Tunneling TCP based protocols through Web proxy server

This document specifies a generic tunneling mechanism for TCP based protocols through Web proxy servers. This tunneling mechanism was initially introduced for the SSL protocol to allow secure Web traffic to pass through firewalls, but its utility is not limited to SSL.

A wide variety of existing client and proxy server implementations conform to this specification. The purpose of this specification is to describe the current practice, to propose some good practices for implementing this specification, and to document the security considerations that are involved with this protocol.