DES Key Cracker

Native desktop app (Node.js + NodeGui) that recovers the 8-byte DES key for a TechMed / Pectus .med scan, using CPU threads plus GPU acceleration:

• macOS: Apple Metal (des_brute kernel)
• Windows: NVIDIA CUDA when the CUDA Toolkit is installed
• Both: multi-core CPU fallback

Search is short printable keys over a charset, padded to 8 bytes.

Machines can cooperate on a LAN. The master listens on a WebSocket port and hands each slave worker (each exposed CPU or GPU) a block described only by generation parameters (start, count, deviceKey, keyLen, charset, padByte) — not a list of keys. Each worker has its own block size; CPU workers default to 1,048,576 keys and GPU workers to 16,777,216 so the GPU keeps more of the keyspace.

Requirements

• Node.js 18+ (the app runs under qode, which NodeGui installs)
• CMake and a C++ toolchain (needed to install @nodegui/nodegui)
• macOS: Xcode command-line tools (clang + Metal)
• Windows CPU: clang++, g++, or MSVC (cl)
• Windows CUDA: CUDA Toolkit (nvcc) and an NVIDIA GPU. Without nvcc the app still runs on CPU.

Build

npm install
npm run build:native
npm run build
npm start

build:native compiles whatever this machine supports into bin/:

Binary	Platform
med_cpu	macOS and Windows
med_gpu	macOS Metal
med_cuda	Windows (or FORCE_CUDA=1 if nvcc is on the PATH)

Using the app

1. Set Role in the toolbar to Master or Slave.
2. Under Devices, tick local cards to use or expose. On the master, set Block size on each local and remote card; Workers (CPU thread count) appears only on CPU cards.
3. Master: choose the .med file, charset, min/max length, and pads. Optionally Start service so other computers can join. Click Start search. The master searches on its selected local devices and assigns a block of that device’s size to every exposed slave device.
4. Slave: tick the devices to expose, set CPU threads on CPU cards if needed, enter the master’s IP and port, and Connect. The slave does not set block size — the master does. Each exposed device stays listed on Workers with current-block progress and a completed-block count. The slave does not need the .med file.

Hits are written under decoded/bruteforce/ (decrypted_*.bin, hit_*.json, results.json).

Do not expose the WebSocket port to the public internet; it has no authentication.

Native runner CLI

All three runners share the same commands:

med_* devices
med_* selftest [--device N]
med_* brute --device N --key-len L --charset S --pad XX \
      --target HEX --fills HEX,... --start I --count N --batch B

Metal also needs --shader native/metal/des_bruteforce.metal. CPU accepts --workers N.