42LoCo42 / exmls

Elixir implementation of the MLS protocol

NOTE - Abandoned

I don’t like Elixir after all, at least not for this kind of project.

My new MLS implementation is CMLS (written, like the name suggests, in C).

ExMLS - MLS in Elixir

This is (or rather, is going to be) an implementation of the Messaging Layer Security (MLS) Protocol, as defined by the RFC 9420.

Why Elixir?

Because I always wanted an excuse to learn the language. Also, there is currently no MLS implementation for Elixir (2023-10-11).

Current Status

• all types (structs, enums, opaques) of the RFC
• functions for array-based binary trees from Appendix C
• a HPKE library connected via NIFs

How to use this project

This project is designed to be used with Nix and optionally direnv (Use nix-direnv for a faster, persistent devshell). Enter a development shell automatically with direnv allow or manually with nix develop. Run just to show all tasks:

• build: hermetically builds the final self-contained binary using Nix
• check_use: an internal check, don’t use this directly
• clean: remove unused dependencies
• docs: generate HTML and EPUB project documentation
• help: list all tasks
• run: run the project in the development environment
• shell: enter an interactive shell that runs the project
• test: run the full testsuite (some code sanity checks, static analysis, regular & doctests). Note that the first start of the static analyser will take a long time.

To run a task, run just taskname, e.g. just build.

Ultimate goals

• a complete implementation of MLS, conforming to the RFC
• an example chat client & server using the implementation