Re: [TLS] Wrapping up cached info
Marsh Ray <marsh@extendedsubset.com> Mon, 17 May 2010 17:50 UTC
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Date: Mon, 17 May 2010 12:50:20 -0500
From: Marsh Ray <marsh@extendedsubset.com>
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To: Nicolas Williams <Nicolas.Williams@oracle.com>
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Cc: tls@ietf.org
Subject: Re: [TLS] Wrapping up cached info
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On 5/17/2010 12:08 PM, Nicolas Williams wrote: > On Mon, May 17, 2010 at 12:02:55PM -0500, Marsh Ray wrote: >> It could perhaps be made to solve the problem, but IMHO it would require >> so much additional complexity (aka attack surface) that it wouldn't be >> worth it. > > Really? It'd be a single extra message consisting of the hash of all > the objects' data, concatenated in some canonical order (or maybe the > hash of the XOR of the object data hashes, to avoid having to define a > canonical order), that the first node to sent a Finished message would > have to send, and which the other node would have to check. Where's all > that additional complexity, and how does it compare with the complexity > of the protocol's security analysis as it stands now? Try this: write up that "single extra message" in unambiguous RFC form. The protocol message definition, the canonical order, server behavior, client behavior, how to require per-server client caches when the server hasn't yet been authenticated, etc. Security considerations for future cached object types. Consider writing code to implement it including test cases with actual checksum collisions. Then put after it "... or we could just use a collision resistant hash function." >> While I don't like to reject anything out-of-hand, injecting data into > > But you just did. Sorry if it sounds that way. I didn't reject it, I said "It could perhaps be made to solve the problem" and asked a bunch of pointed, but answerable, questions. This is my way of saying that I could accept the idea and inviting others to overcome those objections. If I'd really wanted to reject it, I would have made just one unanswerable objection like "I spoke to secret government cryptographers who will not go on record and they said it was insecure" (again, this did not happen just an example). >> the calculation of the Finished messages raises a lot of concerns. The > > You mis-read. Re-read. Which part? I don't get it. - Marsh
- Re: [TLS] Wrapping up cached info Blumenthal, Uri - 0668 - MITLL
- [TLS] Consensus Call: FNV vs SHA1 Joseph Salowey (jsalowey)
- Re: [TLS] Consensus Call: FNV vs SHA1 Simon Josefsson
- Re: [TLS] Consensus Call: FNV vs SHA1 Blumenthal, Uri - 0668 - MITLL
- Re: [TLS] Consensus Call: FNV vs SHA1 Adam Langley
- Re: [TLS] Consensus Call: FNV vs SHA1 Marsh Ray
- Re: [TLS] Consensus Call: FNV vs SHA1 Robert Dugal
- Re: [TLS] Consensus Call: FNV vs SHA1 Stefan Santesson
- Re: [TLS] Consensus Call: FNV vs SHA1 Nicolas Williams
- Re: [TLS] Consensus Call: FNV vs SHA1 Stefan Santesson
- Re: [TLS] Consensus Call: FNV vs SHA1 Martin Rex
- Re: [TLS] Consensus Call: FNV vs SHA1 Jeffrey A. Williams
- Re: [TLS] Consensus Call: FNV vs SHA1 Paul Hoffman
- [TLS] Collisions (Re: Consensus Call: FNV vs SHA1) Nicolas Williams
- [TLS] Nico's suggestions - Re: Consensus Call: FN… Stefan Santesson
- Re: [TLS] Collisions (Re: Consensus Call: FNV vs … Blumenthal, Uri - 0668 - MITLL
- [TLS] Collisions (Re: Nico's suggestions - Re: Co… Nicolas Williams
- Re: [TLS] Collisions (Re: Consensus Call: FNV vs … Nicolas Williams
- Re: [TLS] Consensus Call: FNV vs SHA1 Simon Josefsson
- [TLS] Collisions (Re: Consensus Call: FNV vs SHA1) Nicolas Williams
- Re: [TLS] Collisions (Re: Consensus Call: FNV vs … Nicolas Williams
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Stefan Santesson
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Nicolas Williams
- Re: [TLS] Collisions (Re: Consensus Call: FNV vs … Simon Josefsson
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Stefan Santesson
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Nicolas Williams
- Re: [TLS] Collisions (Re: Consensus Call: FNV vs … Stefan Santesson
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Stefan Santesson
- Re: [TLS] Consensus Call: FNV vs SHA1 Hovav Shacham
- Re: [TLS] Collisions (Re: Consensus Call: FNV vs … Simon Josefsson
- Re: [TLS] Consensus Call: FNV vs SHA1 Yoav Nir
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Martin Rex
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Nicolas Williams
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Stefan Santesson
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Nicolas Williams
- Re: [TLS] Consensus Call: FNV vs SHA1 Nicolas Williams
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Stefan Santesson
- Re: [TLS] Consensus Call: FNV vs SHA1 Simon Josefsson
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Nicolas Williams
- Re: [TLS] Consensus Call: FNV vs SHA1 Michael D'Errico
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Martin Rex
- Re: [TLS] Consensus Call: FNV vs SHA1 Kemp, David P.
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Nicolas Williams
- Re: [TLS] Consensus Call: FNV vs SHA1 Nicolas Williams
- Re: [TLS] Consensus Call: FNV vs SHA1 Blumenthal, Uri - 0668 - MITLL
- Re: [TLS] Consensus Call: FNV vs SHA1 Nicolas Williams
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Martin Rex
- Re: [TLS] Collisions (Re: Consensus Call: FNV vs … Kemp, David P.
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Kemp, David P.
- Re: [TLS] Collisions (Re: Consensus Call: FNV vs … Marsh Ray
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Nicolas Williams
- Re: [TLS] Collisions (Re: Consensus Call: FNV vs … Nicolas Williams
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Marsh Ray
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Marsh Ray
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Nicolas Williams
- Re: [TLS] Collisions (Re: Consensus Call: FNV vs … Marsh Ray
- Re: [TLS] Collisions (Re: Consensus Call: FNV vs … Nicolas Williams
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Marsh Ray
- Re: [TLS] [POSSIBLE SPAM] Re: Collisions (Re: Nic… Kemp, David P.
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Nicolas Williams
- Re: [TLS] [POSSIBLE SPAM] Re: Collisions (Re: Nic… Marsh Ray
- Re: [TLS] [POSSIBLE SPAM] Re: Collisions (Re: Con… Kemp, David P.
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Marsh Ray
- Re: [TLS] Collisions (Re: Consensus Call: FNV vs … Stefan Santesson
- Re: [TLS] [POSSIBLE SPAM] Re: Collisions (Re: Con… Marsh Ray
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Stefan Santesson
- Re: [TLS] Collisions (Re: Consensus Call: FNV vs … Marsh Ray
- Re: [TLS] Collisions (Re: Consensus Call: FNV vs … Stefan Santesson
- Re: [TLS] Collisions (Re: Consensus Call: FNV vs … Marsh Ray
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Simon Josefsson
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Brian Smith
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Marsh Ray
- [TLS] Justification Michael D'Errico
- Re: [TLS] Justification Simon Josefsson
- Re: [TLS] Justification Adam Langley
- Re: [TLS] Justification Brian Smith
- Re: [TLS] Justification Michael D'Errico
- Re: [TLS] Justification Adam Langley
- Re: [TLS] Justification Marsh Ray
- Re: [TLS] Justification Brian Smith
- Re: [TLS] [POSSIBLE SPAM] Re: Collisions (Re: Con… Kemp, David P.
- Re: [TLS] Justification Michael D'Errico
- Re: [TLS] Justification Adam Langley
- [TLS] Use HTTP (Re: Justification) Nicolas Williams
- Re: [TLS] Justification Nicolas Williams
- Re: [TLS] Justification Michael D'Errico
- Re: [TLS] Justification Nicolas Williams
- Re: [TLS] Justification Michael D'Errico
- Re: [TLS] Justification Nicolas Williams
- Re: [TLS] Justification Michael D'Errico
- Re: [TLS] Justification Nicolas Williams
- Re: [TLS] Justification Yoav Nir
- Re: [TLS] Justification Michael D'Errico
- Re: [TLS] Justification Martin Rex
- Re: [TLS] Justification Marsh Ray
- Re: [TLS] Justification Stefan Santesson
- Re: [TLS] Justification Martin Rex
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Yoav Nir
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Stefan Santesson
- Re: [TLS] Justification Nicolas Williams
- Re: [TLS] Wrapping up cached info Marsh Ray
- Re: [TLS] Collisions (Re: Nico's suggestions - Re… Marsh Ray
- Re: [TLS] Justification Dean Anderson
- [TLS] Wrapping up cached info Stefan Santesson
- Re: [TLS] Wrapping up cached info Nicolas Williams
- Re: [TLS] Wrapping up cached info Simon Josefsson
- Re: [TLS] Wrapping up cached info Nicolas Williams
- Re: [TLS] Justification Stefan Santesson
- Re: [TLS] Justification Nicolas Williams
- Re: [TLS] Justification Nicolas Williams
- Re: [TLS] Wrapping up cached info Marsh Ray
- Re: [TLS] Wrapping up cached info Joseph Salowey (jsalowey)
- Re: [TLS] Wrapping up cached info Marsh Ray
- Re: [TLS] Wrapping up cached info Nicolas Williams
- Re: [TLS] Wrapping up cached info Ben Laurie
- Re: [TLS] Wrapping up cached info Yoav Nir
- Re: [TLS] Wrapping up cached info Nicolas Williams
- Re: [TLS] Wrapping up cached info Marsh Ray
- Re: [TLS] Wrapping up cached info Marsh Ray
- Re: [TLS] Wrapping up cached info Ben Laurie
- Re: [TLS] Wrapping up cached info Martin Rex
- [TLS] Possible alternative to current cached info… Michael D'Errico
- Re: [TLS] Wrapping up cached info (and PRF WTF) Kemp, David P.
- Re: [TLS] Wrapping up cached info (and PRF WTF) Martin Rex
- Re: [TLS] Wrapping up cached info Stefan Santesson
- Re: [TLS] Wrapping up cached info (and PRF WTF) Nicolas Williams
- Re: [TLS] Wrapping up cached info Stefan Santesson
- Re: [TLS] Wrapping up cached info Stefan Santesson
- Re: [TLS] Wrapping up cached info Joseph Salowey (jsalowey)
- Re: [TLS] Wrapping up cached info Stefan Santesson
- Re: [TLS] Wrapping up cached info Michael D'Errico
- Re: [TLS] Wrapping up cached info Marsh Ray
- Re: [TLS] Wrapping up cached info Joseph Salowey (jsalowey)
- Re: [TLS] Wrapping up cached info Joseph Salowey (jsalowey)
- Re: [TLS] Wrapping up cached info Marsh Ray
- Re: [TLS] Wrapping up cached info Nicolas Williams
- Re: [TLS] Wrapping up cached info Stefan Santesson
- Re: [TLS] Wrapping up cached info Michael D'Errico
- Re: [TLS] Wrapping up cached info Michael D'Errico
- Re: [TLS] Wrapping up cached info Kemp, David P.
- Re: [TLS] Wrapping up cached info Nicolas Williams
- Re: [TLS] Wrapping up cached info Nicolas Williams
- Re: [TLS] Wrapping up cached info Ben Laurie
- Re: [TLS] Wrapping up cached info Brian Smith
- Re: [TLS] Wrapping up cached info Stefan Santesson
- Re: [TLS] Wrapping up cached info Martin Rex
- Re: [TLS] Wrapping up cached info Brian Smith
- Re: [TLS] Wrapping up cached info Nicolas Williams
- Re: [TLS] Wrapping up cached info Stefan Santesson
- Re: [TLS] Wrapping up cached info Brian Smith
- Re: [TLS] Wrapping up cached info Brian Smith
- Re: [TLS] Wrapping up cached info Nicolas Williams