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Re: New XAUTH draft
On Thu, 30 Sep 1999 21:04:18 EDT you wrote
>
> Dan, I have a question (even though I've been trying hard to delete every
> message that says "XAUTH" or "Hybrid" in it), do *you* prefer hybrid to XAUTH
>?
Yes. Hybrid+XAUTH is much better than XAUTH. It prevents the m-in-m issue
by authenticating the IKE SA (unidirectionally, but authenticating it
nonetheless) prior to doing the XAUTH stuff. But the client does not bind
himself in any way to the SKEYID state even with Hybrid+XAUTH. It might
not matter and I'm not a cryptographer but it just rubs the wrong way.
A much better solution would be for Hybrid to not proceed to XAUTH but to
use its secure channel to authenticate a (raw) public key for the client
and then use that key to do a standard digital signature authentication.
That whole phase 1.5 stuff is an unnecessary complication on an already
extremely complicated protocol. Sometimes you proceed from 1 to 2 other
times it's 1 to 1.5 to 2. Error prone. Yeech.
Dan.
References: