Re: [dns-privacy] NS names, was re-evaluation of the draft, was Re: [Fwd: New Version Notification for draft-vandijk-dprive-ds-dot-signal-and-pin-00.txt]

[John R Levine <[e-mail]>]

>>     That sounds quite painful for servers that serve hundreds or
>>     thousands of zones.

I think this will work for NS with names in the zone.  Still scratching my 
head about NS in other zones.

On a referral, the parent server sends TLSA records as glue along with 
the NS and DS in the referral.  The client connects to the one of those NS 
and checks the cert with TLSA.  It then retrieves the signed NS and TLSA 
from the child to ensure that they match the unsigned ones from the 
parent.  To resist downgrades, if a client gets a referral without a TLSA 
but finds a TLSA in the child zone, it (wave hands a little) complains and 
reconnects using TLS.

I don't think that leaks anything beyond what you can tell from the fact 
that it's making connections to port 853. It doesn't leak what name is 
being referred.

The bad news is that authoritative servers have to be adjusted to send
TLSA as glue, and registry provisioning systems have to handle TLSA glue 
as well as A and AAAA.

For NS with names out of the zones, I guess the client looks for a TLSA 
when it looks for A and AAAA.

Regards,
John Levine, [e-mail], Taughannock Networks, Trumansburg NY
Please consider the environment before reading this e-mail. https://jl.ly