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Re: [TLS] Should we require implementations to send alerts?

Martin Thomson <martin.thomson@gmail.com> Thu, 17 September 2015 21:58 UTC

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Date: Thu, 17 Sep 2015 14:58:43 -0700
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From: Martin Thomson <martin.thomson@gmail.com>
To: Brian Smith <brian@briansmith.org>
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Subject: Re: [TLS] Should we require implementations to send alerts?
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On 17 September 2015 at 14:46, Brian Smith <brian@briansmith.org> wrote:
> Browser vendors, if web servers were to stop sending alerts during handshake
> failures, would you start doing version fallback when a connection is
> closed?

I'm not sure.  We still have a small amount of vestigal fallback code
in our code.  We are gradually killing version fallback off and
removing alerts would likely set that effort back.

We're not sure where we stand with version fallback and 1.3.  We don't
know how much version intolerance 1.3 will generate.  That at least
might not depend on alerts, though we don't know just yet.

I don't see much support for the notion that forbidding alerts is a
good idea.  We use alerts quite a bit for basic diagnosis.  Bad
configurations are pretty commonplace, the most common being one where
there is no common cipher suite.  Being able to isolate the error that
is pretty useful.

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