====== RevocationExtensions Class ======

Extension methods for checking certificate revocation.

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===== Definition =====

<code csharp>
namespace WvdS.System.Security.Cryptography.X509Certificates;

public static class RevocationExtensions
</code>

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===== Methods =====

^  Method  ^  Description  ^
| IsRevoked | Checks if a certificate is revoked |
| FetchCrlAsync | Loads CRL from URL (from certificate extension) |
| CheckRevocationAsync | Combined: Load CRL and check revocation |
| GetCrlDistributionPoints | Extracts CRL URLs from certificate |
| GetOcspUrls | Extracts OCSP URLs from certificate |

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===== Check Revocation =====

**With existing CRL:**

<code csharp>
var certificate = new X509Certificate2("user.cer");
byte[] crlData = File.ReadAllBytes("ca.crl");
var caCert = new X509Certificate2("ca.cer");

RevocationResult result = certificate.IsRevoked(crlData, caCert, CryptoMode.Hybrid);

if (result.Success && result.IsRevoked)
{
    Console.WriteLine($"Certificate revoked on: {result.RevocationDate}");
    Console.WriteLine($"Reason: {result.Reason}");
}
</code>

**Load CRL automatically:**

<code csharp>
RevocationResult result = await certificate.CheckRevocationAsync(
    caCert,
    mode: CryptoMode.Hybrid);
</code>

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===== RevocationResult Class =====

^  Property  ^  Type  ^  Description  ^
| ''IsRevoked'' | bool | Certificate is revoked |
| ''RevocationDate'' | DateTimeOffset? | Time of revocation |
| ''Reason'' | CrlReason? | Revocation reason |
| ''CrlVerified'' | bool | CRL signature was verified |
| ''Success'' | bool | Check was successful |

----

===== CRL Cache =====

<code csharp>
using var cache = new CrlCache(defaultCacheDuration: TimeSpan.FromHours(1));

// Check with automatic CRL caching
RevocationResult result1 = await cache.CheckRevocationAsync(cert1, caCert);
RevocationResult result2 = await cache.CheckRevocationAsync(cert2, caCert); // CRL from cache
</code>

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===== See Also =====

  * [[.:certificaterevocationlistextensions|CertificateRevocationListExtensions]]
  * [[.:x509chainextensions|X509ChainExtensions]]

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

{{tag>crl revocation ocsp}}