de>privateKey</code></td><td><code>string</code></td><td><p>REQUIRED if mode is <code>SIMPLE</code> or <code>MUTUAL</code>. The path to the file
holding the server&rsquo;s private key.</p></td><td>No</td></tr><tr id=Server-TLSOptions-ca_certificates><td><code>caCertificates</code></td><td><code>string</code></td><td><p>REQUIRED if mode is <code>MUTUAL</code>. The path to a file containing
certificate authority certificates to use in verifying a presented
client side certificate.</p></td><td>No</td></tr><tr 