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Re: [TLS] Other S->C signaling methods

Martin Rex <mrex@sap.com> Thu, 26 November 2009 15:56 UTC

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From: Martin Rex <mrex@sap.com>
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Date: Thu, 26 Nov 2009 16:55:51 +0100
In-Reply-To: <6b9359640911260033q4eee63f3sb43aa76c657453b7@mail.gmail.com> from "Kyle Hamilton" at Nov 26, 9 00:33:53 am
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Cc: tls@ietf.org
Subject: Re: [TLS] Other S->C signaling methods
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Kyle Hamilton wrote:
> 
> We've already heard that Microsoft IIS sends an extension in the case
> of working with a particular cipher, even in the event that the client
> didn't request the extension.  (It contains the information necessary
> to work with the cipher suite.)

*I* didn't say that.

There are two test TLS servers on the Internet that will return
an unsolicited ServerHelloExtension when a particular cipher suite
is negotiated.

One of them replies with this:
Server: Apache/1.3.34 (Debian) mod_ssl/2.8.25 OpenSSL/0.9.8e

(I can't reach the other from our internal network).


WinXP and W2K3 do not seem to allow sending ClientHelloExtensions
to Cryptographic Service Providers, but it seems that _somehow_
they allow to receive unsolicited ServerHelloExtensions.


-Martin

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