<PackageReference Include="BouncyCastle.Cryptography" Version="2.3.1" />

Org.BouncyCastle.Crmf.CertificateRequestMessageBuilder

public CertificateRequestMessageBuilder AddExtension(DerObjectIdentifier oid, bool critical, byte[] value)

public CertificateRequestMessageBuilder SetAuthInfoPKMAC(PKMacBuilder pkmacFactory, char[] password)