https://github.com/papatutuwawa/omemo_dart

A Dart implementation of the cryptography needed for OMEMO 0.8.3 (mirror)
https://github.com/papatutuwawa/omemo_dart

cryptography dart double-ratchet flutter omemo x3dh xmpp

Last synced: about 1 month ago
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A Dart implementation of the cryptography needed for OMEMO 0.8.3 (mirror)

• Host: GitHub
• URL: https://github.com/papatutuwawa/omemo_dart
• Owner: PapaTutuWawa
• License: mit
• Created: 2022-08-02T16:18:58.000Z (over 2 years ago)
• Default Branch: master
• Last Pushed: 2023-12-10T12:22:27.000Z (11 months ago)
• Last Synced: 2024-09-23T07:17:50.467Z (about 2 months ago)
• Topics: cryptography, dart, double-ratchet, flutter, omemo, x3dh, xmpp
• Language: Dart
• Homepage: https://codeberg.org/PapaTutuWawa/omemo_dart
• Size: 265 KB
• Stars: 15
• Watchers: 4
• Forks: 1
• Open Issues: 4
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • Funding: .github/FUNDING.yml
  • License: LICENSE

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README

        
# omemo_dart

[![status-badge](https://ci.polynom.me/api/badges/16/status.svg)](https://ci.polynom.me/repos/16)

`omemo_dart` is a Dart library to help developers of Dart/Flutter XMPP clients to implement

[OMEMO](https://xmpp.org/extensions/xep-0384.html) in its newest version - currently 0.8.3.

The library provides an implementation of the [X3DH](https://signal.org/docs/specifications/x3dh/)

key exchange, the [Double Ratchet](https://signal.org/docs/specifications/doubleratchet/) with

the OMEMO 0.8.3 specific `ENCRYPT`, `DECRYPT` and `KDF_*` functions and a very high-level

`OmemoSessionManager` that manages all Double Ratchet sessions and provides a clean and simple

interface for encrypting a message for all known Ratchet sessions we have with a user.

This library also has no dependency on any XMPP library. `omemo_dart` instead defines an

intermediary format for the required data that you, the user, will need to transform to and from

the stanza format of your preferred XMPP library yourself.

## Important Notes

- **Please note that this library has not been audited for its security! Use at your own risk!**

- This library is not tested with other implementations of OMEMO 0.8.3 as I do not know of any client implementing spec compliant OMEMO 0.8.3. It does, however, work with itself.

## Usage

Include `omemo_dart` in your `pubspec.yaml` like this:

```yaml

# [...]

dependencies:

  omemo_dart:

    hosted: https://git.polynom.me/api/packages/PapaTutuWawa/pub

    version: ^0.5.0

  # [...]

# [...]

```

### Example

This repository includes a documented ["example"](./example/omemo_dart_example.dart) that explains the basic usage of the library while

leaving out the XMPP specific bits. For a more functional and integrated example, see the `omemo_client.dart` example from

[moxxmpp](https://codeberg.org/moxxy/moxxmpp).

### Persistence

By default, `omemo_dart` uses in-memory implementations for everything. For a real-world application, this is unsuitable as OMEMO devices would be constantly added.

In order to allow persistence, your application needs to keep track of the following:

- The `OmemoDevice` assigned to the `OmemoManager`

- `JID -> [int]`: The device list for each JID

- `(JID, device) -> Ratchet`: The actual ratchet

If you also use the `BlindTrustBeforeVerificationTrustManager`, you additionally need to keep track of:

- `(JID, device) -> (int, bool)`: The trust level and the enablement state

## Contributing

When submitting a PR, please run the linter using `dart analyze` and make sure that all

tests still pass using `dart test`.

To ensure uniform commit message formatting, please also use `gitlint` to lint your commit

messages' formatting.

## License

Licensed under the MIT license.

See `LICENSE`.

## Support

If you like what I do and you want to support me, feel free to donate to me on Ko-Fi.

[](https://ko-fi.com/papatutuwawa)