gotten very
> easy to get a certificate that will often be accepted.
>
> Just my two cents,
>
> Ted
>
> --Paul Hoffman
>> _______________________________________________
>> dns-privacy mailing list
>> dns-privacy@ietf.org
>> https://www.ietf.org/mailman/listinfo/dns-privacy
>>
> _______________________________________________
> dns-privacy mailing list
> dns-privacy@ietf.org
> https://www.ietf.org/mailman/listinfo/dns-privacy
>