The dnssec module in Kamailio was added during the development of v4.1.0 (expected to be released later in 2013). Therefore this tutorial presents how to add DNSSEC module in the default configuration file of Kamailio, following GIT installation guidelines.
In short, this tutorial focuses on:
Note: the DNSSEC module is several days old at the time of writing initial version of this tutorial. For any assistance, email to <sr-users [at] sip-router.org> – it is a public mailing list that requires subscription, see more details at:
Note: Ubuntu 12.04 was chosen because dnssec tools devel library are provided for this distribution, making the installation of the required dependencies much easier. There are packages for other Linux distribution (e.g., Fedora), most of the steps provided in this tutorial being valid (the rest have to updated for the specifics of the distribution, e.g., how to install packages, create system users or init.d scripts).
For reading more about DNSSEC, head to:
Many related resources, including the required libraries for Kamailio's DNSSEC module, are available at:
The dnssec-tools package should be available on recent Debian/Ubuntu, to install it us:
apt-get install dnssec-tools
You need DNSSEC tools devel libraries to compile Kamailio's DNSSEC module. You can download the libraries from:
The files are:
dns-validator_2.0-1_i386.deb libval-threads_2.0-1_i386.deb libval-threads-dev_2.0-1_i386.deb libsres_2.0-1_i386.deb libsres-dev_2.0-1_i386.deb
Once you download the deb files, install them with dpkg -i …
Here is a quick guide to install Kamailio development version from GIT repository. If you look for a more detailed tutorial, check:
Install the packages needed to build Kamailio:
apt-get install make autoconf gcc flex bison git-core apt-get install libmysqlclient-dev libssl-dev
First of all, you have to create a directory on the file system where the sources will be stored.
mkdir -p /usr/local/src/kamailio-devel cd /usr/local/src/kamailio-devel
Download the sources from GIT using the following commands.
git clone --depth 1 git://git.sip-router.org/sip-router kamailio cd kamailio
Run next set of commands:
cd /usr/local/src/kamailio-devel/kamailio make cfg include_modules="db_mysql dnssec" make all make install
The binaries and executable scripts were installed in:
/usr/local/sbin
These are:
To be able to use the binaries from command line, make sure that '/usr/local/sbin' is set in PATH environment variable. You can check that with 'echo $PATH'. If not and you are using 'bash', open '/root/.bash_profile' and at the end add:
PATH=$PATH:/usr/local/sbin export PATH
Kamailio modules are installed in:
/usr/local/lib/kamailio/modules/
Note: On 64 bit systems, /usr/local/lib64 may be used.
The documentation and readme files are installed in:
/usr/local/share/doc/kamailio/
The man pages are installed in:
/usr/local/share/man/man5/ /usr/local/share/man/man8/
The configuration file was installed in:
/usr/local/etc/kamailio/kamailio.cfg
kamctl is command line tool useful to control Kamailio. It can add or remove SIP user profiles.
Edit /usr/local/etc/kamailio/kamctlrc, locate DBENGINE variable and set it to MYSQL:
DBENGINE=MYSQL
Also, you can set SIP_DOMAIN to you server hostname or IP address.
You can change other values in kamctlrc file, at least it is recommended to change the default passwords for the users to be created to connect to database.
Once you are done updating kamctlrc file, run the script to create the database used by Kamailio:
/usr/local/sbin/kamdbctl create
You can call this script without any parameter to get some help for the usage. You will be asked for the domain name Kamailio is going to serve (e.g., mysipserver.com) and the password of the 'root' MySQL user. The script will create a database named 'kamailio' containing the tables required by Kamailio. You can change the default settings in the kamctlrc file mentioned above.
The script will add two users in MySQL:
- kamailio - (with default password 'kamailiorw') - user which has full access rights to 'kamailio' database
- kamailioro - (with default password 'kamailioro') - user which has read-only access rights to 'kamailio' database
Do change the passwords for these two users to something different that the default values that come with sources.
Kamctl can be used for adding users, for example adding user test with password testpasswd:
kamctl add test testpasswd
The init.d script can be used to start/stop the Kamailio server in a nicer way. A sample of init.d script for Kamailio is provided at:
/usr/local/src/kamailio-devel/kamailio/pkg/kamailio/deb/debian/kamailio.init
The default file for init.d script is provided at:
/usr/local/src/kamailio-devel/kamailio/pkg/kamailio/debian/kamailio.default
Run next command to deploy the init.d scripts:
make install-initd-debian
It will create also user and group kamailio, plus runtime directory /var/run/kamailio.
Now Kamailio can be started or stopped with:
/etc/init.d/kamailio start /etc/init.d/kamailio stop
Next step is to enable user authentication, persistent location service and add dnssec module. You have to edit the configuration file.
/usr/local/etc/kamailio/kamailio.cfg
Follow the instruction in the comments to enable usage of MySQL. Basically you have to add several lines at the top of config file (but after the first line), like:
#!define WITH_MYSQL #!define WITH_AUTH #!define WITH_USRLOCDB
If you changed the password for the 'kamailio' user of MySQL, you have to update the value for DBURL define.
The README of DNSSEC module is available at:
You have to load dnssec module in kamailio.cfg:
loadmodule "dnssec.so"
Add the above line somewhere before the first line starting with modparam.
The module does not require any parameter, you are ready to use the configuration file now.
Start Kamailio with:
/etc/init.d/kamailio start
This tutorial does not include yet (left for future updates) how to setup a DNSSEC-enabled DNS server, there are many useful resources on the web. Among them:
One way to test is to setup two instances of Kamailio, one serving domainA.com and the second domainB.com.
Then alice@domainA.com can call bob@domainB.com. Kamailio instance serving domainA.com will do DNS lookup do discover the IP address of domainB.com
One easy way to test is to use a Open DNS resolver that provides Recursive DNSSEC capabilities. One of those is 8.8.8.8 ( Google Open DNS). As per the FAQ, DNSSEC support is enabled (https://developers.google.com/speed/public-dns/faq#dnssec)
Edit /etc/resolv.conf and modify your nameserver definition to have 'nameserver 8.8.8.8'.
Launch Kamailio with DNSSEC module enabled and try to send a SIP package to the domain www.dnssec-failed.org. DNS resolving for this domain should fail, as it is a test domain which provides an incorrect signature. Kamailio should report: “0(70805) INFO: dnssec [dnssec_func.c:145]: invalid domain www.dnssec-failed.org reason VAL_UNTRUSTED_ANSWER”