Re: [TLS] chairs - please shutdown wiretapping discussion...
Christian Huitema <huitema@huitema.net> Tue, 11 July 2017 20:55 UTC
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To: Stephen Farrell <stephen.farrell@cs.tcd.ie>, Ted Lemon <mellon@fugue.com>
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From: Christian Huitema <huitema@huitema.net>
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Subject: Re: [TLS] chairs - please shutdown wiretapping discussion...
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On 7/11/2017 1:31 PM, Stephen Farrell wrote: > PS: There are also genuine performance reasons why the same > DH public might be re-used in some cases, so there would be > false positives in a survey to consider as well. Well, yes. The classic argument is performance. Saving the cost of exponentiation, computing G^X once for many session instead of once per session. But you reap most of the benefits of that optimization with a fairly small number of repetitions. Performance alone is not a good reason to use the key over extended period, not to share the exact same key between all servers in a farm. The fact is that wide reuse of the same (EC)DH private key does compromise the security of TLS -- including an obvious issue with forward secrecy. I get your argument that this can turn into a cat and mouse game. Clients detect a bad behavior, misbehaving servers adapt by tweaking the behavior to avoid detection, clients get smarter, etc. On the other hand, documenting the attack clearly marks this key reuse as not desirable and not supported. The public statement provides an argument to developers to "just say no" when asked to add the wiretap "feature". Detection by clients also provides a clear signal to enterprises that they should really find another way to solve their problem. In any case, I just submitted PR #1049 (https://github.com/tlswg/tls13-spec/pull/1049). -- 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