FEVERDREAM

A multi-platform Matrix chat client built with Kotlin and Compose Multiplatform, featuring MSN Messenger-style separate windows and end-to-end encryption.

Features

• Multi-platform support: Windows, Mac, Linux
• MSN Messenger-style UI: Separate windows for login, room list, chat windows, and settings
• End-to-end encryption: Olm/Megolm cryptographic ratchets with key backup
• Modular architecture: Clean separation of crypto components (OlmMachine, KeyBackup, RoomKey management)
• Sync token persistence: Efficient incremental synchronization
• Room encryption detection: Automatic detection and handling of encrypted rooms
• Key backup and recovery: Secure backup and restoration of encryption keys
• Error handling: Robust handling of missing keys, session expiration, and network issues

Encryption

This client implements Matrix end-to-end encryption using the Olm and Megolm cryptographic ratchets via the Matrix Rust SDK.

Current Implementation:

• Uses vodozemac cryptographic library via Rust bindings (matrix-sdk-crypto)
• Supports room encryption detection and Megolm group encryption
• UI indicators for encrypted rooms and message status
• Key backup functionality with recovery key generation
• Automatic session renewal for message encryption
• Proper handling of undecryptable historical messages

Implementation Details: The project embeds the Matrix Rust SDK and uses Kotlin bindings for vodozemac, providing a native, high-performance cryptography implementation.

Getting Started

Prerequisites

• JDK 17 or higher
• Gradle (wrapper included)

Building

On Unix-like systems:

JAVA_HOME=/path/to/jdk17 ./gradlew build

On Windows:

set JAVA_HOME=C:\path\to\jdk17
gradlew.bat build

Running

On Unix-like systems:

JAVA_HOME=/path/to/jdk17 ./gradlew run

On Windows:

set JAVA_HOME=C:\path\to\jdk17
gradlew.bat run

Project Structure

• src/desktopMain/kotlin/ - Desktop-specific application code
• matrix-rust-sdk/ - Embedded Matrix Rust SDK for crypto operations
• kotlin-bindings/ - Kotlin bindings for Rust crypto libraries
• crypto_store/ - Local storage for encryption keys and session data
• build.gradle.kts - Build configuration
• settings.gradle.kts - Project settings

Architecture

The application follows a modular design with separate components for:

• OlmMachineManager: Handles OlmMachine lifecycle and initialization
• KeyBackupManager: Manages key backup operations and recovery
• RoomKeyManager: Handles room key requests and sharing
• MessageCacheManager: Manages message caching and retrieval
• SyncManager: Handles Matrix synchronization with token persistence

Contributing

This project uses the Matrix Rust SDK for cryptographic operations. Ensure you have the necessary build tools for cross-compilation if modifying crypto components.

License

#YOLO Public License (YPL) v0.12.34-hunter.2