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How to install CrowdSec Firewall Bouncer on FreeBSD

· 3 min read

This tutorial will give you all the needed configuration steps to have an up and running firewall protection with Crowdsec Agent on FreeBSD systems.

Packages installation

  • Update the current package database and install the following packages. Make sure your systems is configured with a FreeBSD official repository either latest or quaterly
pkg -vvv|awk '/Repositories:/,/}/'
Repositories:
FreeBSD: {
url : "pkg+http://pkg.FreeBSD.org/FreeBSD:12:amd64/latest",
enabled : yes,
...

You can edit the repository config file by editing /etc/pkg/FreeBSD.conf. By default, it should have been setup correctly during the OS installation.

sudo pkg update
sudo pkg install crowdsec crowdsec-firewall-bouncer

Firewall Configuration

  • The FreeBSD firewall pf is not loaded by default, you need to load the kernel module:
sudo kldload pf
  • Enable it in your /etc/rc.conf permanently:
pf_enable="YES"

In order to be able to block and drop traffic, you need to append this minimal /etc/pf.conf configuration in your pf rules:

# create crowdsec table
table <crowdsec-blacklists> persist

# create crowdsec6 table
table <crowdsec6-blacklists> persist

block drop in quick from <crowdsec-blacklists> to any
block drop in quick from <crowdsec6-blacklists> to any

For more details on the firewall configuration, you could refer to the pf.conf(5) man pages.

  • Reload the rules and check config
sudo pfctl -f /etc/pf.conf
sudo pfctl -sr
sudo service pf check
sudo service pf status

Agent Configuration

  • Copy the sample config:
sudo cp /usr/local/etc/crowdsec/config.yaml.sample /usr/local/etc/crowdsec/config.yaml

Review the YAML settings in the file and updates accordingly.

  • Enable it in your /etc/rc.conf:
crowdsec_enable="YES"
crowdsec_config="/usr/local/etc/crowdsec/config.yaml"
crowdsec_flags=" -info"
  • Start the service Crowdsec Agent
sudo service crowdsec start
sudo service crowdsec status
  • List your current machine Agent settings
crowdsec-cli machines list
-------------------------------------------------------------------------------------------------------------
NAME IP ADDRESS LAST UPDATE STATUS VERSION
-------------------------------------------------------------------------------------------------------------
7fb0531dc09a40d288299c8377d6cfe5nJtGyC7TFsUR3XYZ 127.0.0.1 2021-07-22T09:41:47Z ✔️ v1.1.1-freebsd
-------------------------------------------------------------------------------------------------------------

Bouncer Configuration

  • Copy the sample config
sudo cp /usr/local/etc/crowdsec-firewall-bouncer/crowdsec-firewall-bouncer.yaml.sample /usr/local/etc/crowdsec-firewall-bouncer/crowdsec-firewall-bouncer.yaml
  • Add the new bouncer and it will generate the token for {your_api_key} to use
crowdsec-cli bouncers add --name freebsd-pf-bouncer
  • Edit the YAML settings in the file. Make sure the bouncer backend mode is pf (automatically set at installation time). api_url and api_key are mandatory to be set.
api_url: http://localhost:8080/
api_key: <your_api_key>
  • List your current bouncers config
$ crowdsec-cli bouncers list
---------------------------------------------------------------------------------------------------------
NAME IP ADDRESS VALID LAST API PULL TYPE VERSION
---------------------------------------------------------------------------------------------------------
freebsd-pf-bouncer 127.0.0.1 ✔️ 2021-07-22T09:59:33Z crowdsec-firewall-bouncer v0.0.13-freebsd
---------------------------------------------------------------------------------------------------------
  • Enable it in your /etc/rc.conf:
crowdsec_firewall_enable="YES"
  • Start the service Crowdsec Firewall
sudo service crowdsec_firewall start
sudo service crowdsec_firewall status

Scenarios, Parsers and Collections

  • Use the following scenarios, parsers and collections from the Hub:
sudo crowdsec-cli scenarios install crowdsecurity/ssh-bf
sudo crowdsec-cli parsers install crowdsecurity/sshd-logs
sudo crowdsec-cli parsers install crowdsecurity/syslog-logs
sudo crowdsec-cli collections install crowdsecurity/sshd
  • Restart the crowdsec agent
sudo service crowdsec restart

You should now benefit from the Crowdsec signals from the community and your own and be protected against malevolant behaviour.