Update validation related codes to security v2

Change-Id: I5467b87092820666c04f22623f0f1665ce9a1194
diff --git a/src/util/cert-helper.hpp b/src/util/cert-helper.hpp
new file mode 100644
index 0000000..8e7297f
--- /dev/null
+++ b/src/util/cert-helper.hpp
@@ -0,0 +1,70 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2014-2017, Regents of the University of California.
+ *
+ * This file is part of NDNS (Named Data Networking Domain Name Service).
+ * See AUTHORS.md for complete list of NDNS authors and contributors.
+ *
+ * NDNS is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ *
+ * NDNS 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * NDNS, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef NDNS_UTIL_CERT_HELPER_HPP
+#define NDNS_UTIL_CERT_HELPER_HPP
+
+#include "common.hpp"
+#include <ndn-cxx/security/key-chain.hpp>
+#include <ndn-cxx/encoding/tlv.hpp>
+#include <ndn-cxx/security/signing-helpers.hpp>
+
+namespace ndn {
+namespace ndns {
+
+class CertHelper
+{
+public:
+  static security::Identity
+  getIdentity(const KeyChain& keyChain, const Name& identityName);
+
+  static bool
+  doesIdentityExist(const KeyChain& keyChain, const Name& identityName);
+
+  static Name
+  getIdentityNameFromCert(const Name& certName);
+
+  static security::v2::Certificate
+  getCertificate(const KeyChain& keyChain,
+                 const Name& identity,
+                 const Name& certName);
+
+  static security::v2::Certificate
+  getCertificate(const KeyChain& keyChain,
+                 const Name& certName);
+
+  static const Name&
+  getDefaultKeyNameOfIdentity(const KeyChain& keyChain, const Name& identityName);
+
+  static const Name&
+  getDefaultCertificateNameOfIdentity(const KeyChain& keyChain, const Name& identityName);
+
+  static security::v2::Certificate
+  createCertificate(KeyChain& keyChain,
+                    const security::Key& key,
+                    const security::Key& signingKey,
+                    const std::string& issuer,
+                    const time::seconds& certValidity = time::days(10));
+};
+
+
+} // namespace ndns
+} // namespace ndn
+
+#endif // NDNS_UTIL_CERT_HELPER_HPP