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Re: [TLS] simplistic renego protection

Marsh Ray <marsh@extendedsubset.com> Wed, 18 November 2009 18:51 UTC

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Date: Wed, 18 Nov 2009 12:51:47 -0600
From: Marsh Ray <marsh@extendedsubset.com>
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To: Eric Rescorla <ekr@networkresonance.com>, "tls@ietf.org" <tls@ietf.org>
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Subject: Re: [TLS] simplistic renego protection
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Eric Rescorla wrote:
>> Providing a solution only for the latest version of TLS is akin to ask
>> people to upgrade to the latest release of a particular software rather
>> than provide a simple fix to the existing deployed software.
> 
> I really don't understand this argument. Extensions are completely
> compatible with TLS 1.0, 1.1, and as has been observed by
> Martin, compatible in principle with SSLv3. Any fix will require
> some changes to people's software. I don't see how that consists
> at all of providing a solution only for the latest version of
> TLS.

It appears that many SSLv3 servers and some "TLS1.0" do not correctly
ignore unrecognized extensions.

Therefore, it represents a breaking protocol change for the owners of
such systems.

Most admins are responsible for a variety of systems and no tools seem
readily available to even determine one's status.

- Marsh

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