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Re: [TLS] Protocol version for inappropriate_fallback alerts (was: Re: I-D Action: draft-ietf-tls-downgrade-scsv-01.txt)

Martin Thomson <martin.thomson@gmail.com> Tue, 11 November 2014 19:50 UTC

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Date: Tue, 11 Nov 2014 11:50:52 -0800
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From: Martin Thomson <martin.thomson@gmail.com>
To: "mrex@sap.com" <mrex@sap.com>
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Cc: Florian Weimer <fweimer@redhat.com>, "tls@ietf.org" <tls@ietf.org>
Subject: Re: [TLS] Protocol version for inappropriate_fallback alerts (was: Re: I-D Action: draft-ietf-tls-downgrade-scsv-01.txt)
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On 11 November 2014 11:41, Martin Rex <mrex@sap.com> wrote:
> But I do _not_ think that a MUST for ClientHello.client_version
> would be appropriate for an fatal alert that is sent instead
> of ServerHello.  For alerts that early in the handshake a server
> may for simplicity reuse the record layer protocol that was used
> for the in coming ClientHello.


I think that's reasonable.  I think that we sometimes echo the record
layer protocol version, depending on how far we are through the
handshake processing.  I can see why you wouldn't want to dictate this
so strongly.

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