Hidder 📂

Hidder is a Fabric mod designed to work in tandem with the ModSeeker Paper plugin. It provides secure client-side mod verification, detailed system reporting, and encrypted communication with servers running ModSeeker.

---

✨ Features

• Client-Side Only: Runs exclusively on the client; no server-side operations.
• Comprehensive Mod Detection: Detects all installed Fabric mods with version information.
• Resource Pack Detection: Detects folder-based and ZIP-based resource packs.
• Shader Pack Detection: Detects installed shaders.
• Secure Communication: Encrypted channels for mod verification with ModSeeker.
• Native Cryptography: Uses a native C++ library for RSA/AES encryption and digital signatures.
• Replay Attack Protection: Includes timestamps in all signed messages.
• System Info Reporting: Sends OS, Java, Minecraft, and Fabric versions to the server.

---

🛠 Requirements

• Minecraft 1.21.10
• Fabric Loader 0.17.2 or higher
• Fabric API
• Java 21 or higher
• Compatible server running ModSeeker

---

📦 Installation

1. Install Fabric Loader for Minecraft 1.21.10.
2. Download the latest Hidder.jar release.
3. Place the JAR in your mods/ folder.
4. Launch the game.

---

🔗 How It Works

Connection Process

1. Presence Announcement: Hidder announces itself to the server running ModSeeker.
2. Handshake: Waits for server acknowledgment.
3. Mod List Provision: Responds with a full mod list and system info when requested.
4. Encryption: All communication is encrypted using hybrid RSA/AES.

Communication Protocol

Hidder uses a custom plugin-channel protocol to communicate with ModSeeker:

Message Type	Description
ANNOUNCE_PRESENCE	Declares Hidder is installed on the client.
ACKNOWLEDGE_PRESENCE	Server confirms receipt of announcement.
REQUEST_MODLIST	Server requests the client's mod list.
RESPONSE_MODLIST	Client responds with mod list and system info.

---

🔒 Security Implementation

• Native Vault: Uses hidder_vault.dll (Windows) / .so (Linux) for cryptographic operations.
• Hybrid Encryption: RSA public-key encryption secures AES session keys; AES-CBC encrypts payloads.
• Digital Signatures: Messages are signed to prevent tampering.
• Replay Protection: Timestamps included in all signed messages.
• Payload Verification: Server validates signatures and timestamps before accepting data.

---

💻 Native Library

Hidder’s native library provides:

• RSA/AES hybrid encryption
• High-performance signature generation
• Automatic runtime extraction and loading

⚠️ Warning: Do not modify the native library; any changes will invalidate communication with ModSeeker.

---

🛠 Building from Source

Prerequisites

• Visual Studio with C++ tools (for Windows native compilation)
• OpenSSL development libraries
• JDK 21+
• Gradle

Steps

1. Clone the repository.

   git clone https://github.com/RAFIN-G/Hidder 

2. Navigate to the project directory.
3. 🔑 Client Keys To build the client, you need the keys generated by the server:

• Obtain CLIENT_KEYS_CPP.txt (generated by the ModSeeker-Hidder-keygen-tool).
• Paste its contents into native/hidder_vault.cpp, replacing the RSA KEY COMPONENTS section.

4. Compile the native library (Windows):

   native/compile_vault.bat

5. Build the JAR:

   ./gradlew build  # Linux/macOS
   gradlew.bat build # Windows

The compiled JAR will appear in build/libs/.

---

📝 Technical Details

Detection Scope

• All installed Fabric mods with versions
• Resource packs (folder & ZIP)
• Shader packs (folder & ZIP)

System Info Reported

• Java version
• Minecraft version
• Fabric Loader version

Security Highlights

• Messages are encrypted and signed
• Includes timestamps for replay protection
• Enforces server verification policies strictly

---

📄 License

This project is licensed under AGPL-3.0 — see the LICENSE file for details.