Re: [DNSOP] NSEC/NSEC3 for unsigned zones and aggressive use

[Francis Dupont <[e-mail]>]

 In your previous mail you wrote:

>  NSEC needs no keys, only their RRSIGs would which wouldn't exist in
>  unsigned zones. In this case the unsigned NSEC would also not be part of
>  the zone (it would have to be synthesized and maintained outside the
>  zone).

=> but it is created by an authoritative server, isn't it?
And as it is synthesized I can't see a good reason to use NSEC3 instead.

>  Because an unsigned/unauthenticated NSEC/NSEC3 has the potential to nix
>  entire zones, when it was discussed, Mark Andrews suggested that
>  requiring DNS COOKIE to further reduce the chance of cache poisoning
>  (more than source port randomization and random message ID) could be a
>  reasonable idea to think about.

=> it adds a nonce so another (short) bunch of unpredictable bits.
As NSEC is not signed it is more than vulnerable to on-the-path attacks.
I am afraid it is first a massive zone destruction weapon and after
perhaps an optimization...

>  > It seems easier to remember that DNSSEC offers proofs for denial of
>  > existence.

=> still applies...

Regards

[e-mail]

PS: really if this is deployed I can see more "interesting" ways for misuses
than real benefits. Of course it can be a mean to make zone managers
to rush on DNSSEC...