generate a RSA key infrastructure easily
./easyrsa init-pki ./easyrsa build-ca nopass
./easyrsa build-client-full client1 nopass
If you get an error along the lines Easy-RSA error: Unknown cert type 'client', copy or symlink the x509-types folder.
see https://chichivica.github.io/2017/08/02/Install-OpenVPN-on-Fedora-26/
sudo dnf install openvpn easy-rsa cp -ai /usr/share/easy-rsa/3/* . ./easyrsa