Agenda: dnssec-bind-manual-ksk-rollover.txt

Manual Key Rollover Exercise

OBJECTIVE

We are going to roll the KSK for the zones we have just signed.

REMINDERS

 - we are keeping our keys in /etc/namedb/keys/

 - we currently have two or more keys in that directory, one KSK
   and one or more ZSKs.
   Each key is represented by two files, one ending in ".key" (the
   public key) and one ending in ".private" (the private key)

 - there is a DS RRSet in the "root" zone corresponding to our KSK


KSK ROLLOVER

The process is rather similar to the ZSK rollover:

1. Go to the key dir:

    $ cd /etc/namedb/keys/
    $ ls K*

2. Just like in step 2 of the ZSK rollover, generate a new KSK
   You will need to use the "-f KSK" parameter to dnssec-keygen:

   $ dnssec-keygen -f KSK -a RSASHA256 -b 2048 -n ZONE mytld

   This will output something like:

   Kmytld.+008+54511

3. Calculate a DS RRSet for the new KSK.

  $ cd /etc/namedb/keys/
  $ sudo dnssec-dsfromkey Kmytld.+005+54511.key > dsset-mytld-54511.

  (here 54511 is just the ID of the new KSK so we know which DS is
  which).

4. Upload the dsset for your zone, using the web interface or using
   SCP as shown by the root instructor

   Tell an instructor that you have submitted a new DS RRSet, and that
   you would like it to be added to the "root" zone. If you used the
   web interface, this should have happened automatically.

   If using web interface, login as before.

   Under the "Edit Trust Anchor Details" section enter the Key Tag,
   Digest, Algorithm, and Digest type from the output of
   step 3 above. E.g.,

   mytld. IN DS 54511    8          2      983F33D43D1EBB069BF60...
                TAG  Algorithm Digest-Type Digest
                     RSASHA256

   Make sure to eliminate any spaces from the Digest and note that you
   only need one trust anchor.

   Click "Update" when done. Wait a minute for update to propagate.

5. Double check that the new DS is published in the parent (root) zone
    alongside the existing one (you should wait at least 2 x TTL 
    until all the caches are updated):

   $ dig @10.10.0.230 DS mytld
   ...
   ;; ANSWER SECTION:
   mytld    900 IN  DS 52159 8 2 31F1...
   mytld    900 IN  DS 54511 8 2 983F...  // <-- the new KSK
   ...

   Since both DS are now present in the cache, we can roll our KSK.

   Then we add the new KSK to the zone (edit the file), and we comment
   out (remove) the old KSK:

   From this:

$include "/etc/namedb/keys/Kmytld.+008+52159.key"; // KSK

   To this:

;$include "/etc/namedb/keys/Kmytld.+008+52159.key"; // KSK old
$include "/etc/namedb/keys/Kmytld.+008+54511.key"; // KSK new

    Remember to increment the serial number too.

    ... notice how we simply get rid of the old KSK - we don't need
    it - both DS records are there, so it's enough to have only one
    KSK, since we already "know" about its DS "on the internet".

6. Let's sign the zone with the new KSK

  $ cd /etc/namedb/keys
  $ sudo dnssec-signzone -o mytld -k Kmytld.+005+54511 ../master/mytld Kmytld.+005+45000

  $ sudo rndc reload mytld

7. Check with dig - both before and after the TTL expire (or cache flush)

  $ dig dnskey mytld +multi
  $ dig dnskey mytld +dnssec +multi
 
8. Tell an instructor that you would like the original DS resource
   records to be removed from the "root" zone (or remove it yourself
   using the web interface)

9. Sit back and reflect on what an involved and annoying process
this was, and how much better things would be if all your key
rollovers were managed automatically.