# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

## Build

```
cmake -B build -G "Visual Studio 17 2022" -A x64   # Windows (MSVC)
cmake -B build                                       # Linux / macOS
cmake --build build --config Release
```

No external dependencies — uses a built-in minimal JSON parser and custom RC4/crypto implementation.

## Project overview

A cross-platform C++ software licensing utility with three commands:

| Command | Description |
|---|---|
| `regInfo machinecode` | Print a 256-bit machine ID (SHA-256 of CPU + system disk) |
| `regInfo generate -f <jsonfile> [outfile]` | Create an encrypted license file |
| `regInfo read <licensefile>` | Decrypt and display license contents |

The machine code combines CPUID brand string and system disk volume/device serial via SHA-256, formatted as 64 hex characters.

License files (`*.xlts`) use format: `base64(MAGIC[4] + CRC32[4] + RC4_encrypted(JSON))`. The RC4 key is embedded in `src/license.cpp`. Verification ties the license to the machine via the `machinecode` field stored in the encrypted JSON payload.

## Architecture

```
src/
  main.cpp          — CLI dispatch (machinecode / generate / read)
  machine_code.cpp  — Platform-specific CPU + disk identification
  license.cpp       — License file encryption/decryption + validation
  crypto.cpp        — RC4 stream cipher, Base64, CRC32
  json_utils.cpp    — Minimal JSON parser (flat objects, string values only)

include/
  machine_code.h    — getMachineCode() → std::string
  license.h         — LicenseInfo struct, generateLicenseFile(), readLicenseFile()
  crypto.h          — rc4Crypt(), base64Encode/Decode(), crc32()
  json_utils.h      — JsonObject with parse/dump for string-only key/value pairs
```

Platform-specific `#ifdef` sections in `machine_code.cpp` cover Windows (`CPUID`, `GetVolumeInformation`, `IOCTL_STORAGE_GET_DEVICE_NUMBER`), Linux (`/proc/cpuinfo`, `statfs`), and macOS (`sysctl`, `statfs`).