Wednesday, July 15, 2009

Snorby for Snort, a Recipe with Barnyard2 and Unified2

Snorby, an all new frontend (yes, it's still Beta) for snort has recently emerged. As such I decided that I would take a look and give my thoughts as well as a quick recipe to get it running fairly quickly using barnyard2. During my testing of Snorby, I talked with the creator (mephux) about his plans for Snorby and also worked through a couple of bugs, that he jumped on right away.

Note: This posting details how to get Snorby working with apache and passenger, NOT Webrick.. if you want that please read the details of how to do so at the Snorby site.

Recipe Components:
  • FreeBSD 8.0R
  • apache22
  • ruby-gems
  • ruby-iconv
  • prawn (gem)
  • rake (gem)
  • mysql (gem)
  • rails (gem)
  • passenger (formerly modrails)
  • mysql
  • snort
  • barnyard2
  • git
Ok, let's get the dependencies and such out of the way. I am making several assumptions in writing this... the least of which is that you know how to use google if you can't figure something out... also that you already have the base of some of these items installed (ala, FreeBSD, apache, snort). If not, I have previous posts that discuss the setup of said items, and I am again going to drop the google bomb!

We need ruby-gems to get passenger running and ultimately Snorby:
$ cd /usr/ports/devel/git/ && sudo make install clean
...I deselect all of the options, I just want regular old git for this exercise
...output suppressed
$ cd /usr/ports/devel/ruby-gems/ && sudo make install clean
...output suppressed
$ sudo gem install prawn --no-rdoc --no-ri
...output suppressed
$ sudo gem install rake --no-rdoc --no-ri
...output suppressed
$ sudo gem install rails --no-rdoc --no-ri
...output suppressed
$ sudo gem install mysql --no-rdoc --no-ri
...output suppressed
$ sudo gem install passenger --no-rdoc --no-ri
...output suppressed
$ sudo passenger-install-apache2-module through the setup and perform the steps that are noted to activate the passenger capabilities with apache.. ala vi httpd.conf and add the 3 lines that you are told to.
$ cd /usr/local/www/ && sudo git clone git://
...output suppressed/usr/ports/converters/ruby-iconv
$ cd /usr/ports/converters/ruby-iconv && sudo make install clean

At this point you are ready to modify your database and email configuration for Snorby. If you have not done so, you should create a snort database (I have called mine snort and created a user "snorby" with password "snorby".. ok that's not really the password but for this writeup it is! This user has full access (not grant) to the snort database. I have also created the apt tables in this database using the create_mysql sql that is included in both Snorby and Snort!
$ sudo cp /usr/local/www/Snorby/config/database.yml.example /usr/local/www/Snorby/config/database.yml
$ sudo cp /usr/local/www/Snorby/config/email.yml.example /usr/local/www/Snorby/config/email.yml

Now choose your preferred editor and modify the /usr/local/www/Snorby/config/database.yml file.. we are only concerned with the production info... you can also modify the email.yml but don't have to for our current purposes.

Install additional gem requirements and setup Snorby to run!
$ cd /usr/local/www/Snorby && sudo rake gems:install
...output suppressed
$ cd /usr/local/www/Snorby && sudo rake snorby:setup RAILS_ENV=production
...output suppressed

At this point you are ready to tell apache all about Snorby, so lets modify our vhost or apache config again. Simply add the following under the vhost of your choice, you need to be sure that RewriteEngine On and RewriteOptions inherit are specified in this vhost (or in scope of your config):
DocumentRoot /usr/local/www/Snorby/public

RailsBaseURI /

<directory "/usr/local/www/Snorby/public">
AllowOverride All
Order deny,allow
Allow from all

Once this is complete, restart apache and you will get the login for Snorby when you browse to that vhost. The default username is snorby and password is admin.

We are now ready to modify our snort config to output unified2, modify your snort.conf and comment out your old output plugins or simply replace them with the following:
output unified2: filename snortunified2.log, limit 128

Note that unified2 contains all log and alert data, so no longer do you need two files! And now it's time for barnyard2. Go ahead and fetch the latest version from, configure with "--with-mysql" option. Once that is done copy the barnyard.conf to /usr/local/etc/snort/ and let's go ahead and edit that file, putting in the mysql information that you used with Snorby earlier and making sure that we have our input specified as unified2. You should go through and make sure that all of the paths to the map and ref files are specified correctly. Once that's done, you are ready to fire it up!
sudo barnyard2 -c /usr/local/etc/snort/barnyard2.conf -d /var/log/snort -f snortunified2.log -w /var/log/snort/barnyard2.waldo -D

You should now be receiving events in the snort mysql database and seeing them in Snorby.

Please note that there are a number of security considerations that I did not take into account (ala running all this stuff under root) so please take that into consideration.

Overall, I give Snorby a good rating, it certainly has lots of eye candy at this point. Mephux promises that much of the functionality that everyone wants is coming shortly... I would say that Snorby has a good start and promises to be a decent usable frontend for viewing snort events. Is it a sguil, certainly not... but it does look like it will be a decent alternative to BASE.


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