Add certificate fetcher of ndns-appcert and ndns-cert

Validators are updated accordingly

Change-Id: Ibdee00b8f20243448a2ba3011ca87f85ce1ea516
diff --git a/tests/dummy-forwarder.cpp b/tests/dummy-forwarder.cpp
new file mode 100644
index 0000000..61526cb
--- /dev/null
+++ b/tests/dummy-forwarder.cpp
@@ -0,0 +1,79 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014-2017,  Regents of the University of California,
+ *                           Arizona Board of Regents,
+ *                           Colorado State University,
+ *                           University Pierre & Marie Curie, Sorbonne University,
+ *                           Washington University in St. Louis,
+ *                           Beijing Institute of Technology,
+ *                           The University of Memphis.
+ *
+ * This file is part of NDNS (Named Data Networking Domain Name Service) and is
+ * based on the code written as part of NFD (Named Data Networking Daemon).
+ * See AUTHORS.md for complete list of NDNS authors and contributors.
+ *
+ * NDNS is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ *
+ * NDNS 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * NDNS, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "dummy-forwarder.hpp"
+
+#include <boost/asio/io_service.hpp>
+
+namespace ndn {
+namespace ndns {
+namespace tests {
+
+DummyForwarder::DummyForwarder(boost::asio::io_service& io, KeyChain& keyChain)
+  : m_io(io)
+  , m_keyChain(keyChain)
+{
+}
+
+Face&
+DummyForwarder::addFace()
+{
+  auto face = std::make_shared<util::DummyClientFace>(m_io, m_keyChain, util::
+                                                      DummyClientFace::Options{true, true});
+  face->onSendInterest.connect([this, face] (const Interest& interest) {
+      for (auto& otherFace : m_faces) {
+        if (&*face == &*otherFace) {
+          continue;
+        }
+        otherFace->receive(interest);
+      }
+    });
+
+  face->onSendData.connect([this, face] (const Data& data) {
+      for (auto& otherFace : m_faces) {
+        if (&*face == &*otherFace) {
+          continue;
+        }
+        otherFace->receive(data);
+      }
+    });
+
+  face->onSendNack.connect([this, face] (const lp::Nack& nack) {
+      for (auto& otherFace : m_faces) {
+        if (&*face == &*otherFace) {
+          continue;
+        }
+        otherFace->receive(nack);
+      }
+    });
+
+  m_faces.push_back(face);
+  return *face;
+}
+
+} // namespace tests
+} // namespace ndns
+} // namespace ndn