A single hop VPN by using The Tor Network.

Warning

This program makes a concious choice to ignore the security that Tor provides. Any and all traffic sent can and will be tracked to your IP by an exit node. Proceed with caution.

How it works

A normal Tor connection looks like this:

you (client) -> guard -> relay -> exit

This seems rather inefficient if you just want a VPN, why not simple just go directly to the exit?

you (client) -> exit

Unfortunately most Tor nodes block this behavior.

// connection_edge.c
int connection_exit_begin_conn(const relay_msg_t *msg, circuit_t *circ) {
    // snip!
    if ((client_chan ||
        (!connection_or_digest_is_known_relay(or_circ->p_chan->identity_digest) 
        && should_refuse_unknown_exits(options)))) {
        /* Don't let clients use us as a single-hop proxy. It attracts
        * attackers and users who'd be better off with, well, single-hop
        * proxies. */
    // snip!
}

So we can pretend to be a relay and connect to the exit node anyways.

you (relay) -> exit

Taking a Tor Node's relay keys

If you run a Tor relay node it's as simple as copying a folder. From the Tor docs:

Default locations of the keys folder:

Debian/Ubuntu: /var/lib/tor/keys
FreeBSD: /var/db/tor/keys
OpenBSD: /var/tor/keys
Fedora: /var/lib/tor/keys

If you do not curently run a Tor relay node you have two options:

1. Ask a relay owner for their keys
2. Start running a relay node

Install

Grab the latest kurrat-static.zip build from the releases tab. Then unzip, mark as executable, and run in your favorite terminal!

Not on any package managers at the current moment.

If you so choose you can compile from source.

Usage

Starting a connection is simple:

kurrat keys/

(keys/ is just the folder we got in the previous section.)

There is a builtin help menu as well.

$ kurrat --help
kurrat [OPTIONS] key_folder


POSITIONALS:
  key_folder TEXT REQUIRED    The path of your key folder 

OPTIONS:
  -h,     --help              Print this help message and exit 
  -v,     --version           Display program version information and exit 

SOCKS5 OPTIONS:
  -p,     --port UINT         The port the SOCKS5 sever will start on 

EXIT SELECTION:
  -m,     --maxminddb TEXT    The path to a GeoLite2-City maxminddb file 
  -c,     --country TEXT Needs: --maxminddb 
                              The country the tor exit node will be located in 
          --exit_addr TEXT Needs: --exit_port --exit_identity_b64 --exit_ntor_b64 
                              Optional predefined exit node 
          --exit_port TEXT Needs: --exit_addr 
                              Optional predefined exit node port 
          --exit_identity_b64 TEXT Needs: --exit_addr 
                              Optional predefined exit node identity_b64 
          --exit_ntor_b64 TEXT Needs: --exit_addr 
                              Optional predefined exit node ntor key encoded in base64 

Building from source

Prequisites:

• cmake
• make
• a c compiler
• a c++ compiler (with support for c++20 or above)
• git

mkdir build
cd build
cmake .. -DCMAKE_BUILD_TYPE=Release
make -j$(nproc)
sudo make install