# OpenMLS
[![OpenMLS Chat][chat-image]][chat-link]
[![OpenMLS List][list-image]][list-link]
[![Tests & Checks][gh-tests-image]](https://github.com/openmls/openmls/actions/workflows/tests.yml?branch=main)
[![codecov][codecov-image]](https://codecov.io/gh/openmls/openmls)
[![Docs][docs-release-badge]][docs-release-link]
[![Book][book-release-badge]][book-release-link]
![Rust Version][rustc-image]
_OpenMLS_ is a Rust implementation of the Messaging Layer Security (MLS) protocol, as specified in [RFC 9420](https://datatracker.ietf.org/doc/html/rfc9420).
It is a software library that can serve as a building block in applications that require end-to-end encryption of messages.
It has a safe and easy-to-use interface that hides the complexity of the underlying cryptographic operations.
## Supported ciphersuites
- MLS_128_DHKEMX25519_AES128GCM_SHA256_Ed25519 (MTI)
- MLS_128_DHKEMP256_AES128GCM_SHA256_P256
- MLS_128_DHKEMX25519_CHACHA20POLY1305_SHA256_Ed25519
## Supported platforms
OpenMLS is built and tested on the Github CI for the following rust targets.
- x86_64-unknown-linux-gnu
- i686-unknown-linux-gnu
- x86_64-pc-windows-msvc
- i686-pc-windows-msvc
- x86_64-apple-darwin
### Unsupported, but built on CI
The Github CI also builds (but doesn't test) the following rust targets.
- aarch64-apple-darwin
- aarch64-unknown-linux-gnu
- aarch64-linux-android
- aarch64-apple-ios
- aarch64-apple-ios-sim
- wasm32-unknown-unknown
- armv7-linux-androideabi
- x86_64-linux-android
- i686-linux-android
OpenMLS supports 32 bit platforms and above.
## Cryptography Dependencies
OpenMLS does not implement its own cryptographic primitives. Instead, it relies
on existing implementations of the cryptographic primitives used by MLS. There
are two different cryptography providers implemented right now. But consumers
can bring their own implementation. See [traits](https://github.com/openmls/openmls/tree/main/traits) for more
details.
## Features
OpenMLS provides the following features
- **extensions-draft-08**: enable features defined in [MLS extensions draft-08](https://messaginglayersecurity.rocks/mls-extensions/draft-ietf-mls-extensions.html)
- **fork-resolution**: helper functionality for [resolving forks](https://book.openmls.tech/user_manual/fork-resolution.html).
- **js**: enable compilation to wasm
<details>
<summary>Developer features</summary>
- **libcrux-provider**: enable the libcrux crypto provider dependency
- **openmls_rust_crypto**: enable the rust crypto provider
- **sqlite-provider**: enable the sqlite provider
- **backtrace**: enable backtraces
- **content-debug**: allow printing sensitive content of messages for debugging
- **crypto-debug**: allow printing cryptographic key material for debugging
- **test-util**: test utilities
</details>
## Working on OpenMLS
For more details when working on OpenMLS itself please see the [Developer.md].
## Maintenance & Support
OpenMLS is maintained and developed by [Phoenix R&D] and [Cryspen].
## Acknowledgements
[Zulip] graciously provides the OpenMLS community with a "Zulip Cloud Standard" tier [Zulip instance][chat-link].
[chat-image]: https://img.shields.io/badge/zulip-join_chat-blue.svg?style=for-the-badge&logo=zulip
[chat-link]: https://openmls.zulipchat.com
[list-image]: https://img.shields.io/badge/mailing-list-blue.svg?style=for-the-badge
[list-link]: https://groups.google.com/u/0/g/openmls-dev
[rustc-image]: https://img.shields.io/badge/rustc-1.56+-blue.svg?style=for-the-badge&logo=rust
[docs-release-badge]: https://img.shields.io/badge/docs-release-blue.svg?style=for-the-badge
[docs-release-link]: https://docs.rs/crate/openmls/latest
[book-release-badge]: https://img.shields.io/badge/book-release-blue.svg?style=for-the-badge
[book-release-link]: https://book.openmls.tech
[drone-image]: https://img.shields.io/drone/build/openmls/openmls/main?label=ARM64%20Build%20Status&logo=drone&style=for-the-badge
[codecov-image]: https://img.shields.io/codecov/c/github/openmls/openmls/main?logo=codecov&style=for-the-badge
[gh-tests-image]: https://img.shields.io/github/actions/workflow/status/openmls/openmls/tests.yml?branch=main&style=for-the-badge&logo=github
[gh-deploy-docs-image]: https://img.shields.io/github/workflow/status/openmls/openmls/Deploy%20Docs/main?label=Deploy%20Docs&logo=github&style=for-the-badge
[Developer.md]: https://github.com/openmls/openmls/blob/main/Developer.md
[Phoenix R&D]: https://phnx.im
[Cryspen]: https://cryspen.com
[Zulip]: https://zulip.com/