slackbuilds/network/wireguard-linux-compat

WireGuard is a VPN that uses state-of-the-art cryptography. It is
designed as a general purpose VPN for running on embedded interfaces
and super computers alike, fit for many different circumstances.

This script only builds the WireGuard kernel module.  Userspace 
tools are also required to configure and use WireGuard tunnels. Refer
to the wireguard-tools script on Slackbuilds.