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Re: [TLS] Triple Handshake Fix.

Nico Williams <nico@cryptonector.com> Tue, 29 April 2014 22:02 UTC

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Date: Tue, 29 Apr 2014 17:02:49 -0500
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From: Nico Williams <nico@cryptonector.com>
To: Adam Langley <agl@google.com>
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Subject: Re: [TLS] Triple Handshake Fix.
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On Tue, Apr 29, 2014 at 4:05 PM, Adam Langley <agl@google.com> wrote:
> Without a fix for the Triple Handshake issues[1], TLS Channel Bindings
> (at least tls-unique) have a significant problem, not to mention
> client-auth.

tls-unique is fine provided resumption isn't broken.  Resumption is
broken.  There is a proposed fix[2] that IMO is correct and works.

Of course, apps need to know when tls-unique is safe, but since it's
only not safe when using TLS implementations where resumption isn't
safe...  there's not much that can be done other than to disable
tls-unique at build time or find a way to detect safety at run time.

> Microsoft and ourselves are looking to implement the proposed fix[2]
> soon. I'd like to request that the WG adopt the draft and that the
> process for early codepoint assignment for the TLS extension start.

+inf

> [2] https://secure-resumption.com/draft-bhargavan-tls-session-hash-00.txt

Yes.

Nico
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