Method and apparatus for lightweight secure communication tunneling over

Abstract

A lightweight secure tunneling protocol or LSTP permits communicating across one or more firewalls by using a middle server or proxy. Three proxies are used to establish an end-to-end connection that navigates through the firewalls. In a typical configuration, a server is behind a first firewall and a client behind a second firewall are interconnected by an untrusted network (e.g., the Internet) between the firewalls. A first inside firewall SOCKS-aware server-side end proxy connects to the server inside the first firewall. A second inside firewall SOCKS-aware client-side end proxy is connected to by the client inside the second firewall. Both server-side and client-side end proxies can address a third proxy (called a middle proxy) outside the two firewalls. The middle proxy is usually started first, as the other two end proxies (server and client) will initiate the connection to the middle proxy some time after they are started. Since the middle proxy is mutually addressable by both inside proxies, a complete end-to-end connection between the server and client is established. It is the use of one or more middle proxies together with the LSTP that establishes the secure communications link or tunnel across multiple firewalls.