CYBERSECURITY AND POTLUCK: Implementing Zero Trust on a Budget: A Comprehensive Guide
Jun 19, 2024
8 min read
1
2
0
June 1, 2024
In an era where cyber threats are increasingly sophisticated, the Zero Trust architecture has emerged as a crucial strategy in cybersecurity. Zero Trust operates on a fundamental principle: no internal or external user is trusted by default, and verification is required from everyone trying to access resources within the network. However, deploying such a system can be cost-prohibitive. This guide presents an economical solution using open-source tools to deploy a Zero Trust architecture effectively.
 The Need for Zero Trust
Organizations are facing escalating threats from cyber attacks, with breaches often resulting from exploited trust in traditional network defenses. Zero Trust architecture addresses these vulnerabilities by ensuring strict access controls and continuous verification are in place, significantly enhancing security.
 Zero Trust Lite Pathway Overview
The Zero Trust Lite Pathway is designed to provide a scalable and effective Zero Trust environment utilizing free and open-source tools:
A. FreeIPA (Identity Management)
 Official Website: FreeIPA - Identity, Policy, Audit — FreeIPA documentation
You can find the latest version and installation instructions here.
B. OpenVPN (Secure Access Configuration)
Official Website:Â Community Downloads - Open Source VPN | OpenVPN
This page offers various OpenVPN community downloads for different operating systems.
OSQuery (Device Compliance Monitoring)
C. Official Website: OSQuery Downloads
osquery | Easily ask questions about your Linux, Windows, and macOS infrastructure
Download OSQuery for various platforms from this official site.
D. Wireshark (Network Monitoring)
Official Website: Wireshark · Download
Wireshark is available for multiple platforms. Ensure you download the correct version for your operating system.
E. Docker (Containerization Tool)
Official Website:Â Install Docker Desktop on Windows | Docker Docs
Download Docker Desktop or specific Docker engine packages based on your server’s operating system.
 F. Easy-RSA (Certificate Management for OpenVPN)
GitHub Repository:Â GitHub - OpenVPN/easy-rsa: easy-rsa - Simple shell based CA utility
Easy-RSA can be cloned or downloaded from this GitHub page, which also includes the latest updates and documentation.
Â
***Detailed Setup for Zero Trust Architecture***
1. FreeIPA Installation and Configuration
System Requirements:
A server with CentOS 8, 4 CPU cores, 16GB RAM, and 100GB of SSD storage.
 Setup Instructions:
sudo dnf module enable idm:DL1
sudo dnf install -y ipa-server ipa-server-dns
 Setup FreeIPA:
ipa-server-install --setup-dns --no-forwarders --no-ntp
Â
Add Users and Define Roles:
ipa user-add jdoe --first=John --last=Doe --password
ipa role-add "Network Admins"
ipa role-add-member --users=jdoe "Network Admins"
 2. OpenVPN Installation and Integration with FreeIPA
System Requirements:
A server with Ubuntu 20.04, 2 CPU cores, 8GB RAM.
 Setup Instructions:
 Install OpenVPN and Required Packages:
sudo apt update
sudo apt install -y openvpn easy-rsa
Configure PKI:
make-cadir ~/openvpn-ca
cd ~/openvpn-ca
./easyrsa init-pki
./easyrsa build-ca nopass
./easyrsa gen-req server nopass
./easyrsa sign-req server server
 Configure OpenVPN Server:
sudo cp ~/openvpn-ca/pki/private/server.key /etc/openvpn/
sudo cp ~/openvpn-ca/pki/issued/server.crt /etc/openvpn/
sudo cp ~/openvpn-ca/pki/ca.crt /etc/openvpn/
# Create server config file
echo "port 1194
proto udp
dev tun
ca ca.crt
cert server.crt
key server.key
dh none
topology subnet
server 10.8.0.0 255.255.255.0
push 'redirect-gateway def1 bypass-dhcp'
client-to-client
keepalive 10 120
cipher AES-256-CBC
persist-key
persist-tun
user nobody
group nogroup
plugin /usr/lib/openvpn/plugins/openvpn-plugin-auth-pam.so openvpn
status openvpn-status.log
verb 3" > /etc/openvpn/server.conf
 Start OpenVPN Server:
sudo systemctl start openvpn@server
sudo systemctl enable openvpn@server
3. Device Compliance: OSQuery on Each Endpoint Device
Install OSQuery on client devices (Windows, macOS, Linux) for compliance monitoring.
Server 3: Monitoring and Containerization Server
Specifications: Ubuntu 20.04, 4 CPU cores, 16GB RAM.
Primary Roles: Runs Docker for service isolation and Wireshark for network monitoring.
Setup Instructions:
Install Docker:
sudo apt install docker-ce docker-ce-cli containerd.io
docker run -d --name mysecureapp mysecureimage
Install and Configure Wireshark for Continuous Monitoring:
sudo apt install wireshark
4. Setup and Integration Guide for the ELK Stack
Server Requirements:
Server 4: ELK Stack Server
Specifications: Ubuntu 20.04, 4 CPU cores, 16GB RAM, 200GB SSD.
Installation and Configuration Steps:
Install Elasticsearch:
wget -qO - https://artifacts.elastic.co/GPG-KEY-elasticsearch | sudo apt-key add -
sudo apt-get install apt-transport-https
echo "deb https://artifacts.elastic.co/packages/7.x/apt stable main" | sudo tee -a /etc/apt/sources.list.d/elastic-7.x.list
sudo apt-get update && sudo apt-get install elasticsearch
sudo systemctl start elasticsearch
sudo systemctl enable elasticsearch
 Install Logstash:
sudo apt-get install logstash
# Configure Logstash to process input from network devices, security systems, and other servers
Example Logstash Configuration (/etc/logstash/conf.d/logstash.conf):
 input {
 beats {
 port => 5044
 }
}
filter {
 grok {
 match => { "message" => "%{COMBINEDAPACHELOG}"}
 }
}
output {
 elasticsearch {
 hosts => ["localhost:9200"]
 manage_template => false
 index => "%{[@metadata][beat]}-%{[@metadata][version]}-%{+YYYY.MM.dd}"
 document_type => "%{[@metadata][type]}"
 }
}
Install Kibana:
sudo apt-get install kibana
sudo systemctl start kibana
sudo systemctl enable kibana
Configure Kibana by editing the kibana.yml file to set the Elasticsearch URL and enable access through a web browser.
Integration with Network Devices and Servers:
 Configure network devices, Docker containers, and endpoint devices to send logs to Logstash.
Adjust the firewall settings and ensure proper network routes for uninterrupted data flow to Logstash.
Monitoring and Auditing:
Utilize Kibana to monitor network and user activities in real-time, creating dashboards that help in quick identification of anomalies.
Regularly review and audit logs to ensure compliance with the Zero Trust policies.
By implementing the ELK Stack in this manner, you enhance the Zero Trust architecture's effectiveness by ensuring all network transactions are logged and analyzed, contributing to secure access management and threat detection. This step-by-step guide should help clarify its installation, configuration, and role in the broader security framework.
# Configure Wireshark for automated traffic capture
Centralized Logging and Auditing (Optional Dedicated Server or Cloud Service)
Use ELK Stack or a similar solution for centralized logging and auditing across the network.
 Automation and System Integration:
Script Development: Create scripts to automate the setup, configuration changes, and security checks for all components within the Zero Trust framework.
Seamless Integration: Ensure all components are integrated seamlessly to allow for synchronized security responses and real-time decision-making based on security data collected across the network.
Appendix: Script Repository
Detailed scripts for each component will be provided here to facilitate technical implementation, ensuring readers have actionable content to execute the outlined strategies.
1. FreeIPA Identity Management Automation
Where to Apply:
These scripts are run on the server or virtual machine where FreeIPA is installed. This server acts as the central identity management system for your network.
How to Apply:
Script to Add Users: This script is executed when new users need to be added to the system. It can be run manually by an administrator or triggered by a user onboarding process.
Script to Sync Users from Active Directory: This should be scheduled to run at regular intervals (e.g., daily) or triggered by specific events like updates in the Active Directory.
Script 1: Add Users
#!/bin/bash
# Adds a user to FreeIPA with predefined roles and permissions
# Check for proper usage
if [ "$#" -ne 2 ]; then
 echo "Usage: $0 <username> <role>"
 exit 1
fi
username=$1
role=$2
# Create user and set default password (should be changed on first login)
ipa user-add $username --first=FirstName --last=LastName --password
Â
# Assign role to user
ipa role-add-member $role --users=$username
echo "User $username added and assigned role $role"
Script 2: Sync Users from Active Directory
#!/bin/bash
# Syncs users from Active Directory to FreeIPA
# Run synchronization (modify sync tool and parameters based on actual setup)
sync-tool --source ad --target freeipa --full-sync
echo "User synchronization complete"
2. OpenVPN Configuration Script
Where to Apply:
This script is applied on the server designated for OpenVPN. This server handles secure VPN connections and must be robust enough to manage encryption and network traffic.
How to Apply:
The script to configure OpenVPN with FreeIPA authentication is run during the initial setup of the OpenVPN server or whenever there are changes to the authentication system. It sets up OpenVPN to use FreeIPA for validating user credentials, ensuring that only authenticated users can access the network.
Script Repository for Zero Trust Lite Pathway
2. OpenVPN Configuration Script
Script 3: Configure OpenVPN with FreeIPA Authentication
#!/bin/bash
# Configures OpenVPN to use FreeIPA for user authentication
# Install required packages
apt-get install -y openvpn easy-rsa freeipa-client
Â
# Initialize PKI environment
make-cadir /etc/openvpn/easy-rsa
cd /etc/openvpn/easy-rsa
./easyrsa init-pki
./easyrsa build-ca nopass
./easyrsa gen-req server nopass
./easyrsa sign-req server server
Â
# Configure OpenVPN server
cat <<EOF > /etc/openvpn/server.conf
port 1194
proto udp
dev tun
ca ca.crt
cert server.crt
key server.key
dh dh.pem
topology subnet
server 10.8.0.0 255.255.255.0
push "redirect-gateway def1 bypass-dhcp"
client-to-client
keepalive 10 120
cipher AES-256-CBC
user nobody
group nogroup
persist-key
persist-tun
status openvpn-status.log
verb 3
plugin /usr/lib/openvpn/plugins/openvpn-plugin-auth-pam.so login
EOF
Â
# Enable and start OpenVPN
systemctl enable openvpn@server
systemctl start openvpn@server
Â
echo "OpenVPN configured with FreeIPA authentication"
Â
3. OSQuery Device Monitoring Configuration
Where to Apply:
OSQuery scripts are deployed on each device within the organization that you want to monitor for compliance. This includes workstations, laptops, and servers.
How to Apply:
The script to configure OSQuery is executed once during the initial setup of each device. It may also be run again if there are updates or changes to the compliance monitoring policies.
3. OSQuery Device Monitoring Configuration
Script 4: Configure OSQuery for Device Compliance
#!/bin/bash
# Installs and configures OSQuery for monitoring device compliance
# Install OSQuery
apt-get install -y osquery
# Configuration file setup
cat <<EOF > /etc/osquery/osquery.conf
{
 "options": {
 "config_plugin": "filesystem",
 "logger_plugin": "filesystem",
 "logger_snapshot_event_type": true,
 "disable_logging": "false",
 "log_result_events": "true",
 "schedule_splay_percent": 10
 },
 "schedule": {
 "system_info": {
 "query": "SELECT hostname, time, hardware_serial FROM system_info;",
 "interval": 3600
 },
 "system_compliance": {
 "query": "SELECT * FROM processes WHERE on_disk = 0;",
 "interval": 600
 }
 }
}
EOF
Â
# Start and enable OSQuery service
systemctl enable osqueryd
systemctl start osqueryd
echo "OSQuery configured for device compliance monitoring"
 4. Network Monitoring Setup
Where to Apply:
Network monitoring scripts, such as those setting up Wireshark for traffic analysis, are applied on network gateways or servers designated for security monitoring. These are critical points where network traffic can be comprehensively observed.
How to Apply:
Deploy the script initially when setting up network monitoring tools and subsequently whenever adjustments to monitoring settings or upgrades are needed.
Script 5: Network Monitoring Setup
#!/bin/bash
# Setups up network monitoring using open-source tools like Wireshark
Â
# Install Wireshark for capturing and analyzing packets
apt-get install -y wireshark
# Set up capture on network interface (replace eth0 with actual interface)
tshark -i eth0 -a duration:60 -w /var/log/network_capture.pcap
echo "Network monitoring setup complete"
 General Deployment Tips:
Automation and Scheduling: Use tools like cron jobs (Linux) or Task Scheduler (Windows) to automate the execution of these scripts at scheduled times. This automation ensures that the scripts are run consistently and without manual intervention, maintaining the security posture without ongoing administrative effort.
Security Best Practices: Ensure that only authorized personnel have access to these scripts and the servers where they are deployed. Use secure methods (like SSH) for accessing and running these scripts on servers.
Version Control: Use version control systems like Git to manage script versions. This approach allows you to track changes, roll back to previous versions if necessary, and collaborate securely on script development.
Monitoring and Alerts: Implement monitoring for the execution of these scripts to ensure they run as expected. Set up alerts to notify administrators if a script fails to execute or completes with errors.
By applying these scripts effectively, organizations can automate critical aspects of their Zero Trust architecture, thereby enhancing their security posture while reducing the administrative burden on IT staff.
Steps:
Script Development: Write custom scripts to handle routine tasks such as updates, backups, compliance checks, and alerting mechanisms.
System Integration: Ensure all components of the Zero Trust architecture are seamlessly integrated, allowing for automated responses based on predefined security policies and events.
Continuous Improvement: Regularly update scripts and configurations to adapt to new security challenges and improve response strategies based on incident feedback and evolving best practices.
Disclaimer
The information provided in this document is for educational and informational purposes only. While every effort has been made to ensure the accuracy and effectiveness of the information and procedures described herein, the author and publisher accept no responsibility for any errors or omissions, or for any damages resulting from the application of the information or the use of the resources mentioned in this document.
The procedures and guidelines suggested here are subject to change and should be executed with caution and at your own risk. It is recommended to conduct thorough testing and validation in controlled environments before full implementation. Users are encouraged to consult with professional IT or cybersecurity experts to tailor these suggestions to their specific organizational needs and compliance requirements.
Furthermore, adherence to all applicable laws and regulations, including but not limited to privacy laws and intellectual property rights, is the sole responsibility of the user. The author and publisher disclaim any liability in connection with the use of this information.
This disclaimer is intended to be exhaustive and should be read and understood in conjunction with the use of this document.
