diff --git a/tests/unit-tests/client-module.t.cpp b/tests/unit-tests/client-module.t.cpp
new file mode 100644
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+++ b/tests/unit-tests/client-module.t.cpp
@@ -0,0 +1,119 @@
+/* -*- 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 "identity-management-fixture.hpp"
+#include "client-module.hpp"
+#include "challenge-module.hpp"
+#include <ndn-cxx/util/dummy-client-face.hpp>
+#include <ndn-cxx/security/signing-helpers.hpp>
+#include <ndn-cxx/security/transform/public-key.hpp>
+#include <ndn-cxx/security/verification-helpers.hpp>
+
+namespace ndn {
+namespace ndncert {
+namespace tests {
+
+BOOST_FIXTURE_TEST_SUITE(TestClientModule, IdentityManagementV2TimeFixture)
+
+BOOST_AUTO_TEST_CASE(ClientModuleInitialize)
+{
+  util::DummyClientFace face(m_io, {true, true});
+  ClientModule client(face, m_keyChain);
+  client.getClientConf().load("tests/unit-tests/client.conf.test");
+  BOOST_CHECK_EQUAL(client.getClientConf().m_caItems.size(), 2);
+}
+
+BOOST_AUTO_TEST_CASE(ProbeAndNew)
+{
+  util::DummyClientFace face(m_io, {true, true});
+  ClientModule client(face, m_keyChain);
+  client.getClientConf().load("tests/unit-tests/client.conf.test");
+
+  auto identity = addIdentity(Name("/site/CA"));
+  auto key = identity.getDefaultKey();
+  auto cert = key.getDefaultCertificate();
+
+  ClientCaItem item;
+  item.m_caName = Name("/site/CA");
+  item.m_anchor = cert;
+  client.getClientConf().m_caItems.push_back(item);
+
+  int nInterest = 0;
+  face.onSendInterest.connect([&] (const Interest& interest) {
+      nInterest++;
+      if (nInterest == 1) {
+        // PROBE interest and return identifier
+        BOOST_CHECK_EQUAL(interest.getName().toUri(), "/site/CA/_PROBE/zhiyi%40cs.ucla.edu");
+        BOOST_CHECK_EQUAL(interest.getMustBeFresh(), 1);
+
+        auto data = make_shared<Data>();
+        data->setName(interest.getName());
+        JsonSection json = genResponseProbeJson(Name("/site/CA/ucla-cs-zhiyi"), Name(""));
+        std::stringstream ss;
+        boost::property_tree::write_json(ss, json);
+        Block dataContent = makeStringBlock(ndn::tlv::Content, ss.str());
+        data->setContent(dataContent);
+        m_keyChain.sign(*data, signingByCertificate(cert));
+        face.receive(*data);
+      }
+      else {
+        // NEW interest and return challenge list, request ID
+        BOOST_CHECK_EQUAL(interest.getName().getPrefix(3).toUri(), "/site/CA/_NEW");
+        BOOST_CHECK_EQUAL(interest.getName().size(), 6);
+
+        auto data = make_shared<Data>();
+        data->setName(interest.getName());
+        std::list<std::string> challenges;
+        challenges.push_back("EMAIL");
+        challenges.push_back("PIN");
+        JsonSection json = genResponseNewJson("1234", ChallengeModule::WAIT_SELECTION, challenges);
+        std::stringstream ss;
+        boost::property_tree::write_json(ss, json);
+        Block dataContent = makeStringBlock(ndn::tlv::Content, ss.str());
+        data->setContent(dataContent);
+        m_keyChain.sign(*data, signingByCertificate(cert));
+
+        face.receive(*data);
+      }
+    });
+
+  int nCallback = 0;
+  shared_ptr<RequestState> requestState = nullptr;
+  ClientModule::RequestCallback requestCallback = [&] (shared_ptr<RequestState> state) {
+    nCallback++;
+    BOOST_CHECK_EQUAL(state->m_requestId, "1234");
+    BOOST_CHECK_EQUAL(state->m_challengeList.size(), 2);
+    requestState = state;
+  };
+  client.sendProbe(item, "zhiyi@cs.ucla.edu", requestCallback, ClientModule::ErrorCallback());
+
+  advanceClocks(time::milliseconds(200), 20);
+
+  BOOST_CHECK_EQUAL(nInterest, 2);
+  BOOST_CHECK_EQUAL(nCallback, 1);
+  BOOST_CHECK_EQUAL(requestState->m_ca.m_caName.toUri(), "/site/CA");
+  BOOST_CHECK_EQUAL(requestState->m_key.getName().getPrefix(4).toUri(), "/site/CA/ucla-cs-zhiyi/KEY");
+}
+
+BOOST_AUTO_TEST_SUITE_END() // TestClientModule
+
+} // namespace tests
+} // namespace ndncert
+} // namespace ndn