tls {
    # HTTP client's certificate
    certificate "http.client.cert";

    # HTTP client's private key
    certificate_key "http.client.key";

    # HTTP client's certificate's root CA
    client_ca_certificate "http.client.ca";

    # (Optional) HTTP backend's certificate's root CA
    #server_ca_certificate "http.backend.name.ca";

    # Custom certificate verification rules are not supported for HTTP backend
}