Re: [dane] [saag] Need better opportunistic terminology

Tony Finch <dot@dotat.at> Thu, 13 March 2014 12:48 UTC

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Date: Thu, 13 Mar 2014 12:48:45 +0000
From: Tony Finch <dot@dotat.at>
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Subject: Re: [dane] [saag] Need better opportunistic terminology
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Viktor Dukhovni <viktor1dane@dukhovni.org> wrote:
>
> My contention is, for example, that the use of "opportunistic" in
> "opportunistic TLS" to describe TLS in case "0" is a proper use of
> that adjective.

I think a better phrase would be "negotiated unauthenticated TLS".
(Or "unauthenticated STARTTLS" since STARTTLS implies negotiated TLS).
"Opportunistic" implies that someone is taking advantage of someone else
to their detriment, whereas SMTP TLS is by mutual agreement.

> Similarly "opportunistic DANE TLS" for case "2" is also reasonable.  By
> way of contrast one might speak of "mandatory TLS", "mandatory DANE
> TLS", ...

The mandatory cases are where the postmaster has overridden normal
protocol negotiation, which implies that they should get a weirder name
than the normal negotiated cases.

Postfix's use of "opportunistic" is a bit weird. Sendmail and Exim do not
use the term, though Microsoft Exchange does.

Tony.
-- 
f.anthony.n.finch  <dot@dotat.at>  http://dotat.at/
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