Re: Choosing between IKEv2 and JFK

[Dan Harkins <dharkins@tibernian.com>]

  Why does the initiator need to know whether his IP address changed? He's
getting back an opaque blob which is solely for the responder's use. How
that blob was derived is not important to him. He doesn't know HKr either.

  If a NAT box is between the two parties then the address included in the
authenticator blob calculations will be that of the NAT box. This will not
"destroy NAT interop."

  Dan.

On Wed, 13 Mar 2002 09:04:08 PST you wrote
> > Dan Harkins <dharkins@tibernian.com> writes:
> > > Caching authenticator blobs and blacklisting the naughty 
> > ones will not
> > > stop this attack.
> > Right, I see your point. I'd forgotten about the cookie pre-fetch
> > phase. 
> > 
> > I agree that this attack exists with JFK and not with IKEv2. I'm not
> > sure how serious it really is, but it seems like it would be easy to
> > stop. JFK guys, do you have some reason not to include the initiators
> > IP in the authenticator?
> 
> Like including it would destroy NAT interop?
> 
> If the packet goes through a NAT the initiator does not know the IP 
> address that the packets it sends will have when they arrive.
> 
> 		Phill
>