May 26, 2018
Server implementing the AnyConnect SSL VPN protocol
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 protocol provides a dual TCP/UDP VPN channel, and uses the standard IETF security protocols to secure it. Both IPv4 and IPv6 are supported.
Ocserv’s main features are security through provilege separation and sandboxing, accounting, and resilience due to a combined use of TCP and UDP. Authentication occurs in an isolated security module process, and each 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 data leak e.g., heartbleed-style attacks, and privilege escalation due to any bug on the VPN handling worker process. A management interface allows for viewing and querying logged-in users.