Returns ``True`` if peercert is valid according to the configured
        validation mode and hostname.

        The ssl handshake already tested the certificate for a valid
        CA signature; the only thing that remains is to check
        the hostname.

def _verify_cert(self, peercert: Any) -> bool:
        """Returns ``True`` if peercert is valid according to the configured
        validation mode and hostname.

        The ssl handshake already tested the certificate for a valid
        CA signature; the only thing that remains is to check
        the hostname.
        """
        if isinstance(self._ssl_options, dict):
            verify_mode = self._ssl_options.get("cert_reqs", ssl.CERT_NONE)
        elif isinstance(self._ssl_options, ssl.SSLContext):
            verify_mode = self._ssl_options.verify_mode
        assert verify_mode in (ssl.CERT_NONE, ssl.CERT_REQUIRED, ssl.CERT_OPTIONAL)
        if verify_mode == ssl.CERT_NONE or self._server_hostname is None:
            return True
        cert = self.socket.getpeercert()
        if cert is None and verify_mode == ssl.CERT_REQUIRED:
            gen_log.warning("No SSL certificate given")
            return False
        try:
            ssl.match_hostname(peercert, self._server_hostname)
        except ssl.CertificateError as e:
            gen_log.warning("Invalid SSL certificate: %s" % e)
            return False
        else:
            return True