Add the following directive in your client configuration file:
push-peer-info
Add the following directives in your server configuration file:
script-security 2 verb 3 client-connect /etc/openvpn/mac-check.py
Create a file at /etc/openvpn/db.txt where you map each username to a MAC address in the following format:
username-M:A:C:A:D:R:E:S:S pranil.kharche-C4:23:60:FA:CC:1A
When a user connects, their MAC address will be logged under IV_HWADDR. Writing this MAC address in db.txt will grant this user access only from that machine.
Run the following command to give the script access to search through the log file:
chmod 664 /var/log/openvpn.log
Ensure you have Python 3.6 in your bin folder or create a symlink to it. Then, create the openvpn_login_checker.py script: