security: Add new TPM framework

The TPM framework is separated into two parts:
1) The front end class Tpm provides the interface to KeyChain. The public
   interface of Tpm is read-only.
2) The back end classes represent concrete implementations, such as
   tpm::BackEndFile and tpm::BackEndOsx which may also provide
   implementation-specific management interfaces.

New TPM supports different key id type when generating new key.  The
default type is changed to 64-bit random number.

Change-Id: I41154c2ded4b65fb0bef2f4a0d2c5b77843be05d
Refs: #2948
diff --git a/src/security/tpm/tpm.cpp b/src/security/tpm/tpm.cpp
new file mode 100644
index 0000000..234c48d
--- /dev/null
+++ b/src/security/tpm/tpm.cpp
@@ -0,0 +1,150 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2016 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 "tpm.hpp"
+#include "back-end.hpp"
+#include "../../encoding/buffer-stream.hpp"
+
+namespace ndn {
+namespace security {
+namespace tpm {
+
+Tpm::Tpm(const std::string& scheme, const std::string& location, unique_ptr<BackEnd> backEnd)
+  : m_scheme(scheme)
+  , m_location(location)
+  , m_backEnd(std::move(backEnd))
+{
+}
+
+Tpm::~Tpm() = default;
+
+std::string
+Tpm::getTpmLocator() const
+{
+  return m_scheme + ":" + m_location;
+}
+
+bool
+Tpm::hasKey(const Name& keyName) const
+{
+  return m_backEnd->hasKey(keyName);
+}
+
+Name
+Tpm::createKey(const Name& identityName, const KeyParams& params)
+{
+  switch (params.getKeyType()) {
+    case KeyType::RSA:
+    case KeyType::EC: {
+      unique_ptr<KeyHandle> keyHandle = m_backEnd->createKey(identityName, params);
+      Name keyName = keyHandle->getKeyName();
+      m_keys[keyName] = std::move(keyHandle);
+      return keyName;
+    }
+    default: {
+      BOOST_THROW_EXCEPTION(Error("Fail to create a key pair: Unsupported key type"));
+    }
+  }
+}
+
+void
+Tpm::deleteKey(const Name& keyName)
+{
+  auto it = m_keys.find(keyName);
+  if (it != m_keys.end())
+    m_keys.erase(it);
+
+  m_backEnd->deleteKey(keyName);
+}
+
+ConstBufferPtr
+Tpm::getPublicKey(const Name& keyName) const
+{
+  const KeyHandle* key = findKey(keyName);
+
+  if (key == nullptr)
+    return nullptr;
+  else
+    return key->derivePublicKey();
+}
+
+ConstBufferPtr
+Tpm::sign(const uint8_t* buf, size_t size, const Name& keyName, DigestAlgorithm digestAlgorithm) const
+{
+  const KeyHandle* key = findKey(keyName);
+
+  if (key == nullptr)
+    return nullptr;
+  else
+    return key->sign(digestAlgorithm, buf, size);
+}
+
+ConstBufferPtr
+Tpm::decrypt(const uint8_t* buf, size_t size, const Name& keyName) const
+{
+  const KeyHandle* key = findKey(keyName);
+
+  if (key == nullptr)
+    return nullptr;
+  else
+    return key->decrypt(buf, size);
+}
+
+ConstBufferPtr
+Tpm::exportPrivateKey(const Name& keyName, const char* pw, size_t pwLen)
+{
+  return m_backEnd->exportKey(keyName, pw, pwLen);
+}
+
+bool
+Tpm::importPrivateKey(const Name& keyName, const uint8_t* pkcs8, size_t pkcs8Len, const char* pw, size_t pwLen)
+{
+  try {
+    m_backEnd->importKey(keyName, pkcs8, pkcs8Len, pw, pwLen);
+  }
+  catch (const BackEnd::Error&) {
+    return false;
+  }
+  return true;
+}
+
+const KeyHandle*
+Tpm::findKey(const Name& keyName) const
+{
+  auto it = m_keys.find(keyName);
+
+  if (it != m_keys.end())
+    return it->second.get();
+
+  unique_ptr<KeyHandle> handle = m_backEnd->getKeyHandle(keyName);
+
+  if (handle != nullptr) {
+    KeyHandle* key = handle.get();
+    m_keys[keyName] = std::move(handle);
+    return key;
+  }
+
+  return nullptr;
+}
+
+} // namespace tpm
+} // namespace security
+} // namespace ndn