Re: [TLS] (strict) decoding of legacy_record_version?

Benjamin Kaduk <bkaduk@akamai.com> Thu, 10 November 2016 16:22 UTC

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To: Martin Thomson <martin.thomson@gmail.com>, Brian Smith <brian@briansmith.org>
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From: Benjamin Kaduk <bkaduk@akamai.com>
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Date: Thu, 10 Nov 2016 10:22:17 -0600
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Cc: Matt Caswell <matt@openssl.org>, "tls@ietf.org" <tls@ietf.org>
Subject: Re: [TLS] (strict) decoding of legacy_record_version?
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On 11/08/2016 06:25 PM, Martin Thomson wrote:
> On 9 November 2016 at 05:59, Brian Smith <brian@briansmith.org>; wrote:
>> This isn't a pervasively shared goal, though. It's good to let the browsers
>> police things if they want, but I think a lot of implementations would
>> prefer to avoid doing work that isn't necessary for interop or security.
> If you permit someone to enforce it, then that is sufficient.  I don't
> think that we should ever force someone to enforce these sorts of
> things (as you say, sometimes strict enforcement isn't cheap or even
> desirable).
>

Agreed.  We should probably change the text a bit, though, as right now
readers can get two different readings depending on whether they go for
a strict decode_error (or illegal_parameter?) since the struct doesn't
match the definition, or follow the "MUST be ignored for all purposes".

-Ben