hentication while also
   providing ssl connection security. See <a class="xref" href="auth-cert.html" title="21.12. Certificate Authentication">Section 21.12</a> for details.
   (It is not necessary to specify any <code class="literal">clientcert</code> options
   explicitly when using the <code class="literal">cert</code> authentication method.)
   In this case, the <code class="literal">cn</code> (Common Name) provided in
   the certificate is checked against the user name or an applicable mapping.
  <