Track3Sec: 2.8_dnssec-bind-inline-signing-howto.txt

Automated zone INLINE signing with BIND
---------------------------------------

Remember that if you see '#' before a command, it means
you need to run this command as root, either via:

a) sudo -s

b) sudo command

We'll build on the previous labs and enable inline signing on BIND (9.9+)

When doing inline signing, the original zone is never modified: this
allows the operator to make, for example, a dump of a DB to create the
zone, and BIND will just sign it.

When the unsigned zone is updated, named detects the changes, 
and re-signs.

*** ON YOUR MASTER (auth1) SERVER ***

1. We're going to add a couple of statements to the BIND named.conf
   configuration file to enable inline dnssec signing.

   First, edit named.conf under /etc/namedb/, and make the following
    changes:

        zone "mytld" {
        file "/etc/namedb/master/mytld"; // <--- remove ".signed", if there
                                                    
        type master;
        allow-transfer { key mytld-key; }; // <-- leave it if there
        key-directory "/etc/namedb/keys";   // <--- Add this if not done
        auto-dnssec maintain;           // <--- Add this if not yet done
        inline-signing yes;                 // <--- Add this
        // update-policy local;             // <--- Remove if it's there
        };

    Save and exit.

2. Preparing the keys

       If you've done the manual signing lab from before, you have already
       generated keys, and we can reuse those. Otherwise, we'll generate
       a new set of keys.

    a) If you already have keys (otherwise go to step b)

       We need to make sure the directory has the right permissions 
       - since BIND will be managing this, it needs access to the 
       files and the directory:

        # chown -R bind /etc/namedb/keys

       Let's look at the keys:

        # cd /etc/namedb/keys/

    # ls -l Kmytld*
    -rw-r--r--  1 bind  wheel   591 Feb 18 15:52 Kmytld.+008+52159.key
    -rw-------  1 bind  wheel  1774 Feb 18 15:52 Kmytld.+008+52159.private
    -rw-r--r--  1 bind  wheel   417 Feb 18 15:52 Kmytld.+008+51333.key
    -rw-------  1 bind  wheel  1010 Feb 18 15:52 Kmytld.+008+51333.private

      If you have extra ZSK and KSK from manual key rollover exercizes,
      delete the oldest ZSK and KSK.  Make sure to leave just one 
      KSK and one ZSK.  If you delete the wrong ones, reconfig with RZM.


    b) If you don't have keys yet:

        # mkdir -p /etc/namedb/keys
        # chown -R bind /etc/namedb/keys
        # cd /etc/namedb/keys

        - Generate first key pair (Zone Signing Key)

    # dnssec-keygen -a RSASHA256 mytld

    (  will output something like:
    Generating key pair......................+++++ + ....
    Kmytld.+008+51333)

        - Generate second key pair (Key Signing Key)

    # dnssec-keygen -f KSK -a RSASHA256 mytld
    Kmytld.+008+52159

    (once again, some output will show)

        Check that the keys are there:

        # ls -l Kmytld*

      Notice that we don't specify any flags such as algorithm, key size,
      etc... We're using the defaults for now.


3. Now let's take care of the zone file

   If you have made a backup of your zone file, let's copy it back over
   our zone, to start fresh:

        # cd /etc/namedb/master

   Note the serial number in "mytld"

        # cp mytld.backup mytld

   Increment the serial number in mytld to be higher than what we noted
   above.

   Remove the old .signed zone - BIND will create that automatically!

    # rm mytld.signed

   Again, remember to check in named.conf, that you are loading "mytld",
   and *NOT* "mytld.signed".

   We also need to make sure BIND can write in the master directory:

   # chown bind /etc/namedb/master

4. Now reconfig the nameserver

    # rndc reconfig

    At this point you should see some new files appear in the master/ dir:

        # cd /etc/namedb/master
        # ls -l

...
-rw-r--r--  1 root  wheel   497 Sep 13 14:56 mytld
-rw-r--r--  1 root  wheel   497 Sep 12 09:49 mytld.backup
-rw-r--r--  1 bind  wheel   512 Sep 13 15:04 mytld.jbk
-rw-r--r--  1 bind  wheel  1331 Sep 13 15:04 mytld.signed
-rw-r--r--  1 bind  wheel  3581 Sep 13 15:04 mytld.signed.jnl
...

        Check that signing did work:

        # rndc signing -list mytld
        Done signing with key 22603/RSASHA1
        Done signing with key 39978/RSASHA1

        Also look in the logs:

        # less /etc/namedb/log/general

13-Sep-2012 15:04:27.444 reloading configuration succeeded
13-Sep-2012 15:04:27.450 zone mytld/IN (unsigned): loaded serial 2012022301
13-Sep-2012 15:04:27.451 any newly configured zones are now loaded
13-Sep-2012 15:04:27.471 zone mytld/IN (signed): loaded serial 2012022301
13-Sep-2012 15:04:27.493 zone mytld/IN (signed): receive_secure_serial: unchanged
13-Sep-2012 15:04:27.501 zone mytld/IN (signed): reconfiguring zone keys
13-Sep-2012 15:04:27.544 zone mytld/IN (signed): next key event: 13-Sep-2012 16:04:27.501


        # dig @10.10.X.1 mytld NS
        # dig @10.10.X.1 mytld SOA

      Note that the signed zone is not stored in a human readable format.

        To see the contents of the signed zone, one can either do a zone
        transfer (axfr) or:

        # named-checkzone -D -f raw -o - mytld mytld.signed | less

5. Changes to the zone

        So how do we update the zone and resign it ? Simple!

        Let's modify the zone and add a "mail" record with the IP address
        of the auth1 server:

        mail    A       10.10.XX.1  ; X is your group

        So edit the zone file "mytld" and add the line above.

        Remember to increment the serial.

        Now, reload the zone. named will be automatically resign the zone:

        # rndc reload mytld

        Wait a few seconds, then:

        # tail /etc/namedb/log/general

        What do you observe ?

        # dig @10.10.X.1 mail.mytld a
        # dig @10.10.X.1 mytld soa

        Notice the serial

6. If you haven't already uploaded the DS record in a previous lab, it's
   time to communicate it to your parent (the root). Otherwise, goto
   step 8.

    (DS = digest fingerprint of the Key Signing Key).

   Generate a "DS" from your key:

    Find which key is the key signing key:

    # cd /etc/namedb/keys
    # more Kmytld*key
    
    Look at which one has "IN DNSKEY 257". Find the "keyid" and replace
    the string "+008+52159" below with "+008+keyid" where "keyid" is the
    number displayed.

    # dnssec-dsfromkey Kmytld.+008+52159

    Use web based managment interface. (See previous
    BIND manual signing exercize for details).

7. You should be able to verify this:

        # dig @a.root-servers.net DS mytld.

8. After 2 x TTL the changes you observed locally should be visible
   globally.  Test this with

        # dig @10.10.0.230 mail.mytld a +dnssec +multi
        # dig @10.10.0.230 mytld soa +dnssec +multi
        # dig @10.10.0.230 mytld dnskey +dnssec +multi

   You should see the AD bit set in all cases.