Scenarij 12.1: PEM izvoz/uvoz

Ta scenarij opisuje izvoz in uvoz v PEM formatu (Privacy-Enhanced Mail). PEM je najpogostejši format za certifikate in ključe na Linux/Unix sistemih in ga OpenSSL izvorno podpira.

Lastnosti PEM:

• Kodiranje: Base64 z glavo/nogo
• Glava: —–BEGIN CERTIFICATE—– itd.
• Berljivost: Besedilna datoteka, enostavna za pregled
• Veriženje: Več objektov v eni datoteki je možno

using WvdS.Security.Cryptography.X509Certificates.Extensions.PQ;
using System.Security.Cryptography.X509Certificates;
 
using var ctx = PqCryptoContext.Initialize();
 
// Nalaganje certifikata
var cert = new X509Certificate2("certificate.pfx", "password");
 
// Izvoz kot PEM
ctx.ToPemFile(cert, "certificate.pem");
 
// Ali kot niz
string pemString = ctx.ToPem(cert);
Console.WriteLine(pemString);
 
// Izpis:
// -----BEGIN CERTIFICATE-----
// MIIBkTCB+wIJAK... (Base64)
// -----END CERTIFICATE-----

using var ctx = PqCryptoContext.Initialize();
 
// Generiranje ključa
using var keyPair = ctx.GenerateKeyPair(PqAlgorithm.MlDsa65);
 
// Nešifriran PEM (SAMO za teste!)
keyPair.ToPemFile("private-key.pem");
 
// Šifriran PEM (PRIPOROČENO)
keyPair.ToEncryptedPemFile(
    path: "private-key-encrypted.pem",
    password: "StrongPassword123!",
    pbeAlgorithm: PbeAlgorithm.Aes256Cbc,
    iterations: 100000
);
 
// Javni ključ ločeno
keyPair.PublicKey.ToPemFile("public-key.pem");

using var ctx = PqCryptoContext.Initialize();
 
// Nalaganje certifikata iz PEM
var cert = ctx.LoadCertificate("certificate.pem");
Console.WriteLine($"Subject: {cert.Subject}");
Console.WriteLine($"Veljavno do: {cert.NotAfter:d}");
 
// Nalaganje šifriranega zasebnega ključa
var privateKey = ctx.LoadPrivateKey(
    path: "private-key-encrypted.pem",
    password: "StrongPassword123!"
);
 
// Kombinacija certifikata z zasebnim ključem
var certWithKey = ctx.LoadCertificateWithPrivateKey(
    certPath: "certificate.pem",
    keyPath: "private-key-encrypted.pem",
    keyPassword: "StrongPassword123!"
);
 
Console.WriteLine($"Ima zasebni ključ: {certWithKey.HasPrivateKey}");

public class PemChainExporter
{
    public void ExportChainAsPem(
        X509Certificate2 endEntity,
        X509Certificate2Collection chain,
        string outputPath)
    {
        using var ctx = PqCryptoContext.Initialize();
        var sb = new StringBuilder();
 
        // Končni certifikat najprej
        sb.AppendLine("# End-Entity Certificate");
        sb.AppendLine(ctx.ToPem(endEntity));
 
        // Nato vmesne CA
        foreach (var cert in chain.OrderBy(c => c.NotAfter))
        {
            if (cert.Thumbprint != endEntity.Thumbprint)
            {
                sb.AppendLine($"# Intermediate: {cert.Subject}");
                sb.AppendLine(ctx.ToPem(cert));
            }
        }
 
        File.WriteAllText(outputPath, sb.ToString());
        Console.WriteLine($"Veriga izvožena: {outputPath}");
    }
 
    public X509Certificate2Collection ImportChainFromPem(string pemPath)
    {
        using var ctx = PqCryptoContext.Initialize();
        var pemContent = File.ReadAllText(pemPath);
        var collection = new X509Certificate2Collection();
 
        // Ekstrakcija PEM blokov
        var certPattern = @"-----BEGIN CERTIFICATE-----(.*?)-----END CERTIFICATE-----";
        var matches = Regex.Matches(pemContent, certPattern, RegexOptions.Singleline);
 
        foreach (Match match in matches)
        {
            var base64 = match.Groups[1].Value.Trim();
            var certBytes = Convert.FromBase64String(base64);
            collection.Add(new X509Certificate2(certBytes));
        }
 
        Console.WriteLine($"{collection.Count} certifikatov uvoženih");
        return collection;
    }
}

using var ctx = PqCryptoContext.Initialize();
 
// Ustvarjanje ključa in CSR
using var keyPair = ctx.GenerateKeyPair(PqAlgorithm.MlDsa65);
 
var csr = ctx.CreateCertificateRequest(
    keyPair,
    new DnBuilder()
        .AddCN("www.example.com")
        .AddO("Example GmbH")
        .Build()
);
 
// Izvoz CSR kot PEM
string csrPem = ctx.ToPem(csr);
File.WriteAllText("request.csr", csrPem);
 
// Izpis:
// -----BEGIN CERTIFICATE REQUEST-----
// MIIBkTCB+wIJAK... (Base64)
// -----END CERTIFICATE REQUEST-----

using var ctx = PqCryptoContext.Initialize();
 
// Ustvarjanje CRL
var crlBuilder = new CertificateRevocationListBuilder();
// ... dodajanje certifikatov ...
 
var crlBytes = crlBuilder.Build(caCert, caKey, crlNumber, nextUpdate);
 
// Izvoz CRL kot PEM
var crlPem = new StringBuilder();
crlPem.AppendLine("-----BEGIN X509 CRL-----");
crlPem.AppendLine(Convert.ToBase64String(crlBytes, Base64FormattingOptions.InsertLineBreaks));
crlPem.AppendLine("-----END X509 CRL-----");
 
File.WriteAllText("revoked.crl.pem", crlPem.ToString());
 
// Nalaganje CRL iz PEM
var crlContent = File.ReadAllText("revoked.crl.pem");
var base64 = Regex.Match(crlContent, @"-----BEGIN X509 CRL-----(.*?)-----END X509 CRL-----",
    RegexOptions.Singleline).Groups[1].Value.Trim();
var crlData = Convert.FromBase64String(base64);

# Pretvorba DER v PEM
openssl x509 -in cert.der -inform DER -out cert.pem -outform PEM
 
# Pretvorba PEM v DER
openssl x509 -in cert.pem -inform PEM -out cert.der -outform DER
 
# Pregled PEM certifikata
openssl x509 -in cert.pem -text -noout
 
# Šifriranje zasebnega ključa
openssl pkcs8 -topk8 -in key.pem -out key-encrypted.pem -aes256
 
# Dešifriranje zasebnega ključa
openssl pkcs8 -in key-encrypted.pem -out key.pem

« ← Pregled uvoza/izvoza | ↑ Uvoz/Izvoz | 12.2 PFX izvoz → »

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