security: Integrate fetching certificates using Certificate Bundle

Change-Id: Iebac12a5cb9d1f4aa12aad09e8ef27f5b90a5d90
Refs: #3891
diff --git a/src/security/v2/certificate-bundle-fetcher.cpp b/src/security/v2/certificate-bundle-fetcher.cpp
new file mode 100644
index 0000000..e2fdab9
--- /dev/null
+++ b/src/security/v2/certificate-bundle-fetcher.cpp
@@ -0,0 +1,230 @@
+/* -*- 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.
+ */
+
+#include "certificate-bundle-fetcher.hpp"
+#include "face.hpp"
+#include "util/logger.hpp"
+
+namespace ndn {
+namespace security {
+namespace v2 {
+
+NDN_LOG_INIT(ndn.security.v2.CertificateBundleFetcher);
+
+#define NDN_LOG_DEBUG_DEPTH(x) NDN_LOG_DEBUG(std::string(state->getDepth() + 1, '>') << " " << x)
+#define NDN_LOG_TRACE_DEPTH(x) NDN_LOG_TRACE(std::string(state->getDepth() + 1, '>') << " " << x)
+
+CertificateBundleFetcher::CertificateBundleFetcher(unique_ptr<CertificateFetcher> inner,
+                                                   Face& face)
+  : m_inner(std::move(inner))
+  , m_face(face)
+  , m_bundleInterestLifetime(1000)
+{
+  BOOST_ASSERT(m_inner != nullptr);
+}
+
+void
+CertificateBundleFetcher::setBundleInterestLifetime(time::milliseconds time)
+{
+  m_bundleInterestLifetime = time;
+}
+
+time::milliseconds
+CertificateBundleFetcher::getBundleInterestLifetime() const
+{
+  return m_bundleInterestLifetime;
+}
+
+void
+CertificateBundleFetcher::setCertificateStorage(CertificateStorage& certStorage)
+{
+  m_certStorage = &certStorage;
+  m_inner->setCertificateStorage(certStorage);
+}
+
+void
+CertificateBundleFetcher::doFetch(const shared_ptr<CertificateRequest>& certRequest,
+                                  const shared_ptr<ValidationState>& state,
+                                  const ValidationContinuation& continueValidation)
+{
+  auto dataValidationState = dynamic_pointer_cast<DataValidationState>(state);
+  if (dataValidationState == nullptr) {
+    return m_inner->fetch(certRequest, state, continueValidation);
+  }
+
+  // check if a bundle segment was fetched before
+  shared_ptr<BundleNameTag> bundleNameTag = state->getTag<BundleNameTag>();
+  if (bundleNameTag == nullptr) {
+    const Name& originalDataName = dataValidationState->getOriginalData().getName();
+    if (originalDataName.empty()) {
+      return m_inner->fetch(certRequest, state, continueValidation);
+    }
+    // derive certificate bundle name from original data name
+    Name bundleNamePrefix = deriveBundleName(originalDataName);
+    fetchFirstBundleSegment(bundleNamePrefix, certRequest, state, continueValidation);
+  }
+  else {
+    Name fullBundleName = bundleNameTag->get();
+    fetchNextBundleSegment(fullBundleName, fullBundleName.get(-1).getSuccessor(),
+                           certRequest, state, continueValidation);
+  }
+}
+
+void
+CertificateBundleFetcher::fetchFirstBundleSegment(const Name& bundleNamePrefix,
+                                                  const shared_ptr<CertificateRequest>& certRequest,
+                                                  const shared_ptr<ValidationState>& state,
+                                                  const ValidationContinuation& continueValidation)
+{
+  Interest bundleInterest = Interest(bundleNamePrefix);
+  bundleInterest.setInterestLifetime(m_bundleInterestLifetime);
+  bundleInterest.setMustBeFresh(true);
+  bundleInterest.setChildSelector(1);
+
+  m_face.expressInterest(bundleInterest,
+                         [=] (const Interest& interest, const Data& data) {
+                           dataCallback(data, true, certRequest, state, continueValidation);
+                         },
+                         [=] (const Interest& interest, const lp::Nack& nack) {
+                           nackCallback(nack, certRequest, state, continueValidation, bundleNamePrefix);
+                         },
+                         [=] (const Interest& interest) {
+                           timeoutCallback(certRequest, state, continueValidation, bundleNamePrefix);
+                         });
+}
+
+void
+CertificateBundleFetcher::fetchNextBundleSegment(const Name& fullBundleName, const name::Component& segmentNo,
+                                                 const shared_ptr<CertificateRequest>& certRequest,
+                                                 const shared_ptr<ValidationState>& state,
+                                                 const ValidationContinuation& continueValidation)
+{
+  shared_ptr<FinalBlockIdTag> finalBlockId = state->getTag<FinalBlockIdTag>();
+  if (finalBlockId != nullptr && segmentNo > finalBlockId->get()) {
+    return m_inner->fetch(certRequest, state, continueValidation);
+  }
+
+  Interest bundleInterest(fullBundleName.getPrefix(-1).append(segmentNo));
+  bundleInterest.setInterestLifetime(m_bundleInterestLifetime);
+  bundleInterest.setMustBeFresh(false);
+
+  m_face.expressInterest(bundleInterest,
+                         [=] (const Interest& interest, const Data& data) {
+                           dataCallback(data, false, certRequest, state, continueValidation);
+                         },
+                         [=] (const Interest& interest, const lp::Nack& nack) {
+                           nackCallback(nack, certRequest, state, continueValidation, fullBundleName);
+                         },
+                         [=] (const Interest& interest) {
+                           timeoutCallback(certRequest, state, continueValidation, fullBundleName);
+                         });
+}
+
+void
+CertificateBundleFetcher::dataCallback(const Data& bundleData,
+                                       bool isSegmentZeroExpected,
+                                       const shared_ptr<CertificateRequest>& certRequest,
+                                       const shared_ptr<ValidationState>& state,
+                                       const ValidationContinuation& continueValidation)
+{
+  NDN_LOG_DEBUG_DEPTH("Fetched certificate bundle from network " << bundleData.getName());
+
+  name::Component currentSegment = bundleData.getName().get(-1);
+  if (!currentSegment.isSegment()) {
+    return m_inner->fetch(certRequest, state, continueValidation);
+  }
+
+  if (isSegmentZeroExpected && currentSegment.toSegment() != 0) {
+    // fetch segment zero
+    fetchNextBundleSegment(bundleData.getName(), name::Component::fromSegment(0),
+                           certRequest, state, continueValidation);
+  }
+  else {
+    state->setTag(make_shared<BundleNameTag>(bundleData.getName()));
+
+    const name::Component& finalBlockId = bundleData.getMetaInfo().getFinalBlockId();
+    if (!finalBlockId.empty()) {
+      state->setTag(make_shared<FinalBlockIdTag>(finalBlockId));
+    }
+
+    Block bundleContent = bundleData.getContent();
+    bundleContent.parse();
+
+    // store all the certificates in unverified cache
+    for (const auto& block : bundleContent.elements()) {
+      m_certStorage->cacheUnverifiedCert(Certificate(block));
+    }
+
+    auto cert = m_certStorage->getUnverifiedCertCache().find(certRequest->m_interest);
+    continueValidation(*cert, state);
+  }
+}
+
+void
+CertificateBundleFetcher::nackCallback(const lp::Nack& nack,
+                                       const shared_ptr<CertificateRequest>& certRequest,
+                                       const shared_ptr<ValidationState>& state,
+                                       const ValidationContinuation& continueValidation,
+                                       const Name& bundleName)
+{
+  NDN_LOG_DEBUG_DEPTH("NACK (" << nack.getReason() <<  ") while fetching certificate bundle"
+                      << bundleName);
+
+  m_inner->fetch(certRequest, state, continueValidation);
+}
+
+void
+CertificateBundleFetcher::timeoutCallback(const shared_ptr<CertificateRequest>& certRequest,
+                                          const shared_ptr<ValidationState>& state,
+                                          const ValidationContinuation& continueValidation,
+                                          const Name& bundleName)
+{
+  NDN_LOG_DEBUG_DEPTH("Timeout while fetching certificate bundle" << bundleName);
+
+  m_inner->fetch(certRequest, state, continueValidation);
+}
+
+Name
+CertificateBundleFetcher::deriveBundleName(const Name& name)
+{
+  name::Component lastComponent = name.at(-1);
+
+  Name bundleName = name;
+  if (lastComponent.isImplicitSha256Digest()) {
+    if (name.size() >= 2 && name.get(-2).isSegment()) {
+      bundleName = name.getPrefix(-2);
+    }
+    else {
+      bundleName = name.getPrefix(-1);
+    }
+  }
+  else if (lastComponent.isSegment()) {
+    bundleName = name.getPrefix(-1);
+  }
+  bundleName.append("_BUNDLE");
+  bundleName.appendNumber(00);
+
+  return bundleName;
+}
+
+} // namespace v2
+} // namespace security
+} // namespace ndn