diff --git a/tests/test-common.cpp b/tests/test-common.cpp
new file mode 100644
index 0000000..13c05d3
--- /dev/null
+++ b/tests/test-common.cpp
@@ -0,0 +1,78 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014-2017, Regents of the University of California
+ *
+ * This file is part of NDN DeLorean, An Authentication System for Data Archives in
+ * Named Data Networking.  See AUTHORS.md for complete list of NDN DeLorean authors
+ * and contributors.
+ *
+ * NDN DeLorean 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.
+ *
+ * NDN DeLorean 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 a copy of the GNU General Public License along with NDN
+ * DeLorean, e.g., in COPYING.md file.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "test-common.hpp"
+
+#include <ndn-cxx/security/signature-sha256-with-rsa.hpp>
+
+namespace ndn {
+namespace delorean {
+namespace tests {
+
+shared_ptr<Interest>
+makeInterest(const Name& name, uint32_t nonce)
+{
+  auto interest = make_shared<Interest>(name);
+  if (nonce != 0) {
+    interest->setNonce(nonce);
+  }
+  return interest;
+}
+
+shared_ptr<Data>
+makeData(const Name& name)
+{
+  auto data = make_shared<Data>(name);
+  return signData(data);
+}
+
+Data&
+signData(Data& data)
+{
+  ndn::SignatureSha256WithRsa fakeSignature;
+  fakeSignature.setValue(ndn::encoding::makeEmptyBlock(tlv::SignatureValue));
+  data.setSignature(fakeSignature);
+  data.wireEncode();
+
+  return data;
+}
+
+shared_ptr<Link>
+makeLink(const Name& name, std::initializer_list<std::pair<uint32_t, Name>> delegations)
+{
+  auto link = make_shared<Link>(name, delegations);
+  signData(link);
+  return link;
+}
+
+lp::Nack
+makeNack(const Name& name, uint32_t nonce, lp::NackReason reason)
+{
+  Interest interest(name);
+  interest.setNonce(nonce);
+  lp::Nack nack(std::move(interest));
+  nack.setReason(reason);
+  return nack;
+}
+
+} // namespace tests
+} // namespace delorean
+} // namespace ndn