additional-description.cpp

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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2013-2025 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 "ndn-cxx/security/additional-description.hpp"
#include "ndn-cxx/encoding/block-helpers.hpp"
#include "ndn-cxx/util/ostream-joiner.hpp"
 
namespace ndn::security {
 
constexpr size_t KEY_OFFSET = 0;
constexpr size_t VALUE_OFFSET = 1;
 
AdditionalDescription::AdditionalDescription(const Block& block)
{
  wireDecode(block);
}
 
const std::string&
AdditionalDescription::get(const std::string& key) const
{
  if (auto it = m_info.find(key); it != m_info.end()) {
    return it->second;
  }
 
  NDN_THROW(Error("Entry does not exist for key '" + key + "'"));
}
 
void
AdditionalDescription::set(const std::string& key, const std::string& value)
{
  m_info[key] = value;
}
 
bool
AdditionalDescription::has(const std::string& key) const
{
  return m_info.find(key) != m_info.end();
}
 
AdditionalDescription::iterator
AdditionalDescription::begin()
{
  return m_info.begin();
}
 
AdditionalDescription::iterator
AdditionalDescription::end()
{
  return m_info.end();
}
 
AdditionalDescription::const_iterator
AdditionalDescription::begin() const
{
  return m_info.begin();
}
 
AdditionalDescription::const_iterator
AdditionalDescription::end() const
{
  return m_info.end();
}
 
template<encoding::Tag TAG>
size_t
AdditionalDescription::wireEncode(EncodingImpl<TAG>& encoder) const
{
  size_t totalLength = 0;
 
  for (auto it = m_info.rbegin(); it != m_info.rend(); it++) {
    size_t entryLength = 0;
    entryLength += prependStringBlock(encoder, tlv::DescriptionValue, it->second);
    entryLength += prependStringBlock(encoder, tlv::DescriptionKey, it->first);
    entryLength += encoder.prependVarNumber(entryLength);
    entryLength += encoder.prependVarNumber(tlv::DescriptionEntry);
 
    totalLength += entryLength;
  }
 
  totalLength += encoder.prependVarNumber(totalLength);
  totalLength += encoder.prependVarNumber(tlv::AdditionalDescription);
  return totalLength;
}
 
NDN_CXX_DEFINE_WIRE_ENCODE_INSTANTIATIONS(AdditionalDescription);
 
const Block&
AdditionalDescription::wireEncode() const
{
  if (m_wire.hasWire())
    return m_wire;
 
  EncodingEstimator estimator;
  size_t estimatedSize = wireEncode(estimator);
 
  EncodingBuffer buffer(estimatedSize, 0);
  wireEncode(buffer);
 
  m_wire = buffer.block();
  return m_wire;
}
 
void
AdditionalDescription::wireDecode(const Block& wire)
{
  if (wire.type() != tlv::AdditionalDescription) {
    NDN_THROW(Error("AdditionalDescription", wire.type()));
  }
  m_wire = wire;
  m_wire.parse();
 
  m_info.clear();
 
  for (const auto& e : m_wire.elements()) {
    switch (e.type()) {
    case tlv::DescriptionEntry:
      e.parse();
      if (e.elements_size() != 2) {
        NDN_THROW(Error("DescriptionEntry does not have two sub-elements"));
      }
      if (e.elements()[KEY_OFFSET].type() != tlv::DescriptionKey ||
          e.elements()[VALUE_OFFSET].type() != tlv::DescriptionValue) {
        NDN_THROW(Error("Missing DescriptionKey or DescriptionValue field"));
      }
      m_info.insert_or_assign(readString(e.elements()[KEY_OFFSET]),
                              readString(e.elements()[VALUE_OFFSET]));
      break;
    default: // unrecognized element
      // if the TLV-TYPE is critical, abort decoding
      if (tlv::isCriticalType(e.type())) {
        NDN_THROW(Error("Unrecognized element of critical type " + std::to_string(e.type())));
      }
      // otherwise, ignore it
      break;
    }
  }
}
 
std::ostream&
operator<<(std::ostream& os, const AdditionalDescription& desc)
{
  os << "[";
 
  auto join = make_ostream_joiner(os, ", ");
  for (const auto& entry : desc) {
    join = "(" + entry.first + ":" + entry.second + ")";
  }
 
  return os << "]";
}
 
} // namespace ndn::security