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

The SSL Protocol


As is obvious from the name SSL VPN, the Secure Sockets Layer protocol (SSL) is a key element of SSL VPN technology. As such, a basic understanding of SSL will help us understand the workings of SSL VPNs.

Background

Web pages are delivered using the Hypertext Transfer Protocol (HTTP) . HTTP in itself does not offer encryption or any other substantial protection of data transmitted between users and web servers. With the advent of the World Wide Web in the early 1990s and the goal of extending Web usage to actual business activity involving the transmission of confidential information over the Internet came the need to eliminate eavesdropping by unauthorized parties on web communications between computers over the Internet.

Several technologies were proposed to address this need—all of them utilizing encryption to protect sensitive data in transit. The protocol that quickly proved dominant and which ultimately became the standard for secure web communications was SSL.

SSL Version...