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

Viktor Dukhovni <viktor1dane@dukhovni.org> Thu, 06 February 2014 21:57 UTC

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Date: Thu, 6 Feb 2014 21:57:42 +0000
From: Viktor Dukhovni <viktor1dane@dukhovni.org>
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Subject: Re: [dane] I-D Action: draft-ietf-dane-smime-03.txt
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On Thu, Feb 06, 2014 at 10:51:28PM +0100, Jakob Schlyter wrote:

> On 6 feb 2014, at 20:53, Viktor Dukhovni <viktor1dane@dukhovni.org> wrote:
> 
> > Switching gears, was any consensus reached on the endoing of the
> > query label?  A truncated HMAC seems to offer better usability than
> > base32.  I think that the specification is in good shape, modulo
> > the query label encoding.  
> 
> Yes, we're looking at doing a plain sha224 for the LHS lookup
> instead of base32. Paul Wouters will provide some draft text for
> both documents (S/MIME & PGP). I would [not] say we have consensus for
> HMAC-sha224 yet, but that's something we can discuss further.

I think that HMAC-sha224 would be wiser, since otherwise a single
dictionary works for all domains.  The key should be the domain
name.  The question is I think not whether HMAC is necessary, but
rather whether it is sufficient, one might argue for iterated HMAC
with a reasonably high iteration count (unfortunately fixed, but
Moore's law will end any day now, ... promise! )

-- 
	Viktor.