Re: [TLS] TLS or HTTP issue?

Marsh Ray <marsh@extendedsubset.com> Sat, 07 November 2009 08:30 UTC

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Date: Sat, 07 Nov 2009 02:30:31 -0600
From: Marsh Ray <marsh@extendedsubset.com>
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Subject: Re: [TLS] TLS or HTTP issue?
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Nikos Mavrogiannopoulos wrote:
> 
> the application layer
> cannot distinguish between the two sessions (one before renegotiation,
> one after). The problem was for me that you could receive any amount of
> application data even after a rehandshake was requested, thus I had to
> cache them and present to the application after rehandshake was finished.

Yes, yes!

The buffered stream IO model we all take for granted is insufficient to
represent the semantics of a TLS connection in the presence of
renegotiation!

Even with an added callback for cert validation, ambiguities linger!

I think it highly probable that real vulnerabilities exist in
applications due to this mismatch.

The draft-rescorla-tls-renegotiate extension should help quite a bit though.

- Marsh