Microsoft deems all DigiNotar certificates untrustworthy, releases

Måns Nilsson mansaxel at
Mon Sep 12 20:31:59 UTC 2011

Subject: Re: Microsoft deems all DigiNotar certificates untrustworthy, releases Date: Mon, Sep 12, 2011 at 11:46:04AM +0200 Quoting fredrik danerklint (fredan-nanog at
> > > How about a TXT record with the CN string of the CA cert subject in it?
> > > If it exists and there's a conflict, don't trust it.  Seems simple
> > > enough to implement without too much collateral damage.
> > 
> > Needs to be a DNSSEC-validated TXT record, or you've opened yourself up
> > to attacks via DNS poisoning (either insert a malicious TXT that matches
> > your malicious certificate, or insert a malicious TXT that intentionally
> > *doesn't* match the vicitm's certificate)....
> And how do you validate the dnssec to make sure that noone has tampered with 
> it.

Since you are from Sweden, and in an IT job, you probably have personal
relations to someone who has personal relations to one of the swedes
or other nationalities that were present at the key ceremonies for the
root. Once you've established that the signatures on the root KSK are good
(which -- because of the above -- should be doable OOB quite easily for
you) you can start validating the entire chain of trust.

Quite trivial, in fact. 

Måns Nilsson     primary/secondary/besserwisser/machina
MN-1334-RIPE                             +46 705 989668
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