security: Add configuration based validator

Change-Id: Ic5837f4b02a613966c0a2e969c974ebd0786f769
diff --git a/src/main.cpp b/src/main.cpp
index ce89f3f..e360e5d 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -10,7 +10,10 @@
 main(int argc, char** argv)
 {
   try {
-    ndn::nrd::Nrd nrd;
+    // TODO: the configFilename should be obtained from command line arguments.
+    std::string configFilename("nrd.conf");
+
+    ndn::nrd::Nrd nrd(configFilename);
     nrd.enableLocalControlHeader();
     nrd.listen();
   }