Chat-PGP

Welcome to chat PGP. This is an encrypted chat platform based on PGP.

The idea is to create a simple chat platform that is based on strong encryption.

Encryption

Each chat session is encrypted using a symmectrical ChaCha20Poly1305 algorithm with a shared secret that is protected with PGP assymetrical encryption. If you are unfamiliar with OpenPGP and using GnuPG then see this GnuPG guide.

Communication

The communication protocol is built on Zenoh.

Zenoh is an extremely flexible middleware that does not force a network topology onto the project. By providing a configuration file to zenoh, one can configure the entire network oneself; so that one does not have to rely on routers and peers someone else setup for this project. There is support for TLS (one- and two-way) authentication in zenoh.

By default, I have set up a router running on a Digital Ocean Droplet, in a server they claim to be running in Amsterdam. Starting a zenoh router is very simple. I just launch the zenoh daemon, zenohd. You can provide your own router configuration by passing the "-z" flag to the program. By default, however, the client program will connect with other peers via this aforementioned router as specified in zenoh/config.json5:

{
  "mode": "client",
  "connect": {
    "endpoints": ["tcp/174.138.5.172:443"]
  }
}

What I am writing is that you can launch your own network by installing zenohd and changing the "endpoints" in the configuration file above. You can also configure the base TCP/IP connection to be secured with TLS with your own certificates if you want, however, the application level traffic is already encrypted.

./target/release/client -z zenoh/your-config.json5

Build and run

The entry point is the "client" program. It is a program implemented in Rust which can be built with cargo. If you want to build and run with a gpg key with fingerprint D54FED01913E2120AD9DB3CBB0726D4781F979F7, then do this:

 cargo build --release
./target/release/client --gpgkey D54FED01913E2120AD9DB3CBB0726D4781F979F7

If you don't have a gpg-key already, the program will generate one for you with the user id of "[email protected]".

Email infrastructure

It is possible to enable an email feature to the server infrastructure also. In order to do this, you need to run the relay program also connected to the zenoh server. The relay program will store encrypted messages in memory when running and once you are online again, it will send you what it has received.

Only after you have successfully established a peer-to-peer connection you can send "emails" to that peer. To set up a relay broker connected to the zenoh server run the relay program.

cargo build --release
./target/release/relay

You most likely will want to pass the "-z" flag to the relay program, and provide it with the same configuration file that you use for the clients.

Work in progress

This is a work in progress. So far I have this:

• PGP assymetrical encryption using pre-existing pgp-keys (you can create them with gpg)
• Communcations based on Zenoh
• Encrypted one-to-one online chat
• Terminal interface based on ratatui
• E-mail message retrieval via relay

Will work on this:

• Better terminal interface in the near term
• Web front end (on localhost) in the long term
• Apply local gpg keychain as policy for session key verification
• PGP session key signed by main key instead of using the main key for each session establishment

Want to add:

• Group chat (not sure how to implement)

Today the platform only works strictly online, with both peers connected at the same time.

Contribute

Please feel free to test and come with feedback. This project is in its early stage and I would appreciate contributions if you agree with this vision.