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/sign-req.cpp b/tools/ndnsec/sign-req.cpp
new file mode 100644
index 0000000..eced361
--- /dev/null
+++ b/tools/ndnsec/sign-req.cpp
@@ -0,0 +1,95 @@
+/* -*- 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_sign_req(int argc, char** argv)
+{
+  using namespace ndn;
+  using namespace ndn::security;
+  namespace po = boost::program_options;
+
+  std::string name;
+  bool isKeyName = false;
+
+  po::options_description description(
+    "General Usage\n  ndnsec sign-req [-h] [-k] name\nGeneral options");
+  description.add_options()
+    ("help,h", "produce help message")
+    ("key,k", "optional, if specified, name is keyName (e.g. /ndn/edu/ucla/alice/ksk-123456789), otherwise identity name")
+    ("name,n", po::value<std::string>(&name), "name, for example, /ndn/edu/ucla/alice");
+
+  po::positional_options_description p;
+  p.add("name", 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("name") == 0) {
+    std::cerr << "ERROR: name must be specified" << std::endl;
+    std::cerr << description << std::endl;
+    return 1;
+  }
+
+  if (vm.count("key") != 0)
+    isKeyName = true;
+
+  shared_ptr<security::v1::IdentityCertificate> selfSignCert;
+
+  security::v1::KeyChain keyChain;
+
+  if (isKeyName)
+    selfSignCert = keyChain.selfSign(name);
+  else {
+    Name keyName = keyChain.getDefaultKeyNameForIdentity(name);
+    selfSignCert = keyChain.selfSign(keyName);
+  }
+
+  if (selfSignCert != nullptr) {
+    io::save(*selfSignCert, std::cout);
+    return 0;
+  }
+  else {
+    std::cerr << "ERROR: Public key does not exist" << std::endl;
+    return 1;
+  }
+}
+
+} // namespace ndnsec
+} // namespace ndn