Re: [TLS] Another [Well-deserved] attack on TLS CCA
Geoffrey Keating <geoffk@geoffk.org> Tue, 18 June 2013 21:40 UTC
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To: Anders Rundgren <anders.rundgren@telia.com>
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From: Geoffrey Keating <geoffk@geoffk.org>
Date: Tue, 18 Jun 2013 14:39:58 -0700
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Subject: Re: [TLS] Another [Well-deserved] attack on TLS CCA
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Anders Rundgren <anders.rundgren@telia.com> writes: > https://sites.google.com/site/oauthgoog/gnubby > > Luckily for all users Google didn't select TLS CCA (Client Certificate > Authentication) for their coming U2F system; only a moron would base a > future consumer authentication system on a scheme that is only suited > for VPN tunnels and invisible authentications like as ChannelID. > > What's missing you may wonder? Well, how about > > - Compatibility with web sessions including timeout and logout Logout is a client-side function, and occurs (typically) when the user logs out of their local session and/or quits their web browser. Timeout occurs when the TLS connection is closed due to inactivity (typically 60 seconds) and the session resumption token is expired, which is up to the server; or, looking at it another way, when the user's screen lock triggers due to inactivity. > - A working credential filtering system I think this is mostly due to lack of demand. I wouldn't say it isn't "working", just that as commonly implemented, it isn't very good. I wouldn't list these as the biggest problems when trying to use client certificate auth, they can be solved with minor fixes. The first major obstacle you'll hit is trying to get users enrolled. Then there are: - Enrolling multiple devices - Key rollover - Lost devices - Shared devices - Public access terminals and all the other things that people don't think about immediately when they say "let's replace passwords!"
- [TLS] Another [Well-deserved] attack on TLS CCA Anders Rundgren
- Re: [TLS] Another [Well-deserved] attack on TLS C… Adam Langley
- Re: [TLS] Another [Well-deserved] attack on TLS C… Anders Rundgren
- Re: [TLS] Another [Well-deserved] attack on TLS C… Nico Williams
- Re: [TLS] Another [Well-deserved] attack on TLS C… Anders Rundgren
- Re: [TLS] Another [Well-deserved] attack on TLS C… Geoffrey Keating
- Re: [TLS] Another [Well-deserved] attack on TLS C… Anders Rundgren
- Re: [TLS] Another [Well-deserved] attack on TLS C… Geoffrey Keating
- Re: [TLS] Another [Well-deserved] attack on TLS C… Anders Rundgren