Re: Quic: the elephant in the room

[Nico Williams <[e-mail]>]

On Mon, Apr 12, 2021 at 11:33:29AM -0400, Phillip Hallam-Baker wrote:
> On Mon, Apr 12, 2021 at 11:22 AM Michael Thomas <[e-mail]> wrote:
> > Correct. Better: you can do the TLSA request at the same time as the
> > A/AAAA request speculatively. Plus if you've ever had a TLSA record for
> > that domain, you know it's pretty likely you'll get a fresh one even if
> > the last one is expired, so the speculation is minimal.
> 
> Or replace the DNS resolver protocol with a privacy protected one in which
> a single request packet can be answered by multiple response packets. This
> maintains the 'stateless' nature of DNS queries but allows responses of
> 1-32 packets.

As long as it's not over UDP, or otherwise first has a return
routability check.

> Then a query to the responder can return the A record, the AAAA record, the
> SRV record, any relevant TXT and TLSA records [...]

Kinda like "any" queries.

>                                         [...] and the entire cert chain for
> one particular host chosen by the responder.

You get better security properties (w.r.t. possible compromised root or
ccTLD/TLD keys) if the resolver finds the DNSSEC chain on its own using
qname minimization than you get with stapling, but I agree that stapling
is a performance win.  We'll really want transparency for DNSSEC if we
do any kind of full chain stapling.

Nico
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