Subject: Re: [mobile-ip] Issue 20 (extensibility) can be closed

From: Erik Nordmark <[email-masked]>
Date: Tue, 2 Jul 2002 11:40:00 +0200 (CEST)

> I'm curious about whether ABK would fit into this scheme.
> 
> Basically, we see ABK as not needing either HoTI or CoTI. The MN exchanges
> protocol with the CN instructing the CN to load the id-crypto parameters
> from the HA. After the parameters are loaded, the MN can send signed BUs to
> the CN without having to use any other security signaling.

A brief glance at the Okazaki ABK draft makes me think there are DoS
and perhaps reflection opportunities. The ABKP1 causes a P2 to be sent to
the HA, and presumably creates some state on the CN in order to do the
P2/P3 transaction against the HA.

If you want to avoid these threats I think you end up with at least a
CoTI/CoT exchange.

  Erik

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From: "James Kempf" <[email-masked]>
Date: Tue, 2 Jul 2002 11:11:40 -0700

> P2/P3 transaction against the HA.

The ABKP1-ABKp4 message exchange is intended to be stateless on the CN. That
is why the CoA is included in messages ABKp2 and ABKp3.

> If you want to avoid these threats I think you end up with at least a

In the next version, we have some ideas about eliminating the dependence on the CoA entirely by running the parameter loading
transaction through the home agent. If we can get it worked out properly, this should remove the threat of an attacker using a
random CoA.

            jak