IETF Logo Mail Archive

Re: [dane] I-D Action: draft-ietf-dane-smime-04.txt

Viktor Dukhovni <viktor1dane@dukhovni.org> Thu, 09 January 2014 17:39 UTC

Return-Path: <viktor1dane@dukhovni.org>
X-Original-To: dane@ietfa.amsl.com
Delivered-To: dane@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 171731AE502 for <dane@ietfa.amsl.com>; Thu, 9 Jan 2014 09:39:57 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.9
X-Spam-Level:
X-Spam-Status: No, score=-1.9 tagged_above=-999 required=5 tests=[BAYES_00=-1.9] autolearn=ham
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 uv0uLvczxYi3 for <dane@ietfa.amsl.com>; Thu, 9 Jan 2014 09:39:55 -0800 (PST)
Received: from mournblade.imrryr.org (mournblade.imrryr.org [38.117.134.19]) by ietfa.amsl.com (Postfix) with ESMTP id 167BC1AE503 for <dane@ietf.org>; Thu, 9 Jan 2014 09:39:53 -0800 (PST)
Received: by mournblade.imrryr.org (Postfix, from userid 1034) id C2B302AB218; Thu, 9 Jan 2014 17:39:43 +0000 (UTC)
Date: Thu, 09 Jan 2014 17:39:43 +0000
From: Viktor Dukhovni <viktor1dane@dukhovni.org>
To: dane@ietf.org
Message-ID: <20140109173943.GL2317@mournblade.imrryr.org>
References: <89AE05E1-BC6C-46BA-A4CC-A8F29070096D@vpnc.org> <CEF43EFD.F8FB%bdickson@verisign.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
In-Reply-To: <CEF43EFD.F8FB%bdickson@verisign.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
Subject: Re: [dane] I-D Action: draft-ietf-dane-smime-04.txt
X-BeenThere: dane@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
Reply-To: dane@ietf.org
List-Id: DNS-based Authentication of Named Entities <dane.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/dane>, <mailto:dane-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/dane/>
List-Post: <mailto:dane@ietf.org>
List-Help: <mailto:dane-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/dane>, <mailto:dane-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 09 Jan 2014 17:39:57 -0000

On Thu, Jan 09, 2014 at 05:08:28PM +0000, Dickson, Brian wrote:

> So instead of "encoding" per se, what about using a hash function?

An intriguing suggestion.  If the hash is HMAC-SHA1(domain, username),
its hex representation is 40 octets which fits comfortably into a
DNS label.  Dictionary harvesting attacks by following NSEC records
are a bit harder, since HMAC with the domain as a key makes the
use of rainbow tables less useful.

-- 
	Viktor.

v2.23.0 | Report a Bug | By Email