Backup PKI Assets Module

This module is used to backup the OpenVPN Public Key Infrastructure (PKI) to S3 on a server that has been installed using the install-openvpn module.

The PKI is the set of certificates used to verify the server and users' identities for VPN authentication purposes. This normally lives on the OpenVPN server in the /etc/openvpn-ca and /etc/openvpn directories. If we didn't back these files up, we would have to reissue client certificates if the OpenVPN server ever needed to be rebuilt.