Re: [TLS] TLS renegotiation issue
Nicolas Williams <Nicolas.Williams@sun.com> Thu, 05 November 2009 17:24 UTC
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Date: Thu, 05 Nov 2009 11:13:08 -0600
From: Nicolas Williams <Nicolas.Williams@sun.com>
To: Martin Rex <mrex@sap.com>
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Cc: Eric Rescorla <ekr@rtfm.com>, tls@ietf.org
Subject: Re: [TLS] TLS renegotiation issue
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On Thu, Nov 05, 2009 at 06:11:41PM +0100, Martin Rex wrote: > One conceivable approach would be a TLS extension for secure renegotiation > with roughly the following semantics: > > > - on initial TLS handshakes (aka Re-nego of a TLS_NULL_WITH_NULL_NULL) > the client that supports secure renegotiation should send the > TLS extension in the client hello with an empty extension data > to signal to the server that it support secure renegotation. > > - on TLS session renegotiations, the client should sent the TLS extension > with the extension data containing the client.random and server.random > from the existing session. The MITM can make sure they match. Why not just send an extension with the tls-unique channel binding for the first/outer connection, and then make sure that that gets fed as an input for the PRF in the second/inner connection? I.e., proper channel binding. The MITM _cannot_ make sure that the tls-unique CB of the client<->MITM and MITM<->server outer connections match. > - A server that receives a ClientHello without the TLS extension for > secure renegotiation should NOT perform old-style renegotiation > for that session (and get apps with flawed assumptions into trouble), > i.e. NOT support delayed authentication for those TLS clients. Right. > - A server that receives a ClientHello on an initial TLS handshake > with a TLS extension (empty data) for secure renegotiation may decide to > delay client-cert authentication to a securely renegotiated session Right. > - A server that receives a ClientHello with a TLS extension for secure > negotiation and a reference to a previous session MUST compare the > client.random and server.random from the extension data to that of > the current session (and abort if they do not match). And the > server should probably insist on doing a ChangeCipherSpec on both > directions in the renegotiation handshake. See above. > Since Larry is looking for a means to uniquely identify a single > TLS "connection" independent of whether its a single TLS handshake > or renegotiated, we should check whether we can carry-over some > information form the initial handshake on a connection along > with the client.random&server.random. Technically there is no > limit on the number of renegotiations, so a simple pointer > only one TLS session into the past does not seem sufficient > for that purpose. See above. Use tls-unique. Nico --
- [TLS] TLS renegotiation issue Eric Rescorla
- Re: [TLS] TLS renegotiation issue Eric Rescorla
- Re: [TLS] TLS renegotiation issue Marsh Ray
- Re: [TLS] TLS renegotiation issue Eric Rescorla
- Re: [TLS] TLS renegotiation issue Martin Rex
- Re: [TLS] TLS renegotiation issue Marsh Ray
- Re: [TLS] TLS renegotiation issue Nicolas Williams
- Re: [TLS] TLS renegotiation issue Martin Rex
- Re: [TLS] TLS renegotiation issue Nicolas Williams
- Re: [TLS] TLS renegotiation issue Martin Rex
- Re: [TLS] TLS renegotiation issue Nicolas Williams
- Re: [TLS] TLS renegotiation issue Nicolas Williams
- Re: [TLS] TLS renegotiation issue Martin Rex
- Re: [TLS] TLS renegotiation issue Eric Rescorla
- Re: [TLS] TLS renegotiation issue Nicolas Williams
- Re: [TLS] TLS renegotiation issue Nicolas Williams
- Re: [TLS] TLS renegotiation issue Florian Weimer
- Re: [TLS] TLS renegotiation issue Martin Rex
- Re: [TLS] TLS renegotiation issue Michael D'Errico
- Re: [TLS] TLS renegotiation issue Eric Rescorla
- Re: [TLS] TLS renegotiation issue Nicolas Williams
- Re: [TLS] TLS renegotiation issue Eric Rescorla
- Re: [TLS] TLS renegotiation issue Florian Weimer
- Re: [TLS] TLS renegotiation issue Martin Rex
- Re: [TLS] TLS renegotiation issue Martin Rex
- Re: [TLS] TLS renegotiation issue Nicolas Williams
- Re: [TLS] TLS renegotiation issue Nicolas Williams
- Re: [TLS] TLS renegotiation issue Nicolas Williams
- Re: [TLS] TLS renegotiation issue Nicolas Williams
- Re: [TLS] TLS renegotiation issue Eric Rescorla
- Re: [TLS] TLS renegotiation issue Eric Rescorla
- Re: [TLS] TLS renegotiation issue Eric Rescorla
- [TLS] TLS or HTTP issue? (was: TLS renegotiation … Nikos Mavrogiannopoulos
- Re: [TLS] TLS renegotiation issue Yngve N. Pettersen (Developer Opera Software ASA)
- Re: [TLS] TLS renegotiation issue Martin Rex
- Re: [TLS] TLS renegotiation issue Nicolas Williams
- Re: [TLS] TLS renegotiation issue Marsh Ray
- Re: [TLS] TLS renegotiation issue Nicolas Williams
- Re: [TLS] TLS renegotiation issue Nicolas Williams
- Re: [TLS] TLS renegotiation issue Martin Rex
- Re: [TLS] TLS renegotiation issue Cullen Jennings
- Re: [TLS] TLS renegotiation issue Martin Rex
- Re: [TLS] TLS renegotiation issue Michael Gray
- Re: [TLS] TLS renegotiation issue Nicolas Williams
- Re: [TLS] TLS renegotiation issue Nicolas Williams
- Re: [TLS] TLS renegotiation issue Nicolas Williams
- Re: [TLS] TLS renegotiation issue Nicolas Williams
- Re: [TLS] TLS renegotiation issue Martin Rex
- Re: [TLS] TLS renegotiation issue Martin Rex
- Re: [TLS] TLS renegotiation issue Nicolas Williams
- Re: [TLS] TLS or HTTP issue? Florian Weimer
- Re: [TLS] TLS or HTTP issue? Bruno Harbulot
- Re: [TLS] TLS renegotiation issue Blumenthal, Uri - 0662 - MITLL
- Re: [TLS] TLS or HTTP issue? Peter Saint-Andre
- Re: [TLS] TLS or HTTP issue? Martin Rex
- Re: [TLS] TLS or HTTP issue? (was: TLS renegotiat… Nicolas Williams
- Re: [TLS] TLS or HTTP issue? (was: TLS renegotiat… Nathaniel W Filardo
- Re: [TLS] TLS or HTTP issue? Marsh Ray
- Re: [TLS] TLS or HTTP issue? (was: TLS renegotiat… Nicolas Williams
- [TLS] draft-rescorla-tls-renegotiate.txt Martin Rex
- Re: [TLS] draft-rescorla-tls-renegotiate.txt Michael D'Errico
- Re: [TLS] draft-rescorla-tls-renegotiate.txt Martin Rex
- Re: [TLS] draft-rescorla-tls-renegotiate.txt Martin Rex
- Re: [TLS] draft-rescorla-tls-renegotiate.txt Nicolas Williams
- Re: [TLS] TLS renegotiation issue Nicolas Williams
- Re: [TLS] TLS renegotiation issue Marsh Ray
- Re: [TLS] draft-rescorla-tls-renegotiate.txt Robert Relyea
- Re: [TLS] draft-rescorla-tls-renegotiate.txt Michael D'Errico
- Re: [TLS] TLS or HTTP issue? Dean Anderson
- Re: [TLS] TLS renegotiation issue David Harrington
- [TLS] To API or not (Re: TLS renegotiation issue) Nicolas Williams
- Re: [TLS] draft-rescorla-tls-renegotiate.txt Marsh Ray
- [TLS] Simple way to drop re-negotiation in HTTP (… Nicolas Williams
- Re: [TLS] TLS renegotiation issue Michael D'Errico
- Re: [TLS] TLS renegotiation issue Martin Rex
- Re: [TLS] draft-rescorla-tls-renegotiate.txt Martin Rex
- Re: [TLS] Simple way to drop re-negotiation in HT… Marsh Ray
- Re: [TLS] TLS or HTTP issue? Nikos Mavrogiannopoulos
- Re: [TLS] TLS or HTTP issue? Marsh Ray
- Re: [TLS] TLS renegotiation issue Michael D'Errico
- Re: [TLS] TLS renegotiation issue Marsh Ray
- Re: [TLS] TLS or HTTP issue? Michael D'Errico
- Re: [TLS] Test Server (was TLS renegotiation issu… Michael D'Errico
- Re: [TLS] Test Server (was TLS renegotiation issu… Michael D'Errico
- Re: [TLS] TLS renegotiation issue Nagendra Modadugu
- Re: [TLS] TLS renegotiation issue Eric Rescorla
- Re: [TLS] TLS or HTTP issue? Nicolas Williams
- Re: [TLS] TLS renegotiation issue Nicolas Williams
- Re: [TLS] TLS or HTTP issue? Florian Weimer
- Re: [TLS] Simple way to drop re-negotiation in HT… Nicolas Williams
- Re: [TLS] TLS or HTTP issue? Chris Newman
- Re: [TLS] TLS or HTTP issue? (was: TLS renegotiat… Chris Newman
- Re: [TLS] TLS renegotiation issue Bodo Moeller
- Re: [TLS] TLS or HTTP issue? Nikos Mavrogiannopoulos
- [TLS] Comments on draft-rescorla-tls-renegotiate Nicolas Williams
- Re: [TLS] Comments on draft-rescorla-tls-renegoti… Martin Rex
- Re: [TLS] Comments on draft-rescorla-tls-renegoti… David-Sarah Hopwood
- Re: [TLS] Comments on draft-rescorla-tls-renegoti… David-Sarah Hopwood
- Re: [TLS] Comments on draft-rescorla-tls-renegoti… David-Sarah Hopwood
- Re: [TLS] Comments on draft-rescorla-tls-renegoti… Nicolas Williams
- Re: [TLS] Comments on draft-rescorla-tls-renegoti… Nicolas Williams
- Re: [TLS] Comments on draft-rescorla-tls-renegoti… Nicolas Williams
- Re: [TLS] Comments on draft-rescorla-tls-renegoti… Nelson B Bolyard
- Re: [TLS] Comments on draft-rescorla-tls-renegoti… David-Sarah Hopwood
- Re: [TLS] Comments on draft-rescorla-tls-renegoti… David-Sarah Hopwood
- Re: [TLS] Comments on draft-rescorla-tls-renegoti… Bodo Moeller