Re: [dane] I-D Action: draft-ietf-dane-smime-03.txt

Viktor Dukhovni <viktor1dane@dukhovni.org> Sat, 08 February 2014 03:52 UTC

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Date: Sat, 8 Feb 2014 03:52:03 +0000
From: Viktor Dukhovni <viktor1dane@dukhovni.org>
To: dane@ietf.org
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References: <41938fd202ba460285b59132c29ac826@BY2PR09MB029.namprd09.prod.outlook.com> <20140206195322.GD278@mournblade.imrryr.org> <11698F58-B554-4CC8-872F-D2A3BF08986C@kirei.se> <20140206215742.GF278@mournblade.imrryr.org> <alpine.LFD.2.10.1402071254350.21252@bofh.nohats.ca> <20140207181129.GO278@mournblade.imrryr.org> <alpine.LFD.2.10.1402072027090.28278@bofh.nohats.ca> <20140208030346.GV278@mournblade.imrryr.org>
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Subject: Re: [dane] I-D Action: draft-ietf-dane-smime-03.txt
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On Sat, Feb 08, 2014 at 03:03:46AM +0000, Viktor Dukhovni wrote:

> > Also, not using the domain name allows for CNAME/DNAME entries, so for
> > example I can add the same record in my "libreswan.org" zone that is
> > used as DNAME for libreswan.{net|com|ca|fi|nl}. Adding the domain into
> > the hash would break this setup.
> 
> Indeed hashing the domain would cause a problem with DNAMEs.

Or not, note that just becase example.com is a CNAME for example.net
does not mean that joe@example.com is the same *mailbox* (email
recipient) as joe@exampl.net.  Nothing in SMTP makes it so, and
some people in fact use multiple domains hosted at the same target
as independent namespaces.  So from that perspective, hashing the
domain actually better matches SMTP semantics.  It avoids conflating
addresses that are cannot be presumed to be equivalent.

-- 
	Viktor.