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

Chapter 3. How SSL VPNs Work

As described in Chapter 1, SSL VPN products allow users to establish secure remote-access sessions from virtually any Internet-connected web browser. Delivering the ability for people to access e-mail, critical information systems, files, and other network resources from virtually anywhere is not a trivial task. Despite often appearing to onlookers as simple devices, SSL VPNs employ complex and advanced technology.

At present, there are no official standards for SSL VPN technology (other than for SSL, HTTP, and other SSL VPN subcomponents). The few third-party SSL VPN 'certifiers' that exist, primarily examine features, not the internal mechanisms of delivering those features. With a highly competitive climate currently present in the SSL VPN market, vendors are also reluctant to disclose the details of the inner workings of their products. Yet, even without official information from each vendor, it is possible to understand SSL VPN technology. Every offering...