[CentOS] DNSSEC Questions

Fri Feb 15 22:58:17 UTC 2019
Gordon Messmer <gordon.messmer at gmail.com>

On 2/12/19 11:49 PM, Paul R. Ganci wrote:
> Okay so I misunderstood the message I was getting when I checked my 
> DNSSEC setup via http://dnsviz.net/. What you are telling me is that 
> all I had to do was re-sign the zone files but that it was not 
> necessary to generate new keys. This point is definitely one that I 
> missed.
>
> I too run my own authoritative nameservers. I was following the 
> Digital Ocean procedure to setup DNSSEC:


Key rotation and signature rotation are separate concerns.  Most users 
should be able to significantly simplify signature rotation using bind's 
built-in signing management, rather than using dnssec-signzone.  You can 
define your zone like so:

         zone "example.net" IN {
                 type master;
                 file "dynamic/db.example.net";
                 update-policy local;
                 key-directory "keys/example.net";
                 inline-signing yes;
                 auto-dnssec maintain;
         };

...and then either replicate your zone to a public-facing host, or 
export and manually copy the zone (maybe "dig @localhost example.net -t 
axfr"?)

Manual signing is probably only useful if you want your DNSSEC key files 
kept on a system that isn't connected to a network, for security 
reasons, and you have another process for publishing the signed zone files.

(Newer bind releases have a python tool to manage key rotation. I use 
this one: https://bitbucket.org/gordonmessmer/update-dns-keys/)


> So doesn't ldns-signzone create the same kind of digest that requires 
> it be uploaded to the registrar?


Yes, I think so.  If I understand you properly.


> So maybe I asked the wrong question. Is there a way to re-sign the 
> zone files without having to recreate the information found in that 
> dsset-domain.tld. file and uploading it to the registrar?


If you mean the DS records, those should be stable as long as you have 
the same KSK, so there's nothing *new* to upload when your zones are 
re-signed.