security: add certificate bundle decoder

Refs: #5004
Change-Id: I0f035caf8f6975ba2322a7f6629312d3dcab910d
diff --git a/.mailmap b/.mailmap
index 967715e..cacbeb8 100644
--- a/.mailmap
+++ b/.mailmap
@@ -6,3 +6,4 @@
 <lybmath2009@gmail.com> <lybmath@ucla.edu>
 Hila Ben Abraham <hilata@gmail.com>
 Laqin Fan <flq12021@gmail.com>
+Jeremy Clark <jrclark2@memphis.edu>
diff --git a/ndn-cxx/security/certificate.cpp b/ndn-cxx/security/certificate.cpp
index 36dbc39..b54c56d 100644
--- a/ndn-cxx/security/certificate.cpp
+++ b/ndn-cxx/security/certificate.cpp
@@ -51,7 +51,7 @@
 }
 
 Certificate::Certificate(Data&& data)
-  : Data(data)
+  : Data(std::move(data))
 {
   if (!isValidName(getName())) {
     NDN_THROW(Data::Error("Name does not follow the naming convention for certificate"));
diff --git a/ndn-cxx/security/detail/certificate-bundle-decoder.cpp b/ndn-cxx/security/detail/certificate-bundle-decoder.cpp
new file mode 100644
index 0000000..19fba7f
--- /dev/null
+++ b/ndn-cxx/security/detail/certificate-bundle-decoder.cpp
@@ -0,0 +1,67 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2013-2020 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/detail/certificate-bundle-decoder.hpp"
+#include "ndn-cxx/util/scope.hpp"
+
+namespace ndn {
+namespace security {
+namespace detail {
+
+void
+CertificateBundleDecoder::append(const Block& segment)
+{
+  if (m_hasError) {
+    NDN_THROW(tlv::Error("Unrecoverable decoding error"));
+  }
+
+  m_bufferedData.insert(m_bufferedData.end(), segment.value_begin(), segment.value_end());
+  decode();
+}
+
+void
+CertificateBundleDecoder::decode()
+{
+  auto onThrow = make_scope_fail([this] { m_hasError = true; });
+
+  while (!m_bufferedData.empty()) {
+    bool isOk;
+    Block element;
+    std::tie(isOk, element) = Block::fromBuffer(m_bufferedData.data(), m_bufferedData.size());
+    if (!isOk) {
+      return;
+    }
+
+    m_bufferedData.erase(m_bufferedData.begin(), m_bufferedData.begin() + element.size());
+
+    if (element.type() == tlv::Data) {
+      onCertDecoded(Certificate(element));
+    }
+    else if (tlv::isCriticalType(element.type())) {
+      NDN_THROW(tlv::Error("Unrecognized element of critical type " + to_string(element.type())));
+    }
+    // unrecognized non-critical elements are silently skipped
+  }
+}
+
+} // namespace detail
+} // namespace security
+} // namespace ndn
diff --git a/ndn-cxx/security/detail/certificate-bundle-decoder.hpp b/ndn-cxx/security/detail/certificate-bundle-decoder.hpp
new file mode 100644
index 0000000..17f88ca
--- /dev/null
+++ b/ndn-cxx/security/detail/certificate-bundle-decoder.hpp
@@ -0,0 +1,76 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2013-2020 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_CXX_SECURITY_DETAIL_CERTIFICATE_BUNDLE_DECODER_HPP
+#define NDN_CXX_SECURITY_DETAIL_CERTIFICATE_BUNDLE_DECODER_HPP
+
+#include "ndn-cxx/security/certificate.hpp"
+#include "ndn-cxx/util/signal.hpp"
+
+namespace ndn {
+namespace security {
+namespace detail {
+
+/** @brief Helper class to decode a certificate bundle.
+ */
+class CertificateBundleDecoder
+{
+public:
+  /**
+   * @brief Append a bundle segment to the internal decoding buffer and trigger decoding.
+   * @param block      Content element of the segment to be appended
+   * @throw tlv::Error When the decoder encounters an unrecognized element with critical type.
+   *                   No longer accepts segments after throwing.
+   * @warning Must not be called from a handler of #onCertDecoded.
+   * @warning Segments must be appended in order, otherwise the behavior is undefined.
+   */
+  void
+  append(const Block& block);
+
+  /**
+   * @brief Whether the decoder has encountered an unrecoverable error.
+   */
+  bool
+  hasError() const noexcept
+  {
+    return m_hasError;
+  }
+
+public:
+  /**
+   * @brief Emitted every time a certificate is successfully decoded.
+   */
+  util::Signal<CertificateBundleDecoder, Certificate> onCertDecoded;
+
+private:
+  void
+  decode();
+
+private:
+  std::vector<uint8_t> m_bufferedData;
+  bool m_hasError = false;
+};
+
+} // namespace detail
+} // namespace security
+} // namespace ndn
+
+#endif // NDN_CXX_SECURITY_DETAIL_CERTIFICATE_BUNDLE_DECODER_HPP
diff --git a/tests/unit/security/detail/certificate-bundle-decoder.t.cpp b/tests/unit/security/detail/certificate-bundle-decoder.t.cpp
new file mode 100644
index 0000000..b6691ee
--- /dev/null
+++ b/tests/unit/security/detail/certificate-bundle-decoder.t.cpp
@@ -0,0 +1,219 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2013-2020 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/detail/certificate-bundle-decoder.hpp"
+
+#include "tests/boost-test.hpp"
+#include "tests/identity-management-fixture.hpp"
+
+namespace ndn {
+namespace security {
+namespace detail {
+namespace tests {
+
+class CertificateBundleDecoderFixture : public ndn::tests::IdentityManagementFixture
+{
+protected:
+  CertificateBundleDecoderFixture()
+  {
+    auto id1 = addIdentity("/hello/world1");
+    auto cert1 = id1.getDefaultKey().getDefaultCertificate();
+    certBlock1 = cert1.wireEncode();
+    m_certs.push_back(certBlock1);
+
+    auto id2 = addIdentity("/hello/world2");
+    auto cert2 = id2.getDefaultKey().getDefaultCertificate();
+    certBlock2 = cert2.wireEncode();
+    m_certs.push_back(certBlock2);
+
+    cbd.onCertDecoded.connect([this] (const Certificate& receivedCert) {
+      BOOST_CHECK_EQUAL(receivedCert.wireEncode(), m_certs.at(nCertsCompleted));
+      ++nCertsCompleted;
+    });
+  }
+
+protected:
+  CertificateBundleDecoder cbd;
+  Block certBlock1;
+  Block certBlock2;
+  int nCertsCompleted = 0;
+
+private:
+  std::vector<Block> m_certs;
+};
+
+BOOST_AUTO_TEST_SUITE(Security)
+BOOST_FIXTURE_TEST_SUITE(TestCertificateBundleDecoder, CertificateBundleDecoderFixture)
+
+BOOST_AUTO_TEST_CASE(EmptySegment)
+{
+  BOOST_CHECK_EQUAL(cbd.hasError(), false);
+  cbd.append(Block(tlv::Content));
+  BOOST_CHECK_EQUAL(cbd.hasError(), false);
+  BOOST_CHECK_EQUAL(nCertsCompleted, 0);
+}
+
+BOOST_AUTO_TEST_CASE(OneCertOneSegment)
+{
+  // Segment contains full certificate
+  Data d;
+  d.setContent(certBlock1);
+
+  cbd.append(d.getContent());
+  BOOST_CHECK_EQUAL(cbd.hasError(), false);
+  BOOST_CHECK_EQUAL(nCertsCompleted, 1);
+}
+
+BOOST_AUTO_TEST_CASE(TwoCertsOneSegment)
+{
+  // Segment contains two full certificates
+  auto buf = std::make_shared<Buffer>(certBlock1.begin(), certBlock1.end());
+  buf->insert(buf->end(), certBlock2.begin(), certBlock2.end());
+  Data d;
+  d.setContent(std::move(buf));
+
+  cbd.append(d.getContent());
+  BOOST_CHECK_EQUAL(cbd.hasError(), false);
+  BOOST_CHECK_EQUAL(nCertsCompleted, 2);
+}
+
+BOOST_AUTO_TEST_CASE(TwoCertsMultipleSegments)
+{
+  // First segment contains first 250 bytes of cert1
+  Data d;
+  d.setContent(certBlock1.wire(), 250);
+
+  // Second segment contains the rest of cert1 and the first 100 bytes of cert2
+  auto buf = std::make_shared<Buffer>(certBlock1.begin() + 250, certBlock1.end());
+  buf->insert(buf->end(), certBlock2.begin(), certBlock2.begin() + 100);
+  Data d2;
+  d2.setContent(std::move(buf));
+
+  // Third segment contains the rest of cert2
+  Data d3;
+  d3.setContent(std::make_shared<Buffer>(certBlock2.begin() + 100, certBlock2.end()));
+
+  cbd.append(d.getContent());
+  BOOST_CHECK_EQUAL(cbd.hasError(), false);
+  BOOST_CHECK_EQUAL(nCertsCompleted, 0);
+
+  cbd.append(d2.getContent());
+  BOOST_CHECK_EQUAL(cbd.hasError(), false);
+  BOOST_CHECK_EQUAL(nCertsCompleted, 1);
+
+  cbd.append(d3.getContent());
+  BOOST_CHECK_EQUAL(cbd.hasError(), false);
+  BOOST_CHECK_EQUAL(nCertsCompleted, 2);
+}
+
+BOOST_AUTO_TEST_CASE(InvalidCert)
+{
+  // First segment contains all of cert1
+  Data d;
+  d.setContent(certBlock1);
+
+  const uint8_t buf[] = {
+    0x06, 0x20, // Data
+          0x07, 0x11, // Name
+                0x08, 0x05, 0x68, 0x65, 0x6c, 0x6c, 0x6f, // GenericNameComponent 'hello'
+                0x08, 0x01, 0x31, // GenericNameComponent '1'
+                0x08, 0x05, 0x77, 0x6f, 0x72, 0x6c, 0x64, // GenericNameComponent 'world'
+          0x14, 0x00, // MetaInfo empty
+          0x15, 0x00, // Content empty
+          0x16, 0x05, // SignatureInfo
+                0x1b, 0x01, 0x01, // SignatureType RSA
+                0x1c, 0x00, // KeyLocator empty
+          0x17, 0x00 // SignatureValue empty
+  };
+  // Second segment contains non-Certificate data
+  Data d2;
+  d2.setContent(buf, sizeof(buf));
+
+  // Third segment contains all of cert2
+  Data d3;
+  d3.setContent(certBlock2);
+
+  cbd.append(d.getContent());
+  BOOST_CHECK_EQUAL(cbd.hasError(), false);
+  BOOST_CHECK_EQUAL(nCertsCompleted, 1);
+
+  BOOST_CHECK_EXCEPTION(cbd.append(d2.getContent()), tlv::Error, [] (const auto& e) {
+    return e.what() == "Name does not follow the naming convention for certificate"s;
+  });
+  BOOST_CHECK_EQUAL(cbd.hasError(), true);
+  BOOST_CHECK_EQUAL(nCertsCompleted, 1);
+
+  BOOST_CHECK_EXCEPTION(cbd.append(d3.getContent()), tlv::Error, [] (const auto& e) {
+    return e.what() == "Unrecoverable decoding error"s;
+  });
+  BOOST_CHECK_EQUAL(cbd.hasError(), true);
+  BOOST_CHECK_EQUAL(nCertsCompleted, 1);
+}
+
+BOOST_AUTO_TEST_CASE(UnrecognizedCritical)
+{
+  // First segment contains an unrecognized critical element
+  Data d;
+  d.setContent("050B07030102030A0404050607"_block);
+
+  // Second segment contains cert1
+  Data d2;
+  d2.setContent(certBlock1);
+
+  BOOST_CHECK_EXCEPTION(cbd.append(d.getContent()), tlv::Error, [] (const auto& e) {
+    return e.what() == "Unrecognized element of critical type 5"s;
+  });
+  BOOST_CHECK_EQUAL(cbd.hasError(), true);
+  BOOST_CHECK_EQUAL(nCertsCompleted, 0);
+
+  BOOST_CHECK_EXCEPTION(cbd.append(d2.getContent()), tlv::Error, [] (const auto& e) {
+    return e.what() == "Unrecoverable decoding error"s;
+  });
+  BOOST_CHECK_EQUAL(cbd.hasError(), true);
+  BOOST_CHECK_EQUAL(nCertsCompleted, 0);
+}
+
+BOOST_AUTO_TEST_CASE(UnrecognizedNonCritical)
+{
+  // First segment contains an unrecognized non-critical element
+  Data d;
+  d.setContent("4202CAFE"_block);
+
+  // Second segment contains cert1
+  Data d2;
+  d2.setContent(certBlock1);
+
+  cbd.append(d.getContent());
+  BOOST_CHECK_EQUAL(cbd.hasError(), false);
+  BOOST_CHECK_EQUAL(nCertsCompleted, 0);
+
+  cbd.append(d2.getContent());
+  BOOST_CHECK_EQUAL(cbd.hasError(), false);
+  BOOST_CHECK_EQUAL(nCertsCompleted, 1);
+}
+
+BOOST_AUTO_TEST_SUITE_END() // TestCertificateBundleEncoderDecoder
+BOOST_AUTO_TEST_SUITE_END() // Security
+
+} // namespace tests
+} // namespace detail
+} // namespace security
+} // namespace ndn
diff --git a/tests/unit/security/pib/impl/identity-impl.t.cpp b/tests/unit/security/pib/impl/identity-impl.t.cpp
index bb523f4..3890ddc 100644
--- a/tests/unit/security/pib/impl/identity-impl.t.cpp
+++ b/tests/unit/security/pib/impl/identity-impl.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2019 Regents of the University of California.
+ * Copyright (c) 2013-2020 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -34,7 +34,6 @@
 
 BOOST_AUTO_TEST_SUITE(Security)
 BOOST_AUTO_TEST_SUITE(Pib)
-BOOST_AUTO_TEST_SUITE(Detail)
 BOOST_FIXTURE_TEST_SUITE(TestIdentityImpl, ndn::security::tests::PibDataFixture)
 
 using security::Pib;
@@ -149,7 +148,6 @@
 }
 
 BOOST_AUTO_TEST_SUITE_END() // TestIdentityImpl
-BOOST_AUTO_TEST_SUITE_END() // Detail
 BOOST_AUTO_TEST_SUITE_END() // Pib
 BOOST_AUTO_TEST_SUITE_END() // Security
 
diff --git a/tests/unit/security/pib/impl/key-impl.t.cpp b/tests/unit/security/pib/impl/key-impl.t.cpp
index 2a6c641..b2dfd96 100644
--- a/tests/unit/security/pib/impl/key-impl.t.cpp
+++ b/tests/unit/security/pib/impl/key-impl.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2019 Regents of the University of California.
+ * Copyright (c) 2013-2020 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -35,7 +35,6 @@
 
 BOOST_AUTO_TEST_SUITE(Security)
 BOOST_AUTO_TEST_SUITE(Pib)
-BOOST_AUTO_TEST_SUITE(Detail)
 BOOST_FIXTURE_TEST_SUITE(TestKeyImpl, security::tests::PibDataFixture)
 
 using security::Pib;
@@ -189,7 +188,6 @@
 }
 
 BOOST_AUTO_TEST_SUITE_END() // TestKeyImpl
-BOOST_AUTO_TEST_SUITE_END() // Detail
 BOOST_AUTO_TEST_SUITE_END() // Pib
 BOOST_AUTO_TEST_SUITE_END() // Security