Book Image

Mastering OpenVPN

By : Jan Just Keijser, Eric F Crist
Book Image

Mastering OpenVPN

By: Jan Just Keijser, Eric F Crist

Overview of this book

Security on the internet is increasingly vital to both businesses and individuals. Encrypting network traffic using Virtual Private Networks is one method to enhance security. The internet, corporate, and “free internet” networks grow more hostile every day. OpenVPN, the most widely used open source VPN package, allows you to create a secure network across these systems, keeping your private data secure. The main advantage of using OpenVPN is its portability, which allows it to be embedded into several systems. This book is an advanced guide that will help you build secure Virtual Private Networks using OpenVPN. You will begin your journey with an exploration of OpenVPN, while discussing its modes of operation, its clients, its secret keys, and their format types. You will explore PKI: its setting up and working, PAM authentication, and MTU troubleshooting. Next, client-server mode is discussed, the most commonly used deployment model, and you will learn about the two modes of operation using "tun" and "tap" devices. The book then progresses to more advanced concepts, such as deployment scenarios in tun devices which will include integration with back-end authentication, and securing your OpenVPN server using iptables, scripting, plugins, and using OpenVPN on mobile devices and networks. Finally, you will discover the strengths and weaknesses of the current OpenVPN implementation, understand the future directions of OpenVPN, and delve into the troubleshooting techniques for OpenVPN. By the end of the book, you will be able to build secure private networks across the internet and hostile networks with confidence.
Table of Contents (17 chapters)
Mastering OpenVPN
About the Authors
About the Reviewers

Using OpenVPN with HTTP or SOCKS proxies

OpenVPN supports operation through an HTTP or SOCKS proxy with no authentication, with basic authentication and with NTLM authentication. We will cover both HTTP and SOCKS proxy servers, both with and without authentication.

HTTP proxies

HTTP proxies require the use of TCP for the OpenVPN tunnel transport. If you are currently using UDP, the protocol argument in both the server as well as the client configurations will need to be updated:

proto tcp

Once configured, add proxy support to the client by adding the --http-proxy configuration directive. As an example, let's assume your local area network requires an anonymous proxy for outbound connections and that server is at on the default port 1080. Your configuration would be something like this:

http-proxy 1080 none

This will allow your OpenVPN client connection to connect to your remote OpenVPN server through the proxy server on your local network. An authenticated HTTP proxy...