GetMeInternet

Designed to figure out how to get a connection to the internet when using a restricted network such as a public wifi with a webform login required.

Inspired by iodine (ip over DNS) and hans (ip over icmp ping)

http://sites.inka.de/bigred/devel/tcp-tcp.html

Installation

Install crystal and shards (although they usually come together)
Install the sodium development libraries
- for arch linux sudo pacman -S libsodium
- for debian/ubuntu sudo apt install libsodium-dev
Install crystal dependencies
```
crystal deps
```
Compile
```
shards build
```
Debugging version
```
shards build -d
```
Release version (full compiler optimizations)
```
shards build --release
```

Usage

TODO: Write usage instructions here

prereqs:
- crystal https://crystal-lang.org/
- libsodium-dev (a crypto lib)
- libxml2-dev
- libyaml-dev
- shards (it's like "make")
- fork the project on github
- "shards build" to build
chromium will stop tun0 about 2 seconds after startup

workaround <<: in crosh shell, sudo the following
- stop shill
- start shill BLACKLISTED_DEVICEDS=tun0

First, you must select a Pre-shared Key for use between the client and server. Run bin/util to generate a key, then copy the config.yml securely to the other end.

The server bin/server currently takes no arguments, and listens on port 5431. The client bin/client takes one argument, the ip address of the server.

Security notes

For simplicity and connect time reduction, this program uses symmetric cryptography with a single pre-shared key, of which the client and server both have a copy. This is used for both encrypting and authenticating.

Currently, there is no mechanism in place to prevent replay attacks. Therefor, this software should not yet be considered secure.

Furthermore, no formal review of this code's security has been done, and there likely are more security-related problems that are unknown.