[TLS] 0-RTT (Was: Re: 0-RTT and Anti-Replay)
Ilari Liusvaara <ilari.liusvaara@elisanet.fi> Sun, 12 April 2015 16:55 UTC
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Date: Sun, 12 Apr 2015 19:55:42 +0300
From: Ilari Liusvaara <ilari.liusvaara@elisanet.fi>
To: Eric Rescorla <ekr@rtfm.com>
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Subject: [TLS] 0-RTT (Was: Re: 0-RTT and Anti-Replay)
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On Sun, Mar 22, 2015 at 02:49:28PM -0700, Eric Rescorla wrote: > In the interim in Seattle, we had an extensive discussion of 0-RTT > anti-replay in which DKG observed that all the proposed anti-replay > mechanisms provide limited protection. The underlying problem is the > desire to present a uniform interface in which the calling application > can count on reliable delivery of the data it provides in the first > flight, thus requiring the TLS stack to retransmit it automatically. I thought about 0-RTT some more, here are some questions. Few might be protocol-relevant, most are only about guidance. 1) What is the recommended 0-RTT API model on server side (also consider server apps or app implementations that don't support 0-RTT)? 2) What are the semantics of successfully received 0-RTT transfer (especially considering the client-side autoretransmit on failure)? 3) How does 0-RTT interact with ALPN (especially considering potential for multiple protocol candidates)? 4) Can handshake with attempted 0-RTT be securely downgraded to v1.2 (obviously causes the 0-RTT to fail)? 5) There is potential footgun if 0-RTT is used with (DH-)PSK: The PSK authenticates the connection immediately, but 0-RTT is as replayable as ever. What to do with that? 6) The same as above, but when attempting to resume a session. with a client certificate (since cc is property of session)? 7) What guidance to give regarding what data can be put to 0-RTT, considering its replayability? 8) If resumption attempt has 0-RTT data, what keying material is used for the 0-RTT? 9) Can server roll over its 0-RTT keys without waiting for the previous ones to expire? 10) How is attacker establishing a session (or at least decoding server's first application flight) replaying captured 0-RTT data prevented (since that could leak quite a bit of info about what's in 0-RTT blob)? Or not? -Ilari
- [TLS] 0-RTT and Anti-Replay Eric Rescorla
- Re: [TLS] 0-RTT and Anti-Replay Mohamad Badra
- Re: [TLS] 0-RTT and Anti-Replay Eric Rescorla
- Re: [TLS] 0-RTT and Anti-Replay Stephen Checkoway
- Re: [TLS] 0-RTT and Anti-Replay Daniel Kahn Gillmor
- Re: [TLS] 0-RTT and Anti-Replay Andrey Jivsov
- Re: [TLS] 0-RTT and Anti-Replay Eric Rescorla
- Re: [TLS] 0-RTT and Anti-Replay Martin Thomson
- Re: [TLS] 0-RTT and Anti-Replay Andrey Jivsov
- Re: [TLS] 0-RTT and Anti-Replay Colm MacCárthaigh
- Re: [TLS] 0-RTT and Anti-Replay Colm MacCárthaigh
- Re: [TLS] 0-RTT and Anti-Replay Nico Williams
- Re: [TLS] 0-RTT and Anti-Replay Ilari Liusvaara
- Re: [TLS] 0-RTT and Anti-Replay Nico Williams
- Re: [TLS] 0-RTT and Anti-Replay Nico Williams
- Re: [TLS] 0-RTT and Anti-Replay Martin Thomson
- Re: [TLS] 0-RTT and Anti-Replay Eric Rescorla
- Re: [TLS] 0-RTT and Anti-Replay Roland Zink
- Re: [TLS] 0-RTT and Anti-Replay Martin Thomson
- Re: [TLS] 0-RTT and Anti-Replay Colm MacCárthaigh
- Re: [TLS] 0-RTT and Anti-Replay Viktor Dukhovni
- Re: [TLS] 0-RTT and Anti-Replay Martin Thomson
- Re: [TLS] 0-RTT and Anti-Replay Brian Sniffen
- Re: [TLS] 0-RTT and Anti-Replay Salz, Rich
- Re: [TLS] 0-RTT and Anti-Replay Roland Zink
- Re: [TLS] 0-RTT and Anti-Replay Martin Thomson
- Re: [TLS] 0-RTT and Anti-Replay Martin Thomson
- Re: [TLS] 0-RTT and Anti-Replay Viktor Dukhovni
- Re: [TLS] 0-RTT and Anti-Replay Roland Zink
- Re: [TLS] 0-RTT and Anti-Replay Viktor Dukhovni
- Re: [TLS] 0-RTT and Anti-Replay Roland Zink
- Re: [TLS] 0-RTT and Anti-Replay Colm MacCárthaigh
- Re: [TLS] 0-RTT and Anti-Replay Ilari Liusvaara
- Re: [TLS] 0-RTT and Anti-Replay Viktor Dukhovni
- Re: [TLS] 0-RTT and Anti-Replay Ilari Liusvaara
- Re: [TLS] 0-RTT and Anti-Replay Nico Williams
- Re: [TLS] 0-RTT and Anti-Replay Viktor Dukhovni
- Re: [TLS] 0-RTT and Anti-Replay Nico Williams
- Re: [TLS] 0-RTT and Anti-Replay Nico Williams
- Re: [TLS] 0-RTT and Anti-Replay Eric Rescorla
- Re: [TLS] 0-RTT and Anti-Replay Nico Williams
- Re: [TLS] 0-RTT and Anti-Replay Patrick McManus
- Re: [TLS] 0-RTT and Anti-Replay Dave Garrett
- Re: [TLS] 0-RTT and Anti-Replay Martin Thomson
- Re: [TLS] 0-RTT and Anti-Replay Eric Rescorla
- Re: [TLS] 0-RTT and Anti-Replay Eric Rescorla
- Re: [TLS] 0-RTT and Anti-Replay Nico Williams
- Re: [TLS] 0-RTT and Anti-Replay Ilari Liusvaara
- Re: [TLS] 0-RTT and Anti-Replay Watson Ladd
- Re: [TLS] 0-RTT and Anti-Replay Ilari Liusvaara
- [TLS] 0-RTT (Was: Re: 0-RTT and Anti-Replay) Ilari Liusvaara
- Re: [TLS] 0-RTT (Was: Re: 0-RTT and Anti-Replay) Martin Thomson
- Re: [TLS] 0-RTT (Was: Re: 0-RTT and Anti-Replay) Ilari Liusvaara
- Re: [TLS] 0-RTT (Was: Re: 0-RTT and Anti-Replay) Martin Thomson
- Re: [TLS] 0-RTT (Was: Re: 0-RTT and Anti-Replay) Ilari Liusvaara
- Re: [TLS] 0-RTT (Was: Re: 0-RTT and Anti-Replay) Martin Thomson
- Re: [TLS] 0-RTT (Was: Re: 0-RTT and Anti-Replay) Ilari Liusvaara
- Re: [TLS] 0-RTT (Was: Re: 0-RTT and Anti-Replay) Martin Thomson
- Re: [TLS] 0-RTT (Was: Re: 0-RTT and Anti-Replay) Daniel Kahn Gillmor
- Re: [TLS] 0-RTT (Was: Re: 0-RTT and Anti-Replay) Ilari Liusvaara
- Re: [TLS] 0-RTT (Was: Re: 0-RTT and Anti-Replay) Ilari Liusvaara
- Re: [TLS] 0-RTT (Was: Re: 0-RTT and Anti-Replay) Martin Thomson
- Re: [TLS] 0-RTT (Was: Re: 0-RTT and Anti-Replay) Nico Williams
- Re: [TLS] 0-RTT (Was: Re: 0-RTT and Anti-Replay) Ilari Liusvaara
- Re: [TLS] 0-RTT (Was: Re: 0-RTT and Anti-Replay) Ilari Liusvaara