Re: [dane] Feature creep for draft-ietf-dane-smime

Tom Ritter <> Fri, 07 February 2014 11:11 UTC

Return-Path: <>
Received: from localhost ( []) by (Postfix) with ESMTP id 1521B1A1F5E for <>; Fri, 7 Feb 2014 03:11:35 -0800 (PST)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -1.379
X-Spam-Status: No, score=-1.379 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FM_FORGED_GMAIL=0.622, SPF_PASS=-0.001] autolearn=no
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id Eszde9C5aDND for <>; Fri, 7 Feb 2014 03:11:27 -0800 (PST)
Received: from ( [IPv6:2607:f8b0:400e:c03::234]) by (Postfix) with ESMTP id 964671AC441 for <>; Fri, 7 Feb 2014 03:04:30 -0800 (PST)
Received: by with SMTP id bj1so3043455pad.11 for <>; Fri, 07 Feb 2014 03:04:30 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=vg; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :content-type; bh=WQTjYiYU+UcgrJqw8lA1FlCvT9FFE4LVxgksM51Cb/o=; b=oSsQkEPUcCKlD7tVU0AxLJ4mdM4bOJtOPj3aLglXRjTMTwvpaaXk2IXpzzrJHHua7g lcZch3CzgUhneNHBVXythhDafKAUxavY4n8pvnIrSnWp4dkPeNr4NfnqiHgTomC86ODT ArXy6r3uh7UuNjVCdYDq2hEiX5Jlh1VJ7fzpE=
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:content-type; bh=WQTjYiYU+UcgrJqw8lA1FlCvT9FFE4LVxgksM51Cb/o=; b=K8jGm1gBCRiSU+SmpFDJnxNUsw8XFfoCG+gZma9ALRlzeY0kr6Kcvt5c1txg3p6itu M4YTnhh+LI/puNZOhUOUuV7r0tQWyIX8sQ2iT8c60yALHB4QeBqSvbaEOM0uPzI5ES3R oEM1CBzBk6f3fGnShK02Hxqikdw3sqeguL3DMPGFk2I1fR8PGhjrpfjmKhuHUdvm8ULq wgpAn/u+1EB8EtaD1qJfQ5YRZyTrKIEtfiuvCHKoPA+PvUZfdtRHQjesvLPGmq7OTRxf ADVfajf3jmTnpgaNojXfFPJCmi0GrhCPoskIv1RSLB4p6uQ+EYnlQSOU9ljKl88vIcMa 8KYg==
X-Gm-Message-State: ALoCoQl1/FS81o22bEtwfBvHNDv5CruOnMYqxjjcr65VoWkPtEpfJ32nMPe9/+6gxDukclUgfmeh
X-Received: by with SMTP id py6mr7033479pac.21.1391770592739; Fri, 07 Feb 2014 02:56:32 -0800 (PST)
MIME-Version: 1.0
Received: by with HTTP; Fri, 7 Feb 2014 02:56:12 -0800 (PST)
In-Reply-To: <>
References: <> <> <> <> <07a801cf23a1$a5b62c00$f1228400$> <> <>
From: Tom Ritter <>
Date: Fri, 7 Feb 2014 05:56:12 -0500
Message-ID: <>
To: IETF DANE WG list <>
Content-Type: text/plain; charset=ISO-8859-1
Subject: Re: [dane] Feature creep for draft-ietf-dane-smime
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: DNS-based Authentication of Named Entities <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Fri, 07 Feb 2014 11:11:35 -0000

On 6 February 2014 21:02, Viktor Dukhovni <> wrote:
> I am not strongly advocating for this, more thinking out loud, in
> case the issue resonates with the group.

I saw it mentioned, but when I ran into a similar situation, I got
hung up with the normalization/canonicalization process.
Capitalization ('Mark' vs 'mark') and in other languages and Suffixes
( vs and other configurable
characters) being the foremost.

No hashing allows a server to go to lengths to set up a DNS response
that matches their implementation (e.g. perhaps my suffix character is
'G') - hashing either takes that ability away from servers or creates
a way-too-complicated algorithm with unacceptable back-and-forth 'What
is your suffix character' queries.

I lean away from hashing, in favor of robust anti-spam solutions that
take into account things like sender DKIM and SMIME. That said, I also
recognize the value in trying not to decrease security (actual or
perceived) from what is actually deployed milter software.