Re: [TLS] no fallbacks please [was: Downgrade protection, fallbacks, and server time]
Dave Garrett <davemgarrett@gmail.com> Fri, 03 June 2016 04:17 UTC
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From: Dave Garrett <davemgarrett@gmail.com>
To: tls@ietf.org
Date: Fri, 03 Jun 2016 00:17:20 -0400
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Subject: Re: [TLS] no fallbacks please [was: Downgrade protection, fallbacks, and server time]
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Allrighty then; time to dust off and rebase an old changeset I was fiddling with last year on this topic: https://github.com/davegarrett/tls13-spec/commit/058ff1518508b094b8c9f1bd4096be9393f20076 (I cleaned up a bit when rebasing, but it probably needs some work; was just a WIP branch, never a PR) This was the result of prior discussions on-list about TLS version intolerance. The gist of the proposal: 1) Freeze all the various version number fields. 2) Send a list of all supported versions in an extension. (version IDs converted to 16-bit ints instead of 8-bit pairs) 3) Use short (1 or 2 value, based on hello version) predefined lists for hellos from old clients not sending the extension. 4) Compare lists to find highest overlap, avoiding guesswork or problems with noncontinuous lists. 5) Forget the old mess of version intolerance existed. Do we want to consider scrapping the old version negotiation method again? Dave
- Re: [TLS] Downgrade protection, fallbacks, and se… David Benjamin
- Re: [TLS] Downgrade protection, fallbacks, and se… Martin Rex
- [TLS] Downgrade protection, fallbacks, and server… David Benjamin
- Re: [TLS] Downgrade protection, fallbacks, and se… Eric Rescorla
- Re: [TLS] Downgrade protection, fallbacks, and se… David Benjamin
- Re: [TLS] Downgrade protection, fallbacks, and se… Eric Rescorla
- Re: [TLS] Downgrade protection, fallbacks, and se… Martin Thomson
- [TLS] no fallbacks please [was: Downgrade protect… Nikos Mavrogiannopoulos
- Re: [TLS] no fallbacks please [was: Downgrade pro… Yoav Nir
- Re: [TLS] Downgrade protection, fallbacks, and se… Hubert Kario
- Re: [TLS] no fallbacks please [was: Downgrade pro… Hubert Kario
- Re: [TLS] Downgrade protection, fallbacks, and se… David Benjamin
- Re: [TLS] Downgrade protection, fallbacks, and se… Viktor Dukhovni
- Re: [TLS] no fallbacks please [was: Downgrade pro… David Benjamin
- Re: [TLS] Downgrade protection, fallbacks, and se… David Benjamin
- Re: [TLS] Downgrade protection, fallbacks, and se… Hubert Kario
- Re: [TLS] no fallbacks please [was: Downgrade pro… David Benjamin
- Re: [TLS] Downgrade protection, fallbacks, and se… David Benjamin
- Re: [TLS] no fallbacks please [was: Downgrade pro… Hubert Kario
- Re: [TLS] no fallbacks please [was: Downgrade pro… Hubert Kario
- Re: [TLS] Downgrade protection, fallbacks, and se… Viktor Dukhovni
- Re: [TLS] no fallbacks please [was: Downgrade pro… Martin Thomson
- Re: [TLS] no fallbacks please [was: Downgrade pro… Dave Garrett
- Re: [TLS] no fallbacks please [was: Downgrade pro… Nikos Mavrogiannopoulos
- Re: [TLS] no fallbacks please [was: Downgrade pro… Ilari Liusvaara
- Re: [TLS] no fallbacks please [was: Downgrade pro… Hubert Kario
- Re: [TLS] no fallbacks please [was: Downgrade pro… Xiaoyin Liu
- Re: [TLS] no fallbacks please [was: Downgrade pro… Hubert Kario
- Re: [TLS] no fallbacks please [was: Downgrade pro… Eric Rescorla
- Re: [TLS] no fallbacks please [was: Downgrade pro… Andrei Popov
- Re: [TLS] no fallbacks please [was: Downgrade pro… Eric Rescorla
- Re: [TLS] no fallbacks please [was: Downgrade pro… Viktor Dukhovni
- Re: [TLS] no fallbacks please [was: Downgrade pro… David Benjamin
- Re: [TLS] no fallbacks please [was: Downgrade pro… Dave Garrett
- Re: [TLS] no fallbacks please [was: Downgrade pro… Bill Frantz
- Re: [TLS] Downgrade protection, fallbacks, and se… Yaron Sheffer
- Re: [TLS] Downgrade protection, fallbacks, and se… Stefan Winter
- Re: [TLS] no fallbacks please [was: Downgrade pro… Hubert Kario
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Peter Gutmann
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Peter Gutmann
- Re: [TLS] no fallbacks please [was: Downgrade pro… Dave Garrett
- Re: [TLS] no fallbacks please [was: Downgrade pro… Jeffrey Walton
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Peter Gutmann
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Kyle Rose
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Hubert Kario
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Yoav Nir
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Salz, Rich
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Yoav Nir
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Hubert Kario
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Yoav Nir
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … David Benjamin
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Andrei Popov
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Yuhong Bao
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Dave Garrett
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Hubert Kario
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Hubert Kario
- Re: [TLS] [FORGED] Re: no fallbacks please [was: … Nikos Mavrogiannopoulos
- Re: [TLS] no fallbacks please [was: Downgrade pro… Tony Arcieri