Book Image

OpenVPN Cookbook - Second Edition

By : Jan Just Keijser
Book Image

OpenVPN Cookbook - Second Edition

By: Jan Just Keijser

Overview of this book

OpenVPN provides an extensible VPN framework that has been designed to ease site-specific customization, such as providing the capability to distribute a customized installation package to clients, and supporting alternative authentication methods via OpenVPN’s plugin module interface. This book provides you with many different recipes to help you set up, monitor, and troubleshoot an OpenVPN network. You will learn to configure a scalable, load-balanced VPN server farm that can handle thousands of dynamic connections from incoming VPN clients. You will also get to grips with the encryption, authentication, security, extensibility, and certifications features of OpenSSL. You will also get an understanding of IPv6 support and will get a demonstration of how to establish a connection via IPv64. This book will explore all the advanced features of OpenVPN and even some undocumented options, covering all the common network setups such as point-to-point networks and multi-client TUN-style and TAP-style networks. Finally, you will learn to manage, secure, and troubleshoot your virtual private networks using OpenVPN 2.4.
Table of Contents (17 chapters)
OpenVPN Cookbook - Second Edition
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Revoking certificates


A common task when managing a PKI is to revoke certificates that are no longer needed or that have been compromised. This recipe demonstrates how certificates can be revoked using the easy-rsa script and how OpenVPN can be configured to make use of a Certificate Revocation List (CRL).

Getting ready

Set up the client and server certificates using the first recipe from Chapter 2Client-server IP-only Networks. This recipe was performed on a computer running CentOS 6 Linux, but it can easily be run on Windows or Mac OS.

How to do it...

  1. First, we generate a certificate:

    $ cd /etc/openvpn/cookbook
    $ . ./vars
    $ ./build-key client4
    [...]
    
  2. Then, we immediately revoke it:

    $ ./revoke-full client4
    Using configuration from /etc/openvpn/cookbook/openssl-
            1.0.0.cnf
    Enter pass phrase for /etc/openvpn/cookbook/keys/ca.key:
    Revoking Certificate 06.
    Data Base Updated
    Using configuration from /etc/openvpn/cookbook/openssl-
            1.0.0.cnf
    Enter pass phrase for /etc/openvpn/cookbook...