Hidder

# Hidder 📂 Hidder is the **client-side companion** to the [ModSeeker](https://modrinth.com/plugin/modseeker) Paper plugin. Install it on your Fabric client and it handles the rest — reporting your installed mods, detecting your launcher, and proving everything through encrypted, tamper-proof communication that servers can trust. 📦 Mod Reporting Collects all installed mods, resource packs, and shaders — encrypted end-to-end before leaving your client 🔎 Launcher Detection Identifies your launcher using native OS-level inspection — not self-reported, not guessable --- ## Features - **Client-Side Only** — Runs exclusively on the client with zero server-side components - **Native Security Module** — Cryptographic operations run inside a compiled C++ library, not Java bytecode - **Hybrid Encryption** — Mod list data is encrypted using RSA key exchange + AES-256-CBC - **Integrity Signatures** — Every response includes a session-bound HMAC proving data authenticity - **Launcher Detection** — Identifies which launcher started the game using native OS-level APIs - **Replay Attack Protection** — Cryptographic nonces and timestamps prevent reuse of old responses - **Automatic Setup** — Native libraries are extracted and loaded at runtime with no manual configuration --- ## Version Compatibility | Minecraft Version | Fabric Loader | Java | Status | |-------------------|---------------|------|--------| | 26.1 / 26.1.1 | 0.18.0+ | Java 25+ | ✅ Latest | | 1.21.11 | 0.17.2+ | Java 21+ | ✅ Supported | | 1.21.10 | 0.17.2+ | Java 21+ | ✅ Supported | | 1.21.9 | 0.17.2+ | Java 21+ | ✅ Supported | | 1.21.8 | 0.17.2+ | Java 21+ | ✅ Supported | | 1.21.7 | 0.17.2+ | Java 21+ | ✅ Supported | | 1.21.4 | 0.17.2+ | Java 21+ | ✅ Supported | Download the JAR matching your Minecraft version from [Modrinth](https://modrinth.com/mod/hidder) or [Releases](https://github.com/RAFIN-G/Hidder/releases). --- ## Requirements - **Fabric Loader** 0.17.2 or higher (0.18.0+ for 26.1) - **Fabric API** - Java **21+** (Java **25+** for Minecraft 26.1) - A server running [ModSeeker](https://modrinth.com/plugin/modseeker) --- ## Installation 1. Install **Fabric Loader** for your Minecraft version 2. Download the Hidder JAR matching your version from [Modrinth](https://modrinth.com/mod/hidder) or [Releases](https://github.com/RAFIN-G/Hidder/releases) 3. Place the JAR in your `mods/` folder 4. Launch the game No configuration is required. Hidder operates silently and responds automatically when a ModSeeker server requests verification. --- ## How It Works When you join a server running ModSeeker, the following process occurs automatically in the background: ``` Join Server | v [ Announce Presence ] -- Hidder tells the server it's installed | v [ Cryptographic Challenge ] -- Server sends a unique challenge | Hidder signs it using the native security module v [ Launcher Detection ] -- Native module identifies your launcher | Result is sent alongside the challenge response v [ Mod List Collection ] -- Hidder reads your loaded mods from the Fabric runtime | Encrypts and signs the data | Sends it to the server v [ Verification Complete ] -- Server validates everything and admits you ✅ ``` The entire process takes less than a second. You will not notice any delay during normal gameplay. ### What Data Is Collected | Data | Source | Purpose | |------|--------|---------| | Installed mods (with versions) | Fabric Loader runtime registry | Blacklist enforcement | | Resource packs | Game directory scan | Server policy compliance | | Shader packs | Game directory scan | Server policy compliance | | Launcher name | Native OS API inspection | Launcher whitelist enforcement | All collected data is encrypted before transmission and can only be read by the target server. ### Communication Protocol Hidder communicates with ModSeeker over a custom Minecraft plugin messaging channel: | Message | Direction | Description | |---------|-----------|-------------| | `ANNOUNCE_PRESENCE` | Client > Server | Declares that Hidder is installed | | `CHALLENGE` | Server > Client | Cryptographic challenge with unique nonce | | `CHALLENGE_RESPONSE` | Client > Server | Signed response with launcher identification | | `ACKNOWLEDGE_PRESENCE` | Server > Client | Server confirms the handshake | | `REQUEST_MODLIST` | Server > Client | Server requests the encrypted mod list | | `RESPONSE_MODLIST_ENCRYPTED` | Client > Server | Encrypted and integrity-signed mod list | --- ## Security Architecture Hidder's security is built on three principles: **authentication**, **confidentiality**, and **integrity**. ### Authentication Every connection uses a unique cryptographic challenge-response handshake. The server generates a random nonce; Hidder signs it using the native security module. This proves the client is running the authentic, unmodified Hidder mod. ### Confidentiality Mod list data is encrypted using hybrid encryption before transmission. A random AES-256 session key encrypts the payload, and the session key itself is encrypted with the server's RSA public key. Only the target server can decrypt the data. ### Integrity Each encrypted response includes a session-bound HMAC signature computed inside the native module. The server verifies this signature after decryption, ensuring the data was not modified and was produced during the current session — not replayed from a previous one. ### Native Security Module Critical operations run inside a compiled C++ library (`hidder_vault.dll`) rather than Java bytecode: - Cryptographic key operations - HMAC computation - Launcher detection via OS APIs - Data encryption This significantly raises the difficulty of reverse engineering compared to standard Java-based mods. > **Warning:** Do not modify, replace, or delete the native library files. Doing so will break communication with ModSeeker servers. --- ## Detected Launchers Hidder can identify the following launchers through native OS-level inspection: | Launcher | | Launcher | |----------|-|----------| | Prism Launcher | | Lunar Client | | MultiMC | | Badlion Client | | CurseForge | | Feather Client | | Modrinth App | | LabyMod | | ATLauncher | | TLauncher | | GDLauncher | | SKLauncher | | Technic Launcher | | Pojav Launcher | | FTB App | | | Unrecognized launchers are reported as `unknown`. Server administrators decide whether to allow or block unknown launchers. --- ## Technical Summary | Property | Details | |----------|---------| | Mod loader | Fabric | | Minecraft versions | 1.21.4 – 1.21.11, 26.1 | | Java version | 21+ (25+ for 26.1) | | Encryption | RSA-2048 + AES-256-CBC | | Authentication | HMAC-SHA256 | | Signatures | RSA-SHA256 | | Native module | C++ with OpenSSL | | Platform | Windows (native DLL) | --- ## License This project is licensed under **AGPL-3.0**. See the [LICENSE](https://github.com/RAFIN-G/Hidder/blob/main/LICENSE) file for details.