Using OpenDNSSEC v1.2.0

This documentation is based on OpenDNSSEC v1.2.0

Scope

The goal of OpenDNSSEC is to have a complete DNSSEC zone signing system which maintains stability and security of signed domains. DNSSEC adds many cryptographic concerns to DNS; OpenDNSSEC automates those to allow current DNS administrators to adopt DNSSEC. This document provides DNS administrators with the necessary information to get the system up and running with a basic configuration.

Installation

Before you start to use OpenDNSSEC in your production environment you must first decide which hardware you going to run on. When you have a good system to run on, then it is time to install the software that OpenDNSSEC depends on, and finally installing OpenDNSSEC.

Hardware set-up

Here are some short recommendations if you are planning to use OpenDNSSEC with many zones or a single large zone, and where the time is important.

OpenDNSSEC is multi-threaded when it concerns the handling of multiple zone. But it is not currently multi-threaded in the handling of a single zone. So a multi-core machine will not give any benefits if you plan to only run a single large zone. It is thus, in this case, more important to go with a CPU that is fast rather than a CPU with many cores.

The OpenDNSSEC signer engine makes backup files to recover your zone data with no loss. These backup files will use up approximately three times the size of the signed zone on the HDD. The zones are also stored in memory. To keep track of updates, OpenDNSSEC maintains a previous, current and a new version of the zone.

Platform support

OpenDNSSEC has been tested on the following platforms:

  • Debian Linux 5.0
  • Mac OS X 10.5
  • NetBSD
  • OpenBSD 4.4
  • Red Hat Enterprise Linux 5
  • Solaris 10
  • Ubuntu Linux 10.04

Dependencies

OpenDNSSEC depends on a number of open-source packages, all of which must be installed on your system for OpenDNSSEC to build successfully.

The  Installation of depencencies guide shows which packages are required and how to download/install them.

NOTE: You also need an  HSM.

Choose from any vendor that uses the  PKCS#11 interface. Or the software-only implementation of an HSM called SoftHSM created by the OpenDNSSEC project. Follow these instructions on  how to install SoftHSM.

Pre-built Binaries

You can find information about packages for your operating system here: http://www.opendnssec.org/download/packages/

Obtaining the Source Code

The latest version of OpenDNSSEC can be found as a tarball on  http://www.opendnssec.org

The development (unstable) version of OpenDNSSEC is available from the Subversion repository and can be obtained using the following command:

svn co http://svn.opendnssec.org/trunk/OpenDNSSEC OpenDNSSEC

Building & Installing

If you downloaded the tarball then first untar it:

 tar -xzf opendnssec-<VERSION>.tar.gz
 cd OpenDNSSEC

or if you are working from the repository:

 cd OpenDNSSEC
 sh autogen.sh

Then it is time to configure the build scripts:

 ./configure

You may also need some other options to configure.

  --disable-auditor       Disable auditor build (default enabled)
  --enable-eppclient      Enable eppclient build (default disabled) (experimental)
  --enable-timeshift      For debugging purposes
  --with-database-backend Select database backend (sqlite3|mysql) (default sqlite)

Use the following command to find out which other options that are available:

 ./configure --help

The configure script defaults to –prefix=/usr/local, –sysconfdir=/etc, and –localstatedir=/var

Once configured, build OpenDNSSEC using:

 make

… and install using …

 sudo make install

If the build fails it might be because of a missing software dependency. Please read the error messages carefully.

Post-installation

Depending on operating system, there may be a few additional steps required after installation.

Linux Users Linux users need to rebuild the dynamic linker caches. To do this, issue the command:

sudo ldconfig [library-path [library-path ...]]

If OpenDNSSEC or any of the pre-requisites were installed in non-standard directories, the list of library paths should be specified as arguments on the command line.


Dependencies

The following sections list the prerequisite software required for OpenDNSSEC. For Ubuntu users, the name of the package (where relevant) is listed, although note that the version of the package available from the Ubuntu download sites may not be compatible with OpenDNSSEC; in that case, the latest version of the package should be obtained (and built if required). Users of operating systems with different software packaging should consult the appropriate documentation.

Implicit in these sections is the assumption that the operating system has the following languages installed: C, C++, Ruby. If any are absent, consult the documentation for your operating system.

In all cases, a location from where to get a copy of the package source code and build instructions for the package are given.

As there are some dependencies between the prerequisite components, they should be installed in the order listed here. Note, where no version number is specified any fairly recent distribution (e.g. Ubuntu 10.04) will have a new enough version of the software in its standard repositories. Also note that these are minimum version numbers, so they provide API calls that we use; there may be bug fixes in later versions which are useful.

Software min. version for 1.2.0 min. version for trunk
ldns 1.6.7 1.6.7
libxml2, libxml2-dev, libxml2-utils 2.6.16 2.6.16
ruby, rubygems
dnsruby 1.51 1.51
libopenssl-ruby
java not required
sqlite3, libsqlite3, libsqlite3-dev 3.3.9 3.3.9
(mysql-client, libmysqlclient15, libmysqlclient15-dev) 5.0.3 5.0.3

ldns

ldns is a DNS programming library used in the signer component.

Ubuntu Users
Make sure the the packages “libldns-x.z.y” (where “x.y.z” is the ldns version number) and “libldns-dev” are installed on your system.

Installing from Source Distribution
Download a copy of ldns from  http://www.nlnetlabs.nl/downloads/ldns.

When downloaded and unpacked, “cd” into the directory into which you have unpacked the tar file and issue the following commands:

./configure
make
sudo make install

This installs the ldns library in /usr/local/lib. If you require the software to be installed elsewhere, add the switch --prefix=<location> to the ./configure command.

libxml2

libxml2 is a C-library for handling XML. It is used in all parts of OpenDNSSEC.

Ubuntu Users
Install the packages “libxml2″, “libxml2-dev”, and “libxml2-utils”.

Installing from Source Distribution
Download a copy of libxml2 from  http://xmlsoft.org/downloads.html.

When downloaded and unpacked, “cd” into the directory into which you have unpacked the tar file and issue the following commands:

./configure
make
sudo make install

This installs the libxml2 library in /usr/local/lib. If you require the software to be installed elsewhere, add the switch --prefix=<location> to the ./configure command.

Ruby Gems

Ruby Gems is the standard way of installing Ruby packages. It is only used for the installation of the DNSRuby package.

Ubuntu Users
Install the package “rubygems”.

Installing from Source Distribution
Download a copy of RubyGems from  http://rubyforge.org/projects/rubygems.

When downloaded and unpacked, make sure that “ruby” is in your path, then issue the following command:

sudo ruby setup.rb

… to install RubyGems. The command “gem” will be installed in the same place as the “ruby” command.

dnsruby

dnsruby is a third-party DNS library used by the Auditor.

There is no Ubuntu package for dnsruby. Instead, on all operating systems, install dnsruby using the command:

sudo gem install dnsruby

OpenSSL for Ruby

The Auditor uses the OpenSSL library for some operations.

Ubuntu Users
Install the package “libopenssl-ruby”.

Installing from Source Distribution
Most operating systems seem to include this software as part of the operating system. Consult your documentation for more information.

SQlite

SQlite is a cut-down SQL database system, used by the KASP component of OpenDNSSEC.

Ubuntu Users
Install the packages “sqlite3″ and “libsqlite3-dev”.

Installing from Source Distribution
Download a copy of Sqlite from  http://www.sqlite.org/download.html.

When downloaded and unpacked, “cd” into the directory into which you have unpacked the tar file and issue the following commands:

./configure
make
sudo make install

This installs sqlite in /usr/local/bin. If you require the software to be installed elsewhere, add the switch --prefix=<location> to the ./configure command.

MySQL

You can choose to use MySQL instead of SQLite for the KASP database. Currently this is only an experimental feature for OpenDNSSEC.

Ubuntu Users
Install the packages “mysql-client”, “libmysqlclient15″, “libmysqlclient15-dev”.

Installing from Source Distribution
Download it from  http://dev.mysql.com/downloads/mysql

At this site there are links for various different systems, or to the source code if you want to build the code yourself. Full documentation is also available from the download page.


Configuration

The default configuration installs good default values for anyone who just wants to sign their domains with DNSSEC. There are four configuration files for the basic OpenDNSSEC installation. You have conf.xml which is the overall configuration of the system, kasp.xml which contains the policy of signing, then there is zonelist.xml where you list all the zones that you are going to sign, and finally an optional zonefetch.xml for zone transfers.

Date/time durations

Before describing each of the configuration files, we need to explain how timing is described in all of them. All date/time durations in the configuration files are specified as defined by  ISO 8601.

Durations are represented by the format P[n]Y[n]M[n]DT[n]H[n]M[n]S. In these representations, the [n] is replaced by the value for each of the date and time elements that follow the [n]. Leading zeros are not required. The capital letters ‘P’, ‘Y’, ‘M’, ‘W’, ‘D’, ‘T’, ‘H’, ‘M’, and ‘S’ are designators for each of the date and time elements and are not replaced.

  • P is the duration designator (historically called “period”) placed at the start of the duration representation.
  • Y is the year designator that follows the value for the number of years.
  • M is the month designator that follows the value for the number of months.
  • W is the week designator that follows the value for the number of weeks.
  • D is the day designator that follows the value for the number of days.
  • T is the time designator that precedes the time components of the representation.
  • H is the hour designator that follows the value for the number of hours.
  • M is the minute designator that follows the value for the number of minutes.
  • S is the second designator that follows the value for the number of seconds.

For example, “P3Y6M4DT12H30M5S” represents a duration of “three years, six months, four days, twelve hours, thirty minutes, and five seconds”. Date and time elements including their designator may be omitted if their value is zero, and lower order elements may also be omitted for reduced precision. For example, “P23DT23H” and “P4Y” are both acceptable duration representations.

Exception: A year or month vary in duration depending on the current date. For OpenDNSSEC, we assume fixed values

  • One month is assumed to be 31 days.
  • One year is assumed to be 365 days.

conf.xml

The overall configuration of OpenDNSSEC is defined by the contents of the file /etc/opendnssec/conf.xml. In this configuration file you specify logging facilities (only syslog is supported now), system paths, key repositories, privileges, and the database where all key and zone information is stored.

Read more  details about conf.xml

kasp.xml

kasp.xml – found by default in /etc/opendnssec – is the file that defines policies used to sign zones. KASP stands for “Key and Signature Policy?, and each policy details

  • security parameters used for signing zones
  • timing parameters used for signing zones

You can have any number of policies and refer to the proper one by name in for example the zonelist.xml configuration file.

Read more  details about kasp.xml

zonelist.xml

The zonelist.xml file is used when first setting up the system, but also used by the ods-signerd when signing zones. For each zone, it contains a Zone tag with information about

  • the zone’s DNS name
  • the policy from kasp.xml used to sign the zone
  • how to obtain the zone
  • how to publish the zone

Read more  details about zonelist.xml

zonefetch.xml

OpenDNSSEC can sign zonefiles on disk, but can also sign zones received from transfer (AXFR). If you configure a zone fetcher configuration, the Signer Engine will kick off the zone fetcher that will listen to NOTIFY messages from the parent and store AXFR messages on disk.

Information in this file details

  • where to fetch zone data from
  • protection mechanisms to be used

Read more  details about zonefetch.xml

Signer configuration

There are also xml files for each of the zones that the user wants to sign, but those are only used for communication between the Enforcer and the Signer Engine. And they are created automatically be the Enforcer. The location of these files can be found in zonelist.xml.

Check your configuration

The OpenDNSSEC XML configuration files (conf.xml and kasp.xml) offer the user many options to customise the OpenDNSSEC signing system. Not all possible configuration texts are meaningful however.

A tool (ods-kaspcheck) is provided to check that the configuration files (conf.xml and kasp.xml) are semantically sane and contain no inconsistencies. It is advisable to use this tool to check your configuration before starting to use OpenDNSSEC.


conf.xml

The overall configuration of OpenDNSSEC is defined by the contents of the file /etc/opendnssec/conf.xml. In this configuration file you specify logging facilities (only syslog is supported now), system paths, key repositories, privileges, and the database where all key and zone information is stored.

The elements of the file

Preamble

<?xml version="1.0" encoding="UTF-8"?>

<!-- $Id: conf.xml.in 1143 2009-06-24 12:10:40Z jakob $ -->

Each XML file starts with a standard element “<?xml…”. As with any XML file, comments are included between the delimiters “<!–” and “–>”.

Configuration

<Configuration>

The enclosing element of the XML file is the element <Configuration> which, with the closing element </Configuration>, brackets the configuration information.

Repositories

	<RepositoryList>

OpenDNSSEC stores its keys in “repositories”. There must be at least one repository, although the system can be configured to run with multiple repositories.

There are a number of reasons for running with multiple repositories, including:

  • Temporarily running with multiple repositories whilst a switch is made from one repository to another, e.g. when replacing hardware.
  • The chosen type of repository has a limit on the number of keys that can be stored, and multiple repositories are needed to handle the chosen number of keys.
  • Different types of repository are needed for different security levels, e.g. a key-signing key may require a higher level of security than a zone-signing key.

In practice, all repositories are “HSM”s (hardware security modules) or an emulation of one.

SoftHSM

The software emulation of an HSM – SoftHSM – must be installed separately but is part of the OpenDNSSEC project, and its definition is shown below. The element names will be explained later.

		<Repository name="SoftHSM">
			<Module>/usr/local/lib/libsofthsm.so</Module>
			<TokenLabel>OpenDNSSEC</TokenLabel>
			<PIN>1234</PIN>
		</Repository>

HSM

As indicated, any number of repositories can be specified in the configuration file:

<!--
		<Repository name="sca6000">
			<Module>/usr/lib/libpkcs11.so</Module>
			<TokenLabel>Sun Metaslot</TokenLabel>
			<PIN>test:1234</PIN>
			<Capacity>1000</Capacity>
			<RequireBackup/>
			<SkipPublicKey/>
		</Repository>
-->

(The example above is commented out by the XML comment delimiters.)

<Repository> – the definition of a repository is bracketed by the <Repository> and </Repository> elements. The name attribute must be supplied and must be unique. It is this name that is used in the  kasp.xml file to identify which repository holds the keys.

<Module> identifies the dynamic-link library that controls the repository. Each type of HSM will have its own library.

<TokenLabel> identifies the “token” within the HSM that is being used – essentially a form of sub-repository. The token label is also used where there are two repositories of the same type, in that each repository should contain a different token label sub-repository. OpenDNSSEC will automatically go to the right HSM based on this.

<PIN> is the password to the HSM. OpenDNSSEC have this stored en-claire in the configuration file. Later versions will allow the option of requiring the password to be typed in when OpenDNSSEC is started.

<Capacity> indicates the maximum number of keys the HSM can store. It is an optional element – if there is no (realistic) limit to the number of keys, remove it.

<RequireBackup> is an optional element that specifies that keys from this repository may not be used until they are backed up. If backup has been done, then use ods-ksmutil to notify OpenDNSSEC about this. The backup notification is needed for OpenDNSSEC to be able to complete a key rollover.

<SkipPublicKey> is an optional element which specifies that the public key objects should not be stored or handled in the HSM. The public key is needed in order to create the DNSKEY RR. In theory, the public part of the key is also available in the private key object. However, the PKCS#11 API does not require the HSM to behave in this way. We have not seen a HSM where we cannot do this, but you should remove this flag if you are having any problem with it. The benefit of adding this flag is that you save space in your HSM, because you are only storing the private key object.

	</RepositoryList>

The list of repositories ends with the closing tag.

Common

These are the configuration that is shared among the components of OpenDNSSEC.

	<Common>
		<Logging>
			<Syslog><Facility>local0</Facility></Syslog>
		</Logging>

		<PolicyFile>/etc/opendnssec/kasp.xml</PolicyFile>
		<ZoneListFile>/etc/opendnssec/zonelist.xml</ZoneListFile>

		<!--
			<ZoneFetchFile>/etc/opendnssec/zonefetch.xml</ZoneFetchFile>
		-->
	</Common>

All components of HSM log error, warning and progress information. This is configurable and defined in the <Logging> element. Currently, the only syslog() feature configurable via the OpenDNSSEC configuration file is the facility name under which messages are logged. This can be any of the names listed in the operating system’s syslog header file (usually /usr/include/sys/syslog.h, but the location is system dependent). Although any facility listed there can be used, it is recommended that one of the “local” facilities (usually “local0″ through “local7″) be used.

Then you also have pointers to where the policy and zone list files can be found. There are also an optional element where you specify the path of the zone fetch configuration used for inbound AXFR.

Enforcer
The KASP enforcer component of OpenDNSSEC – which deals with key rollover and key generation – has its own section in the configuration file:

	<Enforcer>
	<!--
		<Privileges>
			<User>opendnssec</User>
			<Group>opendnssec</Group>
		</Privileges>
	-->

		<Datastore><SQLite>/var/opendnssec/kasp.db</SQLite></Datastore>
		<Interval>PT3600S</Interval>
		<!-- <ManualKeyGeneration/> -->
		<!-- <DelegationSignerSubmitCommand>/usr/local/sbin/eppclient</DelegationSignerSubmitCommand> -->
	</Enforcer>

The section is bracketed by the <Enforcer> .. </Enforcer> tags.

The Enforcer can drop its privileges if specified.

The database used by the Enforcer is specified by the <Datastore> tag. OpenDNSSEC supports SQLite and MySQL, the choice being indicated by one of two mutually exclusive tags:

SQLite

If SQLite is the database in use, the <Datastore> tag must contain a single <SQLite> tag which specifies the database file in use (as shown above).

MySql

Note: The support of MySQL is considered experimental

If MySQL is in use, then the <Datastore> contains a single <MySQL> tag, which in turn contains elements that describe the database connection. The following XML elements shows this:

		<Datastore>
			<MySQL>
				<Host port="1213">dnssec-db</Host>
				<Database>KASP</Database>
				<Username>kaspuser</Username>
				<Password>abc123</Password>
			</MySQL>
		</Datastore>

<Host> is the name of the system on which the database resides. It is optional – if omitted, the database is assumed to run on the same system as OpenDNSSEC. The “port” attribute gives the port to which the !MySQL connection is made. It too is optional, and defaults to 3306 if omitted.

<Database> is the name of the database holding the KASP Enforcer data.

<Username> is the username needed to connect to the database.

<Password> is the password associated with the username.

Other Enforcer Parameters

<Interval> is how often the Enforcer runs to check whether keys are coming up for expiry and should be rolled. The more frequently this is run, the closer will the usage of keys reflect the policy set for it. However, if the key lifetimes are in the order of months, an <Interval> of the order of a day to a week is sufficient.

<ManualKeyGeneration/> will disable the automatic key generation in the Enforcer. The user have to generate the keys itself with the ods-ksmutil key generate command.

Configure the <DelegationSignerSubmitCommand> if you want to have a program/script receiving the new KSK during a key rollover. This will make it possible to create a fully automatic KSK rollover, where OpenDNSSEC feed your program/script on stdin with the current set of DNSKEYs that we want to have in the parent as DS RRs. There are two examples available: an eppclient and a simple mail script. Remember that theods-ksmutil key ds-seen must be given in order to complete the rollover. This should only be done when the new DS RRs are available on the parents public nameservers.

Signer Configuration

The Signer Engine of OpenDNSSEC – the part that constructs signature records to include in to the zone file – also has its own section in the configuration file:

	<Signer>
	<!--
		<Privileges>
			<User>opendnssec</User>
			<Group>opendnssec</Group>
		</Privileges>
	-->
		<WorkingDirectory>/var/opendnssec/tmp</WorkingDirectory>
		<WorkerThreads>8</WorkerThreads>

	<!--
		<NotifyCommand>/usr/local/bin/my_nameserver_reload_command</NotifyCommand>
	-->
	</Signer>

Delimited by the <Signer> .. </Signer> tags, the components are:

  • <Privileges> the Signer Engine can drop its privileges if specified.
  • <WorkingDirectory> defines the location in which the Signer Engine will create temporary files.
  • <WorkerThreads> specify the number of workers. One worker can handle one zone a time. When it is finished with the zone it takes the next one in queue.
  • <NotifyCommand> optional element that will tell the Signer Engine to call this command when the zone has been signed. Will expand the following variables: %zone (the name of the zone that was signed) and %zonefile (the filename of the signed zone).

Auditor Configuration

The Auditor can check a signed zone against the policy and the unsigned zone. This is to verify that the everything is done correctly.

	<Auditor>
	<!--
		<Privileges>
			<User>opendnssec</User>
			<Group>opendnssec</Group>
		</Privileges>
	-->

		<WorkingDirectory>/var/opendnssec/tmp</WorkingDirectory>
	</Auditor>

Delimited by the <Auditor> .. </Auditor> tags, the components are:

<!Privileges> the Auditor can drop its privileges if specified.

<WorkingDirectory> defines the location in which the Auditor will create temporary files.

</Configuration>

As there are no more elements, the </Configuration> tag closes the file.


kasp.xml

kasp.xml – found by default in /etc/opendnssec – is the file that defines policies used to sign zones. (KASP stands for “Key and Signature Policy.) Each policy comprises a series of parameters that define the way the zone is signed. The hierarchical nature of XML allows the grouping of parameters into logical blocks.

The remainder of this article explains the parameters by referring to the example kasp.xml file supplied with the OpenDNSSEC distribution. Segments of the file are shown in shaded blocks – the explanation of the contents of each block follows it.

All date/time durations are specified as defined by  ISO 8601.

Annotated Policy File

Preamble

<?xml version="1.0" encoding="UTF-8"?>

<!-- $Id: kasp.xml.in 1154 2009-06-24 13:02:25Z jakob $ -->

Each XML file starts with a standard element “<?xml…”. As with any XML file, comments are included between the delimiters “<!–” and “–>”.

Policy Description

<KASP>

The enclosing element of the XML file is the element <KASP> which, with the closing element </KASP>, brackets one or more policies.

	<Policy name="default">

Each policy is included in the <Policy>…</Policy> elements. Each policy has a “name” attribute giving the name of the policy. The name is used to link a policy and the zones signed using it; each policy must have a unique name.

The policy named “default” is special, as it is associated with all zones that do not have a policy explicitly associated with them.

		<Description>A default policy that will amaze you and your friends</Description>

A policy can have a description associated with it. Unlike XML comments, the description can be understood by programs and may be used to document the policy, e.g. a future GUI may display a list of policies along with their description and ask you to select one for editing.

Signatures

The next section of the file is the Signatures section, which lists the parameters for the signatures created using the policy.

		<Signatures>
			<Resign>PT2H</Resign>
			<Refresh>P3D</Refresh>
			<Validity>
					<Default>P7D</Default>
					<Denial>P7D</Denial>
			</Validity>
			<Jitter>PT12H</Jitter>
			<InceptionOffset>PT300S</InceptionOffset>
		</Signatures>

Here:

<Resign> is the re-sign interval, which is the interval between runs of the Signer Engine.

<Refresh> is the refresh interval, detailing when a signature should be refreshed. As signatures are typically valid for much longer than the interval between runs of the signer, there is no need to re-generate the signatures each time the signer is run if there is no change to the data being signed. The signature will be refreshed when the time until the signature expiration is closer than the refresh interval.

<Validity> groups two elements of information related to how long the signatures are valid for – <Default> is the validity interval for all RRSIG records except those related to NSEC or NSEC3 records. In this case, the validity period is given by the value in the <Denial> element.

<Jitter> is the value added to or extracted from the expiration time of signatures to ensure that not all signatures expire at the same time. The actual value of the <Jitter> element is the -j + r %2j, where j is the jitter value and r a random duration, uniformly ranging between -j and j, is added to signature validity period to get the signature expiration time.

<InceptionOffset> is a duration subtracted from the time at which a record is signed to give the start time of the record. This is required to allow for clock skew between the signing system and the system on which the signature is checked. Without it, the possibility exists that the checking system could retrieve a signature whose start time is later than the current time.

The relationship between these elements is shown below.


Authenticated Denial of Existence
Authenticated denial of existence – proving that domain names do not exist in the zone – is handled by the <Denial> section, as shown below:

		<Denial>
			<NSEC3>
				<OptOut/>
				<Resalt>P100D</Resalt>
				<Hash>
					<Algorithm>1</Algorithm>
					<Iterations>5</Iterations>
					<Salt length="8"/>
				</Hash>
			</NSEC3>
		</Denial>

<Denial> includes one element, either <NSEC3> (as shown above) or <NSEC>.

NSEC3
<NSEC3> tells the signer to implement NSEC3 scheme for authenticated denial of existence (described in  RFC 5155). The elements are:

<OptOut/> – if present, enable “opt out”. This is an optimisation that means that NSEC3 records are only created for authoritative data or for secure delegations; insecure delegations have no NSEC3 records. For zones where a majority of the entries are delegations that are not signed – typically TLDs during the take-up phase of DNSSEC – this reduces the number of DNSSEC records in the zone.

<Resalt> is the interval between generating new salt values for the hashing algorithm.

<Algorithm>, <Iterations> and <Salt> are parameters to the hash algorithm, described in  RFC 5155.

NSEC
Should, instead, NSEC be used as the authenticated denial of existence scheme, the <Denial> element will contain the single element <NSEC/> – there are no other parameters.

Key Information
Parameters relating to keys can be found in the <Keys> section.

		<Keys>

Common Parameters
The section starts with a number of parameters relating to both zone-signing keys (ZSK) and key-signing keys (KSK):

			<TTL>PT3600S</TTL>
			<RetireSafety>PT3600S</RetireSafety>
                        <PublishSafety>PT3600S</PublishSafety>
			<ShareKeys/>
			<Purge>P14D</Purge>

<TTL> is the time-to-live value for the DNSKEY resource records.

<PublishSafety> and <RetireSafety> are the publish and retire safety margins for the keys. These intervals are safety margins added to calculated timing values to ensure that keys are published and retired without there being a chance of signatures created with the keys being considered invalid.

If multiple zones are associated with a policy, the presence of <ShareKeys/> indicates that a key can be shared between zones. E.g. if you have 10 zones then you will only use one set of keys instead of 10 sets. This will same space in your HSM. If this tag is absent, keys are not shared between zones.

If <Purge> is present, keys marked as dead will be automatically purged from the database after this interval.

Key-Signing Keys

Parameters for key-signing keys are held in the <KSK> section:

			<KSK>
				<Algorithm length="2048">7</Algorithm>
				<Lifetime>P1Y</Lifetime>
				<Repository>softHSM</Repository>
				<!-- <Standby>1</Standby> (Experimental) -->
				<ManualRollover/>
			</KSK>

<Algorithm> determines the algorithm used for the key (the numbers reserved for each algorithm can be found in the appropriate  IANA registry).

<Lifetime> determines how long the key is used for before it is rolled.

<Repository> determines the location of the keys. Keys are stored in “repositories” (currently, only hardware security modules (HSMs) or devices conforming to the PKCS#11 interface), which are defined in the  conf.xml. In the example above, the key is stored in softHSM – the example configuration file distributed with OpenDNSSEC defines this as being the software emulation of an HSM distributed as part of OpenDNSSEC.

<Standby> Experimental (we are currently not supporting offline HSM, which is needed to get the security level needed to fulfill the idea behind standby keys. Will be fixed in a future version) Determines the number of standby keys held in the zone. These keys allow the currently active key to be immediately retired should it be compromised, so enhancing the security of the system. (Without an standby key, additional time is required to allow information about the new key to reach validator caches – see  http://tools.ietf.org/html/draft-morris-dnsop-dnssec-key-timing for timing details.)

< ManualRollover/?> is an optional tag. This tag indicate that the key rollover will only be initiated on the command by the operator. There is still a second step for the KSK, where the key needs to be published to the parent before the rollover is completed. Read more in the chapter “Running OpenDNSSEC”. The ZSK rollover will although be fully automatic if this tag is not present.

Zone-Signing Keys

Parameters for zone-signing keys are held in the <ZSK> section, and have the same meaning as for the KSK:

			<ZSK>
				<Algorithm length="1024">7</Algorithm>
				<Lifetime>P14D</Lifetime>
				<Repository>softHSM</Repository>
				<!-- <Standby>1</Standby> (Experimental) -->
			</ZSK>

The ZSK information completes the contents of the <Keys> section.

		</Keys>

Zone Information

General information concerning the zones can be found in the <Zone> section:

		<Zone>
			<PropagationDelay>PT9999S</PropagationDelay>
			<SOA>
				<TTL>PT3600S</TTL>
				<Minimum>PT3600S</Minimum>
				<Serial>unixtime</Serial>
			</SOA>
		</Zone>

<PropagationDelay> is the amount of time needed for information changes at the master server for the zone to work its way through to all the secondary nameservers.

The <SOA> element gives values of parameters for the SOA record in the signed zone. N.B. These values will override values set for the SOA record in the input zone file. The values are:

<TTL> – TTL of the SOA record.

<Minimum> – value for the SOA’s “minimum” parameter.

<Serial> – the format of the serial number in the signed zone. This is one of:

  • counter – use an increasing counter (but use the serial from the unsigned zone if possible)
  • datecounter – use increasing counter in YYYYMMDDxx format (xx is incremented within each day)
  • unixtime – the serial number is set to the “Unix time” (seconds since 00:00 on 1 January 1970 (UTC)) at which the signer is run.
  • keep – keep the serial from the unsigned zone (do not resign unless it has been incremented)

Parent Zone Information

If a DNSSEC zone is in a chain of trust, digest information about the KSKs used in the zone will be stored in DS records in the parent zone. To properly roll keys, timing information about the parent zone must be configured in the <Parent> section:

		<Parent>
			<PropagationDelay>PT9999S</PropagationDelay>
			<DS>
				<TTL>PT3600S</TTL>
			</DS>
			<SOA>
				<TTL>PT3600S</TTL>
				<Minimum>PT3600S</Minimum>
			</SOA>
		</Parent>

<PropagationDelay> is the interval between the time a new KSK is published in the zone and the time that the DS record appears in the parent zone.

The <DS> tag holds information about the DS record in the parent. It contains a single element, <TTL>, which should be set to the TTL of the DS record in the parent zone.

<SOA> gives information about parameters of the parent’s SOA record, used by KASP in its calculations. As before, <TTL> is the TTL of the SOA record and <Minimum> is the value of the “minimum” parameter.

Auditing

The zone will be audited before it is written to the signed directory, if the following tag is included. If you are signing a large number of zones and have a high work load on your server, the memory resources might get exhausted because each instance of the auditor has its own Ruby VM.

		<Audit />

If you are signing a very large zone (more than half a million records, for example), then you may wish to use the Partial Auditor. This checks a sample of the zone (rather than every RRSet cryptographic signature), and performs many of the same checks as the full auditor (including key lifetime tracking). To enable this, replace the above Audit tag with :

		<Audit> 
			<Partial /> 
		</Audit>

This is the last section of the policy specification, so the next element is the policy closing tag:

	</Policy>

If there are any additional policies, they could be entered here, starting with <Policy> and ending with </Policy>. However, in this case there are no additional policies, so the file is ended by closing the <KASP> tag:

</KASP>

zonefetch.xml

OpenDNSSEC can sign zonefiles on disk, but can also sign zones received from transfer (AXFR). If you configure a zone fetcher configuration –  XML RelaxNG compact, the Signer Engine will kick off the zone fetcher that will listen to NOTIFY messages from the parent and store AXFR messages on disk. The messages will be stored as the input file adapter plus an additional “.axfr” extension. If the transfer was succesful, the zone fetcher kicks the Signer Engine so that the incoming zone will be signed.

Configuration

The zone fetcher configuration filename must be in  conf.xml. Use the ZoneFetchFile element for that.

NotifyListen:
This defines which interface and port the must bind to listen NOTIFY messages on. You can specify an IPv4/IPv6 address plus port number.

Default:
This has the default values for master servers and tsig credentials.

TSIG:
This configures your TSIG credentials. Name, Algorithm and Secret are required.

RequestTransfer:
This configures your master servers to contact. You can specify multiple IPv4/IPv6 addresses. Unfortunately, only the first encountered port number will be used.

Design

The zone fetcher can run a single time, but the Signer Engine will start it as a daemon. As a daemon, it will accept NOTIFY messages for which it has master servers configured (with RequestTransfer). NOTIFY also does not make use of the TSIG credentials.

You can specify the listening interface and port with NotifyListen. By default, the zone fetcher will listen on any interface, port 53.

To listen on a specific address, use:

    <NotifyListen>
        <IPv4>192.0.2.100</IPv4><Port>53</Port>
    </NotifyListen>

Upon a valid NOTIFY, the zone fetcher sends to one of the master servers. If configured, it adds the TSIG RR. A succesful AXFR response will be stored on disk.

The Signer Engine will know if it have to check for an AXFR on disk before signing a new unsigned zone. Thus, the Signer Engine needs to be kicked with ‘update <zone>’ if a AXFR was received. Luckily, the zone fetcher will do that for you.


zonelist.xml

The list of zones that OpenDNSSEC will sign is held in the zone list file, /etc/opendnssec/zonelist.xml. As well as listing the zones, it also specifies the policy used to sign the zones.

The remainder of this section explains the parameters of the zone list by referring to the example zonelist.xml file supplied with the OpenDNSSEC distribution. Segments of the file are shown in shaded blocks – the explanation of the contents of each block follows it.

Annotated Zone List File

Preamble

<?xml version="1.0" encoding="UTF-8"?>

<!-- $Id: zonelist.xml.in 1147 2009-06-24 12:18:17Z jakob $ -->

Each XML file starts with a standard element “<?xml…”. As with any XML file, comments are included between the delimiters “<!–” and “–>”.

Zone List

<ZoneList>

The enclosing element of the XML file is the element <ZoneList> which, with the closing element </ZoneList>, brackets the list of zones.

Zones
Each zone is defined by a <Zone> element:

	<Zone name="example.com">

The mandatory attribute “name” identifies the zone. Each zone within the zone list must have a unique name.

Policy

		<Policy>default</Policy>

The first element of the <Zone> tag is <Policy>, which identifies the policy used to sign the file. Policies are defined in the  kasp.xml file, and the name in this element must be that of one of the defined policies.

Configuration
Information from the Enforcer to the Signer Engine is passed via a special signer configuration file, the name of which is given by the <SignerConfiguration> section of the zone definition:

		<SignerConfiguration>/var/opendnssec/signconf/example.com.xml</SignerConfiguration>

(Note that this file is a temporary file that passed between OpenDNSSEC components and is not intended to be edited by users.)

Adapters

The next part of the zone element specifies from where OpenDNSSEC gets the zone data and to where the signed data is put.

		<Adapters>
			<Input>
				<File>/var/opendnssec/unsigned/example.com</File>
			</Input>
			<Output>
				<File>/var/opendnssec/signed/example.com</File>
			</Output>
		</Adapters>

The <Adapters> element comprises an <Input> and <Output> element which (fairly obviously) identify the input source and output sink of the data.

Within each element is a tag defining the type of data source/sink and its parameters. At the moment, only the <File> element is defined, which takes as its only data the name of the input unsigned or output signed zone file.

In the future, it is planned to offer the ability to accept and output data in the form of AXFRs and IXFRs.

	</Zone>

The </Zone> tag closes the definition of the zone. As indicated above, one or more zones can be defined in this file.

</ZoneList>

The </ZoneList> element closes the file.

Zone List File Creation

For a small number of zones, the zone list file can be easily edited by hand. Where the number of zones is large – for example, ISPs serving thousands of customers – the intention is that the file be generated by the zone manager’s systems using e.g. the ods-ksmutil zone add command.

File Names

As can be seen in the example above, a number of elements that specify file names (<SignerConfiguration>, <Adapter>/<Input> and <Adapter>/<Output>) include the zone name in the name of the file. Where there are multiple zones, this is strongly recommended as a way of avoiding confusion.


Zone content

OpenDNSSEC can handle various formatting of the zone file, including different directives and Resource Records (RRs).

Formatting

The zone file can be formatted in many ways including multi-lined RR, comments, etc.

Directives

$ORIGIN example.com. What origin to use.
$TTL 1h3m The default TTL to use. Treated as seconds, if no suffix is used: s, m, h, d, w, S, M, H, D, W
$INCLUDE <path> Include a file from a given path

Although OpenDNSSEC makes a copy of the unsigned zone file, it does not copy files included in the zone file. It is therefore recommended that you use absolute paths for included files and, if you make use of the auditor, that you don’t edit them when a sign operation is going on.

RR types

OpenDNSSEC support all of the RR specified by  IANA, with some exceptions.

Not supported: ATMA, APL, EID, NIMLOC, HIP, SINK, NINFO, RKEY, TA
Obsoleted: MD, MF, WKS, GPOS, SIG, KEY, NXT, A6, and NSAP-PTR
Not allowed in master file: NULL, OPT, TKEY, TSIG, IXFR, AXFR, MAILB, MAILA, *

Handling of unknown RR types

But OpenDNSSEC do handle unknown RR types in accordance with  RFC3597. E.g:

example.com.   IN          TYPE1               \# 4 0A000001

A note on keystates.

Most of the keystates are as described in the DNSSEC key timing draft:  http://tools.ietf.org/html/draft-morris-dnsop-dnssec-key-timing-02

We briefly describe them here:

GENERATE

Keys in the generate state have been created and stored but not used yet.

PUBLISH

Keys in the publish state have been published in the zone, but are not yet considered safe to use. (I.e. They have not been in the zone long enough to have propagated through the system.)

READY

Keys in the ready state have been published long enough that we could safely start to use them.

ACTIVE

Keys in the active state are those that are in use.

RETIRE

Keys in the retire state have been in use but have been replaced by a successor, they are post-published while signatures generated with them might still be in the system.

DEAD

Keys in the dead state have been retired long enough for them to be safely removed from the zone.

For standby KSKs there are some extra states which replace PUBLISH and READY. This is because the standby keys are not introduced into the zone until they are needed. Instead their DS record is submitted to the parent. (The idea is that if the key is needed in an emergency the shortest timescale that it can be used in is the publication through the child system.)

DSSUB

The DS has possibly been submitted (if it happened automatically) but in any case we are waiting for the ds-seen command.

DSPUBLISH

The ds-seen command has been given, and we are now waiting for the various propagation delays and safety margins to pass.

DSREADY

The DS record is now considered safe to use, so the standby key is ready.

KEYPUBLISH

We have been asked to use the standby key so we have published it in the zone. Once the key has propagated through the system it will move into the active state.


Running OpenDNSSEC

All directories are prepared by the build script and are set to be owned by root, so all commands in the default configuration must also be run by root. To change this, alter the configuration or privileges on the files and directories.

Before the first start

Before you run the system for the first time you must import your policy and zone list into the database using the following command:

 ods-ksmutil setup

After running this the first time, you will be ready to run OpenDNSSEC with an empty set of zones. On the other hand, if this command is run on an existing database, then will all meta-information about the zones be lost. The keys would then still exist in HSMs, so you should not forget to clean them up.

Starting / Stopping the system

OpenDNSSEC consist of two daemons, ods-signerd and ods-enforcerd. To start and stop them use the following commands:

 ods-control start

A proper-looking response to this commands is:

Starting enforcer...
OpenDNSSEC ods-enforcerd started (version 1.2.0b1), pid 11424
Starting signer engine...
OpenDNSSEC signer engine version 1.2.0b1

At any time, you can stop OpenDNSSEC’s daemons orderly with:

 ods-control stop

After this, your logs should contain messages like:

Stopping enforcer...
Stopping signer engine..
Engine shut down.

Adding / Removing zones

Zones can be added and removed at will. If the optional parameters are not given, then it will default to the policy default and the /var/opendnssec/ subdirectories.

 ods-ksmutil zone add --zone example.com [--policy <policy> --signerconf <signerconf.xml> --input <input> --output <output>] 
 ods-ksmutil zone delete --zone example.com

This command will report positively with a message like:

zonelist filename set to /etc/opendnssec/zonelist.xml.
SQLite database set to: /var/opendnssec/kasp.db
Imported zone: example.com

Note: Using this command thousands of times might be slow since it also writes to zonelist.xml. Use –no-xml to stop this behavior. Then export the zonelist when you are finished: ods-ksmutil zonelist export > zonelist.xml

Alternatively, you could manually edit the zonelist.xml and then give the command:

 ods-ksmutil update zonelist

After zones are added, they will show up in your logs as follows:

ods-enforcerd: Zone example.com found.
ods-enforcerd: Policy for example.com set to default.
ods-enforcerd: Config will be output to /var/opendnssec/signconf/example.com.xml.

If you opened the latter file, you would find the settings that were applied to the zone at the time this file was added.

Marking keys as backed up

You can configure the system to only make keys active once they have been backed up. This is done by editing the  conf.xml file. The user must do backups and then notify OpenDNSSEC about this, so that the key rollover process can continue. The keys must be backed up regulary, because OpenDNSSEC is generating new keys prior to a rollover.

First prepare the backup by telling the Enforcer that you want to do backup of the keys. This is so that keys generated after you have done your backup won’t accidentally be marked as backed up.

For all of the repositories:

 ods-ksmutil backup prepare

or a single repository:

 ods-ksmutil backup prepare --repository <repository>

Then you can safely do your backups. Please read the documentation of your HSM for instructions on how to do backups. When you are done, then notify the Enforcer about this:

For all of the repositories:

 ods-ksmutil backup commit

or a single repository:

 ods-ksmutil backup commit --repository <repository>

Caution: The command ods-ksmutil backup done will mark your keys as backed up in one step. This means that keys may have been generated between you doing the backup and giving the command. Thus accidentally marking them as backed up. This command is deprecated and should not be used, unless you make sure to stop the Enforcer when doing your backup.

Note: Backups are demanded by way of a repository option in conf.xml:

<RequireBackup/>

If you decide you want to change this facility, you should edit conf.xml accordingly, and run:

ods-ksmutil update conf

It will report something along the lines of:

RequireBackup set.

Upload the first DS

Your zone will be signed, once you have setup the system and started it. When you have verified that the zone is operational and working, it is time to upload the trust anchor to the parent zone. The Enforcer is waiting for zone to be connected to the trust chain before considering the KSK to be active.

ods-ksmutil key list

Keys:
Zone:                           Keytype:      State:    Date of next transition:  CKA_ID:                           Repository:                       Keytag:      
example.com                     ZSK           active    2010-10-15 06:59:28       92abca348b96aaef42b5bb62c8daffb0  softHSM2                          28743
example.com                     KSK           ready     waiting for ds-seen       9621ca39306ce050e8dd94c5ab837001  softHSM1                          22499

Export the public key either as DNSKEY or DS, depending on what format your parent zone wants it in. See the section below, Export the public keys, on how to get the key information.

Notify the Enforcer when you can see the DS RR in your parent zone. You usually give the keytag to the Enforcer, but if there are KSKs with the same keytag then use the CKA_ID.

  ods-ksmutil key ds-seen -z example.com -x 22499
or
  ods-ksmutil key ds-seen -z example.com -k 9621ca39306ce050e8dd94c5ab837001

Result:
Found key with CKA_ID 9621ca39306ce050e8dd94c5ab837001
Key 9621ca39306ce050e8dd94c5ab837001 made active

And you will see that your KSK is now active:

ods-ksmutil key list

Keys:
Zone:                           Keytype:      State:    Date of next transition:
example.com                     ZSK           active    2010-10-15 07:20:53     
example.com                     KSK           active    2010-10-15 07:31:03

Export the public keys

You need to publish your key to the parent or to interested parties. The follwing command will extract the trust anchors:

 ods-ksmutil key export --zone example.com
 ods-ksmutil key export --zone example.com --ds

What you get in return is the DNSKEY or DS in BIND-format.

Key rollovers

First step

The rollovers are done automatically according to the policy of the zone. But a manual keyrollover may be desired in cases of emergency, such as having lost a private key. This can be done using the ods-ksmutil command like this:

 ods-ksmutil key rollover --zone example.com --keytype KSK

This will roll the KSK key in a timely manner following the policy used for the zone example.com. If you want to roll the Zone Signing Key use –keytype ZSK instead.

You can also roll all the keys for zones which have a certain policy. This can be useful if you want to move all keys from one key store to another.

 ods-ksmutil key rollover --policy default --keytype KSK

Note: This step is not needed for a scheduled rollover.

Second step for KSKs

Unlike ZSKs, a KSK rollover requires a second step involving manual intervention. This intervention is a multi-stage process. First, the DNSKEY record for the new key is added to the zone. Then, after a suitable interval, the new DS record is submitted to the parent; at this point the old DS record can be removed from the parent.

The stages are:

1. Extract the DNSKEY record for the new key and publish it in the parent zone. (The new record replace any existing records for the zone being signed.) When it is time for this to happen a message with log-level “info” will be sent to syslog looking something like:

Mar 16 11:39:05 sion ods-enforcerd: DS Record set has changed, the current set looks like:
Mar 16 11:39:05 sion ods-enforcerd: example.com. 3600 IN DNSKEY 257 3 7 AwEAAbcTSmphJUMKvegvDgqGspRM8IHlKZqoU5pkPaTtRLkioxGyZ5iIh4bNnvqmx1zWIttuJ6erGUMOatMm3SXxiTr9OLaRPr86KVpo6mzejTqFicGxSp3KsrbUvyIs/V84Ry7XZBKVKVjgppjmqeS8mRtXM4UynwTEJk0hKQfCcmkH0Q/fhZibwBVG+OcBfvTdsQbp8LZN4oVqn/vzhnuxFkE8biTr19jmKTdtgkhp524ML59v7prg7F/+Lb2OJLc8Gg6pastUeqXc/Iv2CdVyOvMWRW39VCzyLbKpmyqB8Hc4Kn1pT5Idqc3/N3qBvXVe3HyyiZbjHGxOT6RZNNT8= ;{id = 51994 (ksk), size = 2048b}
Mar 16 11:39:05 sion ods-enforcerd: Once the new DS records are seen in DNS please issue the ds-seen command for zone example.com with the following cka_ids, 04260cd6eac67280cd2dea94c6e38cb7

The DNSKEY or DS RR can also be retrieved by using the commands in the section Export the public keys.

This step can be automated or semi-automated by placing a command in the <DelegationSignerSubmitCommand> tag. This should point to a binary which will accept the required key(s) on STDIN.

2. When the records indicated have been seen in DNS then this can be communicated to OpenDNSSEC with the ds-seen command as indicated:

  ods-ksmutil key ds-seen --zone example.com --cka_id 04260cd6eac67280cd2dea94c6e38cb7

3. If the DS records were not swapped, i.e. the old DS was left in the parent when the new one was added, then the –no-retire flag can be added to the ds-seen command. Then, at some later time, the old key can be retired with the command:

 ods-ksmutil key ksk-retire --zone example.com ---cka_id 87f1385b114f9f9b299e6b551d728bfb
or
 ods-ksmutil key ksk-retire --zone example.com

The former command will retire the specific key (provided the key is active, and the action will not leave the zone without any active keys). The latter command will retire the oldest active key on the zone, again provided it will not leave the zone without any active keys.

NOTE: If you wish to run like this and use the DelegationSignerSubmitCommand hook then you will need to add the current key back into the set yourself.

Key rollovers on exact dates

Some users want to have more control over their key rollovers and roll keys on exact dates, for example the first day of each month. To do this you need to specify that you want manual key rollovers in the kasp.xml configuration. Add the <ManualRollover/> tag to the type and key you want to roll manually.

When this is done you can add the rollover commands to a cron job, with a command like this:

 ods-ksmutil key rollover --zone example.com --keytype ZSK

(The need to manually time intervals is a limitation of version 1.2 of the software. Future versions of OpenDNSSEC will prompt with reminders at the appropriate times as well as offering alternative KSK rollover methods.)

Updating the policy

When you make changes to a policy or add a new policy in kasp.xml you must update the changes to the database.

 ods-ksmutil update kasp

Updating the unsigned zone

When you update the content of an unsigned zone you must tell the signer engine to re-read the unsigned zone file using the ods-signer command like this:

 ods-signer sign example.com

This also have the effect that you schedule the zone for immediate resigning.

Logs

Currently all logging is handled by syslog. Other logging methods may come later.

There is a lot of output from the daemons of which a lot of things right now are for debugging. We might reduce the amount of logging for later versions of OpenDNSSEC.

The signer outputs some statistics into the logs: .

 [STATS] opendnssec.org RR[count=32 time=1(sec)] NSEC[count=32 time=1(sec)] RRSIG[new=1 reused=31 time=1(sec) avg=1(sig/sec)] AUDIT[time=2(sec)] TOTAL[time=5(sec)]

The RR[...] block says something about reading the unsigned zone file. The line above tells us that there have been 32 RRs read and it took about one second. The count will be 0 on lines were only re-signing occurred. The NSEC[...] block says something about the number of NSEC or NSEC3 records created on the latest run. This count will also be 0 on lines were only re-signing occurred. The RRSIG[...] block says something about the number of created signatures. In the above example, the last time there was only created one new signature, and 31 other signatures were reused. The re-signing was finished in about a second and thus the average number of signatures created per second is in this example 1. The AUDIT[...] block tells us how long the auditor needed to check upon the zone. The TOTAL[...] block tells us how long the re-signing took, including reading the unsigned zone and adding NSEC(3) records, if applicable.


Command Utilities

ods-control

Is a wrapper around the commands below.

 usage: ods-control ksm|hsm|signer|start|stop

The first three options pipe commands to ods-ksmutil, ods-hsmutil, and ods-signer.
The last two options start and stop the two daemons of OpenDNSSEC, ods-enforcerd and ods-signerd.

ods-ksmutil

You need a way to interact to the KASP Enforcer, for example to add and remove zones that are handled by OpenDNSSEC. The ods-ksmutil utility provides a number of commands to make this easier, all commands are invoked on the unix command line.

You must run the setup option before you ever run any sub-system in OpenDNSSEC. This reads the configuration kasp.xml and imports these settings into the KASP Enforcer database. The setup command deletes the current content of the database! (Including information on keys; such that existing keys will become unusable and new keys will need to be generated.)

If you make any changes to kasp.xml these changes must be imported into the database. Use the update command to do this without losing any other data.

To add a zone to be handled by OpenDNSSEC, use the zone add command. This command needs a parameter to specify the zone, and optional parameters for which policy to use and which paths to use for input and output. An example of use:

 ods-ksmutil zone add -z example.com -p default -i /var/example.com -o /var/example.com.signed

The command zone delete is simpler and needs no further parameters but the name of the zone.

A complete list of commands can be found by running:

 ods-ksmutil -h

or they are shown here  http://trac.opendnssec.org/wiki/Signer/Using/Commands/ksmutil

ods-signer

The ods-signer provides a Command Line Interface to the ods-signerd. There are a number of commands you give to ods-signer. If you start the CLI without any command line parameters you enter a shell where you can issue commands:

 ods-signer
 cmd> help
 Commands:
 zones           show the currently known zones
 sign <zone>     read zone and schedule zone for immediate (re-)signing
 sign --all      read all zones and schedule all for immediate (re-)signing.
 clear <zone>    delete the internal storage of this zone.
                 All signatures will be regenerated on the next re-sign.
 queue           show the current task queue.
 flush           execute all scheduled tasks immediately.
 update <zone>   update this zone signer configurations.
 update [--all]  update zone list and all signer configurations.
 start           start the engine.
 reload          reload the engine.
 stop            stop the engine.
 verbosity <nr>  set verbosity.

The same commands can be passed as command line arguments in your unix shell.

ods-hsmutil

The ods-hsmutil utility is designed to interact directly with your HSM and can be used to manually list, create or delete keys. It can also be used to perform a set of basics HSM tests. Be careful before create or deleting keys using ods-hsmutil, as the changes are not synced with the KASP Enforcer.

ods-auditor

The Auditor (ods-auditor) can do an audit of the zones in the system to see if the signer complies to what the policy mandates. It is run automatically (unless disabled) after each resigning of a zone and will stop the signed zone from being distributed if it finds any issues. Any errors found by the ods-auditor will be logged to the configured syslog utility. This should be checked for debug if you have issues.

You can also run the Auditor yourself, to get feedback on the current status, to loop through all zones run:

  ods-auditor

or, to audit just one zone, run:

  ods-auditor -z <zone>

It is possible to override the audit type specified in the kasp.xml Policy for the zone. To run a full audit, use the –full flag, and use –partial to force a partial audit of the zone. i If you are using the partial auditor to audit your very large zone, you may wish to run an occasional off-line full audit. To do this, take a copy of your signed and unsigned zone files, and run :

  ods-auditor -z <zone> --full --signed <path/to/signed/file> --unsigned <path/to/unsigned/file>

ods-hsmspeed

The tool ods-hsmspeed does performance testing on your HSM. This is also useful to find out at what speed you can get from SoftHSM on your CPU.

hsmbully

The hsmbully tool may be used to test your HSM for compliance with PKCS#11. This tool is not part of OpenDNSSEC, but can be found in the SVN repository:

 svn co http://trac.opendnssec.org/browser/trunk/hsmbully hsmbully

Daemons

You can also run the two OpenDNSSEC daemons ods-signerd and ods-enforcerd from the command line, they are installed into the sbin directory.

ods-signerd

This is the component that performs all of the signing. It first reads zonelist.xml and then goes through all zones to sign them if needed. Start the daemon by running:

 ods-signer start

or if you want to use specific command line options:

ods-signerd -h
Usage: ods-signerd [OPTIONS]
Start the OpenDNSSEC signer engine daemon.

Supported options:
 -c | --config <cfgfile> Read configuration from file.
 -d | --no-daemon        Do not daemonize the signer engine.
 -1 | --single-run       Run once, then exit.
 -h | --help             Show this help and exit.
 -i | --info             Print configuration and exit.
 -v | --verbose          Increase verbosity.
 -V | --version          Show version and exit.

BSD licensed, see LICENSE in source package for details.
Version 1.1.0-trunk. Report bugs to <http://trac.opendnssec.org/newticket>.

ods-enforcerd

The Enforcer daemon creates keys if needed (and configured to); it also maintains the states of the keys according to the appropriate policy. As the states of keys change, it communicates these changes to the signer via the configuration files that the signer uses when signing the zones. To run, call:

 ods-enforcerd

ods-kaspcheck

This tool is provided to check that the configuration files (conf.xml and kasp.xml) are semantically sane and contain no inconsistencies. It is advisable to use this tool to check your configuration before starting to use OpenDNSSEC.

ods-kaspcheck -h
Usage: ods-kaspcheck [options]
Specific options:
    -c, --conf [PATH_TO_CONF_FILE]   Path to OpenDNSSEC configuration file
                                       (defaults to the default conf.xml file)
    -k, --kasp [PATH_TO_KASP_FILE]   Path to KASP policy file
                                       (defaults to the path given in the configuration file)
Common options:
    -h, -?, --help                   Show this message

Migrating to OpenDNSSEC

It is possible to migrate a DNSSEC signed zone over to OpenDNSSEC. How to migrate your DNSSEC signed zone over to OpenDNSSEC really depends on how your current solution looks like.

The zone data is no problem. Just place a copy of the unsigned zone in the directory for unsigned zones. But the trick is to maintain the private and public keys.

There are three possible solutions:

  • Export the keys
  • Prepublish DNSKEY record
  • Start fresh

Export the keys

One solution is to move the key pairs and make them accessible by OpenDNSSEC. The goal is to have the key pairs available to the system using PKCS#11.

The key pairs can e.g. be stored:

  • on disc (e.g. BIND .private-key format)
  • on a smartcard with no PKCS#11 interface
  • in an HSM

On disc

When the key pairs are stored on disc, it means that you have access to files containing the key pairs. The key pairs can be imported into your new HSM using the PKCS#11 API or any tool available from your HSM vendor.

The BIND .private-key file can be convert into the PKCS#8 file format using the tool available with SoftHSM. If you have another file format, then OpenSSL probably can help you to convert it into the PKCS#8 file format.

 softhsm-keyconv --topkcs8 --in Kexample.com.+005+42952.private --out key.pem
  • –topkcs8, To indicate that you want to convert from BIND .private-key format to PKCS#8.
  • –in <path>, The path to the BIND .private-key file.
  • –out <path>, A path to the temporary PKCS#8 file.

The PKCS#8 file can then be imported into the SoftHSM token (if you are using SoftHSM as your HSM).

 softhsm --import key.pem --slot 1 --pin 123456 --label A2 --id A2
  • –import <path>, The path to the PKCS#8 file that you want to import. This should point to the temporary file that you created in the previous step.
  • –slot <number>, The key should be imported to a token. Indicate which slot it is connected to.
  • –pin <PIN>, Provide the PIN so that we can login to the token.
  • –label <text>, Choose an arbitrary text string. Not used by OpenDNSSEC.
  • –id <hex>, Choose an ID of the new key pair. The ID is in hexadecimal with a variable length. It must not collide with an existing key pair.

On a smartcard with no PKCS#11 interface

Just connect a smartcard reader to your system and insert your smartcard. Then use opensc and pcscd to give it a PKCS#11 interface. Remember to protect the location where you have your smartcard reader, since the smartcard needs to be online.

On an HSM

You can either move the HSM to the new server and install it there. Or some vendors may have some functionality to export/transfer the key pairs.

The final step

Once you have the key pairs available on the system via PKCS#11, then you must add them to OpenDNSSEC. Give this command before you start OpenDNSSEC. Also make sure that the zone is properly configured with OpenDNSSEC.

 ods-ksmutil key import --cka_id <CKA_ID> --repository <repository> --zone <zone> --bits <size> --algorithm <algorithm> --keystate <state> --keytype <type> --time <time>
  • –cka_id <CKA_ID>, Each key object in the HSM has an ID, the CKA_ID attribute. The private and public key object must have the same ID inorder for OpenDNSESC to find them. The CKA_ID of the key pair to import is indicated, in hexadecimal, by using this option. E.g. A2
  • –repository <repository>, The name of the repository, from conf.xml. E.g. softHSM1
  • –zone <zone>, The name of the zone. E.g. example.com
  • –bits <size>, The key length, E.g. 1024
  • –algorithm <algorithm>, The algorithm. E.g. 5 or 7
  • –keystate <state>, The key state. E.g. active or ready
  • –keytype <type>, The key type. KSK or ZSK
  • –time <time>, The time stamp when the key entered the given state. So that OpenDNSSEC know when to change the state. E.g. 200910301000
  • –retire <retire>, Optional. If you set the state to active, then you may set the time when the key should be retired. E.g. 201001010000. Otherwise will OpenDNSSEC use the key lifetime from the KASP.

The difference between active and ready is:

  • active: Will make the key active, thus used for signing. If there already is an active key, then you will have two of them. If this is not desired, then make sure to give this command right after setup and before you start the system.
  • ready: The key will only be published in the zone. It will become active in a future rollover, if the key parameters match the policy.

Prepublish DNSKEY record

TODO: Need text for this part.

Start fresh

A third solution is to start fresh. Remove any DS records from the parent zone. Stop signing your zone when the DS records are removed from the DNS caches. It is safe to remove the public keys from your zone when the signatures are not present in any DNS caches. Then transfer the zone over to OpenDNSSEC. And let OpenDNSSEC start signing it again. Your zone will not be secured by DNSSEC during this transfer.


Troubleshooting

There are a number of common issues that are straightforward to diagnose and fix… If OpenDNSSEC is not behaving as expected then the first place to look is in the logs. Where these will be depends on your system and your configuration.

The following are log messages which you may see, and what to do about them (if anything).

Enforcer

ods-enforcerd: ERROR: Trying to make non-backed up ZSK active when RequireBackup flag is set
This is not an error as such. It means that in conf.xml you have indicated that keys should not be used unless they are backed up. However, the enforcer has determined that if it continues then a non backed up key will be made active.
The solution Take a backup of your keys (how this is done will depend on your key storage).
Once this has been done then run ods-ksmutil backup done to mark all keys as having been backed up.

ods-enforcerd: WARNING: Making non-backed up KSK active, PLEASE make sure that you know the potential problems of using keys which are not recoverable
This is the same as above, but without RequireBackup being set in conf.xml

ods-enforcerd: WARNING: key rollover not completed as there are no keys in the ready state: ods-enforcerd will try again when it runs next
This is seen when a rollover is happening but there is no replacement key ready (because one has not been published for long enough). It indicates that the rollover will be delayed until the replacement key is ready, the time that this will happen depends on the policy.

ods-enforcerd: Could not call signer engine
If the enforcer makes a change to a zones signer configuration (say it adds a new key) it calls the signer to get it to resign that zone. This message indicates that the signer is not running, although it has been seen on a system where everything is working fine. (See KNOWN_ISSUES.)

ods-enforcerd: Not enough keys to satisfy zsk policy for zone
or ods-enforcerd: Not enough keys to satisfy ksk policy for zone

One of these messages will be seen if the enforcer does not have enough unallocated keys to provide for the zone specified. If the ManualKeyGeneration tag is set in conf.xml then you will need to create new keys usingods-ksmutil key generate, otherwise new keys will be created when the enforcer runs next. (Don’t forget to backup any new keys.)

ods-enforcerd: Rollover of KSK expected at <DATE TIME> for <ZONE>
This is not an error, but a notification of an upcoming (scheduled) rollover. This will appear in your logs at a time prior to the rollover as configured in conf.xml (the Enforcer/RolloverNotification tag).

ods-enforcerd: WARNING: KSK Retirement reached; please submit the new DS for <ZONE> and use ods-ksmutil key ksk-roll to roll the key.
Rolling a KSK requires the DS record of the replacement key to be published in the parent of the zone. This message indicates that your KSK has reached the end of its life (as specified by your policy), and that it is time to submit the DS record to the parent.

ods-enforcerd: Error: database in config file <path_to_conf.xml> does not match libksm
This indicates that either you have libksm built for sqlite, but have specified a MySQL database in conf.xml, or vice versa.
The solution is to either rebuild libksm or to change conf.xml

ods-enforcerd: Error reading config
This usually means that conf.xml is either absent, not readable by the user, or badly formed. There should be a line above this one which gives a more specific error message.

ods-enforcerd: Error getting db lock
When using sqlite any process using the database tries to get an exclusive write lock on a file in the same directory as the kasp.db. If this directory is not writeable by the user then this message will be seen, again a more specific error message should have been issued.

ods-enforcerd: Repository <NAME> is full, cannot create more <KSKs|ZSKs> for policy <POLICY>
In conf.xml a capacity can be specified for a repository. When this is reached then no more keys will be generated in that repository.
The solution is to either run ods-ksmutil key purge to remove dead keys, or to raise this capacity and run ods-ksmutil update conf to push this change into the database. If the repository is really at capacity, and purge does not free up any space, then a new repository will be needed.

ods-enforcerd: Repository <NAME> is nearly full, will create X <KSKs|ZSKs> for policy <POLICY> (reduced from Y)
Y keys were needed to satisfy the policy, but the repository only has room for X more. This warning might precede the error detailed above, and the solution is the same.

ods-enforcerd: NOTE: keys generated in repository <NAME> will not become active until they have been backed up
This is not an error, but a reminder that a backup needs to be done (as new keys have just been generated).

ods-enforcerd: Signconf not written for <ZONE>
Some error has happened and the enforcer will not overwrite the existing signconf file, so the old one will be left in place. There should be a more specific message indicating the root cause just prior to this line. (E.g.attempting to use a non backed up key.)

ods-enforcerd: There are no <KSKs|ZSKs> in the generate state; please use “ods-ksmutil key generate” to make some
ManualKeyGeneration has been set (in conf.xml) and the system has run out of keys.
The solution is to run the ods-ksmutil key generate command, back up the keys, and the system will recover when it runs next.

Signer

These messages might show up in the logs if there is a parse or semantic error in one of the configuration files.
ods-signerd: error: unable to read cfgfile <file>
ods-signerd: error: unable to parse cfgfile <file>
ods-signerd: error: unable to read conf rng file <file>
ods-signerd: error: unable to create XML RelaxNGs parser context
ods-signerd: error: unable to parse a schema definition resource
ods-signerd: error: unable to create RelaxNGs validation context
ods-signerd: error: configuration file validation failed
ods-signerd: error: unable to create new XPath context for cfgile <file>
ods-signerd: error: unable to evaluate required element <element> in cfgfile <file>
ods-signerd: error: cfgfile <file> has errors
ods-signerd: error: unable to evaluate xpath expression <expr>
ods-signerd: error: unable to open zone list file <file>
ods-signerd: error: unable to extract zone name from zonelist
ods-signerd: error: unable to read zone <dname>; skipping
ods-signerd: error: unable to add zone <zone> to zone list
ods-signerd: error: error parsing zone list file <file>
ods-signerd: error: invalid salt <salt>
ods-signerd: error: unable to parse signconf file <file>
ods-signerd: error: unable to read signconf file <file>
ods-signerd: error: signconf-check: no signature resign interval found
ods-signerd: error: signconf-check: no signature resign interval found
ods-signerd: error: signconf-check: no signature default validity found
ods-signerd: error: signconf-check: no signature denial validity found
ods-signerd: error: signconf-check: no signature jitter found
ods-signerd: error: signconf-check: no signature inception offset found
ods-signerd: error: signconf-check: no nsec3 algorithm found
ods-signerd: error: signconf-check: wrong nsec type <rrtype>
ods-signerd: error: signconf-check: no keys found
ods-signerd: error: signconf-check: no dnskey ttl found
ods-signerd: error: signconf-check: no soa ttl found
ods-signerd: error: signconf-check: no soa minimum found
ods-signerd: error: signconf-check: wrong soa serial type <string>

These messages might show up in the logs if the signer engine daemon was unable to start up. All of them are provided with a specific message indicating the cause.
ods-signerd: error: unable to create command handler, <reason>
ods-signerd: error: cannot connect to command handler: <reason>
ods-signerd: error: setup failed: chdir to <directory> failed: <reason>
ods-signerd: error: setup failed: unable to drop privileges
ods-signerd: error: setup failed: unable to fork daemon: <reason>
ods-signerd: error: setup failed: unable to setsid daemon: <reason>
ods-signerd: error: setup failed: unable to write pid file
ods-signerd: error: setup failed: unable to start command handler
ods-signerd: error: setup failed: unable to start command handler
ods-signerd: error: setup failed: error initializing libhsm (errno <no>)
ods-signerd: error: signer setup failed
ods-signerd: error: failed to fork zone fetcher: <reason>
ods-signerd: error: failed to setsid zone fetcher: <reason>
ods-signerd: error: cannot stop zone fetcher: <reason>
ods-signerd: error: cannot start zone fetcher

These messages might show up in the logs if the signer was unable to sign the zone
ods-signerd: error: task [read zone <dname>] failed
File not found or readable, parse error, …
ods-signerd: error: task [add dnskeys to zone <dname>] failed
HSM re-initialized, no privileges for accessing HSM, …
ods-signerd: error: task [update zone <dname>] failed
DNS related errors in zone, for example other RRs next to a CNAME
ods-signerd: error: task [nsecify zone <dname>] failed
ods-signerd: error: task [sign zone <dname>] failed
No privileges for accessing HSM, …
ods-signerd: error: task [audit zone <dname>] failed
Auditor found problems
ods-signerd: error: task [write zone <dname>] failed
Output directory not writable

These messages might show up in the logs if a zone update failed
ods-signerd: error: cannot keep SOA SERIAL from input zone (<serial>): output SOA SERIAL is <serial>
<SOA><Serial> is set to keep in kasp policy file, but SOA SERIAL in unsigned zone file was not increased
ods-signerd: error: occluded (non-glue non-DS) data at <dname> NS
Found unallowed RRs at the delegation
ods-signerd: error: occluded data at <dname> (below <dname> DNAME)
Found RRs below DNAME
ods-signerd: error: occluded (non-glue) data at <dname> (below <dname> NS
Found non-glue RRs below delegation
ods-signerd: error: other data next to <dname> CNAME
Found unallowed RRs next to CNAME
ods-signerd: error: multiple records for singleton type at <dname> <rrtype>
Found multiple RRs of a singleton RRtype (CNAME or DNAME) at the same owner name
ods-signerd: error: update zone <dname> failed: zone data contains errors

These messages might show up in the logs if one of the backup files was corrupted
ods-signerd: error: error creating DNSKEY for key <locator>
ods-signerd: error: error adding DNSKEY[<keytag>] for key <locator>
ods-signerd: error: error creating NSEC3 parameters for zone <dname>
ods-signerd: error: error adding NSEC3PARAMS record to zone <dname>
ods-signerd: error: error adding DNSKEYs to zone <dname>
ods-signerd: error: error adding NSEC3PARAMS RR to zone <dname>
ods-signerd: error: cannot backup zone: cannot open file <file> for writing
ods-signerd: error: error adding key from backup file <file> to key list
ods-signerd: error: error recovering DNSKEY[<keytag>] rr
ods-signerd: error: error recovering nsec3 parameters from file <file>
ods-signerd: error: error recovering NSEC3PARAMS rr
ods-signerd: error: error reading key credentials from backup
ods-signerd: error: error reading RRSIG from backup
ods-signerd: error: expecting RRtype RRSIG from backup
ods-signerd: error: error reading domain from backup file
ods-signerd: error: error adding domain from backup file
ods-signerd: error: error reading NSEC(3) RR from backup file
ods-signerd: error: error adding NSEC(3) RR from backup file
ods-signerd: error: unable to recover zone state from file <file>: <reason>
ods-signerd: error: unable to recover denial of existence from file <file>: <reason>
ods-signerd: error: unable to recover unsorted zone from file <file>: <reason>
ods-signerd: error: unable to recover dnskeys from file <file>: <reason>
ods-signerd: error: unable to recover rrsigs from file <file>: <reason>
ods-signerd: error: domain part in backup file is corrupted
ods-signerd: error: unable to recover RR to domain: failed to add RRset
ods-signerd: error: ods-signerd: error: unable to recover RRSIG to domain: no NSEC RRset
ods-signerd: error: unable to recover RRSIG to domain: no NSEC3 RRset
ods-signerd: error: unable to recover RRSIG to domain: no such RRset
ods-signerd: error: nsec3params part in backup file is corrupted
ods-signerd: error: key part in backup file is corrupted
ods-signerd: error: unable to recover signconf backup file <file>: corrupt

Finally, note that it might take a while if you want to shut down the signer engine daemon. There might be a worker busy that will first finish his job. Especially if a worker is currently busy replacing signatures in a huge zone, this might take several minutes.


Reporting bugs

If you encounter anything strange in either the documentation, the code or in the commands you are using, feel free to post a message to the opendnssec-user mailing list. You can subscribe to it here:

http://lists.opendnssec.org/mailman/listinfo/opendnssec-user

If you have a bug report, please enter it into our trac-system:

http://trac.opendnssec.org/newticket

Be sure to include all the error messages you get, the versions of the other libraries you are using and what actions you did to trigger the error message.