Zone setup and initial preparation


zkt-signer — Secure DNS zone signing tool


zkt-signer [−L file] [−V view] [−c file] [−O optstr] [−fhnr] [−v [−v]] −N named.conf [zone ...]
[−L file] [−V view] [−c file] [−O optstr] [−fhnr] [−v [−v]] [−D directory] [zone ...]
[−L file] [−V view] [−c file] [−O optstr] [−fhnr] [−v [−v]] −o origin [zonefile]


The zkt-signer command is a wrapper around dnssec-signzone(8) and dnssec-keygen(8) to sign a zone and manage the necessary zone keys. It is able to increment the serial number before signing the zone and can trigger named(8) to reload the signed zone file. The command controls several secure zones and, if started in regular intervals via cron(8), can do all that stuff automatically.

In the most useful usage scenario the command will be called with option −N to read the secure zones out of the given named.conf file. If you have a configuration file with views, you have to use option -V viewname or --view viewname to specify the name of the view. Alternately you could link the executable file to a second name like zkt-signer-viewname and use that command to specify the name of the view.
All master zone statements will be scanned for filenames ending with ".signed". These zones will be checked if the necessary zone- and key signing keys are existent and fresh enough to be used in the signing process. If one or more out-dated keys are found, new keying material will be generated via the dnssec-keygen(8) command and the old keys will be marked as depreciated. So the command do anything needed for a zone key rollover as defined by [2].

If the resigning interval is reached or any new key must be announced, the serial number of the zone will be incremented and the dnssec-signzone(8) command will be evoked to sign the zone. After that, if the option −r is given, the rndc(8) command will be called to reload the zone on the nameserver.

In the second form of the command it is possible to specify a directory tree with the option −D dir. Every secure zone found in a subdirectory below dir will be signed. However, it is also possible to reduce the signing to those zones given as arguments.
If −D is ommitted (and neither −N nor −oorigin is specified) the default directory specified in the dnssec.conf file by the parameter zonedir will be used as top level directory.


−L file|dir, −−logfile=file|dir

Specify the name of a log file or a directory where logfiles are created with a name like zkt-YYYY-MM-DDThhmmssZ.log. If the argument is not an absolute path name and a zone directory is specified in the config file, this will be prepended to the given name. This option is also settable in the dnssec.conf file via the parameter LogFile.
The default is no file logging, but error logging to syslog with facility USER at level ERROR is enabled by default. These parameters are settable via the config file parameter SyslogFacility, SyslogLevel, LogFile and Loglevel.
The additional parameter VerboseLog specifies the verbosity (0|1|2) of messages that will be logged with level DEBUG to file and syslog.

−V view, −−view=view

Try to read the default configuration out of a file named dnssec-<view>.conf . Instead of specifying the −V or --view option every time, it is also possible to create a hard- or softlink to the executable file with an additional name like zkt-signer-<view> .

−c file, −−config=file

Read configuration values out of the specified file. Otherwise the default config file is read or build-in defaults will be used.

−O optstr, −−config-option=optstr

Set any config file option via the commandline. Several config file options can be specified via the argument string but have to be delimited by semicolon (or newline).

−f, −−force

Force a resigning of the zone, regardless if the resigning interval is reached or new keys must be announced.

−n, −−noexec

Don’t execute the dnssec-signzone(8) command. Currently this option is of very limited usage.

−r, −−reload

Reload the zone via rndc(8) after successful signing. In a production environment it is recommended to use this option to be sure that a freshly signed zone will be immediately propagated. However, that’s only feasable if named runs on the signing machine, which is not recommended.

−v, −−verbose

Verbose mode (recommended). A second −v will be a little more verbose.

−h, −−help

Print out the online help.


zkt-signer −N /var/named/named.conf −r −v −v

Sign all secure zones found in the named.conf file and, if necessary, trigger a reload of the zone. Print some explanatory remarks on stdout.

zkt-signer −D zonedir/example.net. −f −v −v

Force the signing of the zone found in the directory zonedir/example.net . Do not reload the zone.

zkt-signer −D zonedir −f −v −v example.net.

Same as above.

zkt-signer −f −v −v example.net.

Same as above if the dnssec.conf file contains the path of the parent directory of the example.net zone.

zkt-signer −f −v −v −o example.net. zone.db

Same as above if we are in the directory containing the example.net files.

zkt-signer −−config-option=’ResignInterval 1d; Sigvalidity 28h; \

ZSKlifetime 2d;’ −v −v −o example.net. zone.db
Sign the example.net zone but override some config file values with parameters given on the commandline.

Zone setup and initial preparation

Create a separate directory for every secure zone.

This is useful because there are many additional files needed to secure a zone. Besides the zone file (zone.db), there is a signed zone file (zone.db.signed), a minimum of four files containing the key material, a file called dnskey.db with the current used keys, and the dsset- and keyset-files created by the dnssec-signzone(8) command. So in summary there is a minimum of nine files used per secure zone. For every additional key there are two extra files and every delegated subzone creates also two or three files.

Name the directory just like the zone.

That’s only needed if you want to use the zkt-signer command in directory mode (−D). Then the name of the zone will be parsed out of the directory name.

Change the name of the zone file to zone.db

Otherwise you have to set the name via the dnssec.conf parameter zonefile, or you have to use the option −o to name the zone and specify the zone file as argument.

Add the name of the signed zonefile to the named.conf file

The filename is the name of the zone file with the extension .signed. Create an empty file with the name zone.db.signed in the zone directory.

Include the keyfile in the zone.

The name of the keyfile is settable by the dnssec.conf parameter keyfile . The default is dnskey.db .