A simple end to end encrypted command line messenger.

This is a project for fun and learning. I am not responsible for any damage that may be caused by the use of this software. Also I am not liable for any vulnerabilities or similar.

To setup a server, you must download the latest server.jar and keygen.jar. Put the files into an empty directory, then run keygen.jar. This will create two files. Make sure to keep the prvkey-file secret and in the same folder as server.jar, but distribute the svrkey-file to your clients.

To run the server, you need to run java -jar server.jar <port> in a command line. Switch <port> with the port you want the server to run on. Open this port in your firewalls and tell your users, which port you chose and what your IP-address/hostname is.

To connect to a server, you must have following things:

• the current client.jar file
• the server's svrkey-file
• the port and IP-address/hostname of the server.

Put the client.jar and svrkey files into the same empty directory. Then open a console and run java -jar client.jar <hostname> <port>. Switch <port> with the port of the server and <hostname> with its IP-address/hostname.

The server tells you most of the things you have to enter. There are also some commands you can use. Just enter one into the console to use it.

• !change tells the server, you want to connect to a new chat partner. Optionally, you can attach the user you want to connect to. For example !change jane_doe will connect you to jane_doe, if she is available.
• !exit shuts down the client application.
• !accept is used to confirm the validity of an automatically downloaded key.