Re: [TLS] PR#1091: Changes to provide middlebox robustness

Eric Rescorla <ekr@rtfm.com> Wed, 08 November 2017 00:32 UTC

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From: Eric Rescorla <ekr@rtfm.com>
Date: Tue, 7 Nov 2017 16:32:09 -0800
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To: Watson Ladd <watsonbladd@gmail.com>
Cc: Jana Iyengar <jri@google.com>, "tls@ietf.org" <tls@ietf.org>
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Subject: Re: [TLS] PR#1091: Changes to provide middlebox robustness
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On Tue, Nov 7, 2017 at 4:25 PM, Watson Ladd <watsonbladd@gmail.com>; wrote:

> On Tue, Nov 7, 2017 at 4:05 PM, Jana Iyengar <jri@google.com>; wrote:
> > FWIW: In my experience middleboxes don't ossify based on what the spec
> says,
> > they ossify based on what they see on the wire. So, if common
> > implementations send CCS in a particular way, that's what will get ---
> and,
> > I'll argue, what has gotten --- ossified. I also agree with David and
> Eric
> > that compatibility mode shouldn't be required because QUIC doesn't need
> it.
>
> What does compatibility mode mean here?


It means:

1. Send the fake session_id
2. Send a bunch of spurious CCS values.


If we end up with having two
> slightly different versions of TLS 1.3, one that looks more like TLS
> 1.2 and the other that does not, that doesn't seem like a good thing
> to me.
>

Well, the idea is that this is a purely local decision by one side.

-Ekr


> My understanding is we already have ossification here and the debate
> is what to do about it.
>
>
> --
> "Man is born free, but everywhere he is in chains".
> --Rousseau.
>