~~NOTOC~~
====== Scenario 8.2: Firmare codice ======

<WRAP round info>
**Categoria:** [[.:start|Firme digitali]] \\
**Complessità:** Alta \\
**Prerequisiti:** Certificato Code-Signing \\
**Tempo stimato:** 20-30 minuti
</WRAP>

----

===== Descrizione =====

Questo scenario descrive la **firma di codice e eseguibili** con algoritmi sicuri Post-Quantum. Code Signing consente:

  * **Autenticazione** dell'editore del software
  * **Protezione dell'integrità** contro manipolazioni
  * **Affidabilità** per gli utenti finali
  * **Conformità** con le linee guida di sicurezza

**Formati supportati:**
  * Windows Authenticode (EXE, DLL, MSI)
  * PowerShell Scripts (.ps1)
  * NuGet Packages (.nupkg)
  * Java JAR Files
  * macOS Code Signature

----

===== Workflow =====

<mermaid>
flowchart LR
    CODE[Executable/DLL] --> HASH[Hash Authenticode]
    HASH --> SIGN[Firma ML-DSA + RSA]
    KEY[Chiave Code-Signing] --> SIGN
    SIGN --> TS[Aggiungere timestamp]
    TSA[Server TSA] --> TS
    TS --> OUTPUT[File firmato]

    style SIGN fill:#e8f5e9
    style TS fill:#fff3e0
</mermaid>

----

===== Esempio codice: Firma Authenticode =====

<code csharp>
using WvdS.Security.Cryptography.X509Certificates.Extensions.PQ;
using System.Security.Cryptography;

using var ctx = PqCryptoContext.Initialize();

// Caricare certificato e chiave Code-Signing
var codeSignCert = ctx.LoadCertificate("codesign.crt.pem");
var codeSignKey = ctx.LoadPrivateKey("codesign.key.pem", "KeyPassword!");

// Creare firma Authenticode
var signatureOptions = new AuthenticodeSignatureOptions
{
    Certificate = codeSignCert,
    PrivateKey = codeSignKey,
    HashAlgorithm = HashAlgorithmName.SHA256,
    TimestampUrl = "http://timestamp.digicert.com",
    TimestampHashAlgorithm = HashAlgorithmName.SHA256,
    Mode = CryptoMode.Hybrid,
    Description = "MyApp - Applicazione sicura",
    DescriptionUrl = "https://myapp.example.com"
};

// Firmare EXE
var inputPath = "MyApp.exe";
var outputPath = "MyApp-signed.exe";

ctx.SignAuthenticode(inputPath, outputPath, signatureOptions);

Console.WriteLine($"Codice firmato: {outputPath}");
Console.WriteLine($"  Firmatario: {codeSignCert.Subject}");
Console.WriteLine($"  Timestamp: {signatureOptions.TimestampUrl}");
</code>

----

===== Integrazione Windows SignTool =====

<code csharp>
public class SignToolWrapper
{
    public void Sign(string filePath, string pfxPath, string password, string timestampUrl)
    {
        var process = new Process
        {
            StartInfo = new ProcessStartInfo
            {
                FileName = "signtool.exe",
                Arguments = $"sign " +
                    $"/fd SHA256 " +
                    $"/f \"{pfxPath}\" " +
                    $"/p \"{password}\" " +
                    $"/tr \"{timestampUrl}\" " +
                    $"/td SHA256 " +
                    $"/d \"Firmato con PQ-Crypto\" " +
                    $"\"{filePath}\"",
                RedirectStandardOutput = true,
                RedirectStandardError = true,
                UseShellExecute = false
            }
        };

        process.Start();
        process.WaitForExit();

        if (process.ExitCode != 0)
        {
            var error = process.StandardError.ReadToEnd();
            throw new InvalidOperationException($"SignTool fallito: {error}");
        }

        Console.WriteLine($"Firmato: {filePath}");
    }

    public bool Verify(string filePath)
    {
        var process = new Process
        {
            StartInfo = new ProcessStartInfo
            {
                FileName = "signtool.exe",
                Arguments = $"verify /pa /v \"{filePath}\"",
                RedirectStandardOutput = true,
                UseShellExecute = false
            }
        };

        process.Start();
        process.WaitForExit();

        return process.ExitCode == 0;
    }
}
</code>

----

===== Firmare script PowerShell =====

<code csharp>
public class PowerShellSigner
{
    public void SignScript(string scriptPath, X509Certificate2 cert)
    {
        // Aggiungere firma CMS PowerShell
        var scriptContent = File.ReadAllText(scriptPath);

        // Creare blocco firma
        var signatureBlock = CreatePowerShellSignature(scriptContent, cert);

        // Aggiungere firma allo script
        var signedContent = scriptContent + Environment.NewLine + signatureBlock;
        File.WriteAllText(scriptPath, signedContent);

        Console.WriteLine($"Script PowerShell firmato: {scriptPath}");
    }

    private string CreatePowerShellSignature(string content, X509Certificate2 cert)
    {
        using var ctx = PqCryptoContext.Initialize();

        // Hash dello script
        var hash = SHA256.HashData(Encoding.UTF8.GetBytes(content));

        // Firma CMS
        var contentInfo = new ContentInfo(hash);
        var signedCms = new SignedCms(contentInfo, true);
        var signer = new CmsSigner(cert);
        signedCms.ComputeSignature(signer);

        // Blocco firma codificato Base64
        var signatureBase64 = Convert.ToBase64String(signedCms.Encode());

        return $@"
# SIG # Begin signature block
# {signatureBase64}
# SIG # End signature block";
    }
}
</code>

----

===== Firmare pacchetto NuGet =====

<code csharp>
public class NuGetSigner
{
    public async Task SignPackage(
        string packagePath,
        X509Certificate2 cert,
        AsymmetricAlgorithm privateKey,
        string timestampUrl)
    {
        using var ctx = PqCryptoContext.Initialize();

        // Aprire pacchetto NuGet
        using var package = new ZipArchive(File.Open(packagePath, FileMode.Open), ZipArchiveMode.Update);

        // Creare .signature.p7s
        var signatureEntry = package.CreateEntry(".signature.p7s");

        // Calcolare hash del pacchetto (senza entry firma)
        var packageHash = ComputePackageHash(package);

        // Firma CMS
        var contentInfo = new ContentInfo(packageHash);
        var signedCms = new SignedCms(contentInfo, true);
        var signer = new CmsSigner(cert)
        {
            DigestAlgorithm = new Oid("2.16.840.1.101.3.4.2.1"),
            IncludeOption = X509IncludeOption.WholeChain
        };

        signedCms.ComputeSignature(signer, mode: CryptoMode.Hybrid);

        // Aggiungere timestamp
        await AddTimestamp(signedCms, timestampUrl);

        // Scrivere firma
        using var signatureStream = signatureEntry.Open();
        signatureStream.Write(signedCms.Encode());

        Console.WriteLine($"Pacchetto NuGet firmato: {packagePath}");
    }
}
</code>

----

===== Doppia firma (Legacy + PQ) =====

Per periodo di transizione: entrambe le firme in parallelo

<code csharp>
public class DualSignature
{
    public void SignWithDualSignature(string exePath, SigningCredentials credentials)
    {
        using var ctx = PqCryptoContext.Initialize();

        // 1. Prima firma: SHA-1 (per compatibilità Windows XP/Vista)
        ctx.SignAuthenticode(exePath, exePath, new AuthenticodeSignatureOptions
        {
            Certificate = credentials.LegacyCert,
            PrivateKey = credentials.LegacyKey,
            HashAlgorithm = HashAlgorithmName.SHA1,
            TimestampUrl = credentials.TimestampUrl,
            AppendSignature = false  // Prima firma
        });

        // 2. Seconda firma: SHA-256 + PQ (per sistemi moderni)
        ctx.SignAuthenticode(exePath, exePath, new AuthenticodeSignatureOptions
        {
            Certificate = credentials.PqCert,
            PrivateKey = credentials.PqKey,
            HashAlgorithm = HashAlgorithmName.SHA256,
            Mode = CryptoMode.Hybrid,
            TimestampUrl = credentials.TimestampUrl,
            AppendSignature = true  // Aggiungere seconda firma
        });

        Console.WriteLine("Doppia firma creata (SHA-1 + SHA-256/PQ)");
    }
}
</code>

----

===== Server timestamp =====

^  Fornitore  ^  URL  ^  Protocollo  ^
| DigiCert | http://timestamp.digicert.com | RFC 3161 |
| Sectigo | http://timestamp.sectigo.com | RFC 3161 |
| GlobalSign | http://timestamp.globalsign.com | RFC 3161 |
| SSL.com | http://ts.ssl.com | RFC 3161 |

<WRAP round alert>
**IMPORTANTE:** Senza timestamp la firma non è valida dopo la scadenza del certificato!
</WRAP>

----

===== Requisiti specifici per settore =====

^  Settore  ^  Standard  ^  Requisiti  ^
| **Windows** | Authenticode | Certificato EV per SmartScreen |
| **Automotive** | UNECE R156 | Firma firmware, HSM |
| **Sanità** | DiGAV | Firma qualificata |
| **Industria** | IEC 62443 | Firmware PLC |

----

===== Scenari correlati =====

^  Relazione  ^  Scenario  ^  Descrizione  ^
| **Prerequisito** | [[it:int:pqcrypt:szenarien:zertifikate:codesign_cert|3.3 Cert Code-Signing]] | Creare certificato |
| **Importante** | [[.:timestamp|8.3 Timestamp]] | Validità a lungo termine |
| **Correlato** | [[.:signatur_verifizieren|8.4 Verificare firma]] | Verifica |

----

<< [[.:dokument_signieren|← 8.1 Firmare documento]] | [[.:start|↑ Panoramica firme]] | [[.:timestamp|8.3 Timestamp →]] >>

{{tag>scenario firma codice authenticode powershell nuget}}

----
//Wolfgang van der Stille @ EMSR DATA d.o.o. - Post-Quantum Cryptography Professional//