security: Add trust anchor container

Change-Id: Ia527eee08b9e154eb2d3168182905ec082bd8441
Refs: #3292
diff --git a/src/security/v2/trust-anchor-container.hpp b/src/security/v2/trust-anchor-container.hpp
new file mode 100644
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--- /dev/null
+++ b/src/security/v2/trust-anchor-container.hpp
@@ -0,0 +1,177 @@
+/* -*- 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.
+ */
+
+#ifndef NDN_SECURITY_V2_TRUST_ANCHOR_CONTAINER_HPP
+#define NDN_SECURITY_V2_TRUST_ANCHOR_CONTAINER_HPP
+
+#include "trust-anchor-group.hpp"
+#include "certificate.hpp"
+#include "../../interest.hpp"
+
+#include <boost/multi_index_container.hpp>
+#include <boost/multi_index/hashed_index.hpp>
+#include <boost/multi_index/ordered_index.hpp>
+#include <boost/multi_index/mem_fun.hpp>
+
+namespace ndn {
+namespace security {
+namespace v2 {
+
+/**
+ * @brief represents a container for trust anchors.
+ *
+ * There are two kinds of anchors:
+ * - static anchors that are permanent for the lifetime of the container
+ * - dynamic anchors that are periodically updated.
+ *
+ * Trust anchors are organized in groups. Each group has a unique group id.  The same anchor
+ * certificate (same name without considering the implicit digest) can be inserted into
+ * multiple groups, but no more than once into each.
+ *
+ * Dynamic groups are created using the appropriate TrustAnchorContainer::insert method. Once
+ * created, the dynamic anchor group cannot be updated.
+ *
+ * The returned pointer to Certificate from `find` methods is only guaranteed to be valid until
+ * the next invocation of `find` and may be invalidated afterwards.
+ */
+class TrustAnchorContainer : noncopyable
+{
+public:
+  class Error : public std::runtime_error
+  {
+  public:
+    explicit
+    Error(const std::string& what)
+      : std::runtime_error(what)
+    {
+    }
+  };
+
+  /**
+   * @brief Insert a static trust anchor.
+   *
+   * @param groupId  Certificate group id.
+   * @param cert     Certificate to insert.
+   *
+   * If @p cert (same name without considering implicit digest) already exists in the group @p
+   * groupId, this method has no effect.
+   *
+   * @throw Error @p groupId is a dynamic anchor group .
+   */
+  void
+  insert(const std::string& groupId, Certificate&& cert);
+
+  /**
+   * @brief Insert dynamic trust anchors from path.
+   *
+   * @param groupId        Certificate group id, must not be empty.
+   * @param path           Specifies the path to load the trust anchors.
+   * @param refreshPeriod  Refresh period for the trust anchors, must be positive.
+   *                       Relevant trust anchors will only be updated when find is called
+   * @param isDir          Tells whether the path is a directory or a single file.
+   *
+   * @throw std::invalid_argument @p refreshPeriod is not positive
+   * @throw Error a group with @p groupId already exists
+   */
+  void
+  insert(const std::string& groupId, const boost::filesystem::path& path,
+         time::nanoseconds refreshPeriod, bool isDir = false);
+
+  /**
+   * @brief Search for certificate across all groups (longest prefix match)
+   * @param keyName  Key name prefix for searching the certificate.
+   * @return The found certificate, nullptr if not found.
+   *
+   * @note The returned value may be invalidated after next call to one of `find` methods.
+   */
+  const Certificate*
+  find(const Name& keyName) const;
+
+  /**
+   * @brief Find certificate given interest
+   * @param interest  The input interest packet.
+   * @return The found certificate, nullptr if not found.
+   *
+   * @note The returned value may be invalidated after next call to one of `find` methods.
+   *
+   * @note Interest with implicit digest is not supported.
+   *
+   * @note ChildSelector is not supported.
+   */
+  const Certificate*
+  find(const Interest& interest) const;
+
+  /**
+   * @brief Get trusted anchor group
+   * @throw Error @p groupId does not exist
+   */
+  TrustAnchorGroup&
+  getGroup(const std::string& groupId) const;
+
+  /**
+   * @brief Get number of trust anchors across all groups
+   */
+  size_t
+  size() const;
+
+private:
+  void
+  refresh();
+
+private:
+  using AnchorContainerBase = boost::multi_index::multi_index_container<
+    Certificate,
+    boost::multi_index::indexed_by<
+      boost::multi_index::ordered_unique<
+        boost::multi_index::const_mem_fun<Data, const Name&, &Data::getName>
+      >
+    >
+  >;
+
+  class AnchorContainer : public CertContainerInterface,
+                          public AnchorContainerBase
+  {
+  public:
+    void
+    add(Certificate&& cert) final;
+
+    void
+    remove(const Name& certName) final;
+  };
+
+  using GroupContainer = boost::multi_index::multi_index_container<
+    shared_ptr<TrustAnchorGroup>,
+    boost::multi_index::indexed_by<
+      boost::multi_index::hashed_unique<
+        boost::multi_index::const_mem_fun<TrustAnchorGroup, const std::string&, &TrustAnchorGroup::getId>
+      >
+    >
+  >;
+
+  GroupContainer m_groups;
+  AnchorContainer m_anchors;
+};
+
+} // namespace v2
+} // namespace security
+} // namespace ndn
+
+#endif // NDN_SECURITY_V2_TRUST_ANCHOR_CONTAINER_HPP