Add basic consumer/producer examples

Change-Id: Iee77509efb1ed1444314072c7e03384df4f30d3c
diff --git a/examples/producer.cpp b/examples/producer.cpp
new file mode 100644
index 0000000..ac3165e
--- /dev/null
+++ b/examples/producer.cpp
@@ -0,0 +1,135 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014-2018, Regents of the University of California
+ *
+ * NAC 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 3 of the License, or (at your option) any later version.
+ *
+ * NAC 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 copies of the GNU General Public License and GNU Lesser
+ * General Public License along with ndn-cxx, e.g., in COPYING.md file.  If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of NAC library authors and contributors.
+ */
+
+#include <ndn-cxx/face.hpp>
+#include <ndn-cxx/security/key-chain.hpp>
+#include <ndn-cxx/security/validator-config.hpp>
+
+#include "encryptor.hpp"
+#include "access-manager.hpp"
+
+#include <iostream>
+
+// Enclosing code in ndn simplifies coding (can also use `using namespace ndn`)
+namespace ndn {
+namespace nac {
+// Additional nested namespaces can be used to prevent/limit name conflicts
+namespace examples {
+
+class Producer : noncopyable
+{
+public:
+  Producer()
+    : m_face(nullptr, m_keyChain)
+    , m_validator(m_face)
+    , m_accessManager(m_keyChain.createIdentity("/nac/example", RsaKeyParams()), "test",
+                      m_keyChain, m_face)
+    , m_encryptor("/nac/example/NAC/test",
+                  "/nac/example/CK", signingWithSha256(),
+                  [] (auto...) {
+                    std::cerr << "Failed to publish CK";
+                  }, m_validator, m_keyChain, m_face)\
+  {
+    m_validator.load(R"CONF(
+        trust-anchor
+        {
+          type any
+        }
+      )CONF", "fake-config");
+  }
+
+  void
+  run()
+  {
+    // give access to default identity. If consumer uses the same default identity, he will be able to decrypt
+    m_accessManager.addMember(m_keyChain.getPib().getDefaultIdentity().getDefaultKey().getDefaultCertificate());
+
+    m_face.setInterestFilter("/example/testApp",
+                             bind(&Producer::onInterest, this, _1, _2),
+                             RegisterPrefixSuccessCallback(),
+                             bind(&Producer::onRegisterFailed, this, _1, _2));
+    m_face.processEvents();
+  }
+
+private:
+  void
+  onInterest(const InterestFilter& filter, const Interest& interest)
+  {
+    std::cout << "<< I: " << interest << std::endl;
+
+    // Create new name, based on Interest's name
+    Name dataName(interest.getName());
+    dataName
+      .append("testApp") // add "testApp" component to Interest name
+      .appendVersion();  // add "version" component (current UNIX timestamp in milliseconds)
+
+    static const std::string content = "HELLO KITTY";
+
+    // Create Data packet
+    shared_ptr<Data> data = make_shared<Data>();
+    data->setName(dataName);
+    data->setFreshnessPeriod(10_s); // 10 seconds
+
+    auto blob = m_encryptor.encrypt(reinterpret_cast<const uint8_t*>(content.data()), content.size());
+    data->setContent(blob.wireEncode());
+
+    // Sign Data packet with default identity
+    m_keyChain.sign(*data);
+    // m_keyChain.sign(data, <identityName>);
+    // m_keyChain.sign(data, <certificate>);
+
+    // Return Data packet to the requester
+    std::cout << ">> D: " << *data << std::endl;
+    m_face.put(*data);
+  }
+
+
+  void
+  onRegisterFailed(const Name& prefix, const std::string& reason)
+  {
+    std::cerr << "ERROR: Failed to register prefix \""
+              << prefix << "\" in local hub's daemon (" << reason << ")"
+              << std::endl;
+    m_face.shutdown();
+  }
+
+private:
+  KeyChain m_keyChain;
+  Face m_face;
+  ValidatorConfig m_validator;
+  AccessManager m_accessManager;
+  Encryptor m_encryptor;
+};
+
+} // namespace examples
+} // namespace nac
+} // namespace ndn
+
+int
+main(int argc, char** argv)
+{
+  ndn::nac::examples::Producer producer;
+  try {
+    producer.run();
+  }
+  catch (const std::exception& e) {
+    std::cerr << "ERROR: " << e.what() << std::endl;
+  }
+  return 0;
+}