Re: [TLS] Confirming Consensus on removing RSA key Transport from TLS 1.3
Daniel Kahn Gillmor <dkg@fifthhorseman.net> Sat, 29 March 2014 01:22 UTC
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Date: Fri, 28 Mar 2014 21:22:29 -0400
From: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
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To: Santosh Chokhani <SChokhani@cygnacom.com>, "mrex@sap.com" <mrex@sap.com>, "Joseph Salowey (jsalowey)" <jsalowey@cisco.com>
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Subject: Re: [TLS] Confirming Consensus on removing RSA key Transport from TLS 1.3
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On 03/26/2014 07:25 PM, Santosh Chokhani wrote: > While I agree with most of what you say including some benefits of RSA, the DHE parameter verification by the client while desirable is not a genuine security threat. A rogue server has many other ways to compromise the exchange, The recent https://secure-resumption.com/ showed that one malicious server (which a victim deliberately connects to) could use a weak discrete log DHE group to force a client doing client-cert authentication into signing a pre-master secret of the server operator's choice. The malicious server operator could then replay that pre-master secret to another server (in a non-DHE ciphersuite), creating two sessions with the same session id, master secret, and connection keys (they call this an "Unknown key share attack" or UKS). They didn't find a way to exploit a UKS directly without taking advantage of other flaws in the TLS protocol, but if the option of using a bad group hadn't been there, clients using DHE ciphersuites would have been resistant to the attacks they did find. So permitting the use of an arbitrary DL DH group whose structure is too expensive for the client to verify is something we should try to avoid. --dkg
- [TLS] Confirming Consensus on removing RSA key Tr… Joseph Salowey (jsalowey)
- [TLS] On axing DHE (was: Re: Confirming Consensus… Rene Struik
- Re: [TLS] Confirming Consensus on removing RSA ke… Trevor Perrin
- Re: [TLS] Confirming Consensus on removing RSA ke… Martin Rex
- Re: [TLS] Confirming Consensus on removing RSA ke… Watson Ladd
- Re: [TLS] Confirming Consensus on removing RSA ke… Santosh Chokhani
- Re: [TLS] Confirming Consensus on removing RSA ke… Martin Rex
- Re: [TLS] Confirming Consensus on removing RSA ke… Hanno Böck
- Re: [TLS] Confirming Consensus on removing RSA ke… Nikos Mavrogiannopoulos
- Re: [TLS] Confirming Consensus on removing RSA ke… Jack Lloyd
- Re: [TLS] Confirming Consensus on removing RSA ke… Alyssa Rowan
- Re: [TLS] Confirming Consensus on removing RSA ke… Paul Bakker
- Re: [TLS] Confirming Consensus on removing RSA ke… Alyssa Rowan
- Re: [TLS] Confirming Consensus on removing RSA ke… Hanno Böck
- Re: [TLS] Confirming Consensus on removing RSA ke… Johannes Merkle
- Re: [TLS] Confirming Consensus on removing RSA ke… Paul Bakker
- Re: [TLS] Confirming Consensus on removing RSA ke… Nikos Mavrogiannopoulos
- Re: [TLS] Confirming Consensus on removing RSA ke… Salz, Rich
- Re: [TLS] Confirming Consensus on removing RSA ke… Watson Ladd
- Re: [TLS] Confirming Consensus on removing RSA ke… Salz, Rich
- Re: [TLS] Confirming Consensus on removing RSA ke… Andy Lutomirski
- Re: [TLS] Confirming Consensus on removing RSA ke… Marsh Ray
- Re: [TLS] Confirming Consensus on removing RSA ke… Daniel Kahn Gillmor
- Re: [TLS] Confirming Consensus on removing RSA ke… Daniel Kahn Gillmor
- [TLS] Negotiated Discrete Log DHE revision [was: … Daniel Kahn Gillmor
- Re: [TLS] Negotiated Discrete Log DHE revision [w… Michael D'Errico
- Re: [TLS] Negotiated Discrete Log DHE revision Michael D'Errico
- Re: [TLS] Negotiated Discrete Log DHE revision Henrick Hellström
- Re: [TLS] Negotiated Discrete Log DHE revision [w… Daniel Kahn Gillmor
- Re: [TLS] Negotiated Discrete Log DHE revision Daniel Kahn Gillmor
- Re: [TLS] Negotiated Discrete Log DHE revision Samuel Neves
- Re: [TLS] Negotiated Discrete Log DHE revision Watson Ladd
- Re: [TLS] Negotiated Discrete Log DHE revision Samuel Neves
- Re: [TLS] Negotiated Discrete Log DHE revision Liz meeks
- Re: [TLS] Negotiated Discrete Log DHE revision [w… Fedor Brunner
- Re: [TLS] Negotiated Discrete Log DHE revision [w… Fedor Brunner
- Re: [TLS] Confirming Consensus on removing RSA ke… Joseph Salowey (jsalowey)
- Re: [TLS] Confirming Consensus on removing RSA ke… Martin Rex
- Re: [TLS] Confirming Consensus on removing RSA ke… Eric Rescorla
- Re: [TLS] Confirming Consensus on removing RSA ke… Nikos Mavrogiannopoulos
- Re: [TLS] Confirming Consensus on removing RSA ke… Kurt Roeckx
- Re: [TLS] Confirming Consensus on removing RSA ke… Daniel Kahn Gillmor
- Re: [TLS] Confirming Consensus on removing RSA ke… Eric Rescorla
- Re: [TLS] Confirming Consensus on removing RSA ke… Kurt Roeckx
- Re: [TLS] Confirming Consensus on removing RSA ke… Eric Rescorla
- Re: [TLS] Confirming Consensus on removing RSA ke… Nikos Mavrogiannopoulos
- Re: [TLS] Confirming Consensus on removing RSA ke… Viktor Dukhovni
- Re: [TLS] Confirming Consensus on removing RSA ke… Watson Ladd
- Re: [TLS] Confirming Consensus on removing RSA ke… Nikos Mavrogiannopoulos