Returns the scheme used to store the CA certificate.
If the returned scheme is nm_setting_802_1x_ck_scheme_blob, use get_ca_cert_blob; if nm_setting_802_1x_ck_scheme_path, use get_ca_cert_path; if nm_setting_802_1x_ck_scheme_pkcs11, use get_ca_cert_uri.
this |
the Setting8021x |
scheme used to store the CA certificate (blob or path) |