src/client-module.cpp - ndncert - Gitiles

 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
  * Copyright (c) 2017, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
  * ndncert 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.
  *
  * ndncert 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 copies of the GNU General Public License along with
  * ndncert, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
  *
  * See AUTHORS.md for complete list of ndncert authors and contributors.
  */

 #include "client-module.hpp"
 #include "logging.hpp"
 #include "json-helper.hpp"
 #include <ndn-cxx/security/signing-helpers.hpp>
 #include <ndn-cxx/security/verification-helpers.hpp>

 namespace ndn {
 namespace ndncert {

 _LOG_INIT(ndncert.client);

 ClientModule::ClientModule(Face& face, security::v2::KeyChain& keyChain, size_t retryTimes)
   : m_face(face)
   , m_keyChain(keyChain)
   , m_retryTimes(retryTimes)
 {
 }

 void
 ClientModule::sendProbe(const ClientCaItem& ca, const std::string& probeInfo,
                         const RequestCallback& requestCallback,
                         const ErrorCallback& errorCallback)
 {
   Interest interest(Name(ca.m_caName).append("_PROBE").append(probeInfo));
   interest.setMustBeFresh(true);
   DataCallback dataCb = bind(&ClientModule::handleProbeResponse, this, _1, _2, ca, requestCallback, errorCallback);
   m_face.expressInterest(interest, dataCb,
                          bind(&ClientModule::onNack, this, _1, _2, errorCallback),
                          bind(&ClientModule::onTimeout, this, _1, m_retryTimes, dataCb,
                               requestCallback, errorCallback));

   _LOG_TRACE("PROBE interest sent with Probe info " << probeInfo);
 }

 void
 ClientModule::handleProbeResponse(const Interest& request, const Data& reply,
                                   const ClientCaItem& ca,
                                   const RequestCallback& requestCallback,
                                   const ErrorCallback& errorCallback)
 {
   if (!security::verifySignature(reply, ca.m_anchor)) {
     errorCallback("Cannot verify data from " + ca.m_caName.toUri());
     return;
   };
   JsonSection contentJson = getJsonFromData(reply);
   std::string identityNameString = contentJson.get(JSON_IDNENTIFIER, "");
   if (!identityNameString.empty()) {
     Name identityName(identityNameString);
     sendNew(ca, identityName, requestCallback, errorCallback);

     _LOG_TRACE("Got PROBE response with identity " << identityName);
   }
   else {
     errorCallback("The response does not carry required fields.");
     return;
   }
 }

 void
 ClientModule::sendNew(const ClientCaItem& ca, const Name& identityName,
                       const RequestCallback& requestCallback,
                       const ErrorCallback& errorCallback)
 {
   security::Identity identity = m_keyChain.createIdentity(identityName);

   auto state = make_shared<RequestState>();
   state->m_key = m_keyChain.createKey(identity);
   state->m_ca = ca;
   state->m_isInstalled = false;

   // generate certificate request
   security::v2::Certificate certRequest;
   certRequest.setName(Name(state->m_key.getName()).append("cert-request").appendVersion());
   certRequest.setContentType(tlv::ContentType_Key);
   certRequest.setFreshnessPeriod(time::hours(24));
   certRequest.setContent(state->m_key.getPublicKey().buf(), state->m_key.getPublicKey().size());
   SignatureInfo signatureInfo;
   signatureInfo.setValidityPeriod(security::ValidityPeriod(time::system_clock::now(),
                                                            time::system_clock::now() + time::days(10)));
   m_keyChain.sign(certRequest, signingByKey(state->m_key.getName()).setSignatureInfo(signatureInfo));

   // generate interest
   Interest interest(Name(ca.m_caName).append(Name("_NEW")).append(certRequest.wireEncode()));
   m_keyChain.sign(interest, signingByKey(state->m_key.getName()));

   DataCallback dataCb = bind(&ClientModule::handleNewResponse, this, _1, _2, state, requestCallback, errorCallback);
   m_face.expressInterest(interest, dataCb,
                          bind(&ClientModule::onNack, this, _1, _2, errorCallback),
                          bind(&ClientModule::onTimeout, this, _1, m_retryTimes, dataCb,
                               requestCallback, errorCallback));

   _LOG_TRACE("NEW interest sent with identity " << identityName);
 }

 void
 ClientModule::handleNewResponse(const Interest& request, const Data& reply,
                                 const shared_ptr<RequestState>& state,
                                 const RequestCallback& requestCallback,
                                 const ErrorCallback& errorCallback)
 {
   if (!security::verifySignature(reply, state->m_ca.m_anchor)) {
     errorCallback("Cannot verify data from " + state->m_ca.m_caName.toUri());
     return;
   }

   const JsonSection& json = getJsonFromData(reply);
   state->m_status = json.get(JSON_STATUS, "");
   state->m_requestId = json.get(JSON_REQUEST_ID, "");

   if (!checkStatus(*state, json, errorCallback)) {
     return;
   }

   JsonSection challengesJson = json.get_child(JSON_CHALLENGES);
   std::list<std::string> challengeList;
   for (const auto& challengeJson : challengesJson) {
     challengeList.push_back(challengeJson.second.get<std::string>(JSON_CHALLENGE_TYPE));
   }
   state->m_challengeList = challengeList;

   _LOG_TRACE("Got NEW response with requestID " << state->m_requestId
              << " with status " << state->m_status
              << " with challenge number " << challengeList.size());

   requestCallback(state);
 }

 void
 ClientModule::sendSelect(const shared_ptr<RequestState>& state,
                          const std::string& challengeType,
                          const JsonSection& selectParams,
                          const RequestCallback& requestCallback,
                          const ErrorCallback& errorCallback)
 {
   JsonSection requestIdJson;
   requestIdJson.put(JSON_REQUEST_ID, state->m_requestId);

   state->m_challengeType = challengeType;

   Name interestName(state->m_ca.m_caName);
   interestName.append("_SELECT")
     .append(nameBlockFromJson(requestIdJson))
     .append(challengeType)
     .append(nameBlockFromJson(selectParams));
   Interest interest(interestName);
   m_keyChain.sign(interest, signingByKey(state->m_key.getName()));

   DataCallback dataCb = bind(&ClientModule::handleSelectResponse, this, _1, _2, state, requestCallback, errorCallback);
   m_face.expressInterest(interest, dataCb,
                          bind(&ClientModule::onNack, this, _1, _2, errorCallback),
                          bind(&ClientModule::onTimeout, this, _1, m_retryTimes, dataCb,
                               requestCallback, errorCallback));

    _LOG_TRACE("SELECT interest sent with challenge type " << challengeType);
 }

 void
 ClientModule::handleSelectResponse(const Interest& request,
                                    const Data& reply,
                                    const shared_ptr<RequestState>& state,
                                    const RequestCallback& requestCallback,
                                    const ErrorCallback& errorCallback)
 {
   if (!security::verifySignature(reply, state->m_ca.m_anchor)) {
     errorCallback("Cannot verify data from " + state->m_ca.m_caName.toUri());
     return;
   }

   JsonSection json = getJsonFromData(reply);
   state->m_status = json.get<std::string>(JSON_STATUS);

   if (!checkStatus(*state, json, errorCallback)) {
     return;
   }

   _LOG_TRACE("Got SELECT response with status " << state->m_status);

   requestCallback(state);
 }

 void
 ClientModule::sendValidate(const shared_ptr<RequestState>& state,
                            const JsonSection& validateParams,
                            const RequestCallback& requestCallback,
                            const ErrorCallback& errorCallback)
 {
   JsonSection requestIdJson;
   requestIdJson.put(JSON_REQUEST_ID, state->m_requestId);

   Name interestName(state->m_ca.m_caName);
   interestName.append("_VALIDATE")
     .append(nameBlockFromJson(requestIdJson))
     .append(state->m_challengeType)
     .append(nameBlockFromJson(validateParams));
   Interest interest(interestName);
   m_keyChain.sign(interest, signingByKey(state->m_key.getName()));

   DataCallback dataCb = bind(&ClientModule::handleValidateResponse, this, _1, _2, state, requestCallback, errorCallback);
   m_face.expressInterest(interest, dataCb,
                          bind(&ClientModule::onNack, this, _1, _2, errorCallback),
                          bind(&ClientModule::onTimeout, this, _1, m_retryTimes, dataCb,
                               requestCallback, errorCallback));

   _LOG_TRACE("VALIDATE interest sent");
 }

 void
 ClientModule::handleValidateResponse(const Interest& request,
                                      const Data& reply,
                                      const shared_ptr<RequestState>& state,
                                      const RequestCallback& requestCallback,
                                      const ErrorCallback& errorCallback)
 {
   if (!security::verifySignature(reply, state->m_ca.m_anchor)) {
     errorCallback("Cannot verify data from " + state->m_ca.m_caName.toUri());
     return;
   }

   JsonSection json = getJsonFromData(reply);
   state->m_status = json.get<std::string>(JSON_STATUS);

   if (!checkStatus(*state, json, errorCallback)) {
     return;
   }

   _LOG_TRACE("Got VALIDATE response with status " << state->m_status);

   requestCallback(state);
 }


 void
 ClientModule::requestStatus(const shared_ptr<RequestState>& state,
                             const RequestCallback& requestCallback,
                             const ErrorCallback& errorCallback)
 {
   JsonSection requestIdJson;
   requestIdJson.put(JSON_REQUEST_ID, state->m_requestId);

   Name interestName(state->m_ca.m_caName);
   interestName.append("_STATUS").append(nameBlockFromJson(requestIdJson));
   Interest interest(interestName);

   m_keyChain.sign(interest, signingByKey(state->m_key.getName()));

   DataCallback dataCb = bind(&ClientModule::handleStatusResponse, this, _1, _2, state, requestCallback, errorCallback);
   m_face.expressInterest(interest, dataCb,
                          bind(&ClientModule::onNack, this, _1, _2, errorCallback),
                          bind(&ClientModule::onTimeout, this, _1, m_retryTimes, dataCb,
                               requestCallback, errorCallback));

   _LOG_TRACE("STATUS interest sent");
 }

 void
 ClientModule::handleStatusResponse(const Interest& request, const Data& reply,
                                    const shared_ptr<RequestState>& state,
                                    const RequestCallback& requestCallback,
                                    const ErrorCallback& errorCallback)
 {
   if (!security::verifySignature(reply, state->m_ca.m_anchor)) {
     errorCallback("Cannot verify data from " + state->m_ca.m_caName.toUri());
     return;
   }

   JsonSection json = getJsonFromData(reply);
   state->m_status = json.get<std::string>(JSON_STATUS);

   if (!checkStatus(*state, json, errorCallback)) {
     return;
   }

   _LOG_TRACE("Got STATUS response with status " << state->m_status);

   requestCallback(state);
 }

 void
 ClientModule::requestDownload(const shared_ptr<RequestState>& state,
                               const RequestCallback& requestCallback,
                               const ErrorCallback& errorCallback)
 {
   JsonSection requestIdJson;
   requestIdJson.put(JSON_REQUEST_ID, state->m_requestId);

   Name interestName(state->m_ca.m_caName);
   interestName.append("_DOWNLOAD").append(nameBlockFromJson(requestIdJson));
   Interest interest(interestName);
   interest.setMustBeFresh(true);

   DataCallback dataCb = bind(&ClientModule::handleDownloadResponse, this, _1, _2, state, requestCallback, errorCallback);
   m_face.expressInterest(interest, dataCb,
                          bind(&ClientModule::onNack, this, _1, _2, errorCallback),
                          bind(&ClientModule::onTimeout, this, _1, m_retryTimes, dataCb,
                               requestCallback, errorCallback));

   _LOG_TRACE("DOWNLOAD interest sent");
 }

 void
 ClientModule::handleDownloadResponse(const Interest& request, const Data& reply,
                                      const shared_ptr<RequestState>& state,
                                      const RequestCallback& requestCallback,
                                      const ErrorCallback& errorCallback)
 {
   if (!security::verifySignature(reply, state->m_ca.m_anchor)) {
     errorCallback("Cannot verify data from " + state->m_ca.m_caName.toUri());
     return;
   }

   try {
     security::v2::Certificate cert(reply.getContent().blockFromValue());
     m_keyChain.addCertificate(state->m_key, cert);

     _LOG_TRACE("Got DOWNLOAD response and installed the cert " << cert.getName());
   }
   catch (const std::exception& e) {
     errorCallback(std::string(e.what()));
     return;
   }

   state->m_isInstalled = true;
   requestCallback(state);
 }

 void
 ClientModule::onTimeout(const Interest& interest, int nRetriesLeft, const DataCallback& dataCallback,
                         const RequestCallback& requestCallback, const ErrorCallback& errorCallback)
 {
   if (nRetriesLeft > 0) {
     m_face.expressInterest(interest, dataCallback,
                            bind(&ClientModule::onNack, this, _1, _2, errorCallback),
                            bind(&ClientModule::onTimeout, this, _1, nRetriesLeft - 1, dataCallback,
                                 requestCallback, errorCallback));
   }
   else {
     errorCallback("Run out retries: still timeout");
     return;
   }
 }

 void
 ClientModule::onNack(const Interest& interest, const lp::Nack& nack, const ErrorCallback& errorCallback)
 {
   errorCallback("Got Nack");
 }

 JsonSection
 ClientModule::getJsonFromData(const Data& data)
 {
   Block jsonBlock = data.getContent();
   std::string jsonString = encoding::readString(jsonBlock);
   std::istringstream ss(jsonString);
   JsonSection json;
   boost::property_tree::json_parser::read_json(ss, json);
   return json;
 }

 Block
 ClientModule::nameBlockFromJson(const JsonSection& json)
 {
   std::stringstream ss;
   boost::property_tree::write_json(ss, json);
   return makeStringBlock(ndn::tlv::NameComponent, ss.str());
 }

 bool
 ClientModule::checkStatus(const RequestState& state, const JsonSection& json,
                           const ErrorCallback& errorCallback)
 {
   if (state.m_status == "error") {
     errorCallback(json.get(JSON_ERROR_INFO, ""));
     return false;
   }
   if (state.m_requestId.empty() || state.m_status.empty()) {
     errorCallback("The response does not carry required fields.");
     return false;
   }
   return true;
 }

 } // namespace ndncert
 } // namespace ndn
	/* -- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -- */
	/**
	* Copyright (c) 2017, Regents of the University of California.
	*
	* This file is part of ndncert, a certificate management system based on NDN.
	*
	* ndncert 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.
	*
	* ndncert 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 copies of the GNU General Public License along with
	* ndncert, e.g., in COPYING.md file. If not, see <http://www.gnu.org/licenses/>.
	*
	* See AUTHORS.md for complete list of ndncert authors and contributors.
	*/

	#include "client-module.hpp"
	#include "logging.hpp"
	#include "json-helper.hpp"
	#include <ndn-cxx/security/signing-helpers.hpp>
	#include <ndn-cxx/security/verification-helpers.hpp>

	namespace ndn {
	namespace ndncert {

	_LOG_INIT(ndncert.client);

	ClientModule::ClientModule(Face& face, security::v2::KeyChain& keyChain, size_t retryTimes)
	: m_face(face)
	, m_keyChain(keyChain)
	, m_retryTimes(retryTimes)
	{
	}

	void
	ClientModule::sendProbe(const ClientCaItem& ca, const std::string& probeInfo,
	const RequestCallback& requestCallback,
	const ErrorCallback& errorCallback)
	{
	Interest interest(Name(ca.m_caName).append("_PROBE").append(probeInfo));
	interest.setMustBeFresh(true);
	DataCallback dataCb = bind(&ClientModule::handleProbeResponse, this, _1, _2, ca, requestCallback, errorCallback);
	m_face.expressInterest(interest, dataCb,
	bind(&ClientModule::onNack, this, _1, _2, errorCallback),
	bind(&ClientModule::onTimeout, this, _1, m_retryTimes, dataCb,
	requestCallback, errorCallback));

	_LOG_TRACE("PROBE interest sent with Probe info " << probeInfo);
	}

	void
	ClientModule::handleProbeResponse(const Interest& request, const Data& reply,
	const ClientCaItem& ca,
	const RequestCallback& requestCallback,
	const ErrorCallback& errorCallback)
	{
	if (!security::verifySignature(reply, ca.m_anchor)) {
	errorCallback("Cannot verify data from " + ca.m_caName.toUri());
	return;
	};
	JsonSection contentJson = getJsonFromData(reply);
	std::string identityNameString = contentJson.get(JSON_IDNENTIFIER, "");
	if (!identityNameString.empty()) {
	Name identityName(identityNameString);
	sendNew(ca, identityName, requestCallback, errorCallback);

	_LOG_TRACE("Got PROBE response with identity " << identityName);
	}
	else {
	errorCallback("The response does not carry required fields.");
	return;
	}
	}

	void
	ClientModule::sendNew(const ClientCaItem& ca, const Name& identityName,
	const RequestCallback& requestCallback,
	const ErrorCallback& errorCallback)
	{
	security::Identity identity = m_keyChain.createIdentity(identityName);

	auto state = make_shared<RequestState>();
	state->m_key = m_keyChain.createKey(identity);
	state->m_ca = ca;
	state->m_isInstalled = false;

	// generate certificate request
	security::v2::Certificate certRequest;
	certRequest.setName(Name(state->m_key.getName()).append("cert-request").appendVersion());
	certRequest.setContentType(tlv::ContentType_Key);
	certRequest.setFreshnessPeriod(time::hours(24));
	certRequest.setContent(state->m_key.getPublicKey().buf(), state->m_key.getPublicKey().size());
	SignatureInfo signatureInfo;
	signatureInfo.setValidityPeriod(security::ValidityPeriod(time::system_clock::now(),
	time::system_clock::now() + time::days(10)));
	m_keyChain.sign(certRequest, signingByKey(state->m_key.getName()).setSignatureInfo(signatureInfo));

	// generate interest
	Interest interest(Name(ca.m_caName).append(Name("_NEW")).append(certRequest.wireEncode()));
	m_keyChain.sign(interest, signingByKey(state->m_key.getName()));

	DataCallback dataCb = bind(&ClientModule::handleNewResponse, this, _1, _2, state, requestCallback, errorCallback);
	m_face.expressInterest(interest, dataCb,
	bind(&ClientModule::onNack, this, _1, _2, errorCallback),
	bind(&ClientModule::onTimeout, this, _1, m_retryTimes, dataCb,
	requestCallback, errorCallback));

	_LOG_TRACE("NEW interest sent with identity " << identityName);
	}

	void
	ClientModule::handleNewResponse(const Interest& request, const Data& reply,
	const shared_ptr<RequestState>& state,
	const RequestCallback& requestCallback,
	const ErrorCallback& errorCallback)
	{
	if (!security::verifySignature(reply, state->m_ca.m_anchor)) {
	errorCallback("Cannot verify data from " + state->m_ca.m_caName.toUri());
	return;
	}

	const JsonSection& json = getJsonFromData(reply);
	state->m_status = json.get(JSON_STATUS, "");
	state->m_requestId = json.get(JSON_REQUEST_ID, "");

	if (!checkStatus(*state, json, errorCallback)) {
	return;
	}

	JsonSection challengesJson = json.get_child(JSON_CHALLENGES);
	std::list<std::string> challengeList;
	for (const auto& challengeJson : challengesJson) {
	challengeList.push_back(challengeJson.second.get<std::string>(JSON_CHALLENGE_TYPE));
	}
	state->m_challengeList = challengeList;

	_LOG_TRACE("Got NEW response with requestID " << state->m_requestId
	<< " with status " << state->m_status
	<< " with challenge number " << challengeList.size());

	requestCallback(state);
	}

	void
	ClientModule::sendSelect(const shared_ptr<RequestState>& state,
	const std::string& challengeType,
	const JsonSection& selectParams,
	const RequestCallback& requestCallback,
	const ErrorCallback& errorCallback)
	{
	JsonSection requestIdJson;
	requestIdJson.put(JSON_REQUEST_ID, state->m_requestId);

	state->m_challengeType = challengeType;

	Name interestName(state->m_ca.m_caName);
	interestName.append("_SELECT")
	.append(nameBlockFromJson(requestIdJson))
	.append(challengeType)
	.append(nameBlockFromJson(selectParams));
	Interest interest(interestName);
	m_keyChain.sign(interest, signingByKey(state->m_key.getName()));

	DataCallback dataCb = bind(&ClientModule::handleSelectResponse, this, _1, _2, state, requestCallback, errorCallback);
	m_face.expressInterest(interest, dataCb,
	bind(&ClientModule::onNack, this, _1, _2, errorCallback),
	bind(&ClientModule::onTimeout, this, _1, m_retryTimes, dataCb,
	requestCallback, errorCallback));

	_LOG_TRACE("SELECT interest sent with challenge type " << challengeType);
	}

	void
	ClientModule::handleSelectResponse(const Interest& request,
	const Data& reply,
	const shared_ptr<RequestState>& state,
	const RequestCallback& requestCallback,
	const ErrorCallback& errorCallback)
	{
	if (!security::verifySignature(reply, state->m_ca.m_anchor)) {
	errorCallback("Cannot verify data from " + state->m_ca.m_caName.toUri());
	return;
	}

	JsonSection json = getJsonFromData(reply);
	state->m_status = json.get<std::string>(JSON_STATUS);

	if (!checkStatus(*state, json, errorCallback)) {
	return;
	}

	_LOG_TRACE("Got SELECT response with status " << state->m_status);

	requestCallback(state);
	}

	void
	ClientModule::sendValidate(const shared_ptr<RequestState>& state,
	const JsonSection& validateParams,
	const RequestCallback& requestCallback,
	const ErrorCallback& errorCallback)
	{
	JsonSection requestIdJson;
	requestIdJson.put(JSON_REQUEST_ID, state->m_requestId);

	Name interestName(state->m_ca.m_caName);
	interestName.append("_VALIDATE")
	.append(nameBlockFromJson(requestIdJson))
	.append(state->m_challengeType)
	.append(nameBlockFromJson(validateParams));
	Interest interest(interestName);
	m_keyChain.sign(interest, signingByKey(state->m_key.getName()));

	DataCallback dataCb = bind(&ClientModule::handleValidateResponse, this, _1, _2, state, requestCallback, errorCallback);
	m_face.expressInterest(interest, dataCb,
	bind(&ClientModule::onNack, this, _1, _2, errorCallback),
	bind(&ClientModule::onTimeout, this, _1, m_retryTimes, dataCb,
	requestCallback, errorCallback));

	_LOG_TRACE("VALIDATE interest sent");
	}

	void
	ClientModule::handleValidateResponse(const Interest& request,
	const Data& reply,
	const shared_ptr<RequestState>& state,
	const RequestCallback& requestCallback,
	const ErrorCallback& errorCallback)
	{
	if (!security::verifySignature(reply, state->m_ca.m_anchor)) {
	errorCallback("Cannot verify data from " + state->m_ca.m_caName.toUri());
	return;
	}

	JsonSection json = getJsonFromData(reply);
	state->m_status = json.get<std::string>(JSON_STATUS);

	if (!checkStatus(*state, json, errorCallback)) {
	return;
	}

	_LOG_TRACE("Got VALIDATE response with status " << state->m_status);

	requestCallback(state);
	}


	void
	ClientModule::requestStatus(const shared_ptr<RequestState>& state,
	const RequestCallback& requestCallback,
	const ErrorCallback& errorCallback)
	{
	JsonSection requestIdJson;
	requestIdJson.put(JSON_REQUEST_ID, state->m_requestId);

	Name interestName(state->m_ca.m_caName);
	interestName.append("_STATUS").append(nameBlockFromJson(requestIdJson));
	Interest interest(interestName);

	m_keyChain.sign(interest, signingByKey(state->m_key.getName()));

	DataCallback dataCb = bind(&ClientModule::handleStatusResponse, this, _1, _2, state, requestCallback, errorCallback);
	m_face.expressInterest(interest, dataCb,
	bind(&ClientModule::onNack, this, _1, _2, errorCallback),
	bind(&ClientModule::onTimeout, this, _1, m_retryTimes, dataCb,
	requestCallback, errorCallback));

	_LOG_TRACE("STATUS interest sent");
	}

	void
	ClientModule::handleStatusResponse(const Interest& request, const Data& reply,
	const shared_ptr<RequestState>& state,
	const RequestCallback& requestCallback,
	const ErrorCallback& errorCallback)
	{
	if (!security::verifySignature(reply, state->m_ca.m_anchor)) {
	errorCallback("Cannot verify data from " + state->m_ca.m_caName.toUri());
	return;
	}

	JsonSection json = getJsonFromData(reply);
	state->m_status = json.get<std::string>(JSON_STATUS);

	if (!checkStatus(*state, json, errorCallback)) {
	return;
	}

	_LOG_TRACE("Got STATUS response with status " << state->m_status);

	requestCallback(state);
	}

	void
	ClientModule::requestDownload(const shared_ptr<RequestState>& state,
	const RequestCallback& requestCallback,
	const ErrorCallback& errorCallback)
	{
	JsonSection requestIdJson;
	requestIdJson.put(JSON_REQUEST_ID, state->m_requestId);

	Name interestName(state->m_ca.m_caName);
	interestName.append("_DOWNLOAD").append(nameBlockFromJson(requestIdJson));
	Interest interest(interestName);
	interest.setMustBeFresh(true);

	DataCallback dataCb = bind(&ClientModule::handleDownloadResponse, this, _1, _2, state, requestCallback, errorCallback);
	m_face.expressInterest(interest, dataCb,
	bind(&ClientModule::onNack, this, _1, _2, errorCallback),
	bind(&ClientModule::onTimeout, this, _1, m_retryTimes, dataCb,
	requestCallback, errorCallback));

	_LOG_TRACE("DOWNLOAD interest sent");
	}

	void
	ClientModule::handleDownloadResponse(const Interest& request, const Data& reply,
	const shared_ptr<RequestState>& state,
	const RequestCallback& requestCallback,
	const ErrorCallback& errorCallback)
	{
	if (!security::verifySignature(reply, state->m_ca.m_anchor)) {
	errorCallback("Cannot verify data from " + state->m_ca.m_caName.toUri());
	return;
	}

	try {
	security::v2::Certificate cert(reply.getContent().blockFromValue());
	m_keyChain.addCertificate(state->m_key, cert);

	_LOG_TRACE("Got DOWNLOAD response and installed the cert " << cert.getName());
	}
	catch (const std::exception& e) {
	errorCallback(std::string(e.what()));
	return;
	}

	state->m_isInstalled = true;
	requestCallback(state);
	}

	void
	ClientModule::onTimeout(const Interest& interest, int nRetriesLeft, const DataCallback& dataCallback,
	const RequestCallback& requestCallback, const ErrorCallback& errorCallback)
	{
	if (nRetriesLeft > 0) {
	m_face.expressInterest(interest, dataCallback,
	bind(&ClientModule::onNack, this, _1, _2, errorCallback),
	bind(&ClientModule::onTimeout, this, _1, nRetriesLeft - 1, dataCallback,
	requestCallback, errorCallback));
	}
	else {
	errorCallback("Run out retries: still timeout");
	return;
	}
	}

	void
	ClientModule::onNack(const Interest& interest, const lp::Nack& nack, const ErrorCallback& errorCallback)
	{
	errorCallback("Got Nack");
	}

	JsonSection
	ClientModule::getJsonFromData(const Data& data)
	{
	Block jsonBlock = data.getContent();
	std::string jsonString = encoding::readString(jsonBlock);
	std::istringstream ss(jsonString);
	JsonSection json;
	boost::property_tree::json_parser::read_json(ss, json);
	return json;
	}

	Block
	ClientModule::nameBlockFromJson(const JsonSection& json)
	{
	std::stringstream ss;
	boost::property_tree::write_json(ss, json);
	return makeStringBlock(ndn::tlv::NameComponent, ss.str());
	}

	bool
	ClientModule::checkStatus(const RequestState& state, const JsonSection& json,
	const ErrorCallback& errorCallback)
	{
	if (state.m_status == "error") {
	errorCallback(json.get(JSON_ERROR_INFO, ""));
	return false;
	}
	if (state.m_requestId.empty() \|\| state.m_status.empty()) {
	errorCallback("The response does not carry required fields.");
	return false;
	}
	return true;
	}

	} // namespace ndncert
	} // namespace ndn