Re: [openpgp] [dane] The DANE draft

Paul Wouters <paul@nohats.ca> Thu, 06 August 2015 08:24 UTC

Return-Path: <paul@nohats.ca>
X-Original-To: openpgp@ietfa.amsl.com
Delivered-To: openpgp@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 4C91C1B29C4; Thu, 6 Aug 2015 01:24:01 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -0.81
X-Spam-Level:
X-Spam-Status: No, score=-0.81 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, J_CHICKENPOX_44=0.6, J_CHICKENPOX_46=0.6, T_RP_MATCHES_RCVD=-0.01] autolearn=no
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 DgJiP6RYSnMN; Thu, 6 Aug 2015 01:23:59 -0700 (PDT)
Received: from mx.nohats.ca (mx.nohats.ca [IPv6:2a03:6000:1004:1::68]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 806791B29C2; Thu, 6 Aug 2015 01:23:59 -0700 (PDT)
Received: from localhost (localhost [IPv6:::1]) by mx.nohats.ca (Postfix) with ESMTP id 3mn2sS3hmMz3Nf; Thu, 6 Aug 2015 10:23:56 +0200 (CEST)
Authentication-Results: mx.nohats.ca; dkim=pass (1024-bit key) header.d=nohats.ca header.i=@nohats.ca header.b=sRWcBBIT
X-OPENPGPKEY: Message passed unmodified
X-Virus-Scanned: amavisd-new at mx.nohats.ca
Received: from mx.nohats.ca ([IPv6:::1]) by localhost (mx.nohats.ca [IPv6:::1]) (amavisd-new, port 10024) with ESMTP id Sr8nV4o6jK5Z; Thu, 6 Aug 2015 10:23:55 +0200 (CEST)
Received: from bofh.nohats.ca (206-248-139-105.dsl.teksavvy.com [206.248.139.105]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx.nohats.ca (Postfix) with ESMTPS; Thu, 6 Aug 2015 10:23:55 +0200 (CEST)
Received: from bofh.nohats.ca (bofh.nohats.ca [127.0.0.1]) by bofh.nohats.ca (Postfix) with ESMTP id C0290800B3; Thu, 6 Aug 2015 04:23:54 -0400 (EDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nohats.ca; s=default; t=1438849434; bh=5cSel0yMtjakFg6uAzVu2zcUnUhD52zez2/QjOql84Q=; h=Date:From:To:cc:Subject:In-Reply-To:References; b=sRWcBBITR93cm0hBxJy8MWIRD5unHh7g1C7ghCw1rWOvrvdefhKc5pQsbHOH/Kibs ac9DgKKznXdUeC8rFONlJHMZImY0S34VQfivqn2FL1Zhdcy6tbbh5tEinwGbsGHXCZ rC6+FNN05T50mZIGKBb0HjwVliImmqek7BaJKt/k=
Received: from localhost (paul@localhost) by bofh.nohats.ca (8.15.1/8.15.1/Submit) with ESMTP id t768NsEC019554; Thu, 6 Aug 2015 04:23:54 -0400
X-Authentication-Warning: bofh.nohats.ca: paul owned process doing -bs
Date: Thu, 06 Aug 2015 04:23:54 -0400
From: Paul Wouters <paul@nohats.ca>
To: dane WG list <dane@ietf.org>
In-Reply-To: <55C22D64.9080507@strotmann.de>
Message-ID: <alpine.LFD.2.11.1508060417450.16408@bofh.nohats.ca>
References: <CAMm+LwhYdBLXM8Td8q8SCnzgwywRgMx3wNKeS_Q0JSN4Lh7rZQ@mail.gmail.com> <87bnf1hair.fsf@alice.fifthhorseman.net> <alpine.LFD.2.11.1507250832510.854@bofh.nohats.ca> <87bnem2xjq.fsf@alice.fifthhorseman.net> <alpine.LFD.2.11.1508050331340.1451@bofh.nohats.ca> <55C1F35A.5070904@cs.tcd.ie> <B7419740-25C9-4F8D-85AE-FC6E11BCC038@vpnc.org> <55C22D64.9080507@strotmann.de>
User-Agent: Alpine 2.11 (LFD 23 2013-08-11)
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset="US-ASCII"; format="flowed"
Archived-At: <http://mailarchive.ietf.org/arch/msg/openpgp/1lZscvJZcokAoAC7BbCIfZ-QdsY>
Cc: IETF OpenPGP <openpgp@ietf.org>
Subject: Re: [openpgp] [dane] The DANE draft
X-BeenThere: openpgp@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: "Ongoing discussion of OpenPGP issues." <openpgp.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/openpgp>, <mailto:openpgp-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/openpgp/>
List-Post: <mailto:openpgp@ietf.org>
List-Help: <mailto:openpgp-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/openpgp>, <mailto:openpgp-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 06 Aug 2015 08:24:01 -0000

On Wed, 5 Aug 2015, Carsten Strotmann wrote:

> for OPENPGPKEY/SMIMECERT zones, operators could (maybe SHOULD) use
> NSEC/NSEC3 "narrow" signing to prevent "zone-walking".

email addresses are not secret. That is not the privacy you can protect
at all. Anyone can either do a internet search or just attempt to
deliver an email to figure out if the email address is valid.

The only realy privacy concern is learning who is querying, meaning who
is interested in mailing a particular user - assuming everything else on
the email path is secureb by TLS, and the domain is large enough to
actually hide the userbase (that is, nohats.ca is already a lost cause,
because everyone knows a TLS connection to mx.nohats.ca means you are
going to email me)

> Breaking hashes requires much more "willful intent" than decoding BASE32.

But that difference these days is basically zero as soon as someone puts
up a module for johntheripper or hashcat or something on github.

> The hashing communicates a "don't go here" message, even though it is
> technically not a strong protection.

If the sysadmin does not respect privacy on base32, they will not
respect privacy on hash(very simple names) or even hash(former-lover)

> It is like having a closed door vs. no door at all. No door communicates
> "come in, no secrets, we're open" while the closed door (even if it can
> be opened by minor force) communicates "private space".

I might agree but I think the gain for this is so incredibly small, that
I think the gain for use of online signers plus email address
corrections by the smtp+dnssec combined server is actually a more likely
and minorly useful thing to have.

And don't get me wrong. I'd rather see zonefiles with a hash than with
base32 cut from an esthetical point of view.

Paul