# CLAUDE.md

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

## Build

```bash
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 — built-in SHA-256, RC4, Base64, CRC32, and a minimal JSON parser.

## Commands

| Command | Description |
|---|---|
| `regInfo machinecode` (or `mc`) | Print a 256-bit machine ID as 64 hex chars (SHA-256 of CPU + system disk) |
| `regInfo generate -f <jsonfile> [outfile]` (or `gen`) | Create an encrypted license file from a JSON file |
| `regInfo generate <jsonstr> [outfile]` | Create a license from an inline JSON string |
| `regInfo read <licensefile>` (or `rd`) | Decrypt and display all license fields as pretty-printed JSON |
| `regInfo -f <licensefile> -<field>` | Read and output a single field. Repeat for multiple fields. |
| `regInfo -f <licensefile> -verify` | Validate license, outputting an error code (see below) |

Field flags: `-name`, `-machinecode`, `-phone`, `-unit`, `-authdatetime`, `-over`, `-update`

Verify error codes: `0` = valid, `10001` = file invalid, `10002` = expired, `10004` = machine code mismatch

**Important:** `generateLicenseFile()` in [src/license.cpp](src/license.cpp#L26) currently returns `false` immediately — generation is stubbed out. Reading/verification work normally.

## License file format

Files (`*.xlts`) use: `base64(MAGIC[4] + CRC32[4] + RC4_encrypted(JSON))`

- MAGIC: `RLIC` (4 bytes)
- CRC32: big-endian checksum of the RC4-encrypted payload (4 bytes)
- RC4 key: hardcoded in [src/license.cpp](src/license.cpp#L15-L20)
- JSON payload fields: `name`, `machinecode`, `phone`, `unit`, `authdatetime`, `overdatetime`, `updatedatetime`
- Verification is a simple string comparison of `machinecode` against `getMachineCode()` — intentionally not cryptographically secure

## 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`, `sched_setaffinity` for deterministic CPUID), and macOS (`sysctl`, `statfs`).

## GUI

```
gui/license_gui.py
```

A tkinter-based GUI for generating license files. Fields: name, phone, unit, machinecode (auto-filled), authdatetime (auto today), overdatetime/updatedatetime (date pickers). Filename pattern: `license_<name>_<machinecode[0:8]>.xlts`. Requires Python 3 with tkinter (built-in on most systems).