Mark enums with FlagsAttribute (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1027)

In externally visible method 'X509CRL.X509CRL(IX509CRL crl)', validate parameter 'crl' is non-null before using it. If appropriate, throw an 'ArgumentNullException' when the argument is 'null'. (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1062)

Modify 'VerifySignature' to catch a more specific allowed exception type, or rethrow the exception (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1031)

In externally visible method 'bool X509CRL.IsRevoked(X509Certificate2 certificate)', validate parameter 'certificate' is non-null before using it. If appropriate, throw an 'ArgumentNullException' when the argument is 'null'. (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1062)

In externally visible method 'X509AuthorityKeyIdentifierExtension.X509AuthorityKeyIdentifierExtension(AsnEncodedData encodedExtension, bool critical)', validate parameter 'encodedExtension' is non-null before using it. If appropriate, throw an 'ArgumentNullException' when the argument is 'null'. (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1062)

In externally visible method 'CrlBuilder CrlBuilder.Create(IX509CRL crl)', validate parameter 'crl' is non-null before using it. If appropriate, throw an 'ArgumentNullException' when the argument is 'null'. (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1062)

In externally visible method 'X509CrlNumberExtension.X509CrlNumberExtension(AsnEncodedData encodedExtension, bool critical)', validate parameter 'encodedExtension' is non-null before using it. If appropriate, throw an 'ArgumentNullException' when the argument is 'null'. (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1062)

In externally visible method 'T X509Extensions.FindExtension<T>(X509Certificate2 certificate)', validate parameter 'certificate' is non-null before using it. If appropriate, throw an 'ArgumentNullException' when the argument is 'null'. (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1062)

In externally visible method 'IX509CRL CrlBuilder.CreateSignature(X509SignatureGenerator generator)', validate parameter 'generator' is non-null before using it. If appropriate, throw an 'ArgumentNullException' when the argument is 'null'. (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1062)