Use the ICISite interface GetCheckClientCert method to determine if the server requires certificates from users connecting via implicit SSL. If the Server requires certificates, the GetCheckClientCert method returns a value of TRUE.
Signature:
HRESULT GetCheckClientCert([out, retval] VARIANT_BOOL *prop);
True = Required
False = Not required
Refer to Site Certificates and Keys Parameters for an illustration of how this and other ICISite methods can be accessed in the Administrator interface.