diff --git a/tests/key-chain-fixture.cpp b/tests/key-chain-fixture.cpp
new file mode 100644
index 0000000..5276ae4
--- /dev/null
+++ b/tests/key-chain-fixture.cpp
@@ -0,0 +1,93 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2013-2022 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 "tests/key-chain-fixture.hpp"
+
+#include <ndn-cxx/util/io.hpp>
+
+#include <boost/filesystem/operations.hpp>
+
+namespace ndncert::tests {
+
+using namespace ndn::security;
+
+KeyChainFixture::KeyChainFixture()
+  : m_keyChain("pib-memory:", "tpm-memory:")
+{
+}
+
+KeyChainFixture::~KeyChainFixture()
+{
+  boost::system::error_code ec;
+  for (const auto& certFile : m_certFiles) {
+    boost::filesystem::remove(certFile, ec); // ignore error
+  }
+}
+
+bool
+KeyChainFixture::saveCert(const Data& cert, const std::string& filename)
+{
+  m_certFiles.push_back(filename);
+  try {
+    ndn::io::save(cert, filename);
+    return true;
+  }
+  catch (const ndn::io::Error&) {
+    return false;
+  }
+}
+
+bool
+KeyChainFixture::saveIdentityCert(const Identity& identity, const std::string& filename)
+{
+  Certificate cert;
+  try {
+    cert = identity.getDefaultKey().getDefaultCertificate();
+  }
+  catch (const Pib::Error&) {
+    return false;
+  }
+
+  return saveCert(cert, filename);
+}
+
+bool
+KeyChainFixture::saveIdentityCert(const Name& identityName, const std::string& filename,
+                                  bool allowCreate)
+{
+  Identity id;
+  try {
+    id = m_keyChain.getPib().getIdentity(identityName);
+  }
+  catch (const Pib::Error&) {
+    if (allowCreate) {
+      id = m_keyChain.createIdentity(identityName);
+    }
+  }
+
+  if (!id) {
+    return false;
+  }
+
+  return saveIdentityCert(id, filename);
+}
+
+} // namespace ndncert::tests