#### Everything TLS Related

libsoup comes with TLS support provided by glib-networking. This has multiple backends including gnutls (default on all platforms), SChannel on Windows, or OpenSSL.

## Accepting Invalid or Pinned Certificates

This makes use of the `SoupMessage::accept-certificate` signal.

    static gboolean
    accept_certificate_callback (SoupMessage *msg, GTlsCertificate *certificate,
                                 GTlsCertificateFlags tls_errors, gpointer user_data)
    {
        // Here you can inspect @certificate or compare it against a trusted one
        // and you can see what is considered invalid by @tls_errors.
        // Returning TRUE trusts it anyway.
        return TRUE;
    }

    int main (int argc, char **argv)
    {
        SoupSession *session = soup_session_new ();
        SoupMessage *msg = soup_message_new (SOUP_METHOD_GET, "https://example.org");
        g_signal_connect (msg, "accept-certificate", G_CALLBACK (accept_certificate_callback), NULL);
        GInputStream *in_stream = soup_session_send (session, msg, NULL, NULL);

        if (in_stream) {
            g_object_unref (in_stream);
        }

        return 0;
    }

## Setting a Custom CA

    {
        GError *error = NULL;
        // NOTE: This is blocking IO
        GTlsDatabase *tls_db = g_tls_file_database_new ("/foo/ca.pem", &error);

        if (error) {
            g_printerr ("Failed to load certificates: %s\n", error->message);
            g_error_free (error);
            return;
        }

        SoupSession *session = soup_session_new_with_options ("tls-database", tls_db, NULL);
        g_object_unref (tls_db);
    }

## Using Client Certificates

    static gboolean
    on_request_certificate (SoupMessage *msg, GTlsClientConnection *conn, gpointer user_data)
    {
        GTlsCertificate *client_cert = user_data;

        /* We immediately set this however you can set this later in an async function. */
        soup_message_set_tls_client_certificate (msg, client_cert);

        return TRUE; /* We handled the request */
    }

    int main (int argc, char **argv)
    {
        GError *error = NULL;
        GTlsCertificate *client_cert = g_tls_certificate_new_from_file ("/foo/cert.pem", &error);

        if (error) {
            g_printerr ("Failed to load certificate: %s\n", error->message);
            g_error_free (error);
            return 1;
        }

        SoupSession *session = soup_session_new ();
        SoupMessage *msg = soup_message_new ("GET", "https://example.org");

        /* We can set the certificate ahead of time if we already have one */
        // soup_message_set_tls_client_certificate (msg, client_cert)

        /* However we can also dynamically request one which is useful in
         * applications that show a graphical prompt for example. */
        g_signal_connect (msg, "request-certificate",
                          G_CALLBACK (on_request_certificate), client_cert);

        // Send the message...

        g_object_unref (msg);
        g_object_unref (session);
        g_object_unref (client_cert);
        return 0;
    }