ntunnel

The ntunnel program is designed to tunnel Unix domain sockets over TCP, using the Noise Protocol. The goal is to be secure and simple to use and setup. Due to the flexibility, it can forward any standard stream socket to another stream socket, including TCP sockets.

Example

Generate the keys:

python ntunnel.py genkey serverkey
python ntunnel.py genkey clientkey

Create the target for the pass through:

nc -lU finalsock

Start the server and client:

python ntunnel.py server serverkey unix:$(pwd)/servsock unix:$(pwd)/finalsock
python ntunnel.py client clientkey serverkey.pub unix:$(pwd)/clientsock unix:$(pwd)/servsock

Attach to the client:

nc -U clientsock

Now when you type text into either of the nc windows, you should see the same text come out the other side.

Running Tests

Currently ntunnel requires Python 3.7 or later. If the default virtualenv is not 3.7 or later, you can set the VIRTUALENV variable to specify which one to use, such as: make env VIRTUALENV=virtualenv-3.7

If you want to use an alternate version of python, you can specify VIRTUALENVARGS, such as: make env VIRTUALENV=virtualenv-3.7 VIRTUALENVARGS="-p $(which pypy3)"

Note that I have not tested this w/ pypy3, as when compiling the cryptography libraries, it would pick the wrong ones, despite setting CFLAGS and LDFLAGS. It is likely I could make this work, but do not know how to.

Known Issues

• Server does not verify client public key.

TODO/Future Features

• DoS protection. Limiting number of connections. Limit resource consumption by opening connection and starting negotiation but not completing it, etc.
• Support more than one client key.
• Select forwarding destination based upon client key.