The key manager must be able to get a pin from somewhere. It looks in property, then an environment variable, then a file, and finally in a configuration attribute. At least one must be present. Can we express this ordering and this "at least one" constraint? Perhaps support a "one-of" element which can be used to group a set of properties. The provider provides the ability for the server to access the private key information through the PKCS11 interface. This standard interface is used by cryptographic accelerators and hardware security modules. 1.3.6.1.4.1.26027.1.2.21 ds-cfg-pkcs11-key-manager-provider ds-cfg-key-manager-provider org.opends.server.extensions.PKCS11KeyManagerProvider