Acquire a CLC

To publish offline, the user has to have a signing key pair. The client licensor certificate (CLC) binds a signing key pair to the user through the user's RMS account certificate (RAC). The CLC private key is encrypted by the RAC public key, and the SPC and RAC are required to decrypt the signing key. The client uses the GetClientLicensorCert request to acquire a CLC from that server. More information can be found in [MS-RMPR] section, which details the GetClientLicensorCert request.