Initializes our device as an SSL connection.

        :raises: :py:class:`~alarmdecoder.util.CommError`

def _init_ssl(self):
        """
        Initializes our device as an SSL connection.

        :raises: :py:class:`~alarmdecoder.util.CommError`
        """

        if not have_openssl:
            raise ImportError('SSL sockets have been disabled due to missing requirement: pyopenssl.')

        try:
            ctx = SSL.Context(SSL.TLSv1_METHOD)

            if isinstance(self.ssl_key, crypto.PKey):
                ctx.use_privatekey(self.ssl_key)
            else:
                ctx.use_privatekey_file(self.ssl_key)

            if isinstance(self.ssl_certificate, crypto.X509):
                ctx.use_certificate(self.ssl_certificate)
            else:
                ctx.use_certificate_file(self.ssl_certificate)

            if isinstance(self.ssl_ca, crypto.X509):
                store = ctx.get_cert_store()
                store.add_cert(self.ssl_ca)
            else:
                ctx.load_verify_locations(self.ssl_ca, None)

            verify_method = SSL.VERIFY_PEER
            if (self._ssl_allow_self_signed):
                verify_method = SSL.VERIFY_NONE

            ctx.set_verify(verify_method, self._verify_ssl_callback)

            self._device = SSL.Connection(ctx, self._device)

        except SSL.Error as err:
            raise CommError('Error setting up SSL connection.', err)