A hardened version of OpenVPN that includes as many of the security measures required to operate in a classified environment as possible.
OpenVPN for the Dutch Government
OpenVPN-NL was built according to the guidelines set by the Dutch government's national communications security agency (NBV, also known as the NLNCSA). This includes both hardening patches and improvements in documentation to ease evaluation.
OpenVPN-NL can build a virtual private network (VPN) on top of an untrusted network such as the internet. The OpenVPN-NL software packages contain both the client and the server. The information sent between the client and the server is protected in a way that meets the NBV evaluation criteria. The deployment advisory provides additional pointers for OpenVPN-NL deployments.