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Re: [TLS] Accept draft-turner-ssl-must-not-02 as WG item

Michael D'Errico <mike-list@pobox.com> Sat, 28 August 2010 20:30 UTC

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Date: Sat, 28 Aug 2010 13:31:06 -0700
From: Michael D'Errico <mike-list@pobox.com>
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To: Eric Rescorla <ekr@rtfm.com>
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Subject: Re: [TLS] Accept draft-turner-ssl-must-not-02 as WG item
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Eric Rescorla wrote:
> In Maastricht, we saw a presentation on draft-turner-ssl-must-not:
> 
> http://tools.ietf.org/html/draft-turner-ssl-must-not-02
> 
> The consensus in Maastricht was to adopt this as a WG item. 
> If anyone objects please speak up now.

No objection to taking it on as a WG item, but I do have a concern
with section 3:

    3. Changes to TLS
       [...]
        o TLS servers MUST NOT accept SSL 2.0 ClientHello messages.

I still see many SSLv2 ClientHellos, and none of them are SSLv2-only
clients.  So at this point in time I think MUST NOT is too strong on
the server side.  I don't think using an SSLv2 hello is a security
problem since it supports the TLS_EMPTY_RENEGOTIATION_INFO_SCSV
cipher suite value.

Mike

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