nc_program_manager/.paul/phases/09-license-generator/09-01-PLAN.md

---
phase: 09-license-generator
plan: 01
type: execute
wave: 1
depends_on: ["07-01"]
files_modified:
  - ~/Documents/mine/c#/LicenseGenerator/LicenseGenerator.csproj
  - ~/Documents/mine/c#/LicenseGenerator/LicenseGenerator.sln
  - ~/Documents/mine/c#/LicenseGenerator/Program.cs
  - ~/Documents/mine/c#/LicenseGenerator/InputArgs.cs
  - ~/Documents/mine/c#/LicenseGenerator/Commands/KeygenCommand.cs
  - ~/Documents/mine/c#/LicenseGenerator/Commands/FingerprintCommand.cs
  - ~/Documents/mine/c#/LicenseGenerator/Commands/SignCommand.cs
  - ~/Documents/mine/c#/LicenseGenerator/Properties/AssemblyInfo.cs
  - Licensing/LicenseValidator.cs
autonomous: false
---

<objective>
## Goal
Build a standalone vendor console tool (`LicenseGenerator.exe`) in a separate repository at `~/Documents/mine/c#/LicenseGenerator`. Three commands: `keygen` (RSA pair), `fingerprint` (WMI), `sign` (produce `.lic`). After running keygen, replace the PLACEHOLDER in `LicenseValidator.cs` with the real public key.

## Purpose
Completes the offline license system. Without a real key pair, all production licenses are rejected. This tool gives the vendor the ability to issue machine-bound licenses and embeds the matching public key into the product binary.

## Output
- `~/Documents/mine/c#/LicenseGenerator/` — new standalone .NET 4.7.2 console project and solution
- Git repo initialized, remote: `ssh://git@3nt-git.duckdns.org:222/davide.trentin/license-generator.git`
- `Licensing/LicenseValidator.cs` (in NcProgramManager) — PLACEHOLDER replaced with real RSA 2048-bit public key XML
</objective>

<context>
## Project Context
@.paul/PROJECT.md
@.paul/STATE.md

## Prior Work
@.paul/phases/07-license-core/07-01-SUMMARY.md

## Source Files
@Licensing/LicenseValidator.cs
@Licensing/MachineFingerprint.cs
@Licensing/LicenseFile.cs
</context>

<acceptance_criteria>

## AC-1: keygen produces RSA 2048-bit key pair
```gherkin
Given LicenseGenerator.exe is present
When vendor runs `LicenseGenerator.exe keygen`
Then private.key.xml written to current dir, public key XML printed to stdout
And stdout message instructs vendor to paste public key into LicenseValidator.cs
```

## AC-2: fingerprint command prints machine fingerprint
```gherkin
Given LicenseGenerator.exe running on Windows with WMI access
When vendor runs `LicenseGenerator.exe fingerprint`
Then machine fingerprint string printed to stdout (CPU ProcessorID + BaseBoard SerialNumber, same logic as MachineFingerprint.GetFingerprint())
```

## AC-3: sign command produces valid .lic file
```gherkin
Given private.key.xml exists and fingerprint string is known
When vendor runs `LicenseGenerator.exe sign -key=private.key.xml -fingerprint=<fp> -out=license.lic`
Then license.lic written containing base64 RSA-SHA256 signature
And LicenseValidator(publicKeyXml).Validate(fp, File.ReadAllText("license.lic").Trim()) returns true
```

## AC-4: LicenseValidator.cs uses real public key
```gherkin
Given keygen was run and public key XML captured
When PublicKeyXml constant in LicenseValidator.cs is updated from PLACEHOLDER to real XML
Then a license signed by the matching private key passes Validate()
And a license signed by any other key fails Validate()
```

</acceptance_criteria>

<tasks>

<task type="auto">
  <name>Task 1: Create LicenseGenerator project and git repo</name>
  <files>
    ~/Documents/mine/c#/LicenseGenerator/LicenseGenerator.sln,
    ~/Documents/mine/c#/LicenseGenerator/LicenseGenerator.csproj,
    ~/Documents/mine/c#/LicenseGenerator/Program.cs,
    ~/Documents/mine/c#/LicenseGenerator/InputArgs.cs,
    ~/Documents/mine/c#/LicenseGenerator/Properties/AssemblyInfo.cs,
    ~/Documents/mine/c#/LicenseGenerator/.gitignore
  </files>
  <action>
    Create `~/Documents/mine/c#/LicenseGenerator/` as a fully standalone project (NOT inside NcProgramManager).

    **Directory layout:**
    ```
    LicenseGenerator/
      LicenseGenerator.sln
      LicenseGenerator.csproj
      Program.cs
      InputArgs.cs
      Commands/          (empty dir, populated in Task 2+3)
      Properties/
        AssemblyInfo.cs
      .gitignore
    ```

    **LicenseGenerator.csproj:**
    - OutputType: Exe, TargetFrameworkVersion: v4.7.2, Platform: AnyCPU
    - References: System, System.Core, System.Management
    - Compile includes: Program.cs, InputArgs.cs, Properties/AssemblyInfo.cs, Commands\KeygenCommand.cs, Commands\FingerprintCommand.cs, Commands\SignCommand.cs

    **LicenseGenerator.sln:** minimal VS2019-compatible solution referencing LicenseGenerator.csproj

    **InputArgs.cs** (namespace LicenseGenerator):
    - Field: `string Command` — args[0] if present, else ""
    - Field: `string KeyPath` — value of `-key=`
    - Field: `string Fingerprint` — value of `-fingerprint=`
    - Field: `string OutPath` — value of `-out=`, default "license.lic"
    - Static factory: `InputArgs Parse(string[] args)` — split each arg on first '='

    **Program.cs** (namespace LicenseGenerator):
    - Call `InputArgs.Parse(args)`
    - Switch Command: "keygen" → KeygenCommand.Execute(), "fingerprint" → FingerprintCommand.Execute(), "sign" → SignCommand.Execute(args), default → print usage + Environment.Exit(1)
    - Usage text lists all three commands

    **AssemblyInfo.cs:** standard .NET 4.7.2 template, AssemblyVersion "1.0.0.0", product "LicenseGenerator"

    **.gitignore:** standard C# gitignore (bin/, obj/, *.user, .vs/, packages/)

    **Git setup (run after creating files):**
    ```bash
    cd ~/Documents/mine/c#/LicenseGenerator
    git init
    git remote add origin ssh://git@3nt-git.duckdns.org:222/davide.trentin/license-generator.git
    ```

    Avoid: any reference to NcProgramManager.csproj or NcProgramManager.sln
  </action>
  <verify>
    `ls ~/Documents/mine/c#/LicenseGenerator/` shows .sln, .csproj, Program.cs, InputArgs.cs, Properties/, Commands/, .gitignore
    `git -C ~/Documents/mine/c#/LicenseGenerator remote -v` shows origin pointing to ssh://git@3nt-git.duckdns.org:222/davide.trentin/license-generator.git
  </verify>
  <done>Project structure created; git repo initialized with correct remote.</done>
</task>

<task type="auto">
  <name>Task 2: Implement keygen and fingerprint commands</name>
  <files>
    ~/Documents/mine/c#/LicenseGenerator/Commands/KeygenCommand.cs,
    ~/Documents/mine/c#/LicenseGenerator/Commands/FingerprintCommand.cs
  </files>
  <action>
    **KeygenCommand.cs** (namespace LicenseGenerator.Commands):
    ```csharp
    internal static class KeygenCommand
    {
        internal static void Execute()
        {
            using (var rsa = new RSACryptoServiceProvider(2048))
            {
                string privateXml = rsa.ToXmlString(true);
                string publicXml  = rsa.ToXmlString(false);
                File.WriteAllText("private.key.xml", privateXml);
                Console.WriteLine("=== PUBLIC KEY XML — paste into LicenseValidator.cs ===");
                Console.WriteLine(publicXml);
                Console.WriteLine("========================================================");
                Console.WriteLine("Private key saved: private.key.xml");
                Console.WriteLine("KEEP private.key.xml SECRET — never distribute it.");
            }
        }
    }
    ```
    Usings: System, System.IO, System.Security.Cryptography

    **FingerprintCommand.cs** (namespace LicenseGenerator.Commands):
    - Duplicate WMI logic from MachineFingerprint.GetFingerprint():
      1. ManagementClass("win32_processor") → processorID property
      2. ManagementObjectSearcher("root\\CIMV2", "SELECT * FROM Win32_BaseBoard") → SerialNumber
      3. Concatenate → print to Console.WriteLine
    - Wrap in try/catch: on exception print "Error reading fingerprint (Windows + WMI required): " + ex.Message, Environment.Exit(1)
    - Usings: System, System.Management

    Avoid: referencing MachineFingerprint class from NcProgramManager — keep standalone
  </action>
  <verify>
    On Linux/Mono: `LicenseGenerator.exe keygen` writes private.key.xml and prints RSAKeyValue XML to stdout.
    On Windows: `LicenseGenerator.exe fingerprint` prints non-empty CPU+board string.
  </verify>
  <done>AC-1 satisfied: keygen generates 2048-bit RSA pair. AC-2 satisfied: fingerprint reads WMI.</done>
</task>

<task type="auto">
  <name>Task 3: Implement sign command</name>
  <files>
    ~/Documents/mine/c#/LicenseGenerator/Commands/SignCommand.cs
  </files>
  <action>
    **SignCommand.cs** (namespace LicenseGenerator.Commands):
    ```csharp
    internal static class SignCommand
    {
        internal static void Execute(InputArgs args)
        {
            if (string.IsNullOrEmpty(args.KeyPath))
            {
                Console.Error.WriteLine("Missing: -key=<path-to-private.key.xml>");
                Environment.Exit(1);
            }
            if (string.IsNullOrEmpty(args.Fingerprint))
            {
                Console.Error.WriteLine("Missing: -fingerprint=<machine-fingerprint>");
                Environment.Exit(1);
            }

            string privateXml = File.ReadAllText(args.KeyPath);
            byte[] data = Encoding.UTF8.GetBytes(args.Fingerprint);

            using (var rsa = new RSACryptoServiceProvider())
            {
                rsa.FromXmlString(privateXml);
                byte[] signature = rsa.SignData(data, new SHA256CryptoServiceProvider());
                string base64 = Convert.ToBase64String(signature);
                File.WriteAllText(args.OutPath, base64);
                Console.WriteLine("License written: " + args.OutPath);
            }
        }
    }
    ```
    Usings: System, System.IO, System.Security.Cryptography, System.Text

    SHA256CryptoServiceProvider (not HashAlgorithmName) — .NET 4.7.2 RSACryptoServiceProvider constraint.
    SignData here MUST pair with VerifyData in LicenseValidator — same provider type on both sides.

    Avoid: HashAlgorithmName overloads — not available in .NET 4.7.2 RSACryptoServiceProvider
  </action>
  <verify>
    `LicenseGenerator.exe sign -key=private.key.xml -fingerprint=TEST_FP -out=test.lic` → test.lic contains non-empty base64.
    Cross-check: `new LicenseValidator(publicKeyXml).Validate("TEST_FP", File.ReadAllText("test.lic").Trim())` returns true.
  </verify>
  <done>AC-3 satisfied: sign command produces .lic file verifiable by LicenseValidator.</done>
</task>

<task type="checkpoint:human-action" gate="blocking">
  <what-built>LicenseGenerator project complete — keygen, fingerprint, sign commands implemented.</what-built>
  <how-to-verify>
    1. Build: `msbuild ~/Documents/mine/c#/LicenseGenerator/LicenseGenerator.sln /p:Configuration=Release`
       (or on Windows: build via VS or msbuild)
    2. Navigate to output: `LicenseGenerator/bin/Release/`
    3. Run: `LicenseGenerator.exe keygen`
    4. Capture the PUBLIC KEY XML printed between the `===` banners
    5. Paste the captured XML in the resume signal below

    Note: keygen works on Linux (Mono) and Windows — no WMI needed for key generation.
  </how-to-verify>
  <resume-signal>Paste captured public key XML (the full RSAKeyValue string) to continue</resume-signal>
</task>

<task type="auto">
  <name>Task 4: Replace PublicKeyXml PLACEHOLDER in LicenseValidator.cs</name>
  <files>
    Licensing/LicenseValidator.cs
  </files>
  <action>
    In NcProgramManager project, replace the PLACEHOLDER in `Licensing/LicenseValidator.cs`.

    Current (lines 11-15):
    ```csharp
    private const string PublicKeyXml =
        "<RSAKeyValue>" +
        "<Modulus>PLACEHOLDER</Modulus>" +
        "<Exponent>AQAB</Exponent>" +
        "</RSAKeyValue>";
    ```

    Replace with the real public key XML from keygen output as a single string literal:
    ```csharp
    // Real vendor public key — generated YYYY-MM-DD with LicenseGenerator keygen.
    private const string PublicKeyXml = "[full RSAKeyValue XML from keygen]";
    ```

    Avoid: embedding private key — public key only (keygen ToXmlString(false) output)
    Avoid: multi-line concatenation — single string literal is fine for RSA XML
  </action>
  <verify>
    `msbuild NcProgramManager.csproj` — no errors.
    All 116 existing tests pass (unit tests use ephemeral keys — unaffected).
    grep "PLACEHOLDER" Licensing/LicenseValidator.cs → no match.
  </verify>
  <done>AC-4 satisfied: LicenseValidator.cs uses real 2048-bit public key; production licenses now verifiable.</done>
</task>

<task type="auto">
  <name>Task 5: Initial commit and push LicenseGenerator repo</name>
  <files>
    ~/Documents/mine/c#/LicenseGenerator/ (all files)
  </files>
  <action>
    ```bash
    cd ~/Documents/mine/c#/LicenseGenerator
    git add LicenseGenerator.sln LicenseGenerator.csproj Program.cs InputArgs.cs \
            Commands/KeygenCommand.cs Commands/FingerprintCommand.cs Commands/SignCommand.cs \
            Properties/AssemblyInfo.cs .gitignore
    git commit -m "feat: initial LicenseGenerator — keygen, fingerprint, sign commands"
    git push -u origin main
    ```
    Do NOT commit private.key.xml or any generated .lic files.
    Verify .gitignore excludes bin/, obj/, *.user, .vs/.
  </action>
  <verify>`git -C ~/Documents/mine/c#/LicenseGenerator log --oneline` shows initial commit.</verify>
  <done>LicenseGenerator source pushed to ssh://git@3nt-git.duckdns.org:222/davide.trentin/license-generator.git</done>
</task>

</tasks>

<boundaries>

## DO NOT CHANGE
- `Licensing/MachineFingerprint.cs` — WMI logic duplicated in FingerprintCommand; no changes to original
- `Licensing/LicenseValidator.cs` — touch only the `PublicKeyXml` constant (Task 4 only)
- `Program.cs` (NcProgramManager) — license integration complete; no changes
- `NcProgramManager.Tests/` — no test changes in this plan
- `NcProgramManager.sln` — do NOT add LicenseGenerator; it is a separate solution

## SCOPE LIMITS
- LicenseGenerator is a standalone separate repo — no cross-project reference to NcProgramManager
- No GUI, no installer, no auto-update
- No network calls — fully offline tool
- `fingerprint` command: WMI logic only, Windows-only, no file output
- Do NOT commit private.key.xml to git

</boundaries>

<verification>
Before declaring plan complete:
- [ ] `~/Documents/mine/c#/LicenseGenerator/` exists as independent git repo
- [ ] `git remote -v` shows ssh://git@3nt-git.duckdns.org:222/davide.trentin/license-generator.git
- [ ] `LicenseGenerator.exe keygen` writes private.key.xml + prints RSAKeyValue XML
- [ ] `LicenseGenerator.exe sign -key=private.key.xml -fingerprint=TEST -out=test.lic` writes base64
- [ ] `LicenseValidator.cs` PublicKeyXml has no "PLACEHOLDER"
- [ ] `msbuild NcProgramManager.csproj` passes, all 116 tests pass
- [ ] LicenseGenerator source committed and pushed to remote
</verification>

<success_criteria>
- LicenseGenerator builds as standalone .NET 4.7.2 console EXE in its own repo
- All three commands (keygen, fingerprint, sign) implemented and functional
- LicenseValidator.cs uses real RSA 2048-bit public key
- Existing NcProgramManager test suite unaffected (116 pass, 2 ignored)
- Source pushed to ssh://git@3nt-git.duckdns.org:222/davide.trentin/license-generator.git
</success_criteria>

<output>
After completion, create `.paul/phases/09-license-generator/09-01-SUMMARY.md`
</output>