Re: [TLS] chairs - please shutdown wiretapping discussion...
Christian Huitema <huitema@huitema.net> Tue, 11 July 2017 19:11 UTC
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From: Christian Huitema <huitema@huitema.net>
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Date: Tue, 11 Jul 2017 12:11:09 -0700
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Subject: Re: [TLS] chairs - please shutdown wiretapping discussion...
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On 7/11/2017 6:11 AM, Ted Lemon wrote: > What the draft actually says is that you can install a fixed key on the server rather than generating new keys every time, and then that fixed key can also be installed on monitoring software. This is, I believe, the actual intended use of the proposal. > > It’s also true that you can just exfiltrate every key as it’s generated, but that’s not what’s being proposed and would not, I think, suit the needs of the operators who are making this proposal. > > I don’t see how you could mitigate against deliberate key exfiltration. At some point you really are relying on the security of the endpoint. But being able to detect repeated keys is useful for preventing pervasive monitoring: it requires the monitored either to have access to the key generation stream in realtime, or to request the key for a particular conversation. To paraphrase what Ted says using my own words, the use of static (EC)DH shares is an attack against the integrity of the TLS 1.3 protocol. I think this attack should be documented in the TLS spec, probably in Appendix E since the attack compromises security properties of the protocol, or maybe in Appendix C if we want to outline the implementation issues. Some text like: For various reasons, some implementations may be tempted to use static (EC) DH private key. Using such keys lowers the security guarantees of TLS 1.3. Adversaries that get access to the static (EC) DH private key can now get access to the content of the communication. Adversaries that acquire the key in real-time can compromise the confidentiality of the conversation. Adversaries that acquire the key later can use it to access the content of recorded sessions, thus breaking the forward secrecy promise of the protocol. TLS 1.3 clients should detect the use of static (EC)DH keys by corresponding servers, and should treat servers using such keys as compromised. Clients can perform this detection by comparing keys proposed by servers at different time, or by cooperating with other clients to compare the keys proposed to them by servers. -- Christian Huitema -- Christian Huitema
- [TLS] chairs - please shutdown wiretapping discus… Stephen Farrell
- Re: [TLS] chairs - please shutdown wiretapping di… Yaron Sheffer
- Re: [TLS] chairs - please shutdown wiretapping di… Stephen Farrell
- Re: [TLS] chairs - please shutdown wiretapping di… Paul Turner
- Re: [TLS] chairs - please shutdown wiretapping di… Tony Arcieri
- Re: [TLS] chairs - please shutdown wiretapping di… Stephen Farrell
- Re: [TLS] chairs - please shutdown wiretapping di… Tony Arcieri
- Re: [TLS] chairs - please shutdown wiretapping di… Stephen Farrell
- Re: [TLS] chairs - please shutdown wiretapping di… Yoav Nir
- Re: [TLS] chairs - please shutdown wiretapping di… Russ Housley
- Re: [TLS] chairs - please shutdown wiretapping di… Tony Arcieri
- Re: [TLS] chairs - please shutdown wiretapping di… Eric Mill
- Re: [TLS] chairs - please shutdown wiretapping di… Colm MacCárthaigh
- Re: [TLS] chairs - please shutdown wiretapping di… Dan Brown
- Re: [TLS] chairs - please shutdown wiretapping di… Stephen Farrell
- Re: [TLS] chairs - please shutdown wiretapping di… Sean Turner
- Re: [TLS] chairs - please shutdown wiretapping di… Polk, Tim (Fed)
- Re: [TLS] chairs - please shutdown wiretapping di… Stephen Farrell
- Re: [TLS] chairs - please shutdown wiretapping di… Nikos Mavrogiannopoulos
- Re: [TLS] chairs - please shutdown wiretapping di… Ackermann, Michael
- Re: [TLS] chairs - please shutdown wiretapping di… Colm MacCárthaigh
- Re: [TLS] chairs - please shutdown wiretapping di… Sean Turner
- Re: [TLS] chairs - please shutdown wiretapping di… Yoav Nir
- Re: [TLS] chairs - please shutdown wiretapping di… Nico Williams
- Re: [TLS] chairs - please shutdown wiretapping di… Blumenthal, Uri - 0553 - MITLL
- Re: [TLS] chairs - please shutdown wiretapping di… Stephen Farrell
- Re: [TLS] chairs - please shutdown wiretapping di… Stephen Farrell
- Re: [TLS] chairs - please shutdown wiretapping di… Stephen Farrell
- Re: [TLS] chairs - please shutdown wiretapping di… Stephen Farrell
- Re: [TLS] chairs - please shutdown wiretapping di… Nico Williams
- Re: [TLS] chairs - please shutdown wiretapping di… Watson Ladd
- Re: [TLS] chairs - please shutdown wiretapping di… Ackermann, Michael
- Re: [TLS] chairs - please shutdown wiretapping di… Stephen Farrell
- Re: [TLS] chairs - please shutdown wiretapping di… Ackermann, Michael
- Re: [TLS] chairs - please shutdown wiretapping di… Sean Turner
- Re: [TLS] chairs - please shutdown wiretapping di… Russ Housley
- Re: [TLS] chairs - please shutdown wiretapping di… Stephen Farrell
- Re: [TLS] chairs - please shutdown wiretapping di… Russ Housley
- Re: [TLS] chairs - please shutdown wiretapping di… Stephen Farrell
- Re: [TLS] chairs - please shutdown wiretapping di… Russ Housley
- Re: [TLS] chairs - please shutdown wiretapping di… Stephen Farrell
- Re: [TLS] chairs - please shutdown wiretapping di… Eric Mill
- Re: [TLS] chairs - please shutdown wiretapping di… Jeffrey Walton
- Re: [TLS] chairs - please shutdown wiretapping di… Watson Ladd
- Re: [TLS] chairs - please shutdown wiretapping di… Ted Lemon
- Re: [TLS] chairs - please shutdown wiretapping di… Stephen Farrell
- Re: [TLS] chairs - please shutdown wiretapping di… Ted Lemon
- Re: [TLS] chairs - please shutdown wiretapping di… Ackermann, Michael
- Re: [TLS] chairs - please shutdown wiretapping di… Michael StJohns
- Re: [TLS] chairs - please shutdown wiretapping di… Christian Huitema
- Re: [TLS] chairs - please shutdown wiretapping di… Stephen Farrell
- Re: [TLS] chairs - please shutdown wiretapping di… Stephen Farrell
- Re: [TLS] chairs - please shutdown wiretapping di… Ted Lemon
- Re: [TLS] chairs - please shutdown wiretapping di… Stephen Farrell
- Re: [TLS] chairs - please shutdown wiretapping di… Ted Lemon
- Re: [TLS] chairs - please shutdown wiretapping di… Stephen Farrell
- Re: [TLS] chairs - please shutdown wiretapping di… Christian Huitema
- Re: [TLS] chairs - please shutdown wiretapping di… Ted Lemon
- Re: [TLS] chairs - please shutdown wiretapping di… Blumenthal, Uri - 0553 - MITLL
- Re: [TLS] chairs - please shutdown wiretapping di… Yoav Nir
- Re: [TLS] chairs - please shutdown wiretapping di… Ted Lemon
- Re: [TLS] chairs - please shutdown wiretapping di… Stephen Farrell
- Re: [TLS] chairs - please shutdown wiretapping di… Yoav Nir
- Re: [TLS] chairs - please shutdown wiretapping di… Stephen Farrell
- Re: [TLS] chairs - please shutdown wiretapping di… Nico Williams
- Re: [TLS] chairs - please shutdown wiretapping di… Bill Frantz
- Re: [TLS] chairs - please shutdown wiretapping di… Timothy Jackson
- Re: [TLS] chairs - please shutdown wiretapping di… Kyle Rose
- Re: [TLS] chairs - please shutdown wiretapping di… Ted Lemon
- Re: [TLS] chairs - please shutdown wiretapping di… Kyle Rose
- Re: [TLS] chairs - please shutdown wiretapping di… Ted Lemon
- Re: [TLS] chairs - please shutdown wiretapping di… Richard Barnes
- Re: [TLS] chairs - please shutdown wiretapping di… Kyle Rose
- Re: [TLS] chairs - please shutdown wiretapping di… Ted Lemon
- Re: [TLS] chairs - please shutdown wiretapping di… Ted Lemon
- Re: [TLS] chairs - please shutdown wiretapping di… Kyle Rose
- Re: [TLS] chairs - please shutdown wiretapping di… Ilari Liusvaara
- Re: [TLS] chairs - please shutdown wiretapping di… Stephen Farrell
- Re: [TLS] chairs - please shutdown wiretapping di… Kyle Rose
- Re: [TLS] chairs - please shutdown wiretapping di… Stephen Farrell
- Re: [TLS] chairs - please shutdown wiretapping di… Kyle Rose
- Re: [TLS] chairs - please shutdown wiretapping di… Stephen Farrell
- Re: [TLS] chairs - please shutdown wiretapping di… Kathleen Moriarty
- Re: [TLS] chairs - please shutdown wiretapping di… Stephen Farrell