Re: IKE V2 Open Issues

["Theodore Ts'o" <tytso@mit.edu>]

On Fri, Apr 11, 2003 at 07:44:41PM +0300, Hugo Krawczyk wrote:
> First let me make a clarification that is important to keep in mind
> (and relates to an objection that you raised in another message in this
> thread). The proposal to protect IDi from active attacks applies ONLY
> to the EAP extension of ikev2. All other runs of the protocol (in
> particular peer-to-peer runs) will have the same protection that the WG
> decided long ago (that is, IDr has full protection while IDi has only
> protection against active attacks).

Hugo, 

The proposal that we do things such as "moving IDr, [CERT,] AUTH from
msg 4 to msg 2", but only in the case of legacy authentication, is by
its very nature complicated.

In essence, instead of legacy authentication being just an extra
optional EAP payload, it becomes a different protocol with payloads
appearing in a different order and information being available at
different times.  Doing this would complicate the job of the spec
writer, the implementor, as well as someone trying to reason about the
security properties of IKE.

						- Ted