    def get_federation_http_client(self) -> MatrixFederationHttpClient:
        """
        An HTTP client for federation.
        """
        tls_client_options_factory = context_factory.FederationPolicyForHTTPS(
            self.config
        )
        return MatrixFederationHttpClient(self, tls_client_options_factory)
A web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a Redirect. This simplifies phishing attacks.