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/export.cpp b/tools/ndnsec/export.cpp
new file mode 100644
index 0000000..9b7a0e9
--- /dev/null
+++ b/tools/ndnsec/export.cpp
@@ -0,0 +1,125 @@
+/* -*- 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_export(int argc, char** argv)
+{
+  using namespace ndn;
+  namespace po = boost::program_options;
+
+  std::string identityStr;
+  std::string output;
+  std::string exportPassword;
+  bool isPrivateExport = false;
+
+  po::options_description description("General Usage\n  ndnsec export [-h] [-o output] [-p] identity \nGeneral options");
+  description.add_options()
+    ("help,h", "Produce help message")
+    ("output,o", po::value<std::string>(&output), "(Optional) output file, stdout if not specified")
+    ("private,p", "export info contains private key")
+    ("identity,i", po::value<std::string>(&identityStr), "Identity to export")
+    ;
+
+  po::positional_options_description p;
+  p.add("identity", 1);
+
+  po::variables_map vm;
+  try {
+    po::store(po::command_line_parser(argc, argv).options(description).positional(p).run(), 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("identity") == 0) {
+    std::cerr << "ERROR: identity must be specified" << std::endl;
+    std::cerr << description << std::endl;
+    return 1;
+  }
+
+  if (vm.count("private") != 0)
+    isPrivateExport = true;
+
+  if (vm.count("output") == 0)
+    output = "-";
+
+  Name identity(identityStr);
+  if (!isPrivateExport) {
+    security::v1::KeyChain keyChain;
+    shared_ptr<security::v1::IdentityCertificate> cert =
+      keyChain.getCertificate(keyChain.getDefaultCertificateNameForIdentity(identity));
+
+    if (output == "-")
+      io::save(*cert, std::cout);
+    else
+      io::save(*cert, output);
+
+    return 0;
+  }
+  else {
+    Block wire;
+    try {
+      security::v1::KeyChain keyChain;
+
+      int count = 3;
+      while (!getPassword(exportPassword, "Passphrase for the private key: ")) {
+        count--;
+        if (count <= 0) {
+          std::cerr << "ERROR: invalid password" << std::endl;
+          memset(const_cast<char*>(exportPassword.c_str()), 0, exportPassword.size());
+          return 1;
+        }
+      }
+      shared_ptr<security::v1::SecuredBag> securedBag =
+        keyChain.exportIdentity(identity, exportPassword);
+      memset(const_cast<char*>(exportPassword.c_str()), 0, exportPassword.size());
+
+      if (output == "-")
+        io::save(*securedBag, std::cout);
+      else
+        io::save(*securedBag, output);
+
+      return 0;
+    }
+    catch (const std::runtime_error& e) {
+      std::cerr << "ERROR: " << e.what() << std::endl;
+      memset(const_cast<char*>(exportPassword.c_str()), 0, exportPassword.size());
+      return 1;
+    }
+  }
+}
+
+} // namespace ndnsec
+} // namespace ndn