Zertifikatsverwaltung

Kompakte Beispiele für Zertifikatsverwaltung. → Details: Verwaltung-Szenarien

var caCert = new X509Certificate2("intermediate-ca.pfx", "passwort");
var oldCert = new X509Certificate2("server.pfx", "passwort");
 
var privateKey = oldCert.GetECDsaPrivateKey();
 
var request = new CertificateRequest(
    oldCert.SubjectName, (ECDsa)privateKey, HashAlgorithmName.SHA384);
 
// Extensions übernehmen (außer SKI)
foreach (var ext in oldCert.Extensions)
    if (ext.Oid?.Value != "2.5.29.14")
        request.CertificateExtensions.Add(ext);
 
// Neue Seriennummer
var serial = new byte[20];
RandomNumberGenerator.Fill(serial);
serial[0] &= 0x7F;
 
var renewedCert = request.Create(caCert,
    DateTimeOffset.UtcNow, DateTimeOffset.UtcNow.AddYears(1), serial);

→ Details: Renewal

var oldCert = new X509Certificate2("server.crt");
using var newKey = ECDsa.Create(ECCurve.NamedCurves.nistP384);
 
var request = new CertificateRequest(
    oldCert.SubjectName, newKey, HashAlgorithmName.SHA384);
 
// SANs und EKU übernehmen
if (oldCert.Extensions["2.5.29.17"] is { } san)
    request.CertificateExtensions.Add(san);
if (oldCert.Extensions["2.5.29.37"] is { } eku)
    request.CertificateExtensions.Add(eku);
 
// Neues Zertifikat erstellen, altes widerrufen!

→ Details: Re-Key

var caCert = new X509Certificate2("intermediate-ca.pfx", "passwort");
var crlBuilder = new CertificateRevocationListBuilder();
 
crlBuilder.AddEntry(
    serialNumber: new byte[] { 0x01, 0x23, 0x45 },
    revocationTime: DateTimeOffset.UtcNow,
    reason: X509RevocationReason.KeyCompromise);
 
var crl = crlBuilder.Build(caCert,
    crlNumber: BitConverter.GetBytes(1L),
    nextUpdate: DateTimeOffset.UtcNow.AddDays(7),
    HashAlgorithmName.SHA384);
 
File.WriteAllBytes("intermediate.crl", crl);

→ Details: CRL erstellen

Vor Ablauf (30 Tage):

• Erneuerung planen
• Renewal oder Re-Key entscheiden

Bei Kompromittierung:

• Sofort Re-Key (neuer Schlüssel!)
• Altes Zertifikat widerrufen
• CRL aktualisieren

« ← Kurzreferenz | → Verwaltung-Szenarien (Details) »

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