uire the client to supply a trusted certificate,
   place certificates of the root certificate authorities
   (<acronym class="acronym">CA</acronym>s) you trust in a file in the data
   directory, set the parameter <a class="xref" href="runtime-config-connection.html#GUC-SSL-CA-FILE">ssl_ca_file</a> in
   <code class="filename">postgresql.conf</code> to the new file name, and add the
   authentication option <code class="literal">clientcert=verify-ca</code> or
   <code class="literal">clientcert=verify-full