Firepass: A tunneling software tool.
The key feature of Firepass is that you may use several types of installation of the server part script in the external network. You do not need to bind any port on the external box. Firepass may also be usable for the reverse task, when the server script is located at the corporate web server and when the client interacts with it from the external network.
To run Firepass, you'll need a box located inside your local network, with Perl and the ability to send HTTP messages to the external network (Internet), either directly or indirectly through an HTTP proxy. You'll also need an HTTPd server located on the external network (with Perl also) where you can place/run CGI scripts and establish outgoing connections.
Firepass' key feature is that you can chain several installations of the server and they never need to bind to a port, making it undetectable by most administrators. There is only an unusual HTTP dialog between the client and server, and the HTTP messages are sent fairly often. This can be configured in the Firepass client with a special delay option between HTTP requests, and can be used for any non-time-critical protocols.
Please note that this Firepass version is alpha, so there still may be some bugs, including security bugs. Please read the "HOW IT WORKS" section carefully to understand all the possible risks you may be exposed to. The program comes with no guarantee that it works properly.
The latest release of Firepass includes a new client directive to use an HTTP proxy to resolve hostnames and minor corrections, including fixing a UDP protocol-related bug in the client.
Version 1.1.2a: N/A