Tcpbroker is a software that enables TCP port forwarding by linking two incoming sockets, providing a unique approach to the process.
The software's regular version requires SRP authentication, which means that a special client is needed - brokerclient. This client connects to the remote port and handles client-side authentication. Once authenticated, data is simply passed through. By default, the username for authentication is "broker" and the passphrase is "nakaniau," which means "meet in the middle" in Japanese.
However, if you want to change the passphrase, it can be achieved with tphrase from the libtinysrp distribution system. Currently, the tinysrp protocol has no synchronization, which means that the broker's authentication code is slightly more complicated than a single function call. Nevertheless, the broker still needs to do synchronization to determine which end of the connection to authenticate.
In essence, client synchronization is also necessary when going through a proxy, where there's a preamble of commands to the proxy/gateway server, which can return arbitrary junk. However, the software provides a solution to this problem. If you need to change the preamble, it's not a big deal as it's hardcoded, although it's off by default; check the comments in brokerclient.c.
Overall, TCPBroker is an innovative piece of software that makes TCP port forwarding more efficient, practical, and secure. It's definitely worth giving it a try.
Version 1.1: N/A