~~NOTOC~~
====== Szenario 4.4: Zertifikat- und Schlüssel-Backup ======

<WRAP round info>
**Kategorie:** [[.:start|Zertifikate verwalten]] \\
**Komplexität:** ⭐⭐⭐⭐ (Hoch) \\
**Voraussetzungen:** Zertifikate und Schlüssel vorhanden \\
**Geschätzte Zeit:** 20-30 Minuten
</WRAP>

----

===== Beschreibung =====

Dieses Szenario beschreibt das **sichere Backup** von Zertifikaten, privaten Schlüsseln und CA-Infrastruktur. Ein korrektes Backup-Konzept ist kritisch für:

  * **Disaster Recovery** - Wiederherstellung nach Systemausfall
  * **Business Continuity** - Betriebsfortführung
  * **Compliance** - Nachweispflichten
  * **Key Escrow** - Schlüsselhinterlegung

<WRAP round alert>
**KRITISCH:** Private Schlüssel sind das wertvollste Gut! Backups müssen:
  * Verschlüsselt sein
  * Offline gelagert werden
  * Zugriffsgeschützt sein
  * Regelmäßig getestet werden
</WRAP>

----

===== Workflow =====

<mermaid>
flowchart TD
    START[Backup initiieren] --> COLLECT[Daten sammeln]
    COLLECT --> ENCRYPT[Verschlüsseln]
    ENCRYPT --> SIGN[Signieren]
    SIGN --> STORE1[Primär-Storage]
    SIGN --> STORE2[Sekundär-Storage]
    STORE1 --> VERIFY[Verifizieren]
    STORE2 --> VERIFY
    VERIFY --> LOG[Audit-Log]

    style ENCRYPT fill:#fff3e0
    style STORE1 fill:#e8f5e9
    style STORE2 fill:#e8f5e9
</mermaid>

----

===== Code-Beispiel (C#) =====

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

using var ctx = PqCryptoContext.Initialize();

// Backup-Konfiguration
var backupConfig = new BackupConfiguration
{
    EncryptionPassword = "BackupPassword!Secure2024",
    OutputPath = "backup/",
    Timestamp = DateTime.UtcNow.ToString("yyyyMMdd-HHmmss"),
    IncludeChain = true
};

// CA-Zertifikat und Schlüssel laden
var caCert = ctx.LoadCertificate("root-ca.crt.pem");
var caKey = ctx.LoadPrivateKey("root-ca.key.pem", "CaPassword!");

// Verschlüsseltes PFX erstellen
var pfxData = ctx.ExportToPfx(
    certificate: caCert,
    privateKey: caKey,
    chain: null,  // Root hat keine Chain
    password: backupConfig.EncryptionPassword,
    friendlyName: $"Root-CA Backup {backupConfig.Timestamp}"
);

// Backup-Datei mit Metadaten
var backupPath = Path.Combine(
    backupConfig.OutputPath,
    $"root-ca-backup-{backupConfig.Timestamp}.pfx"
);

Directory.CreateDirectory(backupConfig.OutputPath);
File.WriteAllBytes(backupPath, pfxData);

// Prüfsumme berechnen
var checksum = ctx.ComputeSha256(pfxData);
var checksumPath = backupPath + ".sha256";
File.WriteAllText(checksumPath, Convert.ToHexString(checksum));

// Metadaten speichern
var metadata = new BackupMetadata
{
    BackupDate = DateTime.UtcNow,
    Subject = caCert.Subject,
    SerialNumber = caCert.SerialNumber,
    NotAfter = caCert.NotAfter,
    Checksum = Convert.ToHexString(checksum),
    Algorithm = caCert.PublicKey.Oid.FriendlyName
};

var metadataPath = backupPath + ".meta.json";
File.WriteAllText(metadataPath, JsonSerializer.Serialize(metadata, new JsonSerializerOptions
{
    WriteIndented = true
}));

Console.WriteLine("Backup erstellt:");
Console.WriteLine($"  Datei: {backupPath}");
Console.WriteLine($"  SHA256: {metadata.Checksum}");
Console.WriteLine($"  Größe: {new FileInfo(backupPath).Length:N0} Bytes");
</code>

----

===== Vollständiges CA-Backup =====

<code csharp>
public class CaBackupManager
{
    public void CreateFullBackup(string caDirectory, string backupPassword, string outputPath)
    {
        var timestamp = DateTime.UtcNow.ToString("yyyyMMdd-HHmmss");
        var backupDir = Path.Combine(outputPath, $"ca-backup-{timestamp}");
        Directory.CreateDirectory(backupDir);

        using var ctx = PqCryptoContext.Initialize();

        // 1. Root-CA
        BackupCertificateAndKey(ctx, caDirectory, "root-ca", backupDir, backupPassword);

        // 2. Alle Intermediate-CAs
        foreach (var intCaDir in Directory.GetDirectories(caDirectory, "intermediate-*"))
        {
            var name = Path.GetFileName(intCaDir);
            BackupCertificateAndKey(ctx, intCaDir, name, backupDir, backupPassword);
        }

        // 3. CRL-Dateien
        var crlDir = Path.Combine(backupDir, "crls");
        Directory.CreateDirectory(crlDir);
        foreach (var crl in Directory.GetFiles(caDirectory, "*.crl", SearchOption.AllDirectories))
        {
            File.Copy(crl, Path.Combine(crlDir, Path.GetFileName(crl)));
        }

        // 4. Konfigurationsdateien
        var configDir = Path.Combine(backupDir, "config");
        Directory.CreateDirectory(configDir);
        foreach (var config in Directory.GetFiles(caDirectory, "*.json"))
        {
            File.Copy(config, Path.Combine(configDir, Path.GetFileName(config)));
        }

        // 5. Manifest erstellen
        CreateBackupManifest(backupDir, timestamp);

        Console.WriteLine($"Vollständiges CA-Backup erstellt: {backupDir}");
    }

    private void BackupCertificateAndKey(
        PqCryptoContext ctx,
        string sourceDir,
        string name,
        string backupDir,
        string password)
    {
        var certPath = Path.Combine(sourceDir, $"{name}.crt.pem");
        var keyPath = Path.Combine(sourceDir, $"{name}.key.pem");

        if (!File.Exists(certPath)) return;

        var cert = ctx.LoadCertificate(certPath);

        // Zertifikat im Klartext (PEM)
        var certBackup = Path.Combine(backupDir, "certs", $"{name}.crt.pem");
        Directory.CreateDirectory(Path.GetDirectoryName(certBackup)!);
        cert.ToPemFile(certBackup);

        // Schlüssel verschlüsselt (falls vorhanden)
        if (File.Exists(keyPath))
        {
            // Schlüssel mit neuem Passwort verschlüsseln
            var key = ctx.LoadPrivateKey(keyPath, "OriginalPassword!");  // Anpassen!
            var keyBackup = Path.Combine(backupDir, "keys", $"{name}.key.pem.enc");
            Directory.CreateDirectory(Path.GetDirectoryName(keyBackup)!);
            key.ToEncryptedPemFile(keyBackup, password);
        }
    }

    private void CreateBackupManifest(string backupDir, string timestamp)
    {
        var manifest = new
        {
            Version = "1.0",
            Timestamp = timestamp,
            CreatedAt = DateTime.UtcNow,
            Contents = new
            {
                Certificates = Directory.GetFiles(Path.Combine(backupDir, "certs"), "*.pem").Length,
                Keys = Directory.GetFiles(Path.Combine(backupDir, "keys"), "*.enc").Length,
                CRLs = Directory.GetFiles(Path.Combine(backupDir, "crls"), "*.crl").Length,
                Configs = Directory.GetFiles(Path.Combine(backupDir, "config"), "*.json").Length
            }
        };

        var manifestPath = Path.Combine(backupDir, "MANIFEST.json");
        File.WriteAllText(manifestPath, JsonSerializer.Serialize(manifest, new JsonSerializerOptions
        {
            WriteIndented = true
        }));
    }
}
</code>

----

===== Backup-Verifizierung =====

<code csharp>
public bool VerifyBackup(string backupPath, string password)
{
    using var ctx = PqCryptoContext.Initialize();

    // 1. Prüfsumme verifizieren
    var expectedChecksum = File.ReadAllText(backupPath + ".sha256");
    var actualData = File.ReadAllBytes(backupPath);
    var actualChecksum = Convert.ToHexString(ctx.ComputeSha256(actualData));

    if (expectedChecksum != actualChecksum)
    {
        Console.WriteLine("FEHLER: Prüfsumme stimmt nicht!");
        return false;
    }

    // 2. PFX laden (testet Passwort und Integrität)
    try
    {
        var (cert, key) = ctx.ImportFromPfx(actualData, password);
        Console.WriteLine($"Backup OK: {cert.Subject}");
        Console.WriteLine($"  Gültig bis: {cert.NotAfter:yyyy-MM-dd}");
        Console.WriteLine($"  Schlüssel: {(key != null ? "Vorhanden" : "Fehlt")}");
        return true;
    }
    catch (CryptographicException ex)
    {
        Console.WriteLine($"FEHLER: {ex.Message}");
        return false;
    }
}
</code>

----

===== Branchenspezifische Backup-Anforderungen =====

^  Branche  ^  Vorschrift  ^  Backup-Frequenz  ^  Aufbewahrung  ^  Besonderheit  ^
| **Finanzsektor** | MaRisk | Täglich | 10 Jahre | Georedundanz Pflicht |
| **Healthcare** | DSGVO | Täglich | 30 Jahre | Air-Gap Storage |
| **Energie** | KRITIS-VO | Wöchentlich | 10 Jahre | Offline-Medien |
| **Automotive** | UNECE R155 | Monatlich | Fahrzeug-Lifetime | OTA-Recovery |

----

===== Backup-Strategie 3-2-1 =====

<WRAP round tip>
**3-2-1 Regel:**
  * **3** Kopien der Daten
  * **2** verschiedene Medientypen
  * **1** Kopie Off-Site
</WRAP>

| Kopie | Medium | Ort | Zweck |
|-------|--------|-----|-------|
| 1 | Server-Storage | Rechenzentrum | Operativ |
| 2 | Tape/NAS | Gebäude B | Disaster Recovery |
| 3 | Cloud (verschlüsselt) | Anderer Standort | Georedundanz |

----

===== Verwandte Szenarien =====

^  Beziehung  ^  Szenario  ^  Beschreibung  ^
| **Nächster Schritt** | [[.:archivierung|4.3 Archivierung]] | Langzeit-Aufbewahrung |
| **Verwandt** | [[de:int:pqcrypt:szenarien:schluessel:speicherung|11.2 Schlüsselspeicherung]] | Key Storage |
| **Verwandt** | [[de:int:pqcrypt:szenarien:importexport:pfx_export|12.2 PFX-Export]] | Export-Format |

----

<< [[.:archivierung|← 4.3 Archivierung]] | [[.:start|↑ Verwaltung-Übersicht]] | [[de:int:pqcrypt:szenarien:start|→ Alle Szenarien]] >>

{{tag>szenario verwaltung backup disaster-recovery pfx}}

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