Book Image

SSL VPN : Understanding, evaluating and planning secure, web-based remote access

Book Image

SSL VPN : Understanding, evaluating and planning secure, web-based remote access

Overview of this book

Virtual Private Networks (VPNs) provide remote workers with secure access to their company network via the internet by encrypting all data sent between the company network and the user?s machine (the client). Before SSL VPN this typically required the client machine to have special software installed, or at least be specially configured for the purpose. Clientless SSL VPNs avoid the need for client machines to be specially configured. Any computer with a Web browser can access SSL VPN systems. This has several benefits: Low admin costs, no remote configuration Users can safely access the company network from any machine, be that a public workstation, a palmtop or mobile phone By pass ISP restrictions on custom VPNs by using standard technologies SSL VPN is usually provided by a hardware appliance that forms part of the company network. These appliances act as gateways, providing internal services such as file shares, email servers, and applications in a web based format encrypted using SSL. Existing players and new entrants, such as Nokia, Netilla, Symantec, Whale Communications, and NetScreen technologies, are rushing our SSL VPN products to meet growing demand. This book provides a detailed technical and business introduction to SSL VPN. It explains how SSL VPN devices work along with their benefits and pitfalls. As well as covering SSL VPN technologies, the book also looks at how to authenticate and educate users ? a vital element in ensuring that the security of remote locations is not compromised. The book also looks at strategies for making legacy applications accessible via the SSL VPN.
Table of Contents (14 chapters)
SSL VPN
Credits
About the Authors
Introduction
A Review of TCP, IP, and Ports

Establishing Secure Tunnels Using SSL


Now that we understand what SSL is and how it works, let us discuss how SSL allows us to create tunnels.

Secure Tunnels

A secure tunnel between computers can best be understood as a secure channel of communication between two machines that have an insecure environment between them. The communications tunnel is like a tunnel under a river that allows automobiles to travel from point A on one side of the river to point B on the other side and prevents environmental elements like water from interfering with the traffic as shown in the following diagram:

The communications tunnel allows communications between two computers over public networks securely so that other computers on those networks cannot access the communications between the two machines.

However, unlike the example of the tunnel under the river, network tunneling does not employ a physical barrier between the two computers communicating and other machines. Rather, computer-related tunneling involves...