You can download a pem coded certificate revocation list signed by the newest ca from
To revoke a certificate, you must log in to the administrators panel, and tick the revoked box. This will have two effects: Any attempts to renew a revoked certificate will fail The certificate will be included the next time a Certificate Revocation List is downloaded.
This means that revoking a certificate using the pki does not have immediate effects. To do so, you must re-issue a certificate revocation list to all of your applications.