Re: [dane] Comments on draft-ietf-dane-smime-04

Stephen Kent <kent@bbn.com> Fri, 14 February 2014 16:07 UTC

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Date: Fri, 14 Feb 2014 11:07:41 -0500
From: Stephen Kent <kent@bbn.com>
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Subject: Re: [dane] Comments on draft-ietf-dane-smime-04
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James,

>>>>>> "OE" == Osterweil, Eric <eosterweil@verisign.com> writes:
> OE> With PGP, I can use a key with a diff email than the account from
> OE> which I send it (for ex, I can use my spam account and rely on my
> OE> full name and friends who know me to make the logical leap), do we
> OE> all want DANE to outlaw this for S/MIME?
>
> Absolutely not.
>
> There is no value in forcing the sending email address to match the info
> in any signature over the message (or over any part of the message).
>
> (With emphasis on /forcing/.)
 From an OE perspective, I see your point. Form a general security 
perspective,
I disagree. Folks receiving a signed message tend to assume that the "from"
field has been checked against the Subject or SAN in the signer's cert. It's
a reasonable expectation. When that reasonable assumption is not true, users
are surprised, and surprise is a bad outcome wrt security :-).

Steve