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Re: [TLS] supported_versions in TLS 1.2

Hanno Böck <hanno@hboeck.de> Tue, 16 November 2021 15:45 UTC

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Date: Tue, 16 Nov 2021 16:42:48 +0100
From: Hanno Böck <hanno@hboeck.de>
To: tls@ietf.org
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Subject: Re: [TLS] supported_versions in TLS 1.2
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On Tue, 16 Nov 2021 08:36:31 -0700
Peter Saint-Andre <stpeter@mozilla.com> wrote:

> By our reading, it doesn't make any difference to a TLS 1.2 
> implementation whether it sends or receives the "supported_versions" 
> extension. Corrections welcome, of course! If this is the case, we'd 
> prefer not to recommend that TLS 1.2 implementations specifically add 
> support for this extension, since upgrading to TLS 1.3 is best anyway.

I have a question about this question:
I think it's generally agreed that TLS 1.3 provides much better
security than TLS 1.2 (that was ultimately why it's been created).

Why would you even write a recommendation for what people should do
with TLS 1.2-only implementations? (I understand this is merely
relevant for implementations not supporting TLS 1.3 at all.) Shouldn't
the recommendation be: "Don't. Please support TLS 1.3." ?

-- 
Hanno Böck
https://hboeck.de/

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