Upload a third-party certificate If you trust an uploaded certificate, the DLL of the certificate is allowed to be injected into a McAfee process. Otherwise, the DLL of the certificate is not allowed to be injected into a McAfee process. The certificate must be in one of these formats: .cer files (Base-64 encoded X.509 certificate) Plain text certificate content in Base-64 encoded X.509 Task Select Menu → Policy → Policy Catalog, then select Endpoint Security Common from the Products list in the left pane. From the Category list in the right pane, select Options. Click the name of an editable policy. Click Show Advanced. In the Certificates section, click Upload Client Certificate. Select a certificate file (.cer) or provide certificate text in Base-64 encoded X.509 format. Click Save.