Re: [IPsec] RFC4869 bis submitted

[Paul Hoffman <[e-mail]>]

At 1:51 PM -0800 11/19/09, Bill Sommerfeld wrote:
>On Tue, 2009-11-10 at 17:15 -0500, Law, Laurie wrote:
>> This Internet-Draft makes several minor changes to the suites in RFC
>> 4869 and incorporates comments that have been posted to the ipsec
>> mailing list.
>
>On reading the spec, it's not clear to me whether an IKEv1
>implementation which supports ECP-based DH (rfc4753) with preshared keys
>but not ECDSA (rfc4754) is considered to usefully implement this
>specification.

The text says:
  IKEv1 implementations MUST
  support pre-shared key authentication [RFC2409] for interoperability.
  The authentication method used with IKEv1 MUST be either pre-shared
  key [RFC2409] or ECDSA-256 [RFC4754].
To me, that sounds like preshared keys are just fine for IKEv1 in this profile, but I might be misunderstanding what you mean by "usefully".

>As a practical matter, the ECDSA piece of this spec is likely to be the
>largest and last piece built -- given a working elliptic curve codebase,
>plugging ephemeral ECDH into an IKE implementation is a much smaller
>problem than building ECDSA into both an IKE implementation and the PKI
>client codebase, tools, and keystores it relies on.

Probably true, but ECDSA is far from impossible, as the OpenSSL people have shown for a while now.

--Paul Hoffman, Director
--VPN Consortium