To support X509 certificate-based authentication in Identity Manager, ensure that two-way (client and server) SSL authentication is configured properly. From the client perspective, this means that an X509-compliant user certificate should have been imported into the browser (or be available through a smart card reader), and that the trusted certificate used to sign the user certificate should be imported into the Web application server’s keystore of trusted certificates.
Also, the client certificate used must be enabled for client authentication.