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Re: [TLS] draft-rescorla-tls-renegotiate and MITM resistance

Steve Dispensa <dispensa@phonefactor.com> Tue, 10 November 2009 19:21 UTC

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Date: Tue, 10 Nov 2009 13:21:46 -0600
From: Steve Dispensa <dispensa@phonefactor.com>
To: Nicolas Williams <Nicolas.Williams@sun.com>, Marsh Ray <marsh@extendedsubset.com>
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Thread-Topic: [TLS] draft-rescorla-tls-renegotiate and MITM resistance
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Subject: Re: [TLS] draft-rescorla-tls-renegotiate and MITM resistance
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On 11/10/09 12:15 PM, "Nicolas Williams" <Nicolas.Williams@sun.com> wrote:

> On Tue, Nov 10, 2009 at 12:02:06PM -0600, Marsh Ray wrote:
>> Nicolas Williams wrote:
>>> On Mon, Nov 09, 2009 at 10:08:53PM -0600, Marsh Ray wrote:
>>> 
>>> TLS connections are not so long lived
>> 
>> But there is no defined upper limit.
> 
> True, and indeed, IMAP depends on that.  Are there IMAP/other servers
> the request re-negotiation when a client's cert reaches/nears
> expiration?

Has anyone considered SSL VPN's and/or things like GoToMyPC?

> If so then my assertion that we don't have to worry about key rollover/
> cert expiration would be wrong.  Indeed, it's safer to assume that that
> assertion was wrong as finding out for sure would be hard.

OTOH, we could require that app-level protocols support re-establishment of
the underlying TLS session once crypto state gets stale (in the opinion of
either client or server).

 -Steve

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