Terminal Chat

a Peer to peer terminal chat application featuring end to end AES encryption, a GUI, optional gRPC, and other features.

Installation

go install github.com/HarrisonWAffel/terminal-chat

Program flags

Usage of ./terminal-chat:
  -create
        pass this flag if you wish to begin a conversation and wait for a peer to connect
  -grpc
        pass this flag to start or connect to a gRPC server
  -room-name string
        The room name to be created or connected to
  -screen-name string
        The name you wish to use in the conversation
  -server
        run the application in server mode. Clients connect to the server to
        exchange pion connection information between hosts before establishing the p2p connection
  -server-port string
        The server port that should be used, should begin with : (e.g. :8080)  (default ":8080")
  -server-url string
        The URL of the server you want to connect to communicate p2p connection info with another client

Architecture

                                                    |          Steps
               --------------------                 |  1. Peer One POSTS token
       +------>| Discovery Server | <------+        |     and webRTC info, waits 
       |       --------------------        |        |     
       |                                   |        |  2. DS Stores webRTC   
       |                                   |        |     info using token
       |                                   |        |              
       |                                   |        |  3. Peer Two POSTS webRTC 
       |                                   |        |     info and gives token
       |                                   |        |   
       |                                   |        |  4. DS forwards P2 webRTC
       v                                   v        |     info to P1 and P1 
 ------------                        ------------   |     webRTC info to P2.
 | Peer One | <--------------------> | Peer Two |   | 
 ------------                        ------------   |  5. Clients directly connect 
                                                    |     to one another  

Libraries Used

• Pion/webRTC - webRTC communication
• (optional) go-gRPC - REST alternative
• goCUI - GUI API

How to Run

This application needs to connect to a dedicated server so that peers may share their connection details with one another using custom room-names.

I (at the time of writing) am hosting a free HTTPS terminal-chat server that can be found at this address,

• https://terminal-chat.space

To use this URL by default run this command (and omit the -server-url flag when running any following commands)

export TERMINAL_CHAT_URL=https://terminal-chat.space

Connecting Clients

Once a dedicated server has been created peers can begin to connect with one another using the following commands

To create a new connection token use the following command, you can provide a custom token or use a generated UUID as a token by omitting the -room-name flag and passing n.

./terminal-chat -server-url=${SERVER_URL} -screen-name=host -create -room-name=${TOKEN}

To connect to a conversation run the following command

./terminal-chat -server-url=${SERVER_URL} -screen-name=guest -room-name=${TOKEN}

Creating A Server

A Dockerfile for the server has been provided. This server must be exposed to the internet if you wish to have peers from outside of your local network connect to you. The dedicated server only holds onto connection details for ten minutes at most, and deletes all connection information once both parties have connected to one another.

To start the dedicated server, compile this repository and run one of the following commands,

To run without a docker container

./terminal-chat -server -server-port=":8081"

To run without a docker container as a gRPC server (Note that clients must also pass the -grpc flag when connecting to a grpc server)

./terminal-chat -server -server-port=":8081" -grpc

To run with a docker container

docker build . -t terminal-chat-server && docker run -p 8081:8081 -d terminal-chat-server 

Server Deployment Notes

• when hosting an HTTP/S server you should set all timeouts (gateway, read, write) to 10 minutes to ensure room hosts can receive peer connection information.

• gRPC servers require an HTTP2 compatible cloud environment, other than this requirement the gRPC implementation is generally better than the HTTP/s implementation.