ocserv binary package in Ubuntu Bionic arm64

 OpenConnect server (ocserv) is an SSL VPN server. Its purpose is to be a
 secure, small, fast and configurable VPN server. It implements the OpenConnect
 SSL VPN protocol, and has also (currently experimental) compatibility with
 clients using the AnyConnect SSL VPN protocol. The OpenConnect VPN protocol
 uses the standard IETF security protocols such as TLS 1.2, and Datagram TLS to
 provide the secure VPN service. The server is implemented primarily for the
 GNU/Linux platform but its code is designed to be portable to other UNIX
 variants as well.
 .
 Ocserv's main feature is isolation of the VPN users from the main VPN server
 process. Each authenticated user is assigned an unprivileged worker process,
 and a networking (tun) device. That not only eases the control of the resources
 of each user or group of users, but also prevents privilege escalation due to
 any bug on the VPN handling (worker) server. Each VPN user can be authenticated
 using password, PAM, public key (in a smart card or not) or any combination of
 methods.

Source package