Re: [TLS] I-D Action: draft-ietf-tls-curve25519-00.txt

Martin Thomson <martin.thomson@gmail.com> Fri, 12 June 2015 20:43 UTC

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Date: Fri, 12 Jun 2015 13:43:25 -0700
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From: Martin Thomson <martin.thomson@gmail.com>
To: Ilari Liusvaara <ilari.liusvaara@elisanet.fi>
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Subject: Re: [TLS] I-D Action: draft-ietf-tls-curve25519-00.txt
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On 12 June 2015 at 12:56, Ilari Liusvaara <ilari.liusvaara@elisanet.fi> wrote:
> "Servers MUST NOT select an ECDHE_ECDSA ciphersuite if there are no
> common curves suitable for ECDSA."
>
> You mean MUST NOT select ECDSA certificate? Because TLS 1.2 rules
> seemingly allow selecting ECDHE_RSA ciphersuite with ECDSA
> certificate.

This seems right to me.  The point here is that when a named_curve (or
named_group) identifies 25519, then it can't be used for ECDSA.  25519
is always OK with an _RSA_ suite.