Generic Olm Bindings #

Features #

Currently supported functionality:

• Olm Account creation, one time and fallback key creation, etc.
• Ed25519 and Curve25519 encryption and signing
• Olm encryption and decryption
• Megolm encryption and decryption
• Export to the vodozemac pickle format (encrypted)
• Import from the vodozemac pickle format and the libolm pickle format
• SAS verification
• Public key cryptography (Pk algorithms)

Getting started #

Vodozemac needs Rust to be installed locally. Install Rust

Add the package to your Dart/Flutter project:

flutter pub add vodozemac

You need to build vodozemac first, either the wasm or the native library. For flutter you can use the flutter_vodozemac package:

flutter pub add flutter_vodozemac

Then you can initialize vodozemac for native platforms like this:

import 'package:flutter_vodozemac/flutter_vodozemac.dart' as vod;

await vod.init();

Build for web #

For web you need to build the package by yourself. You can use the script below to do so:

version=$(yq ".dependencies.flutter_vodozemac" < pubspec.yaml)
version=$(expr "$version" : '\^*\(.*\)')
git clone https://github.com/famedly/dart-vodozemac.git -b ${version} .vodozemac
cd .vodozemac
cargo install flutter_rust_bridge_codegen
flutter_rust_bridge_codegen build-web --dart-root dart --rust-root $(readlink -f rust) --release
cd ..
mv .vodozemac/dart/web/pkg ./web/
rm -rf .vodozemac

Usage #

You can find some basic examples in the examples folder and more extensive tests in the tests directory. But the gist of it is this:

// load the library, possibly provide the path to the wasm or native library
init();
// Create an olm account. Alternatively import it.
final account = await Account.create();

// create some one time keys up to a library specific maximum.
print(account.maxNumberOfOneTimeKeys());
await account.generateFallbackKey();
await account.generateOneTimeKeys(20);


// You can sign messages and keys.
String message = "Some str";
final signature = await account.sign(message);
print("Signed '$message', signature '${signature.toBase64()}");

// And verify the signature
try {
  await account.ed25519Key().verify(message: message, signature: signature);
  print("Signature verified");
} catch (e) {
  print("Signature not verified");
}


// You can also create group sessions
final session = await GroupSession.create();
final inbound = session.toInbound();

// and encrypt with them
final encrypted = await session.encrypt('This is a test');
print("Encrypted: $encrypted");
print("Index: ${session.messageIndex()}");

// Or decrypt
final decrypted = await inbound.decrypt(encrypted);
print("Decrypted: $decrypted");

// Olm session usage not pictured.

Additional information #

You can run the tests using dart test, but you might need to adapt the library path. -> You can run cargo build in ../rust directory to get the .dylib file to load