~~NOTOC~~
====== Scenarij 6.1: Kreiranje CRL-a ======

<WRAP round info>
**Kategorija:** [[.:start|Opoziv (Revocation)]] \\
**Složenost:** ⭐⭐⭐ (Srednja) \\
**Preduvjeti:** CA certifikat i ključ \\
**Procijenjeno vrijeme:** 15-20 minuta
</WRAP>

----

===== Opis =====

Ovaj scenarij opisuje **kreiranje Certificate Revocation List (CRL)** prema RFC 5280. CRL-ovi su potpisane liste opozvanih certifikata koje CA objavljuje.

**Polja CRL-a:**
  * **issuer** - DN CA koji izdaje
  * **thisUpdate** - Vrijeme izdavanja
  * **nextUpdate** - Sljedeće planirano ažuriranje
  * **revokedCertificates** - Lista opozvanih serijskih brojeva
  * **signature** - CA potpis

----

===== Tijek rada =====

<mermaid>
flowchart LR
    REV[Opozvani certifikati] --> BUILD[CRL Builder]
    BUILD --> SIGN[Potpisivanje s CA]
    SIGN --> PUBLISH[Objavljivanje]
    PUBLISH --> CDP[Ažuriranje CDP URL-a]

    style SIGN fill:#e8f5e9
</mermaid>

----

===== Primjer koda (C#) =====

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

using var ctx = PqCryptoContext.Initialize();

// Učitavanje CA
var caCert = ctx.LoadCertificate("intermediate-ca.crt.pem");
var caKey = ctx.LoadPrivateKey("intermediate-ca.key.pem", "CaPassword!");

// Kreiranje CRL Buildera
var crlBuilder = new CertificateRevocationListBuilder();

// Dodavanje opozvanih certifikata
crlBuilder.AddEntry(
    serialNumber: new byte[] { 0x01, 0x02, 0x03 },
    revocationTime: new DateTimeOffset(2024, 6, 15, 10, 30, 0, TimeSpan.Zero),
    reason: X509RevocationReason.KeyCompromise
);

crlBuilder.AddEntry(
    serialNumber: new byte[] { 0x01, 0x02, 0x04 },
    revocationTime: DateTimeOffset.UtcNow.AddDays(-7),
    reason: X509RevocationReason.CessationOfOperation
);

// Generiranje CRL-a
byte[] crlBytes = crlBuilder.Build(
    issuerCertificate: caCert,
    crlNumber: BigInteger.Parse("1000"),
    nextUpdate: DateTimeOffset.UtcNow.AddDays(7),
    hashAlgorithm: HashAlgorithmName.SHA256,
    rsaSignaturePadding: null,  // Za PQ nije relevantno
    mode: CryptoMode.Hybrid
);

// Spremanje CRL-a
File.WriteAllBytes("intermediate-ca.crl", crlBytes);

// Konverzija CRL-a u PEM
var crlPem = ctx.ToPem(crlBytes, "X509 CRL");
File.WriteAllText("intermediate-ca.crl.pem", crlPem);

Console.WriteLine("CRL kreiran:");
Console.WriteLine($"  Unosi: {crlBuilder.Entries.Count}");
Console.WriteLine($"  CRL Number: 1000");
Console.WriteLine($"  Next Update: {DateTimeOffset.UtcNow.AddDays(7):yyyy-MM-dd}");
</code>

----

===== Ažuriranje CRL-a iz postojećeg CRL-a =====

<code csharp>
public class CrlUpdater
{
    public byte[] UpdateCrl(
        byte[] existingCrl,
        X509Certificate2 caCert,
        AsymmetricAlgorithm caKey,
        IEnumerable<CrlEntry>? newEntries = null)
    {
        using var ctx = PqCryptoContext.Initialize();

        // Parsiranje postojećeg CRL-a
        var parsedCrl = ctx.ParseCrl(existingCrl);

        // Novi builder s postojećim unosima
        var builder = new CertificateRevocationListBuilder();

        foreach (var entry in parsedCrl.Entries)
        {
            builder.AddEntry(entry.SerialNumber, entry.RevocationTime, entry.Reason);
        }

        // Dodavanje novih unosa
        if (newEntries != null)
        {
            foreach (var entry in newEntries)
            {
                builder.AddEntry(entry.SerialNumber, entry.RevocationTime, entry.Reason);
            }
        }

        // Nova CRL-Nummer (inkrementirana)
        var newCrlNumber = parsedCrl.CrlNumber + 1;

        // Kreiranje novog CRL-a
        return builder.Build(
            issuerCertificate: caCert,
            crlNumber: newCrlNumber,
            nextUpdate: DateTimeOffset.UtcNow.AddDays(7),
            hashAlgorithm: HashAlgorithmName.SHA256,
            mode: CryptoMode.Hybrid
        );
    }
}
</code>

----

===== CRL ekstenzije =====

<code csharp>
// CRL s ekstenzijama
var crlBuilder = new CertificateRevocationListBuilder();

// CRL ekstenzije
crlBuilder.AddExtension(
    oid: "2.5.29.20",  // CRL Number
    critical: false,
    value: BuildCrlNumberExtension(1001)
);

crlBuilder.AddExtension(
    oid: "2.5.29.35",  // Authority Key Identifier
    critical: false,
    value: BuildAkiExtension(caCert)
);

crlBuilder.AddExtension(
    oid: "2.5.29.28",  // Issuing Distribution Point
    critical: true,
    value: BuildIdpExtension(
        distributionPoint: "http://crl.example.com/intermediate.crl",
        onlyContainUserCerts: true
    )
);

// Ekstenzije unosa (po opozvanom certifikatu)
crlBuilder.AddEntry(
    serialNumber: revokedSerial,
    revocationTime: DateTimeOffset.UtcNow,
    reason: X509RevocationReason.KeyCompromise,
    extensions: new X509ExtensionCollection
    {
        // Invalidity Date (kada je stvarno kompromitiran)
        BuildInvalidityDateExtension(compromiseDate),
        // Certificate Issuer (ako je Indirect CRL)
        BuildCertificateIssuerExtension(certIssuerDn)
    }
);
</code>

----

===== Razlozi opoziva (RFC 5280) =====

^  Kod  ^  Razlog  ^  Opis  ^
| 0 | unspecified | Bez specifičnog razloga |
| 1 | keyCompromise | Ključ kompromitiran |
| 2 | cACompromise | CA kompromitiran |
| 3 | affiliationChanged | Pripadnost promijenjena |
| 4 | superseded | Zamijenjen novim certifikatom |
| 5 | cessationOfOperation | Rad ukinut |
| 6 | certificateHold | Privremeno blokiran |
| 8 | removeFromCRL | Ukloniti iz CRL-a (ukinuti Hold) |
| 9 | privilegeWithdrawn | Ovlaštenje povučeno |
| 10 | aACompromise | Attribut-autoritet kompromitiran |

----

===== Konfiguracija CRL Distribution Pointa =====

<code csharp>
// Izdavanje certifikata s CDP-om
var cert = ctx.IssueCertificate(
    csr,
    issuerCert: caCert,
    issuerKey: caKey,
    extensions: new ExtBuilder()
        .CrlDistributionPoint(
            uri: "http://crl.example.com/intermediate.crl",
            ldapUri: "ldap://ldap.example.com/cn=Intermediate-CA,o=Example,c=DE?certificateRevocationList"
        )
        .Build()
);
</code>

----

===== Zahtjevi za CRL po industrijama =====

^  Industrija  ^  Maks. nextUpdate  ^  Format  ^  Distribucija  ^
| **WebPKI** | 7 dana | DER | HTTP |
| **Enterprise** | 24 sata | DER/PEM | HTTP, LDAP |
| **Energetika/SCADA** | 30 dana | DER | Offline |
| **Zdravstvo** | 24 sata | DER | HTTP |

<WRAP round tip>
**Najbolja praksa:** Ažurirati CRL prije nextUpdate (50-75% razdoblja valjanosti).
</WRAP>

----

===== Povezani scenariji =====

^  Odnos  ^  Scenarij  ^  Opis  ^
| **Alternativa** | [[.:ocsp_responder|6.2 OCSP Responder]] | Online provjera |
| **Proširenje** | [[.:delta_crl|6.3 Delta-CRL]] | Inkrementalna ažuriranja |
| **Preduvjet** | [[.:zertifikat_widerrufen|6.4 Opoziv certifikata]] | Proces opoziva |

----

<< [[.:start|← Pregled opoziva]] | [[hr:int:pqcrypt:szenarien:start|↑ Scenariji]] | [[.:ocsp_responder|6.2 OCSP Responder →]] >>

{{tag>scenarij opoziv crl revocation pki}}

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