Re: [TLS] draft-ietf-tls-curve25519-01: Is public key validation necessary or helpful?

Martin Thomson <martin.thomson@gmail.com> Wed, 23 December 2015 01:32 UTC

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Date: Wed, 23 Dec 2015 12:32:08 +1100
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From: Martin Thomson <martin.thomson@gmail.com>
To: Brian Smith <brian@briansmith.org>
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Subject: Re: [TLS] draft-ietf-tls-curve25519-01: Is public key validation necessary or helpful?
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On 23 December 2015 at 11:09, Brian Smith <brian@briansmith.org> wrote:
> If an implementation only implements ECDHE cipher suites then implementing
> the session hash extension is not necessary, according to RFC 7627. I

It doesn't really say that as far as I can see, though I guess that
you could infer that from this statement:

   Handshakes using Ephemeral
   Elliptic Curve Diffie-Hellman (ECDHE) ciphersuites are also
   vulnerable if they allow arbitrary explicit curves or use curves with
   small subgroups.