OpenVPN

OpenVPN is a long established VPN server that encrypts client connections with OpenSSL and issues them certificates and keys you generate and revoke yourself. It supports routed and bridged tunnels, a range of cipher and digest choices, compression, and client profiles for desktop and mobile, all driven by plain text configs.

It remains common in enterprises that already run a certificate authority, and among homelab operators who want a classic client and server VPN for travel or reaching remote machines.

Hosting it yourself keeps the CA and every issued credential on your own disk, hands out access per user without a vendor account, and makes backup a copy of that directory.