Re: [TLS] Negotiate only symmetric cipher via cipher suites (was: Ala Carte Cipher suites - was: DSA should die)
Daniel Kahn Gillmor <dkg@fifthhorseman.net> Mon, 13 April 2015 18:30 UTC
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From: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
To: "Blumenthal, Uri - 0553 - MITLL" <uri@ll.mit.edu>
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Subject: Re: [TLS] Negotiate only symmetric cipher via cipher suites (was: Ala Carte Cipher suites - was: DSA should die)
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On Mon 2015-04-13 13:35:42 -0400, Blumenthal, Uri - 0553 - MITLL wrote: > On 4/13/15, 13:31 , "Daniel Kahn Gillmor" <dkg@fifthhorseman.net> wrote: > >>On Mon 2015-04-13 13:25:20 -0400, Dave Garrett wrote: >>>> So if we have to have non-(EC)DHE PSK, what would it mean if a TLS peer >>>> were to try to negotiate: >>>> >>>> key agreement: PSK >>>> authentication: RSA-PSS >>>> >>>> Do we just say "don't do that"? >>> >>> SGTM >> >>……... >>Once the full cartesian explosion is available by multidimensional >>enumeration, we have to mark out which corners of the space are actually >>bad ideas, and we have to make sure our implementations don't stumble >>into those corners by accident. >> >>This isn't impossible to do, but it seems ripe for subtle implementation >>bugs. > > Cryptographically sound algorithms and protocols should be immune to this > concern. And we should accept only cryptographically sound algorithms & > protocols. :-) What do you think an implementation should do when a peer tries to negotiate the combination above? Require an RSA-PSS signature from the server over some material derived in part from the PSK key agreement mechanism? --dkg
- Re: [TLS] DSA should die Yoav Nir
- Re: [TLS] DSA should die Dave Garrett
- [TLS] DSA should die Hanno Böck
- Re: [TLS] DSA should die Aaron Zauner
- Re: [TLS] DSA should die David Benjamin
- Re: [TLS] DSA should die Stephen Checkoway
- Re: [TLS] DSA should die Tony Arcieri
- Re: [TLS] DSA should die Bill Frantz
- Re: [TLS] DSA should die Tom Ritter
- Re: [TLS] DSA should die Viktor Dukhovni
- Re: [TLS] DSA should die Stephen Farrell
- Re: [TLS] DSA should die Nico Williams
- Re: [TLS] DSA should die Stephen Farrell
- Re: [TLS] DSA should die Viktor Dukhovni
- Re: [TLS] DSA should die Dave Garrett
- Re: [TLS] DSA should die Martin Thomson
- Re: [TLS] DSA should die Nico Williams
- Re: [TLS] DSA should die Martin Rex
- Re: [TLS] DSA should die Watson Ladd
- Re: [TLS] DSA should die Nico Williams
- Re: [TLS] DSA should die CodesInChaos
- Re: [TLS] DSA should die Martin Thomson
- Re: [TLS] DSA should die Dave Garrett
- Re: [TLS] DSA should die Nico Williams
- Re: [TLS] DSA should die Ilari Liusvaara
- Re: [TLS] DSA should die Joseph Salowey
- Re: [TLS] DSA should die Kurt Roeckx
- Re: [TLS] DSA should die Michael StJohns
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Michael StJohns
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Brian Smith
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Tony Arcieri
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Martin Thomson
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Dave Garrett
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Aaron Zauner
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Dave Garrett
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Viktor Dukhovni
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Salz, Rich
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Tony Arcieri
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Yoav Nir
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Brian Smith
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Tony Arcieri
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Ilari Liusvaara
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Brian Sniffen
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Viktor Dukhovni
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Viktor Dukhovni
- Re: [TLS] Negotiate only symmetric cipher via cip… Dave Garrett
- Re: [TLS] Negotiate only symmetric cipher via cip… Daniel Kahn Gillmor
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Aaron Zauner
- Re: [TLS] Negotiate only symmetric cipher via cip… Dave Garrett
- Re: [TLS] Negotiate only symmetric cipher via cip… Daniel Kahn Gillmor
- Re: [TLS] Negotiate only symmetric cipher via cip… Dave Garrett
- Re: [TLS] Negotiate only symmetric cipher via cip… Daniel Kahn Gillmor
- Re: [TLS] Negotiate only symmetric cipher via cip… Andrei Popov
- Re: [TLS] Negotiate only symmetric cipher via cip… Blumenthal, Uri - 0553 - MITLL
- Re: [TLS] Negotiate only symmetric cipher via cip… Viktor Dukhovni
- Re: [TLS] Negotiate only symmetric cipher via cip… Dave Garrett
- Re: [TLS] Negotiate only symmetric cipher via cip… Daniel Kahn Gillmor
- Re: [TLS] Negotiate only symmetric cipher via cip… Ilari Liusvaara
- Re: [TLS] Negotiate only symmetric cipher via cip… Dmitry Belyavsky
- Re: [TLS] Negotiate only symmetric cipher via cip… Daniel Kahn Gillmor
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Geoffrey Keating
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Yoav Nir
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Viktor Dukhovni
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Blumenthal, Uri - 0553 - MITLL
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Geoffrey Keating
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Viktor Dukhovni
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Brian Smith
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Brian Smith
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Daniel Kahn Gillmor
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Salz, Rich
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Viktor Dukhovni
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Dave Garrett
- Re: [TLS] Negotiate only symmetric cipher via cip… Ilari Liusvaara
- Re: [TLS] Ala Carte Cipher suites - was: DSA shou… Yoav Nir