order to use the <b class="option">-require</b> option, one of the following must be true:</p>
<ul class="doctools_itemized">
<li><p>On Linux and Unix systems with OpenSSL already installed, if the CA
certificates are stored in the standard locations, or if the <b class="variable">SSL_CERT_DIR</b>
or <b class="variable">SSL_CERT_FILE</b> environment variables are set, then <b class="option">-cadir</b>,
<b class="option">-cadir</b>, and <b class="option">-castore</b> aren't needed.</p></li>
<li><p>If OpenSSL is not installed in the default location, or when using Mac OS
or Windows and OpenSSL is installed, the <b class="variable">SSL_CERT_DIR</b> and/or 
<b class="variable">SSL_CERT_FILE</b> environment variables or the one of the <b class="option">-cadir</b>,
<b class="option">-cadir</b>, or <b class="option">-castore</b> options must be defined.</p></li>
<li><p>On Windows, starting in OpenSSL 3.2, it is now possible to access the
built-in Windows Certificate Store from OpenSSL. This can be achieved by
setting the <b class="option">-castore</b> option to &quot;<b class="const">org.openssl.winstore://</b>&quot;.</p></li>
<li><p>If OpenSSL is not installed, the CA certificates must be downloaded and
installed with the user software. The CURL team makes them available at