[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Field Variance Analysis
Craig Metz writes:
> >I believe that Hilarie has hit on the way to cut the gordian knot. If
> >the originating system wants to protect options under IPv4, it
> >probably should encapsulate the whole packet and not just the
> >transport.
>
> Consider the goal of protecting source routes.
I'm not sure there is a point to protecting source routes.
Consider the following:
1) The worst the attacker can do is force you to use a different route
than the intended one. He can force you to reply on a reversed bad
source route and can read your messages and keep the intended
recipient from reading them. However, if he's an active attacker in
the line he can do that anyway.
2) We can't authenticate to intermediate nodes so the only thing the
machine on the end knows is what source route options the packet
was sent with, *not* what path it took.
Authentication makes source routing safe not because it makes the
source routes themselves immune from attack but because it
authenticates the endpoints.
Perry