Re: [TLS] Last Call: <draft-ietf-tls-ssl2-must-not-03.txt> (Prohibiting SSL Version 2.0) to Proposed Standard

Michael D'Errico <> Thu, 02 December 2010 06:14 UTC

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Date: Wed, 01 Dec 2010 22:15:20 -0800
From: Michael D'Errico <>
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Subject: Re: [TLS] Last Call: <draft-ietf-tls-ssl2-must-not-03.txt> (Prohibiting SSL Version 2.0) to Proposed Standard
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Matt McCutchen wrote:
> On Wed, 2010-12-01 at 21:49 -0800, Michael D'Errico wrote:
>> If you couldn't put the SCSV into the CLIENT-HELLO, then it would not
>> be OK for servers to accept that message; it would have to be a MUST
>> NOT.
> You have just said the same thing again.  Why?  What potential security
> problem be prevented by the server not accepting a SSL 2.0 CLIENT-HELLO?

I'm not sure why you're objecting to my comment.

We are deprecating SSL version 2.0.  However, we are allowing the
continued acceptance of the SSL 2.0 CLIENT-HELLO by TLS servers.

It would be irresponsible for us to do that if it left open the
renegotiation hole that was closed via the RenegotiationInfo
extension (and SCSV), and I wouldn't support it if that were the

I was merely pointing that out.