tools: Refactor ndnsec tools and update code style

This commit also deletes unused (broken) `op-tool`

Change-Id: I6c45c293d9c22198efd9db8144e32097d73738e5
Refs: #3098
diff --git a/tools/ndnsec/get-default.cpp b/tools/ndnsec/get-default.cpp
new file mode 100644
index 0000000..96ee12e
--- /dev/null
+++ b/tools/ndnsec/get-default.cpp
@@ -0,0 +1,139 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2017 Regents of the University of California.
+ *
+ * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
+ *
+ * ndn-cxx 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.
+ *
+ * ndn-cxx 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 ndn-cxx authors and contributors.
+ */
+
+#include "ndnsec.hpp"
+#include "util.hpp"
+
+namespace ndn {
+namespace ndnsec {
+
+int
+ndnsec_get_default(int argc, char** argv)
+{
+  using namespace ndn;
+  namespace po = boost::program_options;
+
+  bool isGetDefaultId = true;
+  bool isGetDefaultKey = false;
+  bool isGetDefaultCert = false;
+  bool isQuiet = false;
+  std::string identityString;
+  std::string keyName;
+
+  po::options_description description("General Usage\n"
+                                      "  ndnsec get-default [-h] [-k|c] [-i identity|-K key] [-q]\n"
+                                      "General options");
+  description.add_options()
+    ("help,h", "produce help message")
+    ("default_key,k", "get default key")
+    ("default_cert,c", "get default certificate")
+    ("identity,i", po::value<std::string>(&identityString), "target identity")
+    ("key,K", po::value<std::string>(&keyName), "target key")
+    ("quiet,q", "don't output trailing newline")
+    ;
+
+  po::variables_map vm;
+  try {
+    po::store(po::parse_command_line(argc, argv, description), vm);
+    po::notify(vm);
+  }
+  catch (const std::exception& e) {
+    std::cerr << "ERROR: " << e.what() << std::endl;
+    std::cerr << description << std::endl;
+    return 1;
+  }
+
+  if (vm.count("help") != 0) {
+    std::cerr << description << std::endl;
+    ;
+    return 0;
+  }
+
+  if (vm.count("default_cert") != 0) {
+    isGetDefaultCert = true;
+    isGetDefaultId = false;
+  }
+  else if (vm.count("default_key") != 0) {
+    isGetDefaultKey = true;
+    isGetDefaultId = false;
+  }
+
+  if (vm.count("quiet") != 0) {
+    isQuiet = true;
+  }
+
+  security::v1::KeyChain keyChain;
+
+  if (vm.count("key") != 0) {
+    Name keyNdnName(keyName);
+    if (isGetDefaultCert) {
+      std::cout << keyChain.getDefaultCertificateNameForKey(keyNdnName);
+      if (!isQuiet)
+        std::cout << std::endl;
+      return 0;
+    }
+    return 1;
+  }
+  else if (vm.count("identity") != 0) {
+    Name identity(identityString);
+
+    if (isGetDefaultKey) {
+      std::cout << keyChain.getDefaultKeyNameForIdentity(identity);
+      if (!isQuiet)
+        std::cout << std::endl;
+
+      return 0;
+    }
+    if (isGetDefaultCert) {
+      std::cout << keyChain.getDefaultCertificateNameForIdentity(identity);
+      if (!isQuiet)
+        std::cout << std::endl;
+
+      return 0;
+    }
+    return 1;
+  }
+  else {
+    Name identity = keyChain.getDefaultIdentity();
+    if (isGetDefaultId) {
+      std::cout << identity;
+      if (!isQuiet)
+        std::cout << std::endl;
+      return 0;
+    }
+    if (isGetDefaultKey) {
+      std::cout << keyChain.getDefaultKeyNameForIdentity(identity);
+      if (!isQuiet)
+        std::cout << std::endl;
+      return 0;
+    }
+    if (isGetDefaultCert) {
+      std::cout << keyChain.getDefaultCertificateNameForIdentity(identity);
+      if (!isQuiet)
+        std::cout << std::endl;
+      return 0;
+    }
+    return 1;
+  }
+}
+
+} // namespace ndnsec
+} // namespace ndn