pull: Add tls-client-cert-{path,key} (if we have new enough libsoup)

This is an actually working version of client-side certificates.
Depends on:
See: https://bugzilla.gnome.org/show_bug.cgi?id=334021

We detect whether libsoup is new enough for this.

https://bugzilla.gnome.org/show_bug.cgi?id=729356

src/libostree/ostree-tls-cert-interaction.c

@@ -0,0 +1,69 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
+ *
+ * Copyright (C) 2014 Colin Walters <walters@verbum.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include "ostree-tls-cert-interaction.h"
+
+struct _OstreeTlsCertInteraction
+{
+  GTlsInteraction parent_instance;
+
+  GTlsCertificate *cert;
+};
+
+struct _OstreeTlsCertInteractionClass
+{
+  GTlsInteractionClass parent_class;
+};
+
+#include <string.h>
+
+G_DEFINE_TYPE (OstreeTlsCertInteraction, ostree_tls_cert_interaction, G_TYPE_TLS_INTERACTION);
+
+static GTlsInteractionResult
+request_certificate (GTlsInteraction              *interaction,
+                     GTlsConnection               *connection,
+                     GTlsCertificateRequestFlags   flags,
+                     GCancellable                 *cancellable,
+                     GError                      **error)
+{
+  OstreeTlsCertInteraction *self = (OstreeTlsCertInteraction*)interaction;
+  g_tls_connection_set_certificate (connection, self->cert);
+  return G_TLS_INTERACTION_HANDLED;
+}
+
+static void
+ostree_tls_cert_interaction_init (OstreeTlsCertInteraction *interaction)
+{
+}
+
+static void
+ostree_tls_cert_interaction_class_init (OstreeTlsCertInteractionClass *klass)
+{
+  GTlsInteractionClass *interaction_class = G_TLS_INTERACTION_CLASS (klass);
+  interaction_class->request_certificate = request_certificate;
+}
+
+OstreeTlsCertInteraction *
+ostree_tls_cert_interaction_new (GTlsCertificate *cert)
+{
+  OstreeTlsCertInteraction *self = g_object_new (OSTREE_TYPE_TLS_CERT_INTERACTION, NULL);
+  self->cert = g_object_ref (cert);
+  return self;
+}