Add MQTT interoperability test. (#223)

44 files changed, 4206 insertions, 2 deletions

diff --git a/.github/workflows/regression_test.yml b/.github/workflows/regression_test.yml
index e694f838..beec3a8f 100644
--- a/.github/workflows/regression_test.yml
+++ b/.github/workflows/regression_test.yml
@@ -174,6 +174,22 @@ jobs:
       cmake_path: ./test/cmake/nx_secure_interoperability
       result_affix: Secure_Interoperability
       skip_deploy: true
+  MQTT_Interoperability:
+    permissions:
+      contents: read
+      issues: read
+      checks: write
+      pull-requests: write
+      pages: write
+      id-token: write
+    uses: azure-rtos/threadx/.github/workflows/regression_template.yml@master
+    with:
+      install_script: ./scripts/install_mqtt.sh
+      build_script: ./scripts/build_mqtt_interoperability.sh
+      test_script: ./scripts/test_mqtt_interoperability.sh
+      cmake_path: ./test/cmake/mqtt_interoperability
+      result_affix: MQTT_Interoperability
+      skip_deploy: true
   Deploy:
     permissions:
       contents: read
@@ -182,8 +198,8 @@ jobs:
       pull-requests: write
       pages: write
       id-token: write
-    needs: [NetXDuo, Web, MQTT, NetXDuo64, NetXDuo_Fast, Azure_IoT, Secure, Crypto, Secure_Interoperability]
+    needs: [NetXDuo, Web, MQTT, NetXDuo64, NetXDuo_Fast, Azure_IoT, Secure, Crypto, Secure_Interoperability, MQTT_Interoperability]
     uses: azure-rtos/threadx/.github/workflows/regression_template.yml@master
     with:
       skip_test: true
-      deploy_list: "NetXDuo Web MQTT NetXDuo64 NetXDuo_Fast Azure_IoT Secure Crypto Secure_Interoperability"
\ No newline at end of file
+      deploy_list: "NetXDuo Web MQTT NetXDuo64 NetXDuo_Fast Azure_IoT Secure Crypto Secure_Interoperability MQTT_Interoperability"
\ No newline at end of file
diff --git a/scripts/build_mqtt_interoperability.sh b/scripts/build_mqtt_interoperability.sh
new file mode 100755
index 00000000..573c8e6d
--- /dev/null
+++ b/scripts/build_mqtt_interoperability.sh
@@ -0,0 +1,3 @@
+#! /bin/bash
+
+$(dirname `realpath $0`)/../test/cmake/mqtt_interoperability/run.sh build all
diff --git a/scripts/install_mqtt.sh b/scripts/install_mqtt.sh
new file mode 100755
index 00000000..41824416
--- /dev/null
+++ b/scripts/install_mqtt.sh
@@ -0,0 +1,17 @@
+#! /bin/bash
+
+sudo dpkg --add-architecture i386
+
+sudo apt update
+sudo apt install -y \
+    gcc-multilib \
+    g++ \
+    python3-pip \
+    ninja-build \
+    unifdef \
+    dos2unix \
+    gcovr \
+    libpcap-dev:i386 libgcc-s1:i386 \
+    ethtool \
+    mosquitto \
+    mosquitto-clients
\ No newline at end of file
diff --git a/scripts/test_mqtt_interoperability.sh b/scripts/test_mqtt_interoperability.sh
new file mode 100755
index 00000000..b3dac54d
--- /dev/null
+++ b/scripts/test_mqtt_interoperability.sh
@@ -0,0 +1,3 @@
+#! /bin/bash
+
+sudo CTEST_PARALLEL_LEVEL=1 $(dirname `realpath $0`)/../test/cmake/mqtt_interoperability/run.sh test all
diff --git a/test/cmake/mqtt_interoperability/CMakeLists.txt b/test/cmake/mqtt_interoperability/CMakeLists.txt
new file mode 120000
index 00000000..bc5e379c
--- /dev/null
+++ b/test/cmake/mqtt_interoperability/CMakeLists.txt
@@ -0,0 +1 @@
+../mqtt/CMakeLists.txt
\ No newline at end of file
diff --git a/test/cmake/mqtt_interoperability/coverage.sh b/test/cmake/mqtt_interoperability/coverage.sh
new file mode 120000
index 00000000..8474953c
--- /dev/null
+++ b/test/cmake/mqtt_interoperability/coverage.sh
@@ -0,0 +1 @@
+../mqtt/coverage.sh
\ No newline at end of file
diff --git a/test/cmake/mqtt_interoperability/libs b/test/cmake/mqtt_interoperability/libs
new file mode 120000
index 00000000..d4bda9b4
--- /dev/null
+++ b/test/cmake/mqtt_interoperability/libs
@@ -0,0 +1 @@
+../libs
\ No newline at end of file
diff --git a/test/cmake/mqtt_interoperability/regression/CMakeLists.txt b/test/cmake/mqtt_interoperability/regression/CMakeLists.txt
new file mode 100644
index 00000000..c653fded
--- /dev/null
+++ b/test/cmake/mqtt_interoperability/regression/CMakeLists.txt
@@ -0,0 +1,120 @@
+cmake_minimum_required(VERSION 3.0.0 FATAL_ERROR)
+cmake_policy(SET CMP0057 NEW)
+
+project(regression_test LANGUAGES C)
+
+get_filename_component(
+  SOURCE_DIR
+  ${CMAKE_CURRENT_LIST_DIR}/../../../regression/interoperability_test/mqtt_test
+  ABSOLUTE)
+
+if(NOT "-DNXD_MQTT_REQUIRE_TLS" IN_LIST ${CMAKE_BUILD_TYPE})
+  list(APPEND mqtt_test_cases mqtt_subscriber_test)
+  set(mqtt_subscriber_test_file_list
+      ${SOURCE_DIR}/linux_mqtt_subscriber_test_entry.c
+      ${SOURCE_DIR}/linux_mqtt_subscriber_test_server.c
+      ${SOURCE_DIR}/linux_mqtt_subscriber_test_publisher.c
+      ${SOURCE_DIR}/netx_mqtt_subscriber_test.c)
+  list(APPEND mqtt_test_cases mqtt_subscriber_empty_message_test)
+  set(mqtt_subscriber_empty_message_test_file_list
+      ${SOURCE_DIR}/linux_mqtt_subscriber_test_entry.c
+      ${SOURCE_DIR}/linux_mqtt_subscriber_test_server.c
+      ${SOURCE_DIR}/linux_mqtt_subscriber_empty_message_test_publisher.c
+      ${SOURCE_DIR}/netx_mqtt_subscriber_empty_message_test.c)
+endif()
+
+if("-DNX_SECURE_ENABLE" IN_LIST ${CMAKE_BUILD_TYPE})
+  list(APPEND mqtt_test_cases mqtt_tls_subscriber_twice_test)
+  set(mqtt_tls_subscriber_twice_test_file_list
+      ${SOURCE_DIR}/linux_mqtt_tls_subscriber_test_entry.c
+      ${SOURCE_DIR}/linux_mqtt_tls_subscriber_test_server.c
+      ${SOURCE_DIR}/linux_mqtt_tls_subscriber_twice_test_publisher.c
+      ${SOURCE_DIR}/netx_mqtt_tls_subscriber_twice_test.c)
+
+  list(APPEND mqtt_test_cases mqtt_double_subscribers_test)
+  set(mqtt_double_subscribers_test_file_list
+      ${SOURCE_DIR}/linux_mqtt_tls_subscriber_test_entry.c
+      ${SOURCE_DIR}/linux_mqtt_tls_subscriber_test_server.c
+      ${SOURCE_DIR}/linux_mqtt_tls_subscriber_test_publisher.c
+      ${SOURCE_DIR}/netx_mqtt_double_subscribers_test.c)
+
+  list(APPEND mqtt_test_cases mqtt_tls_subscriber_test)
+  set(mqtt_tls_subscriber_test_file_list
+      ${SOURCE_DIR}/linux_mqtt_tls_subscriber_test_entry.c
+      ${SOURCE_DIR}/linux_mqtt_tls_subscriber_test_server.c
+      ${SOURCE_DIR}/linux_mqtt_tls_subscriber_test_publisher.c
+      ${SOURCE_DIR}/netx_mqtt_tls_subscriber_test.c)
+
+  list(APPEND debug_secure_build_mqtt_test_cases mqtt_tls_debug_test)
+  set(mqtt_tls_debug_test_file_list
+      ${SOURCE_DIR}/netx_mqtt_tls_subscriber_test.c)
+endif()
+
+set(test_utility_files
+    ${SOURCE_DIR}/netxtestcontrol.c
+    ${SOURCE_DIR}/nx_crypto_ciphersuites_regression.c
+    ${SOURCE_DIR}/nx_ram_network_driver_test_1500.c
+    ${SOURCE_DIR}/nx_secure_fips_test_utility.c)
+
+get_filename_component(
+  UTILITY_SOURCE_DIR
+  ${CMAKE_CURRENT_LIST_DIR}/../../../regression/interoperability_test/test_frame
+  ABSOLUTE)
+add_library(
+  test_utility
+  ${UTILITY_SOURCE_DIR}/tls_test_get_external_test_process_output.c
+  ${UTILITY_SOURCE_DIR}/tls_test_launch_external_test_process.c
+  ${UTILITY_SOURCE_DIR}/tls_test_launch_external_test_process_in_background.c
+  ${UTILITY_SOURCE_DIR}/tls_test_director_clean_all.c
+  ${UTILITY_SOURCE_DIR}/tls_test_director_cleanup_registered_instances.c
+  ${UTILITY_SOURCE_DIR}/tls_test_director_create.c
+  ${UTILITY_SOURCE_DIR}/tls_test_director_destroy.c
+  ${UTILITY_SOURCE_DIR}/tls_test_director_register_test_instance.c
+  ${UTILITY_SOURCE_DIR}/tls_test_director_test_start.c
+  ${UTILITY_SOURCE_DIR}/tls_test_instance_attributes_access.c
+  ${UTILITY_SOURCE_DIR}/tls_test_instance_append.c
+  ${UTILITY_SOURCE_DIR}/tls_test_instance_create.c
+  ${UTILITY_SOURCE_DIR}/tls_test_instance_destroy.c
+  ${UTILITY_SOURCE_DIR}/tls_test_instance_find_next.c
+  ${UTILITY_SOURCE_DIR}/tls_test_instance_set_exit_status.c
+  ${UTILITY_SOURCE_DIR}/tls_test_instance_shared_buffer_manipulate.c
+  ${UTILITY_SOURCE_DIR}/tls_test_kill_external_test_process.c
+  ${UTILITY_SOURCE_DIR}/tls_test_semaphore_create.c
+  ${UTILITY_SOURCE_DIR}/tls_test_semaphore_destroy.c
+  ${UTILITY_SOURCE_DIR}/tls_test_semaphore_post.c
+  ${UTILITY_SOURCE_DIR}/tls_test_semaphore_wait.c
+  ${UTILITY_SOURCE_DIR}/tls_test_wait_all_child_process.c
+  ${UTILITY_SOURCE_DIR}/tls_test_wait_external_test_process.c
+  ${UTILITY_SOURCE_DIR}/tls_test_uninterruptable_wait.c)
+target_link_libraries(test_utility PUBLIC azrtos::netxduo)
+target_include_directories(test_utility PUBLIC ${UTILITY_SOURCE_DIR})
+
+include(network_config.cmake)
+
+set(PCAP_SOURCE
+  ${CMAKE_CURRENT_LIST_DIR}/../../../regression/interoperability_test/nx_pcap_network_driver.c
+)
+foreach(test_case ${mqtt_test_cases})
+  add_executable(${test_case} ${${test_case}_file_list} ${PCAP_SOURCE})
+  network_config(${test_case})
+  target_link_libraries(${test_case} PRIVATE test_utility pcap)
+  add_test(
+    NAME ${CMAKE_BUILD_TYPE}::${test_case}
+    COMMAND
+      bash -c
+      "export PATH=${SOURCE_DIR}/test_scripts/:$PATH;
+       ip link del ${${test_case}_interface}>/dev/null 2>&1;
+       ip link add ${${test_case}_interface} type veth peer name ${${test_case}_remote_interface} || exit 1;
+       ifconfig ${${test_case}_interface} up || { ip link del ${${test_case}_interface}; exit 1; };
+       ifconfig ${${test_case}_remote_interface} ${${test_case}_remote_ip} up netmask ${TEST_NETMASK} || { ip link del ${${test_case}_interface};exit 1; };
+       ethtool --offload ${${test_case}_remote_interface} tx off || { ip link del ${${test_case}_interface}; exit 1; };
+       tcpdump -i ${${test_case}_remote_interface} -s 0 -w ${CMAKE_CURRENT_BINARY_DIR}/${test_case}.pcap&
+       pid=$!
+       ${CMAKE_CURRENT_BINARY_DIR}/${test_case};
+       exit_code=$?
+       sleep 1;
+       kill -TERM $pid
+       ip link del ${${test_case}_interface} || exit 1;
+       [[ $exit_code = 0 ]] || [[ $exit_code = 233 ]] || { echo Exit code: $exit_code; exit $exit_code; };"
+    WORKING_DIRECTORY ${SOURCE_DIR})
+endforeach()
diff --git a/test/cmake/mqtt_interoperability/regression/network_config.cmake b/test/cmake/mqtt_interoperability/regression/network_config.cmake
new file mode 100644
index 00000000..5f75b945
--- /dev/null
+++ b/test/cmake/mqtt_interoperability/regression/network_config.cmake
@@ -0,0 +1,55 @@
+if(NOT ALLOCATION_PARAMETER)
+  execute_process(COMMAND bash "-c" "git rev-parse --verify HEAD|cut -c1-1"
+                  OUTPUT_VARIABLE ALLOCATION_PARAMETER)
+  math(EXPR ALLOCATION_PARAMETER "0x${ALLOCATION_PARAMETER}")
+endif()
+
+if(NOT TEST_SUBNET_SIZE)
+  set(TEST_SUBNET_SIZE 4)
+endif()
+
+# NX_MAX_PORT is 0xffff.
+math(EXPR PORT_NUMBER "65535 - (${ALLOCATION_PARAMETER} + 1) * 256")
+set(INTERFACE_NUMBER ${PORT_NUMBER})
+math(EXPR TMP "256 - ${TEST_SUBNET_SIZE}")
+set(TEST_NETMASK 255.255.255.${TMP})
+
+set(IP_BYTE_0 10)
+set(IP_BYTE_1 10)
+set(IP_BYTE_2 ${ALLOCATION_PARAMETER})
+set(IP_BYTE_3 1)
+set(IP_BYTE_4 2)
+
+macro(network_config target)
+  target_compile_definitions(
+    ${target}
+    PRIVATE
+    -DINTEROPERABILITY_TEST_ENABLE_PARALLEL_PROCESSING
+    -DTLS_TEST_IP_BYTE_0=${IP_BYTE_0}
+    -DTLS_TEST_IP_BYTE_1=${IP_BYTE_1}
+    -DTLS_TEST_IP_BYTE_2=${IP_BYTE_2}
+    -DTLS_TEST_IP_BYTE_3=${IP_BYTE_3}
+    -DREMOTE_IP_BYTE_0=${IP_BYTE_0}
+    -DREMOTE_IP_BYTE_1=${IP_BYTE_1}
+    -DREMOTE_IP_BYTE_2=${IP_BYTE_2}
+    -DREMOTE_IP_BYTE_3=${IP_BYTE_4}
+    -DDEVICE_SERVER_PORT=${PORT_NUMBER}
+    -DNX_PCAP_SOURCE_NAME=\"veth${INTERFACE_NUMBER}\")
+  set(${target}_interface veth${INTERFACE_NUMBER})
+  set(${target}_ip ${IP_BYTE_0}.${IP_BYTE_1}.${IP_BYTE_2}.${IP_BYTE_3})
+  math(EXPR INTERFACE_NUMBER "${INTERFACE_NUMBER} + 1")
+  set(${target}_remote_interface veth${INTERFACE_NUMBER})
+  set(${target}_remote_ip ${IP_BYTE_0}.${IP_BYTE_1}.${IP_BYTE_2}.${IP_BYTE_4})
+  set(${target}_port ${PORT_NUMBER})
+
+  # Increase numbers for next setup
+  math(EXPR INTERFACE_NUMBER "${INTERFACE_NUMBER} + 1")
+  math(EXPR IP_BYTE_3 "${IP_BYTE_3} + ${TEST_SUBNET_SIZE}")
+  if(${IP_BYTE_3} GREATER 253)
+    math(EXPR IP_BYTE_2 "${IP_BYTE_2} + 1")
+    set(IP_BYTE_3 1)
+  endif()
+  math(EXPR IP_BYTE_4 "${IP_BYTE_3} + 1")
+  math(EXPR PORT_NUMBER "${PORT_NUMBER} + 1")
+
+endmacro()
diff --git a/test/cmake/mqtt_interoperability/run.sh b/test/cmake/mqtt_interoperability/run.sh
new file mode 100755
index 00000000..dc01b08a
--- /dev/null
+++ b/test/cmake/mqtt_interoperability/run.sh
@@ -0,0 +1,9 @@
+#!/bin/bash
+
+cd $(dirname $0)
+
+# if threadx repo does not exist, clone it
+[ -d ../threadx ] || git clone https://github.com/azure-rtos/threadx.git ../threadx --depth 1
+[ -d ../filex ] || git clone https://github.com/azure-rtos/filex.git ../filex --depth 1
+[ -f .run.sh ] || ln -sf ../threadx/scripts/cmake_bootstrap.sh .run.sh
+CTEST_PARALLEL_LEVEL=1 ENABLE_IDLE=ON ./.run.sh $*
\ No newline at end of file
diff --git a/test/cmake/mqtt_interoperability/test.pcap b/test/cmake/mqtt_interoperability/test.pcap
new file mode 100644
index 00000000..58429b9e
--- /dev/null
+++ b/test/cmake/mqtt_interoperability/test.pcap
diff --git a/test/regression/interoperability_test/mqtt_test/ca.c b/test/regression/interoperability_test/mqtt_test/ca.c
new file mode 100644
index 00000000..17bb35e9
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/ca.c
@@ -0,0 +1,132 @@
+unsigned char ca_der[] = {
+  0x30, 0x82, 0x05, 0xfe, 0x30, 0x82, 0x03, 0xe6, 0xa0, 0x03, 0x02, 0x01,
+  0x02, 0x02, 0x01, 0x01, 0x30, 0x0d, 0x06, 0x09, 0x2a, 0x86, 0x48, 0x86,
+  0xf7, 0x0d, 0x01, 0x01, 0x0b, 0x05, 0x00, 0x30, 0x81, 0x8f, 0x31, 0x0b,
+  0x30, 0x09, 0x06, 0x03, 0x55, 0x04, 0x06, 0x13, 0x02, 0x55, 0x53, 0x31,
+  0x13, 0x30, 0x11, 0x06, 0x03, 0x55, 0x04, 0x08, 0x0c, 0x0a, 0x43, 0x61,
+  0x6c, 0x69, 0x66, 0x6f, 0x72, 0x6e, 0x69, 0x61, 0x31, 0x16, 0x30, 0x14,
+  0x06, 0x03, 0x55, 0x04, 0x07, 0x0c, 0x0d, 0x53, 0x61, 0x6e, 0x20, 0x46,
+  0x72, 0x61, 0x6e, 0x63, 0x69, 0x73, 0x63, 0x6f, 0x31, 0x13, 0x30, 0x11,
+  0x06, 0x03, 0x55, 0x04, 0x0a, 0x0c, 0x0a, 0x42, 0x6f, 0x67, 0x75, 0x73,
+  0x20, 0x49, 0x6e, 0x63, 0x2e, 0x31, 0x13, 0x30, 0x11, 0x06, 0x03, 0x55,
+  0x04, 0x0b, 0x0c, 0x0a, 0x4f, 0x70, 0x65, 0x72, 0x61, 0x74, 0x69, 0x6f,
+  0x6e, 0x73, 0x31, 0x29, 0x30, 0x27, 0x06, 0x03, 0x55, 0x04, 0x03, 0x0c,
+  0x20, 0x42, 0x6f, 0x67, 0x75, 0x73, 0x20, 0x49, 0x6e, 0x63, 0x2e, 0x20,
+  0x43, 0x65, 0x72, 0x74, 0x69, 0x66, 0x69, 0x63, 0x61, 0x74, 0x65, 0x20,
+  0x41, 0x75, 0x74, 0x68, 0x6f, 0x72, 0x69, 0x74, 0x79, 0x30, 0x1e, 0x17,
+  0x0d, 0x31, 0x37, 0x30, 0x33, 0x30, 0x38, 0x30, 0x34, 0x34, 0x30, 0x35,
+  0x39, 0x5a, 0x17, 0x0d, 0x32, 0x37, 0x30, 0x33, 0x30, 0x38, 0x30, 0x34,
+  0x34, 0x30, 0x35, 0x39, 0x5a, 0x30, 0x81, 0x8f, 0x31, 0x0b, 0x30, 0x09,
+  0x06, 0x03, 0x55, 0x04, 0x06, 0x13, 0x02, 0x55, 0x53, 0x31, 0x13, 0x30,
+  0x11, 0x06, 0x03, 0x55, 0x04, 0x08, 0x0c, 0x0a, 0x43, 0x61, 0x6c, 0x69,
+  0x66, 0x6f, 0x72, 0x6e, 0x69, 0x61, 0x31, 0x16, 0x30, 0x14, 0x06, 0x03,
+  0x55, 0x04, 0x07, 0x0c, 0x0d, 0x53, 0x61, 0x6e, 0x20, 0x46, 0x72, 0x61,
+  0x6e, 0x63, 0x69, 0x73, 0x63, 0x6f, 0x31, 0x13, 0x30, 0x11, 0x06, 0x03,
+  0x55, 0x04, 0x0a, 0x0c, 0x0a, 0x42, 0x6f, 0x67, 0x75, 0x73, 0x20, 0x49,
+  0x6e, 0x63, 0x2e, 0x31, 0x13, 0x30, 0x11, 0x06, 0x03, 0x55, 0x04, 0x0b,
+  0x0c, 0x0a, 0x4f, 0x70, 0x65, 0x72, 0x61, 0x74, 0x69, 0x6f, 0x6e, 0x73,
+  0x31, 0x29, 0x30, 0x27, 0x06, 0x03, 0x55, 0x04, 0x03, 0x0c, 0x20, 0x42,
+  0x6f, 0x67, 0x75, 0x73, 0x20, 0x49, 0x6e, 0x63, 0x2e, 0x20, 0x43, 0x65,
+  0x72, 0x74, 0x69, 0x66, 0x69, 0x63, 0x61, 0x74, 0x65, 0x20, 0x41, 0x75,
+  0x74, 0x68, 0x6f, 0x72, 0x69, 0x74, 0x79, 0x30, 0x82, 0x02, 0x22, 0x30,
+  0x0d, 0x06, 0x09, 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x01,
+  0x05, 0x00, 0x03, 0x82, 0x02, 0x0f, 0x00, 0x30, 0x82, 0x02, 0x0a, 0x02,
+  0x82, 0x02, 0x01, 0x00, 0xb6, 0x60, 0x88, 0x5b, 0xc9, 0x12, 0x1d, 0x2b,
+  0x6b, 0x51, 0x62, 0x62, 0xe5, 0x94, 0x12, 0x43, 0xfa, 0x27, 0x25, 0xa4,
+  0x3d, 0x91, 0x18, 0x45, 0x34, 0x43, 0xfa, 0x59, 0x65, 0x7b, 0xc3, 0xf5,
+  0x74, 0x9c, 0xa6, 0xf5, 0x80, 0x91, 0xf0, 0x1d, 0x3b, 0x7d, 0xfb, 0x6b,
+  0x4c, 0x44, 0xdb, 0x06, 0x8a, 0x4a, 0x7e, 0x3f, 0x1b, 0xae, 0x77, 0x61,
+  0x5b, 0x66, 0x61, 0x35, 0x49, 0x77, 0xd9, 0x4f, 0x1b, 0xb9, 0xd1, 0x5d,
+  0x23, 0x48, 0x8f, 0x1f, 0xf1, 0xf5, 0x63, 0x8c, 0xd1, 0xe7, 0xa5, 0xa8,
+  0x9b, 0x9c, 0x62, 0xce, 0x92, 0x09, 0xd4, 0xc4, 0xdf, 0x4f, 0x72, 0x5a,
+  0x43, 0xb9, 0xbc, 0xf5, 0xec, 0xe2, 0x85, 0xfa, 0x61, 0x72, 0xc1, 0x02,
+  0xc5, 0x7a, 0x95, 0x6e, 0x03, 0xc5, 0x29, 0xc7, 0x96, 0x39, 0xf8, 0x4e,
+  0xc4, 0x7c, 0xc7, 0x35, 0x3d, 0x9d, 0xb7, 0x53, 0x68, 0xef, 0xfa, 0x6c,
+  0x18, 0xa4, 0x3f, 0x17, 0x92, 0xdc, 0x1a, 0x61, 0x01, 0x75, 0x3c, 0xa9,
+  0x7e, 0x6c, 0xad, 0xbe, 0x8a, 0x62, 0x8e, 0xe8, 0xa2, 0xa9, 0xc5, 0x0a,
+  0xf1, 0x0e, 0xf3, 0xff, 0xd3, 0x29, 0xc8, 0x74, 0xcd, 0x7c, 0xed, 0xe6,
+  0xbe, 0x9f, 0xc9, 0x85, 0x3b, 0xe4, 0x63, 0x28, 0xd2, 0xe9, 0x38, 0xf6,
+  0xdf, 0x2c, 0x19, 0x01, 0xb7, 0xa1, 0x5d, 0x85, 0x15, 0x44, 0x62, 0x0e,
+  0x00, 0xc1, 0x37, 0x6d, 0xbc, 0xdc, 0xca, 0x47, 0xb4, 0x52, 0x17, 0x1b,
+  0xa3, 0xcc, 0x19, 0xae, 0xd9, 0x73, 0xc7, 0x5b, 0x76, 0xe1, 0xde, 0x10,
+  0x4e, 0xf9, 0x02, 0xe1, 0x68, 0x3a, 0x10, 0x51, 0x5b, 0x0e, 0x7c, 0x44,
+  0x1b, 0x64, 0x25, 0xa9, 0xa1, 0x9f, 0x48, 0x2a, 0x35, 0x15, 0x0b, 0x36,
+  0x83, 0xf7, 0xdf, 0x62, 0x95, 0x74, 0x31, 0xdd, 0x1b, 0xfd, 0xeb, 0x82,
+  0x84, 0xcb, 0x5d, 0xf8, 0x71, 0xc3, 0x78, 0x30, 0xe9, 0xb8, 0x2f, 0xe7,
+  0x59, 0xd2, 0xeb, 0x98, 0x03, 0xd0, 0x17, 0x03, 0x88, 0xc4, 0x6b, 0x6c,
+  0x14, 0x5c, 0x95, 0x18, 0xc0, 0xbf, 0x42, 0x95, 0xfe, 0x23, 0xb3, 0x0b,
+  0x6c, 0x46, 0x59, 0xc8, 0x11, 0x27, 0xc6, 0x5a, 0x09, 0x45, 0x09, 0x3f,
+  0x23, 0xf0, 0xd9, 0x5d, 0x49, 0x40, 0x95, 0xda, 0x9f, 0x89, 0xca, 0x84,
+  0x7a, 0xf2, 0x49, 0x0d, 0x43, 0xa2, 0x8b, 0x68, 0x16, 0x2d, 0xdc, 0xff,
+  0xd5, 0x82, 0xfc, 0x3f, 0x6f, 0xb7, 0x98, 0x34, 0xdb, 0xbe, 0x0b, 0xea,
+  0x2a, 0x64, 0xfa, 0x99, 0x0c, 0x39, 0x05, 0xe6, 0x8b, 0x9b, 0xd1, 0x6e,
+  0x1c, 0x9a, 0x19, 0x0f, 0xde, 0xba, 0xae, 0x33, 0xbe, 0x88, 0x8e, 0x1a,
+  0x51, 0x9f, 0x26, 0xbb, 0x87, 0xad, 0x76, 0x54, 0x7a, 0xae, 0xd3, 0x62,
+  0xa4, 0x9d, 0x94, 0x10, 0xc4, 0x0b, 0x64, 0x19, 0xfd, 0xb9, 0x2b, 0xd6,
+  0x19, 0x87, 0x62, 0xac, 0x43, 0x9b, 0xb0, 0x56, 0x27, 0x90, 0xa0, 0xb5,
+  0xef, 0xc3, 0x05, 0x20, 0x1e, 0xa4, 0xe5, 0x46, 0xf5, 0x28, 0x5c, 0x02,
+  0xaf, 0xcb, 0x31, 0x2f, 0xba, 0xa5, 0x4b, 0x4b, 0x1d, 0xc9, 0x25, 0xfe,
+  0xd4, 0x15, 0x8a, 0xa0, 0xde, 0xe3, 0x0b, 0x97, 0x57, 0x2c, 0xc2, 0xf1,
+  0x9c, 0xad, 0x49, 0xb5, 0xa3, 0x19, 0xb9, 0xcb, 0x84, 0xdf, 0xd9, 0x24,
+  0xe4, 0x03, 0x1d, 0xa7, 0xca, 0x58, 0xaf, 0x35, 0x28, 0x92, 0x3c, 0x1d,
+  0x44, 0x10, 0x91, 0xfc, 0x41, 0x1e, 0x67, 0x43, 0x37, 0xa6, 0x8b, 0xd2,
+  0x47, 0x27, 0x57, 0xa9, 0x51, 0x32, 0x59, 0xce, 0xb3, 0xf4, 0x5b, 0x87,
+  0xa1, 0xdb, 0x1b, 0x11, 0x78, 0xf4, 0x75, 0xf9, 0x3f, 0xa2, 0x26, 0x7f,
+  0x46, 0x45, 0x9c, 0x68, 0xf2, 0xa4, 0xdf, 0xc1, 0x94, 0x71, 0x23, 0xa1,
+  0x15, 0x9a, 0xad, 0x6e, 0xe4, 0x3a, 0x24, 0xe4, 0x1b, 0xee, 0x50, 0x87,
+  0x02, 0x03, 0x01, 0x00, 0x01, 0xa3, 0x63, 0x30, 0x61, 0x30, 0x0e, 0x06,
+  0x03, 0x55, 0x1d, 0x0f, 0x01, 0x01, 0xff, 0x04, 0x04, 0x03, 0x02, 0x01,
+  0x06, 0x30, 0x0f, 0x06, 0x03, 0x55, 0x1d, 0x13, 0x01, 0x01, 0xff, 0x04,
+  0x05, 0x30, 0x03, 0x01, 0x01, 0xff, 0x30, 0x1d, 0x06, 0x03, 0x55, 0x1d,
+  0x0e, 0x04, 0x16, 0x04, 0x14, 0xf6, 0x6a, 0x39, 0x1f, 0xaa, 0x47, 0xa3,
+  0x54, 0x5e, 0x0f, 0x06, 0xa1, 0xe4, 0xec, 0x85, 0x40, 0xb0, 0x6c, 0x45,
+  0x46, 0x30, 0x1f, 0x06, 0x03, 0x55, 0x1d, 0x23, 0x04, 0x18, 0x30, 0x16,
+  0x80, 0x14, 0xf6, 0x6a, 0x39, 0x1f, 0xaa, 0x47, 0xa3, 0x54, 0x5e, 0x0f,
+  0x06, 0xa1, 0xe4, 0xec, 0x85, 0x40, 0xb0, 0x6c, 0x45, 0x46, 0x30, 0x0d,
+  0x06, 0x09, 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x0b, 0x05,
+  0x00, 0x03, 0x82, 0x02, 0x01, 0x00, 0xa2, 0x1a, 0x64, 0x34, 0x1b, 0x37,
+  0xb3, 0x42, 0x3a, 0x0a, 0x05, 0xd0, 0x59, 0x2d, 0x17, 0xad, 0xc7, 0xfc,
+  0x0c, 0x32, 0xc2, 0x1f, 0x00, 0xa6, 0xf8, 0x88, 0xc0, 0xe5, 0x49, 0x5d,
+  0x3e, 0x0b, 0xbf, 0xec, 0x32, 0xeb, 0x9c, 0xf9, 0x18, 0x39, 0x3a, 0x98,
+  0x00, 0xb8, 0x76, 0x43, 0xa6, 0x60, 0x3b, 0xb8, 0x35, 0xf4, 0x2a, 0x30,
+  0xf7, 0x6c, 0x74, 0x79, 0x18, 0x27, 0x73, 0x5b, 0xa0, 0xf6, 0xb7, 0x30,
+  0x15, 0xa5, 0x11, 0x0f, 0xa1, 0xcd, 0xad, 0xeb, 0x18, 0xd6, 0x8c, 0x1a,
+  0xb1, 0x24, 0x66, 0x03, 0x54, 0xfb, 0x9a, 0x21, 0xf4, 0xe1, 0x94, 0x5f,
+  0xe4, 0x6f, 0x48, 0xe7, 0x40, 0x64, 0xad, 0xd4, 0x0a, 0xa1, 0xe0, 0xf9,
+  0xa0, 0x6b, 0xa5, 0xa3, 0x52, 0x70, 0xbd, 0x7e, 0xd1, 0x4b, 0x62, 0xc4,
+  0x5b, 0x7e, 0xde, 0x23, 0xc2, 0x04, 0xb9, 0x38, 0x4d, 0x69, 0xdc, 0xf5,
+  0xe2, 0x43, 0x92, 0x5d, 0x55, 0x2f, 0xae, 0x4c, 0x18, 0xe6, 0x5c, 0xf5,
+  0x01, 0x49, 0xc1, 0x30, 0xa5, 0xe4, 0x4f, 0x99, 0xbc, 0xc1, 0xf5, 0xe0,
+  0x27, 0xa5, 0x8b, 0xd8, 0x03, 0xb5, 0x1c, 0x3f, 0x29, 0x21, 0x38, 0x77,
+  0x16, 0x87, 0x89, 0xf3, 0xc8, 0x2f, 0x81, 0x9e, 0xbc, 0x2d, 0xeb, 0xdc,
+  0xa3, 0x56, 0xe6, 0x83, 0xaf, 0x3f, 0xeb, 0x31, 0xcd, 0x33, 0x69, 0x7f,
+  0x77, 0x13, 0x10, 0x1a, 0x74, 0xa5, 0x1d, 0xe6, 0x57, 0xe5, 0x0e, 0xb6,
+  0x38, 0x23, 0xb0, 0x15, 0xc7, 0x12, 0xf1, 0x94, 0x5d, 0x7a, 0x01, 0x53,
+  0x10, 0x2a, 0x0b, 0x38, 0x28, 0x96, 0xc6, 0x5f, 0xdc, 0x53, 0x9d, 0x79,
+  0xdc, 0x54, 0xb6, 0x2d, 0x88, 0x6d, 0x72, 0x1d, 0x33, 0x18, 0xb2, 0x45,
+  0xf5, 0x7c, 0xcf, 0x9d, 0xe8, 0xe3, 0x23, 0xc9, 0x34, 0x06, 0xd4, 0x19,
+  0x8e, 0x3c, 0x45, 0xf2, 0x76, 0x32, 0x69, 0x8d, 0xfe, 0xb2, 0x7a, 0x16,
+  0x72, 0x97, 0x84, 0x46, 0x88, 0x7f, 0x7c, 0xdb, 0xa2, 0x21, 0x31, 0xf6,
+  0x3d, 0xe2, 0xbe, 0xc9, 0x07, 0x01, 0x8d, 0x1d, 0x88, 0x05, 0xf0, 0x6d,
+  0xca, 0xcb, 0x97, 0xbf, 0x11, 0xeb, 0x32, 0xe2, 0x86, 0x40, 0xcb, 0xb3,
+  0xb5, 0xa4, 0xc5, 0xa0, 0x06, 0xc2, 0x5b, 0xb2, 0x3a, 0xf5, 0x64, 0x12,
+  0xe8, 0x5e, 0xd7, 0x87, 0x1c, 0x46, 0xff, 0x98, 0x0b, 0xb5, 0x51, 0x89,
+  0xdd, 0xeb, 0x90, 0x8a, 0xad, 0xb6, 0x3e, 0x78, 0xd7, 0x95, 0x16, 0x5f,
+  0x58, 0x12, 0x48, 0x1e, 0x64, 0x25, 0x3c, 0xeb, 0x46, 0xe7, 0xbf, 0xbe,
+  0xf7, 0x47, 0xcd, 0x52, 0x24, 0x05, 0x83, 0x44, 0x93, 0xe4, 0x63, 0x94,
+  0xf6, 0x70, 0x52, 0x7c, 0x2f, 0x03, 0x60, 0xe5, 0xc2, 0xc8, 0xf4, 0x5b,
+  0x39, 0xd5, 0x57, 0x58, 0x20, 0x05, 0x30, 0xd8, 0x8a, 0x8c, 0x54, 0x6d,
+  0x39, 0x95, 0xcf, 0x8a, 0x45, 0xf0, 0xc7, 0xc6, 0xc5, 0xfc, 0xd4, 0xd3,
+  0xbc, 0x3f, 0xa6, 0x65, 0xab, 0xc0, 0x57, 0xe9, 0xa0, 0xf9, 0x7a, 0x41,
+  0x0a, 0x82, 0x48, 0x37, 0x2b, 0x7f, 0x28, 0x96, 0x76, 0xcc, 0xb7, 0xd3,
+  0xac, 0x26, 0xd4, 0x6c, 0x68, 0x3b, 0xcb, 0x7b, 0x96, 0x32, 0xc7, 0xfd,
+  0x5c, 0x46, 0x1f, 0x9c, 0xff, 0x6b, 0xf3, 0x25, 0x53, 0xc6, 0xa5, 0x53,
+  0xdb, 0x4e, 0x16, 0x03, 0x14, 0x31, 0x0e, 0xd6, 0xda, 0xb5, 0x56, 0x2f,
+  0x4b, 0x15, 0x00, 0xe9, 0x57, 0x2b, 0x3a, 0xa5, 0xa6, 0x5c, 0x4d, 0xf9,
+  0x0c, 0x39, 0x4f, 0x19, 0x51, 0xd8, 0x2a, 0x0b, 0x58, 0x12, 0xd9, 0x37,
+  0x2b, 0x8c, 0xd2, 0x22, 0xe6, 0xf2, 0xcb, 0xbf, 0x2f, 0xae, 0x7c, 0xe5,
+  0xe2, 0xb5, 0x69, 0x65, 0x4f, 0x60, 0xe8, 0x31, 0x3a, 0xb6, 0xef, 0xa8,
+  0x5d, 0x56, 0xe6, 0xfa, 0xab, 0x26, 0x82, 0x2d, 0xac, 0x69, 0xbd, 0x6d,
+  0x63, 0x21
+};
+unsigned int ca_der_len = 1538;
diff --git a/test/regression/interoperability_test/mqtt_test/generic_test_entry_0.c b/test/regression/interoperability_test/mqtt_test/generic_test_entry_0.c
new file mode 100644
index 00000000..d06cdf08
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/generic_test_entry_0.c
@@ -0,0 +1,96 @@
+#include "tls_test_frame.h"
+
+/* Declare the test entries of test instances. */
+INT mqtt_server_entry(TLS_TEST_INSTANCE* instance_ptr);
+INT mqtt_publisher_entry(TLS_TEST_INSTANCE* instance_ptr);
+INT mqtt_subscriber_entry(TLS_TEST_INSTANCE* instance_ptr);
+
+/* Declare semaphores. */
+TLS_TEST_SEMAPHORE* semaphore_mqtt_server_prepared;
+TLS_TEST_SEMAPHORE* semaphore_mqtt_topic_subscribed;
+TLS_TEST_SEMAPHORE* semaphore_mqtt_message_published;
+TLS_TEST_SEMAPHORE* semaphore_mqtt_test_finished;
+
+INT main(INT argc, CHAR* argv[])
+{
+INT status;
+TLS_TEST_INSTANCE *ins0, *ins1, *ins2;
+TLS_TEST_DIRECTOR *director;
+INT exit_status[3];
+
+    /* Create three test instances. */
+    status = tls_test_instance_create(&ins0,                          /* test instance ptr */
+                                      "mqtt_server",                  /* instance name */
+                                      mqtt_server_entry,              /* test entry */
+                                      0,                              /* delay(seconds) */
+                                      20,                             /* timeout(seconds) */
+                                      1024,                           /* shared buffer size */
+                                      NULL);                          /* reserved */
+    return_value_if_fail(TLS_TEST_SUCCESS == status, status);
+
+    status = tls_test_instance_create(&ins1, 
+                                      "mqtt_subscriber",
+                                      mqtt_subscriber_entry,
+                                      0,
+                                      20,
+                                      1024,
+                                      NULL);
+    return_value_if_fail(TLS_TEST_SUCCESS == status, status);
+
+    status = tls_test_instance_create(&ins2, 
+                                      "mqtt_publisher",
+                                      mqtt_publisher_entry,
+                                      0,
+                                      20,
+                                      1024,
+                                      NULL);
+    return_value_if_fail(TLS_TEST_SUCCESS == status, status);
+
+    /* Create test semaphores whose value will be initialized as zero. */
+    status = tls_test_semaphore_create(&semaphore_mqtt_server_prepared, 0);
+    return_value_if_fail(TLS_TEST_SUCCESS == status, status);
+    status = tls_test_semaphore_create(&semaphore_mqtt_message_published, 0);
+    return_value_if_fail(TLS_TEST_SUCCESS == status, status);
+    status = tls_test_semaphore_create(&semaphore_mqtt_topic_subscribed, 0);
+    return_value_if_fail(TLS_TEST_SUCCESS == status, status);
+    status = tls_test_semaphore_create(&semaphore_mqtt_test_finished, 0);
+    return_value_if_fail(TLS_TEST_SUCCESS == status, status);
+
+    /* Create the test director. */
+    status = tls_test_director_create(&director, NULL /* reserved */);
+    return_value_if_fail(TLS_TEST_SUCCESS == status, status);
+
+    /* Register test instances to the director. */
+    status = tls_test_director_register_test_instance(director, ins0);
+    status += tls_test_director_register_test_instance(director, ins1);
+    status += tls_test_director_register_test_instance(director, ins2);
+    return_value_if_fail(TLS_TEST_SUCCESS == status, status);
+
+    /* Launch test. */
+    status = tls_test_director_test_start(director);
+    return_value_if_fail(TLS_TEST_SUCCESS == status, status);
+
+    /* Show test results. */
+    tls_test_instance_show_exit_status(ins0);
+    tls_test_instance_show_exit_status(ins1);
+    tls_test_instance_show_exit_status(ins2);
+
+    /* Collect exit code. */
+    tls_test_instance_get_exit_status(ins0, &(exit_status[0]));
+    tls_test_instance_get_exit_status(ins1, &(exit_status[1]));
+    tls_test_instance_get_exit_status(ins1, &(exit_status[2]));
+
+    /* Destroy all created instances. */
+    tls_test_director_clean_all(director);
+
+    /* Destroy the semaphore. */
+    tls_test_semaphore_destroy(semaphore_mqtt_server_prepared);
+    tls_test_semaphore_destroy(semaphore_mqtt_topic_subscribed);
+    tls_test_semaphore_destroy(semaphore_mqtt_message_published);
+    tls_test_semaphore_destroy(semaphore_mqtt_test_finished);
+
+    /* Check the exit codes of two instances. */
+    return_value_if_fail((TLS_TEST_NOT_AVAILABLE != exit_status[0]) && (TLS_TEST_NOT_AVAILABLE != exit_status[1]) && (TLS_TEST_NOT_AVAILABLE != exit_status[2]), TLS_TEST_NOT_AVAILABLE);
+    return_value_if_fail((0 == exit_status[0]) && (0 == exit_status[1]) && (0 == exit_status[2]), TLS_TEST_UNKNOWN_TYPE_ERROR);
+    return TLS_TEST_SUCCESS;
+}
diff --git a/test/regression/interoperability_test/mqtt_test/linux_mqtt_subscriber_empty_message_test_publisher.c b/test/regression/interoperability_test/mqtt_test/linux_mqtt_subscriber_empty_message_test_publisher.c
new file mode 100644
index 00000000..e4392470
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/linux_mqtt_subscriber_empty_message_test_publisher.c
@@ -0,0 +1,36 @@
+#include "mqtt_interoperability_test.h"
+
+/* Global semaphore address. */
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_topic_subscribed;
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_message_published;
+
+INT mqtt_publisher_entry(TLS_TEST_INSTANCE* instance_ptr)
+{
+CHAR* name;
+/* Publish a messge to the test topic. */
+CHAR* external_cmd[] = { "no_tls_pub.sh","-p", STRING(MQTT_PORT), "-t", "test", "-n", NULL};
+INT status, exit_status;
+
+    /* Get the name of the test instance. */
+    status = tls_test_instance_get_name(instance_ptr, &name);
+    return_value_if_fail(TLS_TEST_SUCCESS == status, status);
+
+    /* Wait for the subscriber. */
+    tls_test_semaphore_wait(semaphore_mqtt_topic_subscribed);
+
+    /* Wait for subscriber for one seconds. */
+    tls_test_sleep(1);
+    print_error_message("Instance %s: get semaphore_mqtt_topic_subscribed.\n", name);
+
+    /* Call an external script in the directory prepared_test_program. */
+    status = tls_test_launch_external_test_process(&exit_status, external_cmd);
+    return_value_if_fail(TLS_TEST_SUCCESS == status, status);
+
+    /* Post the semaphore to indicate that one message is published. */
+    tls_test_sleep(1);
+    tls_test_semaphore_post(semaphore_mqtt_message_published);
+
+    /* Check for exit status of the external script. */
+    return_value_if_fail(0 == exit_status, TLS_TEST_INSTANCE_FAILED);
+    return 0;
+};
diff --git a/test/regression/interoperability_test/mqtt_test/linux_mqtt_subscriber_test_entry.c b/test/regression/interoperability_test/mqtt_test/linux_mqtt_subscriber_test_entry.c
new file mode 100644
index 00000000..03e6b657
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/linux_mqtt_subscriber_test_entry.c
@@ -0,0 +1 @@
+#include "generic_test_entry_0.c"
diff --git a/test/regression/interoperability_test/mqtt_test/linux_mqtt_subscriber_test_publisher.c b/test/regression/interoperability_test/mqtt_test/linux_mqtt_subscriber_test_publisher.c
new file mode 100644
index 00000000..f4f30ee9
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/linux_mqtt_subscriber_test_publisher.c
@@ -0,0 +1,36 @@
+#include "mqtt_interoperability_test.h"
+
+/* Global semaphore address. */
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_topic_subscribed;
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_message_published;
+
+INT mqtt_publisher_entry(TLS_TEST_INSTANCE* instance_ptr)
+{
+CHAR* name;
+/* Publish a messge to the test topic. */
+CHAR* external_cmd[] = { "no_tls_pub.sh","-p", STRING(MQTT_PORT), "-t", "test", "-m", "hello", NULL};
+INT status, exit_status;
+
+    /* Get the name of the test instance. */
+    status = tls_test_instance_get_name(instance_ptr, &name);
+    return_value_if_fail(TLS_TEST_SUCCESS == status, status);
+
+    /* Wait for the subscriber. */
+    tls_test_semaphore_wait(semaphore_mqtt_topic_subscribed);
+
+    /* Wait for subscriber for one seconds. */
+    tls_test_sleep(1);
+    print_error_message("Instance %s: get semaphore_mqtt_topic_subscribed.\n", name);
+
+    /* Call an external script in the directory prepared_test_program. */
+    status = tls_test_launch_external_test_process(&exit_status, external_cmd);
+    return_value_if_fail(TLS_TEST_SUCCESS == status, status);
+
+    /* Post the semaphore to indicate that one message is published. */
+    tls_test_sleep(1);
+    tls_test_semaphore_post(semaphore_mqtt_message_published);
+
+    /* Check for exit status of the external script. */
+    return_value_if_fail(0 == exit_status, TLS_TEST_INSTANCE_FAILED);
+    return 0;
+};
diff --git a/test/regression/interoperability_test/mqtt_test/linux_mqtt_subscriber_test_server.c b/test/regression/interoperability_test/mqtt_test/linux_mqtt_subscriber_test_server.c
new file mode 100644
index 00000000..abb539e8
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/linux_mqtt_subscriber_test_server.c
@@ -0,0 +1,47 @@
+#include "mqtt_interoperability_test.h"
+
+#ifdef NXD_MQTT_REQUIRE_TLS
+INT mqtt_server_entry(TLS_TEST_INSTANCE* instance_ptr)
+{
+    return TLS_TEST_NOT_AVAILABLE;
+}
+#else
+/* Global semaphore address. */
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_server_prepared;
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_test_finished;
+
+INT mqtt_server_entry(TLS_TEST_INSTANCE* instance_ptr)
+{
+CHAR* name;
+CHAR* external_cmd[] = { "no_tls_server.sh", "-p", STRING(MQTT_PORT), NULL};
+INT status, exit_status;
+TLS_TEST_EXTERNAL_TEST_PROCESS external_test_process;
+
+    /* Get the name of the test instance. */
+    status = tls_test_instance_get_name(instance_ptr, &name);
+    return_value_if_fail(TLS_TEST_SUCCESS == status, status);
+
+    /* Launch the mqtt server in background. */
+    status = tls_test_launch_external_test_process_in_background(&external_test_process, external_cmd);
+    return_value_if_fail(TLS_TEST_SUCCESS == status, status);
+
+    /* Post the semaphore to indicate that mqtt server is prepared. */
+    tls_test_sleep(2);
+    print_error_message("Instance %s: post semaphore_mqtt_server_prepared.\n", name);
+    tls_test_semaphore_post(semaphore_mqtt_server_prepared);
+
+    /* Wait for the termination of the test. */
+    print_error_message("Instance %s: wait for semaphore_mqtt_test_finished.\n", name);
+    tls_test_semaphore_wait(semaphore_mqtt_test_finished);
+
+    /* Kill the mqtt server by SIGTERM. */
+    status = tls_test_kill_external_test_process(&external_test_process);
+    status += tls_test_wait_external_test_process(&external_test_process, &exit_status);
+    return_value_if_fail(TLS_TEST_SUCCESS == status, TLS_TEST_UNKNOWN_TYPE_ERROR);
+
+    /* Make sure that the mqtt server is killed by SIGTERM. */
+    /* For a shell process killed by signal, the return value must be (128 + signal number). */
+    return_value_if_fail(128 + SIGTERM == exit_status, TLS_TEST_INSTANCE_FAILED);
+    return 0;
+}
+#endif
diff --git a/test/regression/interoperability_test/mqtt_test/linux_mqtt_tls_subscriber_test_entry.c b/test/regression/interoperability_test/mqtt_test/linux_mqtt_tls_subscriber_test_entry.c
new file mode 100644
index 00000000..03e6b657
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/linux_mqtt_tls_subscriber_test_entry.c
@@ -0,0 +1 @@
+#include "generic_test_entry_0.c"
diff --git a/test/regression/interoperability_test/mqtt_test/linux_mqtt_tls_subscriber_test_publisher.c b/test/regression/interoperability_test/mqtt_test/linux_mqtt_tls_subscriber_test_publisher.c
new file mode 100644
index 00000000..4c112f2d
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/linux_mqtt_tls_subscriber_test_publisher.c
@@ -0,0 +1,43 @@
+#include "mqtt_interoperability_test.h"
+
+#ifndef NX_SECURE_ENABLE
+INT mqtt_publisher_entry(TLS_TEST_INSTANCE* instance_ptr)
+{
+    return 0;
+}
+#else
+/* Global semaphore address. */
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_topic_subscribed;
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_message_published;
+
+INT mqtt_publisher_entry(TLS_TEST_INSTANCE* instance_ptr)
+{
+CHAR* name;
+/* Publish a messge to the test topic. */
+CHAR* external_cmd[] = { "pub.sh","-p", STRING(MQTT_PORT), "-t", "test", "-m", "hello", NULL};
+INT status, exit_status;
+
+    /* Get the name of the test instance. */
+    status = tls_test_instance_get_name(instance_ptr, &name);
+    return_value_if_fail(TLS_TEST_SUCCESS == status, status);
+
+    /* Wait for the subscriber. */
+    tls_test_semaphore_wait(semaphore_mqtt_topic_subscribed);
+
+    /* Wait for subscriber for one seconds. */
+    tls_test_sleep(1);
+    print_error_message("Instance %s: get semaphore_mqtt_topic_subscribed.\n", name);
+
+    /* Call an external script in the directory prepared_test_program. */
+    status = tls_test_launch_external_test_process(&exit_status, external_cmd);
+    return_value_if_fail(TLS_TEST_SUCCESS == status, status);
+
+    /* Post the semaphore to indicate that one message is published. */
+    tls_test_sleep(1);
+    tls_test_semaphore_post(semaphore_mqtt_message_published);
+
+    /* Check for exit status of the external script. */
+    return_value_if_fail(0 == exit_status, TLS_TEST_INSTANCE_FAILED);
+    return 0;
+};
+#endif
diff --git a/test/regression/interoperability_test/mqtt_test/linux_mqtt_tls_subscriber_test_server.c b/test/regression/interoperability_test/mqtt_test/linux_mqtt_tls_subscriber_test_server.c
new file mode 100644
index 00000000..274e462a
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/linux_mqtt_tls_subscriber_test_server.c
@@ -0,0 +1,47 @@
+#include "mqtt_interoperability_test.h"
+
+#ifndef NX_SECURE_ENABLE
+INT mqtt_server_entry(TLS_TEST_INSTANCE* instance_ptr)
+{
+    return TLS_TEST_NOT_AVAILABLE;
+}
+#else
+/* Global semaphore address. */
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_server_prepared;
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_test_finished;
+
+INT mqtt_server_entry(TLS_TEST_INSTANCE* instance_ptr)
+{
+CHAR* name;
+CHAR* external_cmd[] = { "certificate_server.sh", "-p", STRING(MQTT_PORT), NULL};
+INT status, exit_status;
+TLS_TEST_EXTERNAL_TEST_PROCESS external_test_process;
+
+    /* Get the name of the test instance. */
+    status = tls_test_instance_get_name(instance_ptr, &name);
+    return_value_if_fail(TLS_TEST_SUCCESS == status, status);
+
+    /* Launch the mqtt server in background. */
+    status = tls_test_launch_external_test_process_in_background(&external_test_process, external_cmd);
+    return_value_if_fail(TLS_TEST_SUCCESS == status, status);
+
+    /* Post the semaphore to indicate that mqtt server is prepared. */
+    tls_test_sleep(1);
+    print_error_message("Instance %s: post semaphore_mqtt_server_prepared.\n", name);
+    tls_test_semaphore_post(semaphore_mqtt_server_prepared);
+
+    /* Wait for the termination of the test. */
+    print_error_message("Instance %s: wait for semaphore_mqtt_test_finished.\n", name);
+    tls_test_semaphore_wait(semaphore_mqtt_test_finished);
+
+    /* Kill the mqtt server by SIGTERM. */
+    status = tls_test_kill_external_test_process(&external_test_process);
+    status += tls_test_wait_external_test_process(&external_test_process, &exit_status);
+    return_value_if_fail(TLS_TEST_SUCCESS == status, TLS_TEST_UNKNOWN_TYPE_ERROR);
+
+    /* Make sure that the mqtt server is killed by SIGTERM. */
+    /* For a shell process killed by signal, the return value must be (128 + signal number). */
+    return_value_if_fail(128 + SIGTERM == exit_status, TLS_TEST_INSTANCE_FAILED);
+    return 0;
+}
+#endif
diff --git a/test/regression/interoperability_test/mqtt_test/linux_mqtt_tls_subscriber_twice_test_publisher.c b/test/regression/interoperability_test/mqtt_test/linux_mqtt_tls_subscriber_twice_test_publisher.c
new file mode 100644
index 00000000..17e6913e
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/linux_mqtt_tls_subscriber_twice_test_publisher.c
@@ -0,0 +1,48 @@
+#include "mqtt_interoperability_test.h"
+
+#ifndef NX_SECURE_ENABLE
+INT mqtt_publisher_entry(TLS_TEST_INSTANCE* instance_ptr)
+{
+    return 0;
+}
+#else
+/* Global semaphore address. */
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_topic_subscribed;
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_message_published;
+
+INT mqtt_publisher_entry(TLS_TEST_INSTANCE* instance_ptr)
+{
+CHAR* name;
+/* Publish a messge to the test topic. */
+CHAR* external_cmd[] = { "pub.sh","-p", STRING(MQTT_PORT), "-t", "test", "-m", "hello", NULL};
+INT status, exit_status;
+UINT i;
+
+    /* Get the name of the test instance. */
+    status = tls_test_instance_get_name(instance_ptr, &name);
+    return_value_if_fail(TLS_TEST_SUCCESS == status, status);
+
+    for (i = 0; i < 3; i++)
+    {
+
+        /* Wait for the subscriber. */
+        tls_test_semaphore_wait(semaphore_mqtt_topic_subscribed);
+
+        /* Wait for subscriber for one seconds. */
+        tls_test_sleep(1);
+        print_error_message("Instance %s: get semaphore_mqtt_topic_subscribed.\n", name);
+
+        /* Call an external script in the directory prepared_test_program. */
+        status = tls_test_launch_external_test_process(&exit_status, external_cmd);
+        return_value_if_fail(TLS_TEST_SUCCESS == status, status);
+
+        /* Post the semaphore to indicate that one message is published. */
+        tls_test_sleep(1);
+        tls_test_semaphore_post(semaphore_mqtt_message_published);
+    }
+
+    /* Check for exit status of the external script. */
+    return_value_if_fail(0 == exit_status, TLS_TEST_INSTANCE_FAILED);
+    return 0;
+};
+#endif
diff --git a/test/regression/interoperability_test/mqtt_test/mqtt_interoperability_test.h b/test/regression/interoperability_test/mqtt_test/mqtt_interoperability_test.h
new file mode 100644
index 00000000..55ca6e49
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/mqtt_interoperability_test.h
@@ -0,0 +1,15 @@
+#ifndef __MQTT_INTEROPERABILITY_TEST__
+#define __MQTT_INTEROPERABILITY_TEST__
+
+#include "tls_test_frame.h"
+
+#define MQTT_PORT 8884
+
+#ifndef MQTT_PORT
+#define MQTT_PORT 8883
+#endif /* MQTT_PORT */
+
+#define STRING(s) str(s)
+#define str(s) #s
+
+#endif /* __MQTT_INEROPERABILITY_TEST__ */
diff --git a/test/regression/interoperability_test/mqtt_test/netx_mqtt_double_subscribers_test.c b/test/regression/interoperability_test/mqtt_test/netx_mqtt_double_subscribers_test.c
new file mode 100644
index 00000000..e976963f
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/netx_mqtt_double_subscribers_test.c
@@ -0,0 +1,329 @@
+#include "mqtt_interoperability_test.h"
+#include "ca.c"
+
+#ifndef NX_SECURE_ENABLE
+INT mqtt_subscriber_entry(TLS_TEST_INSTANCE* instance_ptr)
+{
+    print_error_message( "NX_SEUCRE_ENABLE is not defined.\n");
+    return 0;
+}
+#else /* ifdef NX_SECURE_ENABLE */
+
+#include "nxd_mqtt_client.h"
+
+/* Define the ThreadX and NetX object control blocks...  */
+
+NX_PACKET_POOL    pool_0;
+NX_IP             ip_0;  
+
+NX_TCP_SOCKET tcp_socket;
+
+#define REMOTE_SERVER_PORT          4433
+#define LOCAL_CLIENT_PORT           30024
+
+/* Define the IP thread's stack area.  */
+ULONG             ip_thread_stack[3 * 1024 / sizeof(ULONG)];
+
+/* Define packet pool for the demonstration.  */
+#define NX_PACKET_POOL_SIZE ((1536 + sizeof(NX_PACKET)) * 64)
+ULONG             packet_pool_area[NX_PACKET_POOL_SIZE/sizeof(ULONG) + 64 / sizeof(ULONG)];
+
+/* Define the ARP cache area.  */
+ULONG             arp_space_area[512 / sizeof(ULONG)];
+
+/* Define the demo thread.  */
+ULONG             demo_thread_stack[6 * 1024 / sizeof(ULONG)];
+TX_THREAD         demo_thread;
+
+/* Define the pcap driver function. */
+VOID    _nx_pcap_network_driver(NX_IP_DRIVER *driver_req_ptr);
+
+/* Define a global variable for the pointer of current test instance. */
+TLS_TEST_INSTANCE* client_instance_ptr;
+void client_thread_entry(ULONG thread_input);
+
+#ifdef DEBUG_NX_SECURE
+INT main()
+{
+    tx_kernel_enter();
+}
+#else
+/* Declare semaphores. */
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_server_prepared;
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_topic_subscribed;
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_message_published;
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_test_finished;
+
+INT mqtt_subscriber_entry(TLS_TEST_INSTANCE* instance_ptr)
+{
+    client_instance_ptr = instance_ptr;
+    tx_kernel_enter();
+}
+#endif
+
+#ifdef CTEST
+VOID test_application_define(void *first_unused_memory)
+#else
+void    tx_application_define(void *first_unused_memory)
+#endif
+{
+UINT  status;
+
+    /* Initialize the NetX system.  */
+    nx_system_initialize();
+    
+    /* Create a packet pool.  */
+    status =  nx_packet_pool_create(&pool_0, "NetX Main Packet Pool", 1536,  (ULONG*)(((int)packet_pool_area + 64) & ~63) , NX_PACKET_POOL_SIZE);
+    show_error_message_if_fail(NX_SUCCESS == status);
+
+    /* Create an IP instance.  */
+    status = nx_ip_create(&ip_0, 
+                          "NetX IP Instance 0", 
+                          TLS_TEST_IP_ADDRESS_NUMBER,                           
+                          0xFFFFFF00UL, 
+                          &pool_0,
+                          _nx_pcap_network_driver,
+                          (UCHAR*)ip_thread_stack,
+                          sizeof(ip_thread_stack),
+                          1);
+    show_error_message_if_fail(NX_SUCCESS == status);
+    
+    /* Enable ARP and supply ARP cache memory for IP Instance 0.  */
+    status =  nx_arp_enable(&ip_0, (void *)arp_space_area, sizeof(arp_space_area));
+    show_error_message_if_fail(NX_SUCCESS == status);
+
+    /* Enable TCP traffic.  */
+    status =  nx_tcp_enable(&ip_0);
+    show_error_message_if_fail(NX_SUCCESS == status);
+
+    /* Enable UDP traffic.  */
+    status =  nx_udp_enable(&ip_0);
+    show_error_message_if_fail(NX_SUCCESS == status);
+
+    /* Enable ICMP.  */
+    status =  nx_icmp_enable(&ip_0);
+    show_error_message_if_fail(NX_SUCCESS == status);
+
+    status =  nx_ip_fragment_enable(&ip_0);
+    show_error_message_if_fail(NX_SUCCESS == status);
+    tx_thread_create(&demo_thread, "demo thread", client_thread_entry, 0,
+            demo_thread_stack, sizeof(demo_thread_stack),
+            16, 16, 4, TX_AUTO_START);
+}
+
+/* Declare the MQTT client control block. */
+static NXD_MQTT_CLIENT              mqtt_client;
+static NXD_MQTT_CLIENT              mqtt_client_0;
+#define  CLIENT_ID_STRING           "mytestclient"
+#define  CLIENT_0_ID_STRING         "mysecondtestclient"
+#define  MQTT_CLIENT_STACK_SIZE     4096
+
+/* Define the priority of the MQTT internal thread. */
+#define MQTT_THREAD_PRIORTY         2
+
+/* Declare a 2000-byte memory space the application supplies to the MQTT client instance. */
+static ULONG                        client_memory[2000 / sizeof(ULONG)];
+static ULONG                        client_0_memory[2000 / sizeof(ULONG)];
+
+/* Declare the MQTT thread stack space. */
+static ULONG                        mqtt_client_stack[MQTT_CLIENT_STACK_SIZE / sizeof(ULONG)];
+static ULONG                        mqtt_client_0_stack[MQTT_CLIENT_STACK_SIZE / sizeof(ULONG)];
+
+/* Define the MQTT keep alive timer for 5 minutes */
+#define MQTT_KEEP_ALIVE_TIMER       300
+
+/* Define the subscribed topic. */
+#define TOPIC_NAME                  "test"
+
+#define QOS0                        0
+#define QOS1                        1
+
+/* Declare external cryptosuites. */
+extern const NX_SECURE_TLS_CRYPTO nx_crypto_tls_ciphers;
+
+/* Define crypto metadata buffer. */
+static UCHAR metadata_buffer[5*4096];
+static UCHAR metadata_buffer_0[5*4096];
+
+/* Declare buffers to hold message and topic. */
+static UCHAR message_buffer[NXD_MQTT_MAX_MESSAGE_LENGTH];
+static UCHAR topic_buffer[NXD_MQTT_MAX_TOPIC_NAME_LENGTH];
+
+/* For remote certificate. */
+NX_SECURE_X509_CERT remote_certificate, remote_issuer;
+NX_SECURE_X509_CERT remote_certificate_0, remote_issuer_0, ca_certificate;
+UCHAR remote_cert_buffer[2000];
+UCHAR remote_issuer_buffer[2000];
+UCHAR remote_cert_buffer_0[2000];
+UCHAR remote_issuer_buffer_0[2000];
+
+/* Define the callback function for tls connection. */
+UINT tls_setup_method(NXD_MQTT_CLIENT* client_ptr, NX_SECURE_TLS_SESSION* tls_session,
+        NX_SECURE_X509_CERT* certificate, NX_SECURE_X509_CERT* trusted_certificate)
+{
+    nx_secure_tls_remote_certificate_allocate(tls_session, &remote_certificate, remote_cert_buffer, sizeof(remote_cert_buffer));
+    nx_secure_tls_remote_certificate_allocate(tls_session, &remote_issuer, remote_issuer_buffer, sizeof(remote_issuer_buffer));
+
+    nx_secure_x509_certificate_initialize(&ca_certificate, ca_der, ca_der_len,
+                                          NX_NULL, 0, NX_NULL, 0, NX_SECURE_X509_KEY_TYPE_NONE);
+    nx_secure_tls_trusted_certificate_add(tls_session, &ca_certificate);
+
+    return(NX_SUCCESS);
+}
+
+UINT tls_setup_method_0(NXD_MQTT_CLIENT* client_ptr, NX_SECURE_TLS_SESSION* tls_session,
+        NX_SECURE_X509_CERT* certificate, NX_SECURE_X509_CERT* trusted_certificate)
+{
+    nx_secure_tls_remote_certificate_allocate(tls_session, &remote_certificate_0, remote_cert_buffer_0, sizeof(remote_cert_buffer_0));
+    nx_secure_tls_remote_certificate_allocate(tls_session, &remote_issuer_0, remote_issuer_buffer_0, sizeof(remote_issuer_buffer_0));
+
+    nx_secure_x509_certificate_initialize(&ca_certificate, ca_der, ca_der_len,
+                                          NX_NULL, 0, NX_NULL, 0, NX_SECURE_X509_KEY_TYPE_NONE);
+    nx_secure_tls_trusted_certificate_add(tls_session, &ca_certificate);
+
+    return(NX_SUCCESS);
+}
+
+static UCHAR tls_packet_buffer[4096];
+static UCHAR tls_packet_buffer_0[4096];
+
+void client_thread_entry(ULONG thread_input)
+{
+UINT        status, topic_length, message_length;
+NXD_ADDRESS server_ip;
+INT         test_result = 0;
+    
+    /* Address of remote server. */
+    print_error_message( "remote ip address number %lu, remote ip address string %s.\n", REMOTE_IP_ADDRESS_NUMBER, REMOTE_IP_ADDRESS_STRING);
+    
+    /* Create MQTT client instance. */
+    status = nxd_mqtt_client_create(&mqtt_client, "my_client", CLIENT_ID_STRING, strlen(CLIENT_ID_STRING),
+                                    &ip_0, &pool_0, (VOID*)mqtt_client_stack, sizeof(mqtt_client_stack), 
+                                    MQTT_THREAD_PRIORTY,
+                                    (UCHAR*)client_memory, sizeof(client_memory));
+    exit_if_fail(NX_SUCCESS == status, TLS_TEST_UNKNOWN_TYPE_ERROR);
+
+    /* Create the second MQTT client instance. */
+    status = nxd_mqtt_client_create(&mqtt_client_0, "my_client_0", CLIENT_0_ID_STRING, strlen(CLIENT_0_ID_STRING),
+                                    &ip_0, &pool_0, (VOID*)mqtt_client_0_stack, sizeof(mqtt_client_0_stack), 
+                                    MQTT_THREAD_PRIORTY,
+                                    (UCHAR*)client_0_memory, sizeof(client_0_memory));
+    exit_if_fail(NX_SUCCESS == status, TLS_TEST_UNKNOWN_TYPE_ERROR);
+    
+    /* Create a tls session. */
+    status = nx_secure_tls_session_create(&(mqtt_client.nxd_mqtt_tls_session),
+                                          &nx_crypto_tls_ciphers,
+                                          metadata_buffer,
+                                          sizeof(metadata_buffer));
+    status += nx_secure_tls_session_packet_buffer_set(&(mqtt_client.nxd_mqtt_tls_session), tls_packet_buffer, sizeof(tls_packet_buffer));
+    exit_if_fail(NX_SUCCESS == status, TLS_TEST_UNKNOWN_TYPE_ERROR);
+
+    /* Create a tls session for the second MQTT client instance. */
+    status = nx_secure_tls_session_create(&(mqtt_client_0.nxd_mqtt_tls_session),
+                                          &nx_crypto_tls_ciphers,
+                                          metadata_buffer_0,
+                                          sizeof(metadata_buffer_0));
+    status += nx_secure_tls_session_packet_buffer_set(&(mqtt_client_0.nxd_mqtt_tls_session), tls_packet_buffer_0, sizeof(tls_packet_buffer_0));
+    exit_if_fail(NX_SUCCESS == status, TLS_TEST_UNKNOWN_TYPE_ERROR);
+
+#ifndef DEBUG_NX_SECURE
+    /* Wait for the mqtt server. */
+    tls_test_semaphore_wait(semaphore_mqtt_server_prepared);
+    print_error_message( "subscriber get semaphore_server_prepared.\n");
+#endif
+
+    /* Start the connection to the server. */
+    server_ip.nxd_ip_version = 4;
+    server_ip.nxd_ip_address.v4 = REMOTE_IP_ADDRESS_NUMBER;
+
+    /* Connect mqtt server with tls. */
+    status = nxd_mqtt_client_secure_connect(&mqtt_client, &server_ip, MQTT_PORT, 
+                                            tls_setup_method,
+                                            MQTT_KEEP_ALIVE_TIMER, 1, NX_WAIT_FOREVER);
+    exit_if_fail(NX_SUCCESS == status, TLS_TEST_UNKNOWN_TYPE_ERROR);
+    
+    /* Subscribe to the topic with QoS level 0. */
+    status = nxd_mqtt_client_subscribe(&mqtt_client, TOPIC_NAME, strlen(TOPIC_NAME), QOS0);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+
+    /* So as the second MQTT client instance. */
+    status = nxd_mqtt_client_secure_connect(&mqtt_client_0, &server_ip, MQTT_PORT, 
+                                            tls_setup_method_0,
+                                            MQTT_KEEP_ALIVE_TIMER, 1, NX_WAIT_FOREVER);
+    exit_if_fail(NX_SUCCESS == status, TLS_TEST_UNKNOWN_TYPE_ERROR);
+
+    status = nxd_mqtt_client_subscribe(&mqtt_client_0, TOPIC_NAME, strlen(TOPIC_NAME), QOS0);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+
+#ifndef DEBUG_NX_SECURE
+    /* Post the semaphore to indicate that the given topic is subscribed. */
+    tls_test_semaphore_post(semaphore_mqtt_topic_subscribed);
+    
+    /* Wait for the publisher. */
+    tls_test_semaphore_wait(semaphore_mqtt_message_published);
+#endif
+
+    /* Though the publisher put the semaphore, Wait for a moment. */
+    tx_thread_sleep(5 * NX_IP_PERIODIC_RATE);
+
+    /* Get MQTT message. */
+    status = nxd_mqtt_client_message_get(&mqtt_client, topic_buffer, sizeof(topic_buffer), &topic_length, 
+                                         message_buffer, sizeof(message_buffer), &message_length);
+    printf("func: %s, line %d, status = %d.\n", __func__, __LINE__, status);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+
+    /* Verify test result. */
+    if(status == NXD_MQTT_SUCCESS)
+    {
+        add_error_counter_if_fail( 5 == message_length, test_result);
+        add_error_counter_if_fail( 'h' == message_buffer[0], test_result);
+        add_error_counter_if_fail( 'e' == message_buffer[1], test_result);
+        add_error_counter_if_fail( 'l' == message_buffer[2], test_result);
+        add_error_counter_if_fail( 'l' == message_buffer[3], test_result);
+        add_error_counter_if_fail( 'o' == message_buffer[4], test_result);
+    }
+    
+    /* So as the second MQTT client instance. */
+    status = nxd_mqtt_client_message_get(&mqtt_client_0, topic_buffer, sizeof(topic_buffer), &topic_length, 
+                                         message_buffer, sizeof(message_buffer), &message_length);
+    printf("func: %s, line %d, status = %d.\n", __func__, __LINE__, status);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+
+    /* Verify test result. */
+    if(status == NXD_MQTT_SUCCESS)
+    {
+        add_error_counter_if_fail( 5 == message_length, test_result);
+        add_error_counter_if_fail( 'h' == message_buffer[0], test_result);
+        add_error_counter_if_fail( 'e' == message_buffer[1], test_result);
+        add_error_counter_if_fail( 'l' == message_buffer[2], test_result);
+        add_error_counter_if_fail( 'l' == message_buffer[3], test_result);
+        add_error_counter_if_fail( 'o' == message_buffer[4], test_result);
+    }
+
+    /* Now unsubscribe the topic. */
+    status = nxd_mqtt_client_unsubscribe(&mqtt_client, TOPIC_NAME, strlen(TOPIC_NAME));
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+    status = nxd_mqtt_client_unsubscribe(&mqtt_client_0, TOPIC_NAME, strlen(TOPIC_NAME));
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+
+    /* Disconnect from the broker. */
+    status = nxd_mqtt_client_disconnect(&mqtt_client);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+    status = nxd_mqtt_client_disconnect(&mqtt_client_0);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+
+    /* Delete the client instance, release all the resources. */
+    status = nxd_mqtt_client_delete(&mqtt_client);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+    status = nxd_mqtt_client_delete(&mqtt_client_0);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+    
+#ifndef DEBUG_NX_SECURE
+    /* Post the semaphore to indicate that the test is finished. */
+    status = tls_test_semaphore_post(semaphore_mqtt_test_finished);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+#endif
+
+    exit(test_result);
+}
+#endif /* ifndef NX_SECURE_ENABLE */
diff --git a/test/regression/interoperability_test/mqtt_test/netx_mqtt_subscriber_empty_message_test.c b/test/regression/interoperability_test/mqtt_test/netx_mqtt_subscriber_empty_message_test.c
new file mode 100644
index 00000000..9c30bbff
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/netx_mqtt_subscriber_empty_message_test.c
@@ -0,0 +1,195 @@
+#include "mqtt_interoperability_test.h"
+#include "nxd_mqtt_client.h"
+
+#ifdef NXD_MQTT_REQUIRE_TLS
+INT mqtt_subscriber_entry(TLS_TEST_INSTANCE* instance_ptr)
+{
+    print_error_message( "Require TLS.\n");
+    return 0;
+}
+#else /* ifdef NX_SECURE_ENABLE */
+/* Define the ThreadX and NetX object control blocks...  */
+
+NX_PACKET_POOL    pool_0;
+NX_IP             ip_0;  
+
+NX_TCP_SOCKET tcp_socket;
+
+#define REMOTE_SERVER_PORT          4433
+#define LOCAL_CLIENT_PORT           30024
+
+/* Define the IP thread's stack area.  */
+ULONG             ip_thread_stack[3 * 1024 / sizeof(ULONG)];
+
+/* Define packet pool for the demonstration.  */
+#define NX_PACKET_POOL_SIZE ((1536 + sizeof(NX_PACKET)) * 32)
+ULONG             packet_pool_area[NX_PACKET_POOL_SIZE/sizeof(ULONG) + 64 / sizeof(ULONG)];
+
+/* Define the ARP cache area.  */
+ULONG             arp_space_area[512 / sizeof(ULONG)];
+
+/* Define the demo thread.  */
+ULONG             demo_thread_stack[6 * 1024 / sizeof(ULONG)];
+TX_THREAD         demo_thread;
+
+/* Define the pcap driver function. */
+VOID    _nx_pcap_network_driver(NX_IP_DRIVER *driver_req_ptr);
+
+/* Define a global variable for the pointer of current test instance. */
+TLS_TEST_INSTANCE* client_instance_ptr;
+void client_thread_entry(ULONG thread_input);
+
+/* Declare semaphores. */
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_server_prepared;
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_topic_subscribed;
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_message_published;
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_test_finished;
+
+INT mqtt_subscriber_entry(TLS_TEST_INSTANCE* instance_ptr)
+{
+    client_instance_ptr = instance_ptr;
+    tx_kernel_enter();
+}
+
+#ifdef CTEST
+VOID test_application_define(void *first_unused_memory)
+#else
+void    tx_application_define(void *first_unused_memory)
+#endif
+{
+UINT  status;
+
+    /* Initialize the NetX system.  */
+    nx_system_initialize();
+    
+    /* Create a packet pool.  */
+    status =  nx_packet_pool_create(&pool_0, "NetX Main Packet Pool", 1536,  (ULONG*)(((int)packet_pool_area + 64) & ~63) , NX_PACKET_POOL_SIZE);
+    show_error_message_if_fail(NX_SUCCESS == status);
+
+    /* Create an IP instance.  */
+    status = nx_ip_create(&ip_0, 
+                          "NetX IP Instance 0", 
+                          TLS_TEST_IP_ADDRESS_NUMBER,                           
+                          0xFFFFFF00UL, 
+                          &pool_0,
+                          _nx_pcap_network_driver,
+                          (UCHAR*)ip_thread_stack,
+                          sizeof(ip_thread_stack),
+                          1);
+    show_error_message_if_fail(NX_SUCCESS == status);
+    
+    /* Enable ARP and supply ARP cache memory for IP Instance 0.  */
+    status =  nx_arp_enable(&ip_0, (void *)arp_space_area, sizeof(arp_space_area));
+    show_error_message_if_fail(NX_SUCCESS == status);
+
+    /* Enable TCP traffic.  */
+    status =  nx_tcp_enable(&ip_0);
+    show_error_message_if_fail(NX_SUCCESS == status);
+
+    /* Enable UDP traffic.  */
+    status =  nx_udp_enable(&ip_0);
+    show_error_message_if_fail(NX_SUCCESS == status);
+
+    /* Enable ICMP.  */
+    status =  nx_icmp_enable(&ip_0);
+    show_error_message_if_fail(NX_SUCCESS == status);
+
+    status =  nx_ip_fragment_enable(&ip_0);
+    show_error_message_if_fail(NX_SUCCESS == status);
+    tx_thread_create(&demo_thread, "demo thread", client_thread_entry, 0,
+            demo_thread_stack, sizeof(demo_thread_stack),
+            16, 16, 4, TX_AUTO_START);
+}
+
+/* Declare the MQTT client control block. */
+static NXD_MQTT_CLIENT              mqtt_client;
+#define  CLIENT_ID_STRING           "mytestclient"
+#define  MQTT_CLIENT_STACK_SIZE     4096
+
+/* Define the priority of the MQTT internal thread. */
+#define MQTT_THREAD_PRIORTY         2
+
+/* Declare a 2000-byte memory space the application supplies to the MQTT client instance. */
+static ULONG                        client_memory[2000 / sizeof(ULONG)];
+
+/* Declare the MQTT thread stack space. */
+static ULONG                        mqtt_client_stack[MQTT_CLIENT_STACK_SIZE / sizeof(ULONG)];
+
+/* Define the MQTT keep alive timer for 5 minutes */
+#define MQTT_KEEP_ALIVE_TIMER       300
+
+/* Define the subscribed topic. */
+#define TOPIC_NAME                  "test"
+
+#define QOS0                        0
+#define QOS1                        1
+
+/* Declare buffers to hold message and topic. */
+static UCHAR message_buffer[NXD_MQTT_MAX_MESSAGE_LENGTH];
+static UCHAR topic_buffer[NXD_MQTT_MAX_TOPIC_NAME_LENGTH];
+
+void client_thread_entry(ULONG thread_input)
+{
+UINT        status, topic_length, message_length = 0xFFFFFFFF;
+NXD_ADDRESS server_ip;
+INT         test_result = 0;
+    
+    /* Address of remote server. */
+    print_error_message( "remote ip address number %lu, remote ip address string %s.\n", REMOTE_IP_ADDRESS_NUMBER, REMOTE_IP_ADDRESS_STRING);
+    
+    /* Create MQTT client instance. */
+    status = nxd_mqtt_client_create(&mqtt_client, "my_client", CLIENT_ID_STRING, strlen(CLIENT_ID_STRING),
+                                    &ip_0, &pool_0, (VOID*)mqtt_client_stack, sizeof(mqtt_client_stack), 
+                                    MQTT_THREAD_PRIORTY,
+                                    (UCHAR*)client_memory, sizeof(client_memory));
+    exit_if_fail(NX_SUCCESS == status, TLS_TEST_UNKNOWN_TYPE_ERROR);
+    
+    /* Wait for the mqtt server. */
+    tls_test_semaphore_wait(semaphore_mqtt_server_prepared);
+    print_error_message( "subscriber get semaphore_server_prepared.\n");
+
+    /* Start the connection to the server. */
+    server_ip.nxd_ip_version = 4;
+    server_ip.nxd_ip_address.v4 = REMOTE_IP_ADDRESS_NUMBER;
+    status = nxd_mqtt_client_connect(&mqtt_client, &server_ip, MQTT_PORT, 
+                                     MQTT_KEEP_ALIVE_TIMER, 0, NX_WAIT_FOREVER);
+    exit_if_fail(NX_SUCCESS == status, TLS_TEST_UNKNOWN_TYPE_ERROR);
+    
+    /* Subscribe to the topic with QoS level 0. */
+    status = nxd_mqtt_client_subscribe(&mqtt_client, TOPIC_NAME, strlen(TOPIC_NAME), QOS0);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+
+    /* Post the semaphore to indicate that the given topic is subscribed. */
+    tls_test_semaphore_post(semaphore_mqtt_topic_subscribed);
+    
+    /* Wait for the publisher. */
+    tls_test_semaphore_wait(semaphore_mqtt_message_published);
+    status = nxd_mqtt_client_message_get(&mqtt_client, topic_buffer, sizeof(topic_buffer), &topic_length, 
+                                         message_buffer, sizeof(message_buffer), &message_length);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+
+    /* Verify test result. */
+    if(status == NXD_MQTT_SUCCESS)
+    {
+        add_error_counter_if_fail( 0 == message_length, test_result);
+    }
+    
+    /* Now unsubscribe the topic. */
+    status = nxd_mqtt_client_unsubscribe(&mqtt_client, TOPIC_NAME, strlen(TOPIC_NAME));
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+
+    /* Disconnect from the broker. */
+    status = nxd_mqtt_client_disconnect(&mqtt_client);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+
+    /* Delete the client instance, release all the resources. */
+    status = nxd_mqtt_client_delete(&mqtt_client);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+    
+    /* Post the semaphore to indicate that the test is finished. */
+    status = tls_test_semaphore_post(semaphore_mqtt_test_finished);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+
+    exit(test_result);
+}
+#endif
diff --git a/test/regression/interoperability_test/mqtt_test/netx_mqtt_subscriber_test.c b/test/regression/interoperability_test/mqtt_test/netx_mqtt_subscriber_test.c
new file mode 100644
index 00000000..799bffd4
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/netx_mqtt_subscriber_test.c
@@ -0,0 +1,200 @@
+#include "mqtt_interoperability_test.h"
+#include "nxd_mqtt_client.h"
+
+#ifdef NXD_MQTT_REQUIRE_TLS
+INT mqtt_subscriber_entry(TLS_TEST_INSTANCE* instance_ptr)
+{
+    print_error_message( "Require TLS.\n");
+    return 0;
+}
+#else /* ifdef NX_SECURE_ENABLE */
+/* Define the ThreadX and NetX object control blocks...  */
+
+NX_PACKET_POOL    pool_0;
+NX_IP             ip_0;  
+
+NX_TCP_SOCKET tcp_socket;
+
+#define REMOTE_SERVER_PORT          4433
+#define LOCAL_CLIENT_PORT           30024
+
+/* Define the IP thread's stack area.  */
+ULONG             ip_thread_stack[3 * 1024 / sizeof(ULONG)];
+
+/* Define packet pool for the demonstration.  */
+#define NX_PACKET_POOL_SIZE ((1536 + sizeof(NX_PACKET)) * 32)
+ULONG             packet_pool_area[NX_PACKET_POOL_SIZE/sizeof(ULONG) + 64 / sizeof(ULONG)];
+
+/* Define the ARP cache area.  */
+ULONG             arp_space_area[512 / sizeof(ULONG)];
+
+/* Define the demo thread.  */
+ULONG             demo_thread_stack[6 * 1024 / sizeof(ULONG)];
+TX_THREAD         demo_thread;
+
+/* Define the pcap driver function. */
+VOID    _nx_pcap_network_driver(NX_IP_DRIVER *driver_req_ptr);
+
+/* Define a global variable for the pointer of current test instance. */
+TLS_TEST_INSTANCE* client_instance_ptr;
+void client_thread_entry(ULONG thread_input);
+
+/* Declare semaphores. */
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_server_prepared;
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_topic_subscribed;
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_message_published;
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_test_finished;
+
+INT mqtt_subscriber_entry(TLS_TEST_INSTANCE* instance_ptr)
+{
+    client_instance_ptr = instance_ptr;
+    tx_kernel_enter();
+}
+
+#ifdef CTEST
+VOID test_application_define(void *first_unused_memory)
+#else
+void    tx_application_define(void *first_unused_memory)
+#endif
+{
+UINT  status;
+
+    /* Initialize the NetX system.  */
+    nx_system_initialize();
+    
+    /* Create a packet pool.  */
+    status =  nx_packet_pool_create(&pool_0, "NetX Main Packet Pool", 1536,  (ULONG*)(((int)packet_pool_area + 64) & ~63) , NX_PACKET_POOL_SIZE);
+    show_error_message_if_fail(NX_SUCCESS == status);
+
+    /* Create an IP instance.  */
+    status = nx_ip_create(&ip_0, 
+                          "NetX IP Instance 0", 
+                          TLS_TEST_IP_ADDRESS_NUMBER,                           
+                          0xFFFFFF00UL, 
+                          &pool_0,
+                          _nx_pcap_network_driver,
+                          (UCHAR*)ip_thread_stack,
+                          sizeof(ip_thread_stack),
+                          1);
+    show_error_message_if_fail(NX_SUCCESS == status);
+    
+    /* Enable ARP and supply ARP cache memory for IP Instance 0.  */
+    status =  nx_arp_enable(&ip_0, (void *)arp_space_area, sizeof(arp_space_area));
+    show_error_message_if_fail(NX_SUCCESS == status);
+
+    /* Enable TCP traffic.  */
+    status =  nx_tcp_enable(&ip_0);
+    show_error_message_if_fail(NX_SUCCESS == status);
+
+    /* Enable UDP traffic.  */
+    status =  nx_udp_enable(&ip_0);
+    show_error_message_if_fail(NX_SUCCESS == status);
+
+    /* Enable ICMP.  */
+    status =  nx_icmp_enable(&ip_0);
+    show_error_message_if_fail(NX_SUCCESS == status);
+
+    status =  nx_ip_fragment_enable(&ip_0);
+    show_error_message_if_fail(NX_SUCCESS == status);
+    tx_thread_create(&demo_thread, "demo thread", client_thread_entry, 0,
+            demo_thread_stack, sizeof(demo_thread_stack),
+            16, 16, 4, TX_AUTO_START);
+}
+
+/* Declare the MQTT client control block. */
+static NXD_MQTT_CLIENT              mqtt_client;
+#define  CLIENT_ID_STRING           "mytestclient"
+#define  MQTT_CLIENT_STACK_SIZE     4096
+
+/* Define the priority of the MQTT internal thread. */
+#define MQTT_THREAD_PRIORTY         2
+
+/* Declare a 2000-byte memory space the application supplies to the MQTT client instance. */
+static ULONG                        client_memory[2000 / sizeof(ULONG)];
+
+/* Declare the MQTT thread stack space. */
+static ULONG                        mqtt_client_stack[MQTT_CLIENT_STACK_SIZE / sizeof(ULONG)];
+
+/* Define the MQTT keep alive timer for 5 minutes */
+#define MQTT_KEEP_ALIVE_TIMER       300
+
+/* Define the subscribed topic. */
+#define TOPIC_NAME                  "test"
+
+#define QOS0                        0
+#define QOS1                        1
+
+/* Declare buffers to hold message and topic. */
+static UCHAR message_buffer[NXD_MQTT_MAX_MESSAGE_LENGTH];
+static UCHAR topic_buffer[NXD_MQTT_MAX_TOPIC_NAME_LENGTH];
+
+void client_thread_entry(ULONG thread_input)
+{
+UINT        status, topic_length, message_length;
+NXD_ADDRESS server_ip;
+INT         test_result = 0;
+    
+    /* Address of remote server. */
+    print_error_message( "remote ip address number %lu, remote ip address string %s.\n", REMOTE_IP_ADDRESS_NUMBER, REMOTE_IP_ADDRESS_STRING);
+    
+    /* Create MQTT client instance. */
+    status = nxd_mqtt_client_create(&mqtt_client, "my_client", CLIENT_ID_STRING, strlen(CLIENT_ID_STRING),
+                                    &ip_0, &pool_0, (VOID*)mqtt_client_stack, sizeof(mqtt_client_stack), 
+                                    MQTT_THREAD_PRIORTY,
+                                    (UCHAR*)client_memory, sizeof(client_memory));
+    exit_if_fail(NX_SUCCESS == status, TLS_TEST_UNKNOWN_TYPE_ERROR);
+    
+    /* Wait for the mqtt server. */
+    tls_test_semaphore_wait(semaphore_mqtt_server_prepared);
+    print_error_message( "subscriber get semaphore_server_prepared.\n");
+
+    /* Start the connection to the server. */
+    server_ip.nxd_ip_version = 4;
+    server_ip.nxd_ip_address.v4 = REMOTE_IP_ADDRESS_NUMBER;
+    status = nxd_mqtt_client_connect(&mqtt_client, &server_ip, MQTT_PORT, 
+                                     MQTT_KEEP_ALIVE_TIMER, 0, NX_WAIT_FOREVER);
+    exit_if_fail(NX_SUCCESS == status, TLS_TEST_UNKNOWN_TYPE_ERROR);
+    
+    /* Subscribe to the topic with QoS level 0. */
+    status = nxd_mqtt_client_subscribe(&mqtt_client, TOPIC_NAME, strlen(TOPIC_NAME), QOS0);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+
+    /* Post the semaphore to indicate that the given topic is subscribed. */
+    tls_test_semaphore_post(semaphore_mqtt_topic_subscribed);
+    
+    /* Wait for the publisher. */
+    tls_test_semaphore_wait(semaphore_mqtt_message_published);
+    status = nxd_mqtt_client_message_get(&mqtt_client, topic_buffer, sizeof(topic_buffer), &topic_length, 
+                                         message_buffer, sizeof(message_buffer), &message_length);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+
+    /* Verify test result. */
+    if(status == NXD_MQTT_SUCCESS)
+    {
+        add_error_counter_if_fail( 5 == message_length, test_result);
+        add_error_counter_if_fail( 'h' == message_buffer[0], test_result);
+        add_error_counter_if_fail( 'e' == message_buffer[1], test_result);
+        add_error_counter_if_fail( 'l' == message_buffer[2], test_result);
+        add_error_counter_if_fail( 'l' == message_buffer[3], test_result);
+        add_error_counter_if_fail( 'o' == message_buffer[4], test_result);
+    }
+    
+    /* Now unsubscribe the topic. */
+    status = nxd_mqtt_client_unsubscribe(&mqtt_client, TOPIC_NAME, strlen(TOPIC_NAME));
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+
+    /* Disconnect from the broker. */
+    status = nxd_mqtt_client_disconnect(&mqtt_client);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+
+    /* Delete the client instance, release all the resources. */
+    status = nxd_mqtt_client_delete(&mqtt_client);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+    
+    /* Post the semaphore to indicate that the test is finished. */
+    status = tls_test_semaphore_post(semaphore_mqtt_test_finished);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+
+    exit(test_result);
+}
+#endif
diff --git a/test/regression/interoperability_test/mqtt_test/netx_mqtt_tls_subscriber_test.c b/test/regression/interoperability_test/mqtt_test/netx_mqtt_tls_subscriber_test.c
new file mode 100644
index 00000000..4bd5f859
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/netx_mqtt_tls_subscriber_test.c
@@ -0,0 +1,269 @@
+#include "mqtt_interoperability_test.h"
+#include "ca.c"
+
+#ifndef NX_SECURE_ENABLE
+INT mqtt_subscriber_entry(TLS_TEST_INSTANCE* instance_ptr)
+{
+    print_error_message( "NX_SEUCRE_ENABLE is not defined.\n");
+    return 0;
+}
+#else /* ifdef NX_SECURE_ENABLE */
+
+#include "nxd_mqtt_client.h"
+
+/* Define the ThreadX and NetX object control blocks...  */
+
+NX_PACKET_POOL    pool_0;
+NX_IP             ip_0;  
+
+NX_TCP_SOCKET tcp_socket;
+
+#define REMOTE_SERVER_PORT          4433
+#define LOCAL_CLIENT_PORT           30024
+
+/* Define the IP thread's stack area.  */
+ULONG             ip_thread_stack[3 * 1024 / sizeof(ULONG)];
+
+/* Define packet pool for the demonstration.  */
+#define NX_PACKET_POOL_SIZE ((1536 + sizeof(NX_PACKET)) * 64)
+ULONG             packet_pool_area[NX_PACKET_POOL_SIZE/sizeof(ULONG) + 64 / sizeof(ULONG)];
+
+/* Define the ARP cache area.  */
+ULONG             arp_space_area[512 / sizeof(ULONG)];
+
+/* Define the demo thread.  */
+ULONG             demo_thread_stack[6 * 1024 / sizeof(ULONG)];
+TX_THREAD         demo_thread;
+
+/* Define the pcap driver function. */
+VOID    _nx_pcap_network_driver(NX_IP_DRIVER *driver_req_ptr);
+
+/* Define a global variable for the pointer of current test instance. */
+TLS_TEST_INSTANCE* client_instance_ptr;
+void client_thread_entry(ULONG thread_input);
+
+#ifdef DEBUG_NX_SECURE
+INT main()
+{
+    tx_kernel_enter();
+}
+#else
+/* Declare semaphores. */
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_server_prepared;
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_topic_subscribed;
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_message_published;
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_test_finished;
+
+INT mqtt_subscriber_entry(TLS_TEST_INSTANCE* instance_ptr)
+{
+    client_instance_ptr = instance_ptr;
+    tx_kernel_enter();
+}
+#endif
+
+#ifdef CTEST
+VOID test_application_define(void *first_unused_memory)
+#else
+void    tx_application_define(void *first_unused_memory)
+#endif
+{
+UINT  status;
+
+    /* Initialize the NetX system.  */
+    nx_system_initialize();
+    
+    /* Create a packet pool.  */
+    status =  nx_packet_pool_create(&pool_0, "NetX Main Packet Pool", 1536,  (ULONG*)(((int)packet_pool_area + 64) & ~63) , NX_PACKET_POOL_SIZE);
+    show_error_message_if_fail(NX_SUCCESS == status);
+
+    /* Create an IP instance.  */
+    status = nx_ip_create(&ip_0, 
+                          "NetX IP Instance 0", 
+                          TLS_TEST_IP_ADDRESS_NUMBER,                           
+                          0xFFFFFF00UL, 
+                          &pool_0,
+                          _nx_pcap_network_driver,
+                          (UCHAR*)ip_thread_stack,
+                          sizeof(ip_thread_stack),
+                          1);
+    show_error_message_if_fail(NX_SUCCESS == status);
+    
+    /* Enable ARP and supply ARP cache memory for IP Instance 0.  */
+    status =  nx_arp_enable(&ip_0, (void *)arp_space_area, sizeof(arp_space_area));
+    show_error_message_if_fail(NX_SUCCESS == status);
+
+    /* Enable TCP traffic.  */
+    status =  nx_tcp_enable(&ip_0);
+    show_error_message_if_fail(NX_SUCCESS == status);
+
+    /* Enable UDP traffic.  */
+    status =  nx_udp_enable(&ip_0);
+    show_error_message_if_fail(NX_SUCCESS == status);
+
+    /* Enable ICMP.  */
+    status =  nx_icmp_enable(&ip_0);
+    show_error_message_if_fail(NX_SUCCESS == status);
+
+    status =  nx_ip_fragment_enable(&ip_0);
+    show_error_message_if_fail(NX_SUCCESS == status);
+    tx_thread_create(&demo_thread, "demo thread", client_thread_entry, 0,
+            demo_thread_stack, sizeof(demo_thread_stack),
+            16, 16, 4, TX_AUTO_START);
+}
+
+/* Declare the MQTT client control block. */
+static NXD_MQTT_CLIENT              mqtt_client;
+#define  CLIENT_ID_STRING           "mytestclient"
+#define  MQTT_CLIENT_STACK_SIZE     4096
+
+/* Define the priority of the MQTT internal thread. */
+#define MQTT_THREAD_PRIORTY         2
+
+/* Declare a 2000-byte memory space the application supplies to the MQTT client instance. */
+static ULONG                        client_memory[2000 / sizeof(ULONG)];
+
+/* Declare the MQTT thread stack space. */
+static ULONG                        mqtt_client_stack[MQTT_CLIENT_STACK_SIZE / sizeof(ULONG)];
+
+/* Define the MQTT keep alive timer for 5 minutes */
+#define MQTT_KEEP_ALIVE_TIMER       300
+
+/* Define the subscribed topic. */
+#define TOPIC_NAME                  "test"
+
+#define QOS0                        0
+#define QOS1                        1
+
+/* Declare external cryptosuites. */
+extern const NX_SECURE_TLS_CRYPTO nx_crypto_tls_ciphers;
+
+/* Define crypto metadata buffer. */
+static UCHAR metadata_buffer[5*4096];
+
+/* Declare buffers to hold message and topic. */
+static UCHAR message_buffer[NXD_MQTT_MAX_MESSAGE_LENGTH];
+static UCHAR topic_buffer[NXD_MQTT_MAX_TOPIC_NAME_LENGTH];
+
+/* For remote certificate. */
+NX_SECURE_X509_CERT remote_certificate, remote_issuer, ca_certificate;
+UCHAR remote_cert_buffer[2000];
+UCHAR remote_issuer_buffer[2000];
+static UCHAR tls_packet_buffer[4096];
+
+/* Define the TLS setup fail function for tls connection. */
+UINT tls_setup_fail(NXD_MQTT_CLIENT* client_ptr, NX_SECURE_TLS_SESSION* tls_session,
+        NX_SECURE_X509_CERT* certificate, NX_SECURE_X509_CERT* trusted_certificate)
+{
+    return 1;
+}
+
+/* Define the callback function for tls connection. */
+UINT tls_setup_method(NXD_MQTT_CLIENT* client_ptr, NX_SECURE_TLS_SESSION* tls_session,
+        NX_SECURE_X509_CERT* certificate, NX_SECURE_X509_CERT* trusted_certificate)
+{
+    
+    /* Create a tls session. */
+    if (nx_secure_tls_session_create(tls_session,
+                                     &nx_crypto_tls_ciphers,
+                                     metadata_buffer,
+                                     sizeof(metadata_buffer)))
+    {
+        return 1;
+    }
+    
+    nx_secure_tls_session_packet_buffer_set(tls_session, tls_packet_buffer, sizeof(tls_packet_buffer));
+    nx_secure_tls_remote_certificate_allocate(tls_session, &remote_certificate, remote_cert_buffer, sizeof(remote_cert_buffer));
+    nx_secure_tls_remote_certificate_allocate(tls_session, &remote_issuer, remote_issuer_buffer, sizeof(remote_issuer_buffer));
+
+    nx_secure_x509_certificate_initialize(&ca_certificate, ca_der, ca_der_len,
+                                          NX_NULL, 0, NX_NULL, 0, NX_SECURE_X509_KEY_TYPE_NONE);
+    nx_secure_tls_trusted_certificate_add(tls_session, &ca_certificate);
+
+    return(NX_SUCCESS);
+}
+
+void client_thread_entry(ULONG thread_input)
+{
+UINT        status, topic_length, message_length;
+NXD_ADDRESS server_ip;
+INT         test_result = 0;
+    
+    /* Address of remote server. */
+    print_error_message( "remote ip address number %lu, remote ip address string %s.\n", REMOTE_IP_ADDRESS_NUMBER, REMOTE_IP_ADDRESS_STRING);
+    
+    /* Create MQTT client instance. */
+    status = nxd_mqtt_client_create(&mqtt_client, "my_client", CLIENT_ID_STRING, strlen(CLIENT_ID_STRING),
+                                    &ip_0, &pool_0, (VOID*)mqtt_client_stack, sizeof(mqtt_client_stack), 
+                                    MQTT_THREAD_PRIORTY,
+                                    (UCHAR*)client_memory, sizeof(client_memory));
+    exit_if_fail(NX_SUCCESS == status, TLS_TEST_UNKNOWN_TYPE_ERROR);
+
+#ifndef DEBUG_NX_SECURE
+    /* Wait for the mqtt server. */
+    tls_test_semaphore_wait(semaphore_mqtt_server_prepared);
+    print_error_message( "subscriber get semaphore_server_prepared.\n");
+#endif
+
+    /* Start the connection to the server. */
+    server_ip.nxd_ip_version = 4;
+    server_ip.nxd_ip_address.v4 = REMOTE_IP_ADDRESS_NUMBER;
+
+    /* Test TLS setup fail. */
+    status = nxd_mqtt_client_secure_connect(&mqtt_client, &server_ip, MQTT_PORT, 
+                                            tls_setup_fail,
+                                            MQTT_KEEP_ALIVE_TIMER, 1, NX_WAIT_FOREVER);
+    exit_if_fail(1 == status, TLS_TEST_UNKNOWN_TYPE_ERROR);
+
+    /* Connect mqtt server with tls. */
+    status = nxd_mqtt_client_secure_connect(&mqtt_client, &server_ip, MQTT_PORT, 
+                                            tls_setup_method,
+                                            MQTT_KEEP_ALIVE_TIMER, 1, NX_WAIT_FOREVER);
+    exit_if_fail(NX_SUCCESS == status, TLS_TEST_UNKNOWN_TYPE_ERROR);
+    
+    /* Subscribe to the topic with QoS level 0. */
+    status = nxd_mqtt_client_subscribe(&mqtt_client, TOPIC_NAME, strlen(TOPIC_NAME), QOS0);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+
+#ifndef DEBUG_NX_SECURE
+    /* Post the semaphore to indicate that the given topic is subscribed. */
+    tls_test_semaphore_post(semaphore_mqtt_topic_subscribed);
+    
+    /* Wait for the publisher. */
+    tls_test_semaphore_wait(semaphore_mqtt_message_published);
+#endif
+    status = nxd_mqtt_client_message_get(&mqtt_client, topic_buffer, sizeof(topic_buffer), &topic_length, 
+                                         message_buffer, sizeof(message_buffer), &message_length);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+
+    /* Verify test result. */
+    if(status == NXD_MQTT_SUCCESS)
+    {
+        add_error_counter_if_fail( 5 == message_length, test_result);
+        add_error_counter_if_fail( 'h' == message_buffer[0], test_result);
+        add_error_counter_if_fail( 'e' == message_buffer[1], test_result);
+        add_error_counter_if_fail( 'l' == message_buffer[2], test_result);
+        add_error_counter_if_fail( 'l' == message_buffer[3], test_result);
+        add_error_counter_if_fail( 'o' == message_buffer[4], test_result);
+    }
+    
+    /* Now unsubscribe the topic. */
+    status = nxd_mqtt_client_unsubscribe(&mqtt_client, TOPIC_NAME, strlen(TOPIC_NAME));
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+
+    /* Disconnect from the broker. */
+    status = nxd_mqtt_client_disconnect(&mqtt_client);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+
+    /* Delete the client instance, release all the resources. */
+    status = nxd_mqtt_client_delete(&mqtt_client);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+    
+#ifndef DEBUG_NX_SECURE
+    /* Post the semaphore to indicate that the test is finished. */
+    status = tls_test_semaphore_post(semaphore_mqtt_test_finished);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+#endif
+
+    exit(test_result);
+}
+#endif /* ifndef NX_SECURE_ENABLE */
diff --git a/test/regression/interoperability_test/mqtt_test/netx_mqtt_tls_subscriber_twice_test.c b/test/regression/interoperability_test/mqtt_test/netx_mqtt_tls_subscriber_twice_test.c
new file mode 100644
index 00000000..b46865bb
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/netx_mqtt_tls_subscriber_twice_test.c
@@ -0,0 +1,284 @@
+#include "mqtt_interoperability_test.h"
+#include "ca.c"
+
+#ifndef NX_SECURE_ENABLE
+INT mqtt_subscriber_entry(TLS_TEST_INSTANCE* instance_ptr)
+{
+    print_error_message( "NX_SEUCRE_ENABLE is not defined.\n");
+    return 0;
+}
+#else /* ifdef NX_SECURE_ENABLE */
+
+#include "nxd_mqtt_client.h"
+
+/* Define the ThreadX and NetX object control blocks...  */
+
+NX_PACKET_POOL    pool_0;
+NX_IP             ip_0;  
+
+NX_TCP_SOCKET tcp_socket;
+
+#define REMOTE_SERVER_PORT          4433
+#define LOCAL_CLIENT_PORT           30024
+
+/* Define the IP thread's stack area.  */
+ULONG             ip_thread_stack[3 * 1024 / sizeof(ULONG)];
+
+/* Define packet pool for the demonstration.  */
+#define NX_PACKET_POOL_SIZE ((1536 + sizeof(NX_PACKET)) * 64)
+ULONG             packet_pool_area[NX_PACKET_POOL_SIZE/sizeof(ULONG) + 64 / sizeof(ULONG)];
+
+/* Define the ARP cache area.  */
+ULONG             arp_space_area[512 / sizeof(ULONG)];
+
+/* Define the demo thread.  */
+ULONG             demo_thread_stack[6 * 1024 / sizeof(ULONG)];
+TX_THREAD         demo_thread;
+
+/* Define the pcap driver function. */
+VOID    _nx_pcap_network_driver(NX_IP_DRIVER *driver_req_ptr);
+
+/* Define a global variable for the pointer of current test instance. */
+TLS_TEST_INSTANCE* client_instance_ptr;
+void client_thread_entry(ULONG thread_input);
+
+#ifdef DEBUG_NX_SECURE
+INT main()
+{
+    tx_kernel_enter();
+}
+#else
+/* Declare semaphores. */
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_server_prepared;
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_topic_subscribed;
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_message_published;
+extern TLS_TEST_SEMAPHORE* semaphore_mqtt_test_finished;
+
+INT mqtt_subscriber_entry(TLS_TEST_INSTANCE* instance_ptr)
+{
+    client_instance_ptr = instance_ptr;
+    tx_kernel_enter();
+}
+#endif
+
+#ifdef CTEST
+VOID test_application_define(void *first_unused_memory)
+#else
+void    tx_application_define(void *first_unused_memory)
+#endif
+{
+UINT  status;
+
+    /* Initialize the NetX system.  */
+    nx_system_initialize();
+    
+    /* Create a packet pool.  */
+    status =  nx_packet_pool_create(&pool_0, "NetX Main Packet Pool", 1536,  (ULONG*)(((int)packet_pool_area + 64) & ~63) , NX_PACKET_POOL_SIZE);
+    show_error_message_if_fail(NX_SUCCESS == status);
+
+    /* Create an IP instance.  */
+    status = nx_ip_create(&ip_0, 
+                          "NetX IP Instance 0", 
+                          TLS_TEST_IP_ADDRESS_NUMBER,                           
+                          0xFFFFFF00UL, 
+                          &pool_0,
+                          _nx_pcap_network_driver,
+                          (UCHAR*)ip_thread_stack,
+                          sizeof(ip_thread_stack),
+                          1);
+    show_error_message_if_fail(NX_SUCCESS == status);
+    
+    /* Enable ARP and supply ARP cache memory for IP Instance 0.  */
+    status =  nx_arp_enable(&ip_0, (void *)arp_space_area, sizeof(arp_space_area));
+    show_error_message_if_fail(NX_SUCCESS == status);
+
+    /* Enable TCP traffic.  */
+    status =  nx_tcp_enable(&ip_0);
+    show_error_message_if_fail(NX_SUCCESS == status);
+
+    /* Enable UDP traffic.  */
+    status =  nx_udp_enable(&ip_0);
+    show_error_message_if_fail(NX_SUCCESS == status);
+
+    /* Enable ICMP.  */
+    status =  nx_icmp_enable(&ip_0);
+    show_error_message_if_fail(NX_SUCCESS == status);
+
+    status =  nx_ip_fragment_enable(&ip_0);
+    show_error_message_if_fail(NX_SUCCESS == status);
+    tx_thread_create(&demo_thread, "demo thread", client_thread_entry, 0,
+            demo_thread_stack, sizeof(demo_thread_stack),
+            16, 16, 4, TX_AUTO_START);
+}
+
+/* Declare the MQTT client control block. */
+static NXD_MQTT_CLIENT              mqtt_client;
+#define  CLIENT_ID_STRING           "mytestclient"
+#define  MQTT_CLIENT_STACK_SIZE     4096
+
+/* Define the priority of the MQTT internal thread. */
+#define MQTT_THREAD_PRIORTY         2
+
+/* Declare a 2000-byte memory space the application supplies to the MQTT client instance. */
+static ULONG                        client_memory[2000 / sizeof(ULONG)];
+
+/* Declare the MQTT thread stack space. */
+static ULONG                        mqtt_client_stack[MQTT_CLIENT_STACK_SIZE / sizeof(ULONG)];
+
+/* Define the MQTT keep alive timer for 5 minutes */
+#define MQTT_KEEP_ALIVE_TIMER       300
+
+/* Define the subscribed topic. */
+#define TOPIC_NAME                  "test"
+
+#define QOS0                        0
+#define QOS1                        1
+
+/* Declare external cryptosuites. */
+extern const NX_SECURE_TLS_CRYPTO nx_crypto_tls_ciphers;
+
+/* Define crypto metadata buffer. */
+static UCHAR metadata_buffer[5*4096];
+
+/* Declare buffers to hold message and topic. */
+static UCHAR message_buffer[NXD_MQTT_MAX_MESSAGE_LENGTH];
+static UCHAR topic_buffer[NXD_MQTT_MAX_TOPIC_NAME_LENGTH];
+
+/* For remote certificate. */
+NX_SECURE_X509_CERT remote_certificate, remote_issuer, ca_certificate;
+UCHAR remote_cert_buffer[2000];
+UCHAR remote_issuer_buffer[2000];
+static UCHAR tls_packet_buffer[4096];
+static UINT error_counter;
+
+/* Define the callback function for tls connection. */
+UINT tls_setup_method(NXD_MQTT_CLIENT* client_ptr, NX_SECURE_TLS_SESSION* tls_session,
+        NX_SECURE_X509_CERT* certificate, NX_SECURE_X509_CERT* trusted_certificate)
+{
+    
+    /* Create a tls session. */
+    if (nx_secure_tls_session_create(tls_session,
+                                     &nx_crypto_tls_ciphers,
+                                     metadata_buffer,
+                                     sizeof(metadata_buffer)))
+    {
+        error_counter++;
+        return 1;
+    }
+    
+    nx_secure_tls_session_packet_buffer_set(tls_session, tls_packet_buffer, sizeof(tls_packet_buffer));
+    nx_secure_tls_remote_certificate_allocate(tls_session, &remote_certificate, remote_cert_buffer, sizeof(remote_cert_buffer));
+    nx_secure_tls_remote_certificate_allocate(tls_session, &remote_issuer, remote_issuer_buffer, sizeof(remote_issuer_buffer));
+
+    nx_secure_x509_certificate_initialize(&ca_certificate, ca_der, ca_der_len,
+                                          NX_NULL, 0, NX_NULL, 0, NX_SECURE_X509_KEY_TYPE_NONE);
+    nx_secure_tls_trusted_certificate_add(tls_session, &ca_certificate);
+
+    return(NX_SUCCESS);
+}
+
+void client_thread_entry(ULONG thread_input)
+{
+UINT        status, topic_length, message_length;
+NXD_ADDRESS server_ip;
+INT         test_result = 0;
+UINT        i;
+    
+    /* Address of remote server. */
+    print_error_message( "remote ip address number %lu, remote ip address string %s.\n", REMOTE_IP_ADDRESS_NUMBER, REMOTE_IP_ADDRESS_STRING);
+    
+    /* Create MQTT client instance. */
+    status = nxd_mqtt_client_create(&mqtt_client, "my_client", CLIENT_ID_STRING, strlen(CLIENT_ID_STRING),
+                                    &ip_0, &pool_0, (VOID*)mqtt_client_stack, sizeof(mqtt_client_stack), 
+                                    MQTT_THREAD_PRIORTY,
+                                    (UCHAR*)client_memory, sizeof(client_memory));
+    exit_if_fail(NX_SUCCESS == status, TLS_TEST_UNKNOWN_TYPE_ERROR);
+
+#ifndef DEBUG_NX_SECURE
+    /* Wait for the mqtt server. */
+    tls_test_semaphore_wait(semaphore_mqtt_server_prepared);
+    print_error_message( "subscriber get semaphore_server_prepared.\n");
+#endif
+
+    error_counter = 0;
+    for (i = 0; i < 4; i++)
+    {
+
+        if (i == 0)
+        {
+
+            /* Start the connection to the server. */
+            server_ip.nxd_ip_version = 4;
+            server_ip.nxd_ip_address.v4 = 0x7F000001;
+
+            /* Connect mqtt server with tls to port not bound. */
+            status = nxd_mqtt_client_secure_connect(&mqtt_client, &server_ip, 443, 
+                                                    tls_setup_method,
+                                                    MQTT_KEEP_ALIVE_TIMER, 1, NX_WAIT_FOREVER);
+            exit_if_fail(NX_SUCCESS != status, TLS_TEST_UNKNOWN_TYPE_ERROR);
+            continue;
+        }
+        else
+        {
+
+            /* Start the connection to the server. */
+            server_ip.nxd_ip_version = 4;
+            server_ip.nxd_ip_address.v4 = REMOTE_IP_ADDRESS_NUMBER;
+
+            /* Connect mqtt server with tls. */
+            status = nxd_mqtt_client_secure_connect(&mqtt_client, &server_ip, MQTT_PORT, 
+                                                    tls_setup_method,
+                                                    MQTT_KEEP_ALIVE_TIMER, 1, NX_WAIT_FOREVER);
+            exit_if_fail(NX_SUCCESS == status, TLS_TEST_UNKNOWN_TYPE_ERROR);
+        }
+        
+        /* Subscribe to the topic with QoS level 0. */
+        status = nxd_mqtt_client_subscribe(&mqtt_client, TOPIC_NAME, strlen(TOPIC_NAME), QOS0);
+        add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+
+#ifndef DEBUG_NX_SECURE
+        /* Post the semaphore to indicate that the given topic is subscribed. */
+        tls_test_semaphore_post(semaphore_mqtt_topic_subscribed);
+        
+        /* Wait for the publisher. */
+        tls_test_semaphore_wait(semaphore_mqtt_message_published);
+#endif
+        status = nxd_mqtt_client_message_get(&mqtt_client, topic_buffer, sizeof(topic_buffer), &topic_length, 
+                                             message_buffer, sizeof(message_buffer), &message_length);
+        add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+
+        /* Verify test result. */
+        if(status == NXD_MQTT_SUCCESS)
+        {
+            add_error_counter_if_fail( 5 == message_length, test_result);
+            add_error_counter_if_fail( 'h' == message_buffer[0], test_result);
+            add_error_counter_if_fail( 'e' == message_buffer[1], test_result);
+            add_error_counter_if_fail( 'l' == message_buffer[2], test_result);
+            add_error_counter_if_fail( 'l' == message_buffer[3], test_result);
+            add_error_counter_if_fail( 'o' == message_buffer[4], test_result);
+        }
+        
+        /* Now unsubscribe the topic. */
+        status = nxd_mqtt_client_unsubscribe(&mqtt_client, TOPIC_NAME, strlen(TOPIC_NAME));
+        add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+
+        /* Disconnect from the broker. */
+        status = nxd_mqtt_client_disconnect(&mqtt_client);
+        add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+
+        add_error_counter_if_fail(error_counter == 0, test_result);
+    }
+
+    /* Delete the client instance, release all the resources. */
+    status = nxd_mqtt_client_delete(&mqtt_client);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+    
+#ifndef DEBUG_NX_SECURE
+    /* Post the semaphore to indicate that the test is finished. */
+    status = tls_test_semaphore_post(semaphore_mqtt_test_finished);
+    add_error_counter_if_fail(NX_SUCCESS == status, test_result);
+#endif
+
+    exit(test_result);
+}
+#endif /* ifndef NX_SECURE_ENABLE */
diff --git a/test/regression/interoperability_test/mqtt_test/test_scripts/CA/ca/ca.crt b/test/regression/interoperability_test/mqtt_test/test_scripts/CA/ca/ca.crt
new file mode 100644
index 00000000..f2a0500b
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/test_scripts/CA/ca/ca.crt
@@ -0,0 +1,35 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
diff --git a/test/regression/interoperability_test/mqtt_test/test_scripts/CA/certs/broker.server.crt b/test/regression/interoperability_test/mqtt_test/test_scripts/CA/certs/broker.server.crt
new file mode 100644
index 00000000..008368e4
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/test_scripts/CA/certs/broker.server.crt
@@ -0,0 +1,32 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
diff --git a/test/regression/interoperability_test/mqtt_test/test_scripts/CA/certs/ew2017.client.crt b/test/regression/interoperability_test/mqtt_test/test_scripts/CA/certs/ew2017.client.crt
new file mode 100644
index 00000000..930f2c90
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/test_scripts/CA/certs/ew2017.client.crt
@@ -0,0 +1,31 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
diff --git a/test/regression/interoperability_test/mqtt_test/test_scripts/CA/private/broker.server.key b/test/regression/interoperability_test/mqtt_test/test_scripts/CA/private/broker.server.key
new file mode 100644
index 00000000..2158ee86
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/test_scripts/CA/private/broker.server.key
@@ -0,0 +1,28 @@
+-----BEGIN PRIVATE KEY-----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+-----END PRIVATE KEY-----
diff --git a/test/regression/interoperability_test/mqtt_test/test_scripts/CA/private/ew2017.client.key b/test/regression/interoperability_test/mqtt_test/test_scripts/CA/private/ew2017.client.key
new file mode 100644
index 00000000..457211e6
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/test_scripts/CA/private/ew2017.client.key
@@ -0,0 +1,28 @@
+-----BEGIN PRIVATE KEY-----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+-----END PRIVATE KEY-----
diff --git a/test/regression/interoperability_test/mqtt_test/test_scripts/bridge_server.sh b/test/regression/interoperability_test/mqtt_test/test_scripts/bridge_server.sh
new file mode 100644
index 00000000..4f64f1ba
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/test_scripts/bridge_server.sh
@@ -0,0 +1,5 @@
+#! /bin/sh
+if [ -d "../mosquitto-1.6.9/src/" ]; then 
+    export PATH=$PATH;../mosquitto-1.4.10/src/
+fi
+mosquitto -c ./mosquitto-bridge.conf -v -p 8883
diff --git a/test/regression/interoperability_test/mqtt_test/test_scripts/certificate_server.sh b/test/regression/interoperability_test/mqtt_test/test_scripts/certificate_server.sh
new file mode 100755
index 00000000..b7711aaf
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/test_scripts/certificate_server.sh
@@ -0,0 +1,14 @@
+#! /bin/bash
+
+function kill_mqtt_server(){
+    kill $mqtt_server_pid
+    wait
+}
+
+dir=`dirname $0`
+dir=`realpath $dir`
+cd $dir
+mosquitto -c ./mosquitto.conf -v $* &
+mqtt_server_pid=$!
+trap kill_mqtt_server TERM ALRM
+wait
diff --git a/test/regression/interoperability_test/mqtt_test/test_scripts/mosquitto-bridge.conf b/test/regression/interoperability_test/mqtt_test/test_scripts/mosquitto-bridge.conf
new file mode 100644
index 00000000..b9b618e5
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/test_scripts/mosquitto-bridge.conf
@@ -0,0 +1,511 @@
+# Config file for mosquitto
+#
+# See mosquitto.conf(5) for more information.
+#
+# Default values are shown, uncomment to change.
+#
+# Use the # character to indicate a comment, but only if it is the 
+# very first character on the line.
+
+# =================================================================
+# General configuration
+# =================================================================
+
+# Time in seconds to wait before resending an outgoing QoS=1 or 
+# QoS=2 message.
+#retry_interval 20
+
+# Time in seconds between updates of the $SYS tree.
+# Set to 0 to disable the publishing of the $SYS tree.
+#sys_interval 10
+
+# Time in seconds between cleaning the internal message store of 
+# unreferenced messages. Lower values will result in lower memory 
+# usage but more processor time, higher values will have the 
+# opposite effect.
+# Setting a value of 0 means the unreferenced messages will be 
+# disposed of as quickly as possible.
+#store_clean_interval 10
+
+# Write process id to a file. Default is a blank string which means 
+# a pid file shouldn't be written.
+# This should be set to /var/run/mosquitto.pid if mosquitto is
+# being run automatically on boot with an init script and 
+# start-stop-daemon or similar.
+#pid_file
+
+# When run as root, drop privileges to this user and its primary 
+# group.
+# Leave blank to stay as root, but this is not recommended.
+# If run as a non-root user, this setting has no effect.
+# Note that on Windows this has no effect and so mosquitto should 
+# be started by the user you wish it to run as.
+#user mosquitto
+
+# The maximum number of QoS 1 and 2 messages currently inflight per 
+# client.
+# This includes messages that are partway through handshakes and 
+# those that are being retried. Defaults to 20. Set to 0 for no 
+# maximum. Setting to 1 will guarantee in-order delivery of QoS 1 
+# and 2 messages.
+#max_inflight_messages 20
+
+# The maximum number of QoS 1 and 2 messages to hold in a queue 
+# above those that are currently in-flight.  Defaults to 100. Set 
+# to 0 for no maximum (not recommended).
+# See also queue_qos0_messages.
+#max_queued_messages 100
+
+# Set to true to queue messages with QoS 0 when a persistent client is
+# disconnected. These messages are included in the limit imposed by
+# max_queued_messages.
+# Defaults to false.
+# This is a non-standard option for the MQTT v3.1 spec but is allowed in
+# v3.1.1.
+#queue_qos0_messages false
+
+# This option sets the maximum publish payload size that the broker will allow.
+# Received messages that exceed this size will not be accepted by the broker.
+# The default value is 0, which means that all valid MQTT messages are
+# accepted. MQTT imposes a maximum payload size of 268435455 bytes. 
+#message_size_limit 0
+
+# This option controls whether a client is allowed to connect with a zero
+# length client id or not. This option only affects clients using MQTT v3.1.1
+# and later. If set to false, clients connecting with a zero length client id
+# are disconnected. If set to true, clients will be allocated a client id by
+# the broker. This means it is only useful for clients with clean session set
+# to true.
+#allow_zero_length_clientid true
+
+# If allow_zero_length_clientid is true, this option allows you to set a prefix
+# to automatically generated client ids to aid visibility in logs.
+#auto_id_prefix
+
+# This option allows persistent clients (those with clean session set to false)
+# to be removed if they do not reconnect within a certain time frame.
+#
+# This is a non-standard option in MQTT V3.1 but allowed in MQTT v3.1.1.
+#
+# Badly designed clients may set clean session to false whilst using a randomly
+# generated client id. This leads to persistent clients that will never
+# reconnect. This option allows these clients to be removed.
+#
+# The expiration period should be an integer followed by one of h d w m y for
+# hour, day, week, month and year respectively. For example
+#
+# persistent_client_expiration 2m
+# persistent_client_expiration 14d
+# persistent_client_expiration 1y
+#
+# The default if not set is to never expire persistent clients.
+#persistent_client_expiration
+
+# If a client is subscribed to multiple subscriptions that overlap, e.g. foo/#
+# and foo/+/baz , then MQTT expects that when the broker receives a message on
+# a topic that matches both subscriptions, such as foo/bar/baz, then the client
+# should only receive the message once.
+# Mosquitto keeps track of which clients a message has been sent to in order to
+# meet this requirement. The allow_duplicate_messages option allows this
+# behaviour to be disabled, which may be useful if you have a large number of
+# clients subscribed to the same set of topics and are very concerned about
+# minimising memory usage.
+# It can be safely set to true if you know in advance that your clients will
+# never have overlapping subscriptions, otherwise your clients must be able to
+# correctly deal with duplicate messages even when then have QoS=2.
+#allow_duplicate_messages false
+
+# The MQTT specification requires that the QoS of a message delivered to a
+# subscriber is never upgraded to match the QoS of the subscription. Enabling
+# this option changes this behaviour. If upgrade_outgoing_qos is set true,
+# messages sent to a subscriber will always match the QoS of its subscription.
+# This is a non-standard option explicitly disallowed by the spec.
+#upgrade_outgoing_qos false
+
+# =================================================================
+# Default listener
+# =================================================================
+
+# IP address/hostname to bind the default listener to. If not
+# given, the default listener will not be bound to a specific 
+# address and so will be accessible to all network interfaces.
+# bind_address ip-address/host name
+#bind_address
+
+# Port to use for the default listener.
+#port 1883
+listener 8884
+
+# The maximum number of client connections to allow. This is 
+# a per listener setting.
+# Default is -1, which means unlimited connections.
+# Note that other process limits mean that unlimited connections 
+# are not really possible. Typically the default maximum number of 
+# connections possible is around 1024.
+#max_connections -1
+
+# Choose the protocol to use when listening.
+# This can be either mqtt or websockets.
+# Websockets support is currently disabled by default at compile time.
+# Certificate based TLS may be used with websockets, except that
+# only the cafile, certfile, keyfile and ciphers options are supported.
+#protocol mqtt
+
+# When a listener is using the websockets protocol, it is possible to serve
+# http data as well. Set http_dir to a directory which contains the files you
+# wish to serve. If this option is not specified, then no normal http
+# connections will be possible.
+#http_dir
+
+# Set use_username_as_clientid to true to replace the clientid that a client
+# connected with with its username. This allows authentication to be tied to
+# the clientid, which means that it is possible to prevent one client
+# disconnecting another by using the same clientid.
+# If a client connects with no username it will be disconnected as not
+# authorised when this option is set to true.
+# Do not use in conjunction with clientid_prefixes.
+# See also use_identity_as_username.
+#use_username_as_clientid
+
+# -----------------------------------------------------------------
+# Certificate based SSL/TLS support
+# -----------------------------------------------------------------
+# The following options can be used to enable SSL/TLS support for 
+# this listener. Note that the recommended port for MQTT over TLS
+# is 8883, but this must be set manually.
+#
+# See also the mosquitto-tls man page.
+
+# At least one of cafile or capath must be defined. They both 
+# define methods of accessing the PEM encoded Certificate 
+# Authority certificates that have signed your server certificate 
+# and that you wish to trust.
+# cafile defines the path to a file containing the CA certificates.
+# capath defines a directory that will be searched for files
+# containing the CA certificates. For capath to work correctly, the
+# certificate files must have ".crt" as the file ending and you must run
+# "c_rehash <path to capath>" each time you add/remove a certificate.
+cafile CA/ca/ca.crt
+#capath
+
+# Path to the PEM encoded server certificate.
+#certfile ./cert.pem
+certfile CA/certs/broker.server.crt
+
+
+# Path to the PEM encoded keyfile.
+#keyfile ./keyout.pem
+keyfile CA/private/broker.server.key
+
+# This option defines the version of the TLS protocol to use for this listener.
+# The default value allows v1.2, v1.1 and v1.0, if they are all supported by
+# the version of openssl that the broker was compiled against. For openssl >=
+# 1.0.1 the valid values are tlsv1.2 tlsv1.1 and tlsv1. For openssl < 1.0.1 the
+# valid values are tlsv1.
+#tls_version tlsv1.2
+
+# By default a TLS enabled listener will operate in a similar fashion to a
+# https enabled web server, in that the server has a certificate signed by a CA
+# and the client will verify that it is a trusted certificate. The overall aim
+# is encryption of the network traffic. By setting require_certificate to true,
+# the client must provide a valid certificate in order for the network
+# connection to proceed. This allows access to the broker to be controlled
+# outside of the mechanisms provided by MQTT.
+#require_certificate true
+
+# If require_certificate is true, you may set use_identity_as_username to true
+# to use the CN value from the client certificate as a username. If this is
+# true, the password_file option will not be used for this listener.
+#use_identity_as_username false
+
+# If you have require_certificate set to true, you can create a certificate
+# revocation list file to revoke access to particular client certificates. If
+# you have done this, use crlfile to point to the PEM encoded revocation file.
+#crlfile
+
+# If you wish to control which encryption ciphers are used, use the ciphers
+# option. The list of available ciphers can be optained using the "openssl
+# ciphers" command and should be provided in the same format as the output of
+# that command.
+# If unset defaults to DEFAULT:!aNULL:!eNULL:!LOW:!EXPORT:!SSLv2:@STRENGTH
+#ciphers DEFAULT:!aNULL:!eNULL:!LOW:!EXPORT:!SSLv2:@STRENGTH
+
+# -----------------------------------------------------------------
+# Pre-shared-key based SSL/TLS support
+# -----------------------------------------------------------------
+# The following options can be used to enable PSK based SSL/TLS support for
+# this listener. Note that the recommended port for MQTT over TLS is 8883, but
+# this must be set manually.
+#
+# See also the mosquitto-tls man page and the "Certificate based SSL/TLS
+# support" section. Only one of certificate or PSK encryption support can be
+# enabled for any listener.
+
+# The psk_hint option enables pre-shared-key support for this listener and also
+# acts as an identifier for this listener. The hint is sent to clients and may
+# be used locally to aid authentication. The hint is a free form string that
+# doesn't have much meaning in itself, so feel free to be creative.
+# If this option is provided, see psk_file to define the pre-shared keys to be
+# used or create a security plugin to handle them.
+#psk_hint Client_identity
+
+# Set use_identity_as_username to have the psk identity sent by the client used
+# as its username. Authentication will be carried out using the PSK rather than
+# the MQTT username/password and so password_file will not be used for this
+# listener.
+#use_identity_as_username true
+
+# When using PSK, the encryption ciphers used will be chosen from the list of
+# available PSK ciphers. If you want to control which ciphers are available,
+# use the "ciphers" option.  The list of available ciphers can be optained
+# using the "openssl ciphers" command and should be provided in the same format
+# as the output of that command.
+#ciphers
+
+# =================================================================
+# Persistence
+# =================================================================
+
+# If persistence is enabled, save the in-memory database to disk 
+# every autosave_interval seconds. If set to 0, the persistence 
+# database will only be written when mosquitto exits. See also
+# autosave_on_changes.
+# Note that writing of the persistence database can be forced by 
+# sending mosquitto a SIGUSR1 signal.
+#autosave_interval 1800
+
+# If true, mosquitto will count the number of subscription changes, retained
+# messages received and queued messages and if the total exceeds
+# autosave_interval then the in-memory database will be saved to disk.
+# If false, mosquitto will save the in-memory database to disk by treating
+# autosave_interval as a time in seconds.
+#autosave_on_changes false
+
+# Save persistent message data to disk (true/false).
+# This saves information about all messages, including 
+# subscriptions, currently in-flight messages and retained 
+# messages.
+# retained_persistence is a synonym for this option.
+#persistence false
+
+# The filename to use for the persistent database, not including 
+# the path.
+#persistence_file mosquitto.db
+
+# Location for persistent database. Must include trailing /
+# Default is an empty string (current directory).
+# Set to e.g. /var/lib/mosquitto/ if running as a proper service on Linux or
+# similar.
+#persistence_location
+
+# =================================================================
+# Logging
+# =================================================================
+
+# Places to log to. Use multiple log_dest lines for multiple 
+# logging destinations.
+# Possible destinations are: stdout stderr syslog topic file
+#
+# stdout and stderr log to the console on the named output.
+#
+# syslog uses the userspace syslog facility which usually ends up 
+# in /var/log/messages or similar.
+#
+# topic logs to the broker topic '$SYS/broker/log/<severity>', 
+# where severity is one of D, E, W, N, I, M which are debug, error, 
+# warning, notice, information and message. Message type severity is used by
+# the subscribe/unsubscribe log_types and publishes log messages to
+# $SYS/broker/log/M/susbcribe or $SYS/broker/log/M/unsubscribe.
+#
+# The file destination requires an additional parameter which is the file to be
+# logged to, e.g. "log_dest file /var/log/mosquitto.log". The file will be
+# closed and reopened when the broker receives a HUP signal. Only a single file
+# destination may be configured.
+#
+# Note that if the broker is running as a Windows service it will default to
+# "log_dest none" and neither stdout nor stderr logging is available.
+# Use "log_dest none" if you wish to disable logging.
+#log_dest stderr
+
+# If using syslog logging (not on Windows), messages will be logged to the
+# "daemon" facility by default. Use the log_facility option to choose which of
+# local0 to local7 to log to instead. The option value should be an integer
+# value, e.g. "log_facility 5" to use local5.
+#log_facility
+
+# Types of messages to log. Use multiple log_type lines for logging
+# multiple types of messages.
+# Possible types are: debug, error, warning, notice, information, 
+# none, subscribe, unsubscribe, websockets, all.
+# Note that debug type messages are for decoding the incoming/outgoing
+# network packets. They are not logged in "topics".
+#log_type error
+#log_type warning
+#log_type notice
+#log_type information
+
+# Change the websockets logging level. This is a global option, it is not
+# possible to set per listener. This is an integer that is interpreted by
+# libwebsockets as a bit mask for its lws_log_levels enum. See the
+# libwebsockets documentation for more details. "log_type websockets" must also
+# be enabled.
+#websockets_log_level 0
+
+# If set to true, client connection and disconnection messages will be included
+# in the log.
+#connection_messages true
+
+# If set to true, add a timestamp value to each log message.
+#log_timestamp true
+
+# =================================================================
+# Security
+# =================================================================
+
+# If set, only clients that have a matching prefix on their 
+# clientid will be allowed to connect to the broker. By default, 
+# all clients may connect.
+# For example, setting "secure-" here would mean a client "secure-
+# client" could connect but another with clientid "mqtt" couldn't.
+#clientid_prefixes
+
+# Boolean value that determines whether clients that connect 
+# without providing a username are allowed to connect. If set to 
+# false then a password file should be created (see the 
+# password_file option) to control authenticated client access. 
+# Defaults to true.
+allow_anonymous true
+
+# In addition to the clientid_prefixes, allow_anonymous and TLS 
+# authentication options, username based authentication is also 
+# possible. The default support is described in "Default 
+# authentication and topic access control" below. The auth_plugin 
+# allows another authentication method to be used.
+# Specify the path to the loadable plugin and see the 
+# "Authentication and topic access plugin options" section below.
+#auth_plugin
+
+# -----------------------------------------------------------------
+# Default authentication and topic access control
+# -----------------------------------------------------------------
+
+# Control access to the broker using a password file. This file can be
+# generated using the mosquitto_passwd utility. If TLS support is not compiled
+# into mosquitto (it is recommended that TLS support should be included) then
+# plain text passwords are used, in which case the file should be a text file
+# with lines in the format:
+# username:password
+# The password (and colon) may be omitted if desired, although this 
+# offers very little in the way of security.
+# 
+# See the TLS client require_certificate and use_identity_as_username options
+# for alternative authentication options.
+#password_file
+
+# Access may also be controlled using a pre-shared-key file. This requires
+# TLS-PSK support and a listener configured to use it. The file should be text
+# lines in the format:
+# identity:key
+# The key should be in hexadecimal format without a leading "0x".
+#psk_file ./psk_file.txt
+
+# Control access to topics on the broker using an access control list
+# file. If this parameter is defined then only the topics listed will
+# have access.
+# If the first character of a line of the ACL file is a # it is treated as a
+# comment.
+# Topic access is added with lines of the format:
+#
+# topic [read|write|readwrite] <topic>
+# 
+# The access type is controlled using "read", "write" or "readwrite". This
+# parameter is optional (unless <topic> contains a space character) - if not
+# given then the access is read/write.  <topic> can contain the + or #
+# wildcards as in subscriptions.
+# 
+# The first set of topics are applied to anonymous clients, assuming
+# allow_anonymous is true. User specific topic ACLs are added after a 
+# user line as follows:
+#
+# user <username>
+#
+# The username referred to here is the same as in password_file. It is
+# not the clientid.
+#
+#
+# If is also possible to define ACLs based on pattern substitution within the
+# topic. The patterns available for substition are:
+#
+# %c to match the client id of the client
+# %u to match the username of the client
+#
+# The substitution pattern must be the only text for that level of hierarchy.
+#
+# The form is the same as for the topic keyword, but using pattern as the
+# keyword.
+# Pattern ACLs apply to all users even if the "user" keyword has previously
+# been given.
+#
+# If using bridges with usernames and ACLs, connection messages can be allowed
+# with the following pattern:
+# pattern write $SYS/broker/connection/%c/state
+#
+# pattern [read|write|readwrite] <topic>
+#
+# Example:
+#
+# pattern write sensor/%u/data
+#
+#acl_file
+
+# -----------------------------------------------------------------
+# Authentication and topic access plugin options
+# -----------------------------------------------------------------
+
+# If the auth_plugin option above is used, define options to pass to the
+# plugin here as described by the plugin instructions. All options named
+# using the format auth_opt_* will be passed to the plugin, for example:
+#
+# auth_opt_db_host
+# auth_opt_db_port 
+# auth_opt_db_username
+# auth_opt_db_password
+
+# =================================================================
+# External config files
+# =================================================================
+
+# External configuration files may be included by using the 
+# include_dir option. This defines a directory that will be searched
+# for config files. All files that end in '.conf' will be loaded as
+# a configuration file. It is best to have this as the last option
+# in the main file. This option will only be processed from the main
+# configuration file. The directory specified must not contain the 
+# main configuration file.
+#include_dir
+
+# =================================================================
+# rsmb options - unlikely to ever be supported
+# =================================================================
+
+#ffdc_output
+#max_log_entries
+#trace_level
+#trace_output
+
+
+
+# Bridge
+connection awsiot
+address a1m35stuxxwf0e.iot.us-west-2.amazonaws.com:8883
+topic # both 0
+bridge_protocol_version mqttv311
+bridge_insecure false
+cleansession true
+clientid bridgeawsiot
+start_type automatic
+notifications false
+log_type all
+bridge_cafile aws_keys/ca.pem
+bridge_certfile aws_keys/643ad617ec-certificate.pem.crt
+bridge_keyfile aws_keys/643ad617ec-private.pem.key
diff --git a/test/regression/interoperability_test/mqtt_test/test_scripts/mosquitto-psk.conf b/test/regression/interoperability_test/mqtt_test/test_scripts/mosquitto-psk.conf
new file mode 100644
index 00000000..204a0e03
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/test_scripts/mosquitto-psk.conf
@@ -0,0 +1,492 @@
+# Config file for mosquitto
+#
+# See mosquitto.conf(5) for more information.
+#
+# Default values are shown, uncomment to change.
+#
+# Use the # character to indicate a comment, but only if it is the 
+# very first character on the line.
+
+# =================================================================
+# General configuration
+# =================================================================
+
+# Time in seconds to wait before resending an outgoing QoS=1 or 
+# QoS=2 message.
+#retry_interval 20
+
+# Time in seconds between updates of the $SYS tree.
+# Set to 0 to disable the publishing of the $SYS tree.
+#sys_interval 10
+
+# Time in seconds between cleaning the internal message store of 
+# unreferenced messages. Lower values will result in lower memory 
+# usage but more processor time, higher values will have the 
+# opposite effect.
+# Setting a value of 0 means the unreferenced messages will be 
+# disposed of as quickly as possible.
+#store_clean_interval 10
+
+# Write process id to a file. Default is a blank string which means 
+# a pid file shouldn't be written.
+# This should be set to /var/run/mosquitto.pid if mosquitto is
+# being run automatically on boot with an init script and 
+# start-stop-daemon or similar.
+#pid_file
+
+# When run as root, drop privileges to this user and its primary 
+# group.
+# Leave blank to stay as root, but this is not recommended.
+# If run as a non-root user, this setting has no effect.
+# Note that on Windows this has no effect and so mosquitto should 
+# be started by the user you wish it to run as.
+#user mosquitto
+
+# The maximum number of QoS 1 and 2 messages currently inflight per 
+# client.
+# This includes messages that are partway through handshakes and 
+# those that are being retried. Defaults to 20. Set to 0 for no 
+# maximum. Setting to 1 will guarantee in-order delivery of QoS 1 
+# and 2 messages.
+#max_inflight_messages 20
+
+# The maximum number of QoS 1 and 2 messages to hold in a queue 
+# above those that are currently in-flight.  Defaults to 100. Set 
+# to 0 for no maximum (not recommended).
+# See also queue_qos0_messages.
+#max_queued_messages 100
+
+# Set to true to queue messages with QoS 0 when a persistent client is
+# disconnected. These messages are included in the limit imposed by
+# max_queued_messages.
+# Defaults to false.
+# This is a non-standard option for the MQTT v3.1 spec but is allowed in
+# v3.1.1.
+#queue_qos0_messages false
+
+# This option sets the maximum publish payload size that the broker will allow.
+# Received messages that exceed this size will not be accepted by the broker.
+# The default value is 0, which means that all valid MQTT messages are
+# accepted. MQTT imposes a maximum payload size of 268435455 bytes. 
+#message_size_limit 0
+
+# This option controls whether a client is allowed to connect with a zero
+# length client id or not. This option only affects clients using MQTT v3.1.1
+# and later. If set to false, clients connecting with a zero length client id
+# are disconnected. If set to true, clients will be allocated a client id by
+# the broker. This means it is only useful for clients with clean session set
+# to true.
+#allow_zero_length_clientid true
+
+# If allow_zero_length_clientid is true, this option allows you to set a prefix
+# to automatically generated client ids to aid visibility in logs.
+#auto_id_prefix
+
+# This option allows persistent clients (those with clean session set to false)
+# to be removed if they do not reconnect within a certain time frame.
+#
+# This is a non-standard option in MQTT V3.1 but allowed in MQTT v3.1.1.
+#
+# Badly designed clients may set clean session to false whilst using a randomly
+# generated client id. This leads to persistent clients that will never
+# reconnect. This option allows these clients to be removed.
+#
+# The expiration period should be an integer followed by one of h d w m y for
+# hour, day, week, month and year respectively. For example
+#
+# persistent_client_expiration 2m
+# persistent_client_expiration 14d
+# persistent_client_expiration 1y
+#
+# The default if not set is to never expire persistent clients.
+#persistent_client_expiration
+
+# If a client is subscribed to multiple subscriptions that overlap, e.g. foo/#
+# and foo/+/baz , then MQTT expects that when the broker receives a message on
+# a topic that matches both subscriptions, such as foo/bar/baz, then the client
+# should only receive the message once.
+# Mosquitto keeps track of which clients a message has been sent to in order to
+# meet this requirement. The allow_duplicate_messages option allows this
+# behaviour to be disabled, which may be useful if you have a large number of
+# clients subscribed to the same set of topics and are very concerned about
+# minimising memory usage.
+# It can be safely set to true if you know in advance that your clients will
+# never have overlapping subscriptions, otherwise your clients must be able to
+# correctly deal with duplicate messages even when then have QoS=2.
+#allow_duplicate_messages false
+
+# The MQTT specification requires that the QoS of a message delivered to a
+# subscriber is never upgraded to match the QoS of the subscription. Enabling
+# this option changes this behaviour. If upgrade_outgoing_qos is set true,
+# messages sent to a subscriber will always match the QoS of its subscription.
+# This is a non-standard option explicitly disallowed by the spec.
+#upgrade_outgoing_qos false
+
+# =================================================================
+# Default listener
+# =================================================================
+
+# IP address/hostname to bind the default listener to. If not
+# given, the default listener will not be bound to a specific 
+# address and so will be accessible to all network interfaces.
+# bind_address ip-address/host name
+#bind_address
+
+# Port to use for the default listener.
+#port 1883
+listener 8884
+
+# The maximum number of client connections to allow. This is 
+# a per listener setting.
+# Default is -1, which means unlimited connections.
+# Note that other process limits mean that unlimited connections 
+# are not really possible. Typically the default maximum number of 
+# connections possible is around 1024.
+#max_connections -1
+
+# Choose the protocol to use when listening.
+# This can be either mqtt or websockets.
+# Websockets support is currently disabled by default at compile time.
+# Certificate based TLS may be used with websockets, except that
+# only the cafile, certfile, keyfile and ciphers options are supported.
+#protocol mqtt
+
+# When a listener is using the websockets protocol, it is possible to serve
+# http data as well. Set http_dir to a directory which contains the files you
+# wish to serve. If this option is not specified, then no normal http
+# connections will be possible.
+#http_dir
+
+# Set use_username_as_clientid to true to replace the clientid that a client
+# connected with with its username. This allows authentication to be tied to
+# the clientid, which means that it is possible to prevent one client
+# disconnecting another by using the same clientid.
+# If a client connects with no username it will be disconnected as not
+# authorised when this option is set to true.
+# Do not use in conjunction with clientid_prefixes.
+# See also use_identity_as_username.
+#use_username_as_clientid
+
+# -----------------------------------------------------------------
+# Certificate based SSL/TLS support
+# -----------------------------------------------------------------
+# The following options can be used to enable SSL/TLS support for 
+# this listener. Note that the recommended port for MQTT over TLS
+# is 8883, but this must be set manually.
+#
+# See also the mosquitto-tls man page.
+
+# At least one of cafile or capath must be defined. They both 
+# define methods of accessing the PEM encoded Certificate 
+# Authority certificates that have signed your server certificate 
+# and that you wish to trust.
+# cafile defines the path to a file containing the CA certificates.
+# capath defines a directory that will be searched for files
+# containing the CA certificates. For capath to work correctly, the
+# certificate files must have ".crt" as the file ending and you must run
+# "c_rehash <path to capath>" each time you add/remove a certificate.
+#cafile
+#capath
+
+# Path to the PEM encoded server certificate.
+#certfile
+
+
+# Path to the PEM encoded keyfile.
+#keyfile
+
+# This option defines the version of the TLS protocol to use for this listener.
+# The default value allows v1.2, v1.1 and v1.0, if they are all supported by
+# the version of openssl that the broker was compiled against. For openssl >=
+# 1.0.1 the valid values are tlsv1.2 tlsv1.1 and tlsv1. For openssl < 1.0.1 the
+# valid values are tlsv1.
+#tls_version
+
+# By default a TLS enabled listener will operate in a similar fashion to a
+# https enabled web server, in that the server has a certificate signed by a CA
+# and the client will verify that it is a trusted certificate. The overall aim
+# is encryption of the network traffic. By setting require_certificate to true,
+# the client must provide a valid certificate in order for the network
+# connection to proceed. This allows access to the broker to be controlled
+# outside of the mechanisms provided by MQTT.
+#require_certificate false
+
+# If require_certificate is true, you may set use_identity_as_username to true
+# to use the CN value from the client certificate as a username. If this is
+# true, the password_file option will not be used for this listener.
+#use_identity_as_username false
+
+# If you have require_certificate set to true, you can create a certificate
+# revocation list file to revoke access to particular client certificates. If
+# you have done this, use crlfile to point to the PEM encoded revocation file.
+#crlfile
+
+# If you wish to control which encryption ciphers are used, use the ciphers
+# option. The list of available ciphers can be optained using the "openssl
+# ciphers" command and should be provided in the same format as the output of
+# that command.
+# If unset defaults to DEFAULT:!aNULL:!eNULL:!LOW:!EXPORT:!SSLv2:@STRENGTH
+#ciphers DEFAULT:!aNULL:!eNULL:!LOW:!EXPORT:!SSLv2:@STRENGTH
+
+# -----------------------------------------------------------------
+# Pre-shared-key based SSL/TLS support
+# -----------------------------------------------------------------
+# The following options can be used to enable PSK based SSL/TLS support for
+# this listener. Note that the recommended port for MQTT over TLS is 8883, but
+# this must be set manually.
+#
+# See also the mosquitto-tls man page and the "Certificate based SSL/TLS
+# support" section. Only one of certificate or PSK encryption support can be
+# enabled for any listener.
+
+# The psk_hint option enables pre-shared-key support for this listener and also
+# acts as an identifier for this listener. The hint is sent to clients and may
+# be used locally to aid authentication. The hint is a free form string that
+# doesn't have much meaning in itself, so feel free to be creative.
+# If this option is provided, see psk_file to define the pre-shared keys to be
+# used or create a security plugin to handle them.
+psk_hint Client_identity
+
+# Set use_identity_as_username to have the psk identity sent by the client used
+# as its username. Authentication will be carried out using the PSK rather than
+# the MQTT username/password and so password_file will not be used for this
+# listener.
+use_identity_as_username true
+
+# When using PSK, the encryption ciphers used will be chosen from the list of
+# available PSK ciphers. If you want to control which ciphers are available,
+# use the "ciphers" option.  The list of available ciphers can be optained
+# using the "openssl ciphers" command and should be provided in the same format
+# as the output of that command.
+#ciphers
+
+# =================================================================
+# Persistence
+# =================================================================
+
+# If persistence is enabled, save the in-memory database to disk 
+# every autosave_interval seconds. If set to 0, the persistence 
+# database will only be written when mosquitto exits. See also
+# autosave_on_changes.
+# Note that writing of the persistence database can be forced by 
+# sending mosquitto a SIGUSR1 signal.
+#autosave_interval 1800
+
+# If true, mosquitto will count the number of subscription changes, retained
+# messages received and queued messages and if the total exceeds
+# autosave_interval then the in-memory database will be saved to disk.
+# If false, mosquitto will save the in-memory database to disk by treating
+# autosave_interval as a time in seconds.
+#autosave_on_changes false
+
+# Save persistent message data to disk (true/false).
+# This saves information about all messages, including 
+# subscriptions, currently in-flight messages and retained 
+# messages.
+# retained_persistence is a synonym for this option.
+#persistence false
+
+# The filename to use for the persistent database, not including 
+# the path.
+#persistence_file mosquitto.db
+
+# Location for persistent database. Must include trailing /
+# Default is an empty string (current directory).
+# Set to e.g. /var/lib/mosquitto/ if running as a proper service on Linux or
+# similar.
+#persistence_location
+
+# =================================================================
+# Logging
+# =================================================================
+
+# Places to log to. Use multiple log_dest lines for multiple 
+# logging destinations.
+# Possible destinations are: stdout stderr syslog topic file
+#
+# stdout and stderr log to the console on the named output.
+#
+# syslog uses the userspace syslog facility which usually ends up 
+# in /var/log/messages or similar.
+#
+# topic logs to the broker topic '$SYS/broker/log/<severity>', 
+# where severity is one of D, E, W, N, I, M which are debug, error, 
+# warning, notice, information and message. Message type severity is used by
+# the subscribe/unsubscribe log_types and publishes log messages to
+# $SYS/broker/log/M/susbcribe or $SYS/broker/log/M/unsubscribe.
+#
+# The file destination requires an additional parameter which is the file to be
+# logged to, e.g. "log_dest file /var/log/mosquitto.log". The file will be
+# closed and reopened when the broker receives a HUP signal. Only a single file
+# destination may be configured.
+#
+# Note that if the broker is running as a Windows service it will default to
+# "log_dest none" and neither stdout nor stderr logging is available.
+# Use "log_dest none" if you wish to disable logging.
+#log_dest stderr
+
+# If using syslog logging (not on Windows), messages will be logged to the
+# "daemon" facility by default. Use the log_facility option to choose which of
+# local0 to local7 to log to instead. The option value should be an integer
+# value, e.g. "log_facility 5" to use local5.
+#log_facility
+
+# Types of messages to log. Use multiple log_type lines for logging
+# multiple types of messages.
+# Possible types are: debug, error, warning, notice, information, 
+# none, subscribe, unsubscribe, websockets, all.
+# Note that debug type messages are for decoding the incoming/outgoing
+# network packets. They are not logged in "topics".
+#log_type error
+#log_type warning
+#log_type notice
+#log_type information
+
+# Change the websockets logging level. This is a global option, it is not
+# possible to set per listener. This is an integer that is interpreted by
+# libwebsockets as a bit mask for its lws_log_levels enum. See the
+# libwebsockets documentation for more details. "log_type websockets" must also
+# be enabled.
+#websockets_log_level 0
+
+# If set to true, client connection and disconnection messages will be included
+# in the log.
+#connection_messages true
+
+# If set to true, add a timestamp value to each log message.
+#log_timestamp true
+
+# =================================================================
+# Security
+# =================================================================
+
+# If set, only clients that have a matching prefix on their 
+# clientid will be allowed to connect to the broker. By default, 
+# all clients may connect.
+# For example, setting "secure-" here would mean a client "secure-
+# client" could connect but another with clientid "mqtt" couldn't.
+#clientid_prefixes
+
+# Boolean value that determines whether clients that connect 
+# without providing a username are allowed to connect. If set to 
+# false then a password file should be created (see the 
+# password_file option) to control authenticated client access. 
+# Defaults to true.
+allow_anonymous true
+
+# In addition to the clientid_prefixes, allow_anonymous and TLS 
+# authentication options, username based authentication is also 
+# possible. The default support is described in "Default 
+# authentication and topic access control" below. The auth_plugin 
+# allows another authentication method to be used.
+# Specify the path to the loadable plugin and see the 
+# "Authentication and topic access plugin options" section below.
+#auth_plugin
+
+# -----------------------------------------------------------------
+# Default authentication and topic access control
+# -----------------------------------------------------------------
+
+# Control access to the broker using a password file. This file can be
+# generated using the mosquitto_passwd utility. If TLS support is not compiled
+# into mosquitto (it is recommended that TLS support should be included) then
+# plain text passwords are used, in which case the file should be a text file
+# with lines in the format:
+# username:password
+# The password (and colon) may be omitted if desired, although this 
+# offers very little in the way of security.
+# 
+# See the TLS client require_certificate and use_identity_as_username options
+# for alternative authentication options.
+#password_file
+
+# Access may also be controlled using a pre-shared-key file. This requires
+# TLS-PSK support and a listener configured to use it. The file should be text
+# lines in the format:
+# identity:key
+# The key should be in hexadecimal format without a leading "0x".
+psk_file ./psk_file.txt
+
+# Control access to topics on the broker using an access control list
+# file. If this parameter is defined then only the topics listed will
+# have access.
+# If the first character of a line of the ACL file is a # it is treated as a
+# comment.
+# Topic access is added with lines of the format:
+#
+# topic [read|write|readwrite] <topic>
+# 
+# The access type is controlled using "read", "write" or "readwrite". This
+# parameter is optional (unless <topic> contains a space character) - if not
+# given then the access is read/write.  <topic> can contain the + or #
+# wildcards as in subscriptions.
+# 
+# The first set of topics are applied to anonymous clients, assuming
+# allow_anonymous is true. User specific topic ACLs are added after a 
+# user line as follows:
+#
+# user <username>
+#
+# The username referred to here is the same as in password_file. It is
+# not the clientid.
+#
+#
+# If is also possible to define ACLs based on pattern substitution within the
+# topic. The patterns available for substition are:
+#
+# %c to match the client id of the client
+# %u to match the username of the client
+#
+# The substitution pattern must be the only text for that level of hierarchy.
+#
+# The form is the same as for the topic keyword, but using pattern as the
+# keyword.
+# Pattern ACLs apply to all users even if the "user" keyword has previously
+# been given.
+#
+# If using bridges with usernames and ACLs, connection messages can be allowed
+# with the following pattern:
+# pattern write $SYS/broker/connection/%c/state
+#
+# pattern [read|write|readwrite] <topic>
+#
+# Example:
+#
+# pattern write sensor/%u/data
+#
+#acl_file
+
+# -----------------------------------------------------------------
+# Authentication and topic access plugin options
+# -----------------------------------------------------------------
+
+# If the auth_plugin option above is used, define options to pass to the
+# plugin here as described by the plugin instructions. All options named
+# using the format auth_opt_* will be passed to the plugin, for example:
+#
+# auth_opt_db_host
+# auth_opt_db_port 
+# auth_opt_db_username
+# auth_opt_db_password
+
+# =================================================================
+# External config files
+# =================================================================
+
+# External configuration files may be included by using the 
+# include_dir option. This defines a directory that will be searched
+# for config files. All files that end in '.conf' will be loaded as
+# a configuration file. It is best to have this as the last option
+# in the main file. This option will only be processed from the main
+# configuration file. The directory specified must not contain the 
+# main configuration file.
+#include_dir
+
+# =================================================================
+# rsmb options - unlikely to ever be supported
+# =================================================================
+
+#ffdc_output
+#max_log_entries
+#trace_level
+#trace_output
diff --git a/test/regression/interoperability_test/mqtt_test/test_scripts/mosquitto.conf b/test/regression/interoperability_test/mqtt_test/test_scripts/mosquitto.conf
new file mode 100644
index 00000000..15a217f5
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/test_scripts/mosquitto.conf
@@ -0,0 +1,494 @@
+# Config file for mosquitto
+#
+# See mosquitto.conf(5) for more information.
+#
+# Default values are shown, uncomment to change.
+#
+# Use the # character to indicate a comment, but only if it is the 
+# very first character on the line.
+
+# =================================================================
+# General configuration
+# =================================================================
+
+# Time in seconds to wait before resending an outgoing QoS=1 or 
+# QoS=2 message.
+#retry_interval 20
+
+# Time in seconds between updates of the $SYS tree.
+# Set to 0 to disable the publishing of the $SYS tree.
+#sys_interval 10
+
+# Time in seconds between cleaning the internal message store of 
+# unreferenced messages. Lower values will result in lower memory 
+# usage but more processor time, higher values will have the 
+# opposite effect.
+# Setting a value of 0 means the unreferenced messages will be 
+# disposed of as quickly as possible.
+#store_clean_interval 10
+
+# Write process id to a file. Default is a blank string which means 
+# a pid file shouldn't be written.
+# This should be set to /var/run/mosquitto.pid if mosquitto is
+# being run automatically on boot with an init script and 
+# start-stop-daemon or similar.
+#pid_file
+
+# When run as root, drop privileges to this user and its primary 
+# group.
+# Leave blank to stay as root, but this is not recommended.
+# If run as a non-root user, this setting has no effect.
+# Note that on Windows this has no effect and so mosquitto should 
+# be started by the user you wish it to run as.
+user root
+
+# The maximum number of QoS 1 and 2 messages currently inflight per 
+# client.
+# This includes messages that are partway through handshakes and 
+# those that are being retried. Defaults to 20. Set to 0 for no 
+# maximum. Setting to 1 will guarantee in-order delivery of QoS 1 
+# and 2 messages.
+#max_inflight_messages 20
+
+# The maximum number of QoS 1 and 2 messages to hold in a queue 
+# above those that are currently in-flight.  Defaults to 100. Set 
+# to 0 for no maximum (not recommended).
+# See also queue_qos0_messages.
+#max_queued_messages 100
+
+# Set to true to queue messages with QoS 0 when a persistent client is
+# disconnected. These messages are included in the limit imposed by
+# max_queued_messages.
+# Defaults to false.
+# This is a non-standard option for the MQTT v3.1 spec but is allowed in
+# v3.1.1.
+#queue_qos0_messages false
+
+# This option sets the maximum publish payload size that the broker will allow.
+# Received messages that exceed this size will not be accepted by the broker.
+# The default value is 0, which means that all valid MQTT messages are
+# accepted. MQTT imposes a maximum payload size of 268435455 bytes. 
+#message_size_limit 0
+
+# This option controls whether a client is allowed to connect with a zero
+# length client id or not. This option only affects clients using MQTT v3.1.1
+# and later. If set to false, clients connecting with a zero length client id
+# are disconnected. If set to true, clients will be allocated a client id by
+# the broker. This means it is only useful for clients with clean session set
+# to true.
+#allow_zero_length_clientid true
+
+# If allow_zero_length_clientid is true, this option allows you to set a prefix
+# to automatically generated client ids to aid visibility in logs.
+#auto_id_prefix
+
+# This option allows persistent clients (those with clean session set to false)
+# to be removed if they do not reconnect within a certain time frame.
+#
+# This is a non-standard option in MQTT V3.1 but allowed in MQTT v3.1.1.
+#
+# Badly designed clients may set clean session to false whilst using a randomly
+# generated client id. This leads to persistent clients that will never
+# reconnect. This option allows these clients to be removed.
+#
+# The expiration period should be an integer followed by one of h d w m y for
+# hour, day, week, month and year respectively. For example
+#
+# persistent_client_expiration 2m
+# persistent_client_expiration 14d
+# persistent_client_expiration 1y
+#
+# The default if not set is to never expire persistent clients.
+#persistent_client_expiration
+
+# If a client is subscribed to multiple subscriptions that overlap, e.g. foo/#
+# and foo/+/baz , then MQTT expects that when the broker receives a message on
+# a topic that matches both subscriptions, such as foo/bar/baz, then the client
+# should only receive the message once.
+# Mosquitto keeps track of which clients a message has been sent to in order to
+# meet this requirement. The allow_duplicate_messages option allows this
+# behaviour to be disabled, which may be useful if you have a large number of
+# clients subscribed to the same set of topics and are very concerned about
+# minimising memory usage.
+# It can be safely set to true if you know in advance that your clients will
+# never have overlapping subscriptions, otherwise your clients must be able to
+# correctly deal with duplicate messages even when then have QoS=2.
+#allow_duplicate_messages false
+
+# The MQTT specification requires that the QoS of a message delivered to a
+# subscriber is never upgraded to match the QoS of the subscription. Enabling
+# this option changes this behaviour. If upgrade_outgoing_qos is set true,
+# messages sent to a subscriber will always match the QoS of its subscription.
+# This is a non-standard option explicitly disallowed by the spec.
+#upgrade_outgoing_qos false
+
+# =================================================================
+# Default listener
+# =================================================================
+
+# IP address/hostname to bind the default listener to. If not
+# given, the default listener will not be bound to a specific 
+# address and so will be accessible to all network interfaces.
+# bind_address ip-address/host name
+#bind_address
+
+# Port to use for the default listener.
+#port 1883
+listener 8884
+
+# The maximum number of client connections to allow. This is 
+# a per listener setting.
+# Default is -1, which means unlimited connections.
+# Note that other process limits mean that unlimited connections 
+# are not really possible. Typically the default maximum number of 
+# connections possible is around 1024.
+#max_connections -1
+
+# Choose the protocol to use when listening.
+# This can be either mqtt or websockets.
+# Websockets support is currently disabled by default at compile time.
+# Certificate based TLS may be used with websockets, except that
+# only the cafile, certfile, keyfile and ciphers options are supported.
+#protocol mqtt
+
+# When a listener is using the websockets protocol, it is possible to serve
+# http data as well. Set http_dir to a directory which contains the files you
+# wish to serve. If this option is not specified, then no normal http
+# connections will be possible.
+#http_dir
+
+# Set use_username_as_clientid to true to replace the clientid that a client
+# connected with with its username. This allows authentication to be tied to
+# the clientid, which means that it is possible to prevent one client
+# disconnecting another by using the same clientid.
+# If a client connects with no username it will be disconnected as not
+# authorised when this option is set to true.
+# Do not use in conjunction with clientid_prefixes.
+# See also use_identity_as_username.
+#use_username_as_clientid
+
+# -----------------------------------------------------------------
+# Certificate based SSL/TLS support
+# -----------------------------------------------------------------
+# The following options can be used to enable SSL/TLS support for 
+# this listener. Note that the recommended port for MQTT over TLS
+# is 8883, but this must be set manually.
+#
+# See also the mosquitto-tls man page.
+
+# At least one of cafile or capath must be defined. They both 
+# define methods of accessing the PEM encoded Certificate 
+# Authority certificates that have signed your server certificate 
+# and that you wish to trust.
+# cafile defines the path to a file containing the CA certificates.
+# capath defines a directory that will be searched for files
+# containing the CA certificates. For capath to work correctly, the
+# certificate files must have ".crt" as the file ending and you must run
+# "c_rehash <path to capath>" each time you add/remove a certificate.
+cafile CA/ca/ca.crt
+#capath
+
+# Path to the PEM encoded server certificate.
+#certfile ./cert.pem
+certfile CA/certs/broker.server.crt
+
+
+# Path to the PEM encoded keyfile.
+#keyfile ./keyout.pem
+keyfile CA/private/broker.server.key
+
+# This option defines the version of the TLS protocol to use for this listener.
+# The default value allows v1.2, v1.1 and v1.0, if they are all supported by
+# the version of openssl that the broker was compiled against. For openssl >=
+# 1.0.1 the valid values are tlsv1.2 tlsv1.1 and tlsv1. For openssl < 1.0.1 the
+# valid values are tlsv1.
+#tls_version tlsv1.2
+
+# By default a TLS enabled listener will operate in a similar fashion to a
+# https enabled web server, in that the server has a certificate signed by a CA
+# and the client will verify that it is a trusted certificate. The overall aim
+# is encryption of the network traffic. By setting require_certificate to true,
+# the client must provide a valid certificate in order for the network
+# connection to proceed. This allows access to the broker to be controlled
+# outside of the mechanisms provided by MQTT.
+#require_certificate true
+
+# If require_certificate is true, you may set use_identity_as_username to true
+# to use the CN value from the client certificate as a username. If this is
+# true, the password_file option will not be used for this listener.
+#use_identity_as_username false
+
+# If you have require_certificate set to true, you can create a certificate
+# revocation list file to revoke access to particular client certificates. If
+# you have done this, use crlfile to point to the PEM encoded revocation file.
+#crlfile
+
+# If you wish to control which encryption ciphers are used, use the ciphers
+# option. The list of available ciphers can be optained using the "openssl
+# ciphers" command and should be provided in the same format as the output of
+# that command.
+# If unset defaults to DEFAULT:!aNULL:!eNULL:!LOW:!EXPORT:!SSLv2:@STRENGTH
+#ciphers DEFAULT:!aNULL:!eNULL:!LOW:!EXPORT:!SSLv2:@STRENGTH
+
+# -----------------------------------------------------------------
+# Pre-shared-key based SSL/TLS support
+# -----------------------------------------------------------------
+# The following options can be used to enable PSK based SSL/TLS support for
+# this listener. Note that the recommended port for MQTT over TLS is 8883, but
+# this must be set manually.
+#
+# See also the mosquitto-tls man page and the "Certificate based SSL/TLS
+# support" section. Only one of certificate or PSK encryption support can be
+# enabled for any listener.
+
+# The psk_hint option enables pre-shared-key support for this listener and also
+# acts as an identifier for this listener. The hint is sent to clients and may
+# be used locally to aid authentication. The hint is a free form string that
+# doesn't have much meaning in itself, so feel free to be creative.
+# If this option is provided, see psk_file to define the pre-shared keys to be
+# used or create a security plugin to handle them.
+#psk_hint Client_identity
+
+# Set use_identity_as_username to have the psk identity sent by the client used
+# as its username. Authentication will be carried out using the PSK rather than
+# the MQTT username/password and so password_file will not be used for this
+# listener.
+#use_identity_as_username true
+
+# When using PSK, the encryption ciphers used will be chosen from the list of
+# available PSK ciphers. If you want to control which ciphers are available,
+# use the "ciphers" option.  The list of available ciphers can be optained
+# using the "openssl ciphers" command and should be provided in the same format
+# as the output of that command.
+#ciphers
+
+# =================================================================
+# Persistence
+# =================================================================
+
+# If persistence is enabled, save the in-memory database to disk 
+# every autosave_interval seconds. If set to 0, the persistence 
+# database will only be written when mosquitto exits. See also
+# autosave_on_changes.
+# Note that writing of the persistence database can be forced by 
+# sending mosquitto a SIGUSR1 signal.
+#autosave_interval 1800
+
+# If true, mosquitto will count the number of subscription changes, retained
+# messages received and queued messages and if the total exceeds
+# autosave_interval then the in-memory database will be saved to disk.
+# If false, mosquitto will save the in-memory database to disk by treating
+# autosave_interval as a time in seconds.
+#autosave_on_changes false
+
+# Save persistent message data to disk (true/false).
+# This saves information about all messages, including 
+# subscriptions, currently in-flight messages and retained 
+# messages.
+# retained_persistence is a synonym for this option.
+#persistence false
+
+# The filename to use for the persistent database, not including 
+# the path.
+#persistence_file mosquitto.db
+
+# Location for persistent database. Must include trailing /
+# Default is an empty string (current directory).
+# Set to e.g. /var/lib/mosquitto/ if running as a proper service on Linux or
+# similar.
+#persistence_location
+
+# =================================================================
+# Logging
+# =================================================================
+
+# Places to log to. Use multiple log_dest lines for multiple 
+# logging destinations.
+# Possible destinations are: stdout stderr syslog topic file
+#
+# stdout and stderr log to the console on the named output.
+#
+# syslog uses the userspace syslog facility which usually ends up 
+# in /var/log/messages or similar.
+#
+# topic logs to the broker topic '$SYS/broker/log/<severity>', 
+# where severity is one of D, E, W, N, I, M which are debug, error, 
+# warning, notice, information and message. Message type severity is used by
+# the subscribe/unsubscribe log_types and publishes log messages to
+# $SYS/broker/log/M/susbcribe or $SYS/broker/log/M/unsubscribe.
+#
+# The file destination requires an additional parameter which is the file to be
+# logged to, e.g. "log_dest file /var/log/mosquitto.log". The file will be
+# closed and reopened when the broker receives a HUP signal. Only a single file
+# destination may be configured.
+#
+# Note that if the broker is running as a Windows service it will default to
+# "log_dest none" and neither stdout nor stderr logging is available.
+# Use "log_dest none" if you wish to disable logging.
+#log_dest stderr
+
+# If using syslog logging (not on Windows), messages will be logged to the
+# "daemon" facility by default. Use the log_facility option to choose which of
+# local0 to local7 to log to instead. The option value should be an integer
+# value, e.g. "log_facility 5" to use local5.
+#log_facility
+
+# Types of messages to log. Use multiple log_type lines for logging
+# multiple types of messages.
+# Possible types are: debug, error, warning, notice, information, 
+# none, subscribe, unsubscribe, websockets, all.
+# Note that debug type messages are for decoding the incoming/outgoing
+# network packets. They are not logged in "topics".
+#log_type error
+#log_type warning
+#log_type notice
+#log_type information
+
+# Change the websockets logging level. This is a global option, it is not
+# possible to set per listener. This is an integer that is interpreted by
+# libwebsockets as a bit mask for its lws_log_levels enum. See the
+# libwebsockets documentation for more details. "log_type websockets" must also
+# be enabled.
+#websockets_log_level 0
+
+# If set to true, client connection and disconnection messages will be included
+# in the log.
+#connection_messages true
+
+# If set to true, add a timestamp value to each log message.
+#log_timestamp true
+
+# =================================================================
+# Security
+# =================================================================
+
+# If set, only clients that have a matching prefix on their 
+# clientid will be allowed to connect to the broker. By default, 
+# all clients may connect.
+# For example, setting "secure-" here would mean a client "secure-
+# client" could connect but another with clientid "mqtt" couldn't.
+#clientid_prefixes
+
+# Boolean value that determines whether clients that connect 
+# without providing a username are allowed to connect. If set to 
+# false then a password file should be created (see the 
+# password_file option) to control authenticated client access. 
+# Defaults to true.
+allow_anonymous true
+
+# In addition to the clientid_prefixes, allow_anonymous and TLS 
+# authentication options, username based authentication is also 
+# possible. The default support is described in "Default 
+# authentication and topic access control" below. The auth_plugin 
+# allows another authentication method to be used.
+# Specify the path to the loadable plugin and see the 
+# "Authentication and topic access plugin options" section below.
+#auth_plugin
+
+# -----------------------------------------------------------------
+# Default authentication and topic access control
+# -----------------------------------------------------------------
+
+# Control access to the broker using a password file. This file can be
+# generated using the mosquitto_passwd utility. If TLS support is not compiled
+# into mosquitto (it is recommended that TLS support should be included) then
+# plain text passwords are used, in which case the file should be a text file
+# with lines in the format:
+# username:password
+# The password (and colon) may be omitted if desired, although this 
+# offers very little in the way of security.
+# 
+# See the TLS client require_certificate and use_identity_as_username options
+# for alternative authentication options.
+#password_file
+
+# Access may also be controlled using a pre-shared-key file. This requires
+# TLS-PSK support and a listener configured to use it. The file should be text
+# lines in the format:
+# identity:key
+# The key should be in hexadecimal format without a leading "0x".
+#psk_file ./psk_file.txt
+
+# Control access to topics on the broker using an access control list
+# file. If this parameter is defined then only the topics listed will
+# have access.
+# If the first character of a line of the ACL file is a # it is treated as a
+# comment.
+# Topic access is added with lines of the format:
+#
+# topic [read|write|readwrite] <topic>
+# 
+# The access type is controlled using "read", "write" or "readwrite". This
+# parameter is optional (unless <topic> contains a space character) - if not
+# given then the access is read/write.  <topic> can contain the + or #
+# wildcards as in subscriptions.
+# 
+# The first set of topics are applied to anonymous clients, assuming
+# allow_anonymous is true. User specific topic ACLs are added after a 
+# user line as follows:
+#
+# user <username>
+#
+# The username referred to here is the same as in password_file. It is
+# not the clientid.
+#
+#
+# If is also possible to define ACLs based on pattern substitution within the
+# topic. The patterns available for substition are:
+#
+# %c to match the client id of the client
+# %u to match the username of the client
+#
+# The substitution pattern must be the only text for that level of hierarchy.
+#
+# The form is the same as for the topic keyword, but using pattern as the
+# keyword.
+# Pattern ACLs apply to all users even if the "user" keyword has previously
+# been given.
+#
+# If using bridges with usernames and ACLs, connection messages can be allowed
+# with the following pattern:
+# pattern write $SYS/broker/connection/%c/state
+#
+# pattern [read|write|readwrite] <topic>
+#
+# Example:
+#
+# pattern write sensor/%u/data
+#
+#acl_file
+
+# -----------------------------------------------------------------
+# Authentication and topic access plugin options
+# -----------------------------------------------------------------
+
+# If the auth_plugin option above is used, define options to pass to the
+# plugin here as described by the plugin instructions. All options named
+# using the format auth_opt_* will be passed to the plugin, for example:
+#
+# auth_opt_db_host
+# auth_opt_db_port 
+# auth_opt_db_username
+# auth_opt_db_password
+
+# =================================================================
+# External config files
+# =================================================================
+
+# External configuration files may be included by using the 
+# include_dir option. This defines a directory that will be searched
+# for config files. All files that end in '.conf' will be loaded as
+# a configuration file. It is best to have this as the last option
+# in the main file. This option will only be processed from the main
+# configuration file. The directory specified must not contain the 
+# main configuration file.
+#include_dir
+
+# =================================================================
+# rsmb options - unlikely to ever be supported
+# =================================================================
+
+#ffdc_output
+#max_log_entries
+#trace_level
+#trace_output
diff --git a/test/regression/interoperability_test/mqtt_test/test_scripts/mosquitto_no_tls.conf b/test/regression/interoperability_test/mqtt_test/test_scripts/mosquitto_no_tls.conf
new file mode 100644
index 00000000..15047b65
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/test_scripts/mosquitto_no_tls.conf
@@ -0,0 +1,494 @@
+# Config file for mosquitto
+#
+# See mosquitto.conf(5) for more information.
+#
+# Default values are shown, uncomment to change.
+#
+# Use the # character to indicate a comment, but only if it is the 
+# very first character on the line.
+
+# =================================================================
+# General configuration
+# =================================================================
+
+# Time in seconds to wait before resending an outgoing QoS=1 or 
+# QoS=2 message.
+#retry_interval 20
+
+# Time in seconds between updates of the $SYS tree.
+# Set to 0 to disable the publishing of the $SYS tree.
+#sys_interval 10
+
+# Time in seconds between cleaning the internal message store of 
+# unreferenced messages. Lower values will result in lower memory 
+# usage but more processor time, higher values will have the 
+# opposite effect.
+# Setting a value of 0 means the unreferenced messages will be 
+# disposed of as quickly as possible.
+#store_clean_interval 10
+
+# Write process id to a file. Default is a blank string which means 
+# a pid file shouldn't be written.
+# This should be set to /var/run/mosquitto.pid if mosquitto is
+# being run automatically on boot with an init script and 
+# start-stop-daemon or similar.
+#pid_file
+
+# When run as root, drop privileges to this user and its primary 
+# group.
+# Leave blank to stay as root, but this is not recommended.
+# If run as a non-root user, this setting has no effect.
+# Note that on Windows this has no effect and so mosquitto should 
+# be started by the user you wish it to run as.
+user root
+
+# The maximum number of QoS 1 and 2 messages currently inflight per 
+# client.
+# This includes messages that are partway through handshakes and 
+# those that are being retried. Defaults to 20. Set to 0 for no 
+# maximum. Setting to 1 will guarantee in-order delivery of QoS 1 
+# and 2 messages.
+#max_inflight_messages 20
+
+# The maximum number of QoS 1 and 2 messages to hold in a queue 
+# above those that are currently in-flight.  Defaults to 100. Set 
+# to 0 for no maximum (not recommended).
+# See also queue_qos0_messages.
+#max_queued_messages 100
+
+# Set to true to queue messages with QoS 0 when a persistent client is
+# disconnected. These messages are included in the limit imposed by
+# max_queued_messages.
+# Defaults to false.
+# This is a non-standard option for the MQTT v3.1 spec but is allowed in
+# v3.1.1.
+#queue_qos0_messages false
+
+# This option sets the maximum publish payload size that the broker will allow.
+# Received messages that exceed this size will not be accepted by the broker.
+# The default value is 0, which means that all valid MQTT messages are
+# accepted. MQTT imposes a maximum payload size of 268435455 bytes. 
+#message_size_limit 0
+
+# This option controls whether a client is allowed to connect with a zero
+# length client id or not. This option only affects clients using MQTT v3.1.1
+# and later. If set to false, clients connecting with a zero length client id
+# are disconnected. If set to true, clients will be allocated a client id by
+# the broker. This means it is only useful for clients with clean session set
+# to true.
+#allow_zero_length_clientid true
+
+# If allow_zero_length_clientid is true, this option allows you to set a prefix
+# to automatically generated client ids to aid visibility in logs.
+#auto_id_prefix
+
+# This option allows persistent clients (those with clean session set to false)
+# to be removed if they do not reconnect within a certain time frame.
+#
+# This is a non-standard option in MQTT V3.1 but allowed in MQTT v3.1.1.
+#
+# Badly designed clients may set clean session to false whilst using a randomly
+# generated client id. This leads to persistent clients that will never
+# reconnect. This option allows these clients to be removed.
+#
+# The expiration period should be an integer followed by one of h d w m y for
+# hour, day, week, month and year respectively. For example
+#
+# persistent_client_expiration 2m
+# persistent_client_expiration 14d
+# persistent_client_expiration 1y
+#
+# The default if not set is to never expire persistent clients.
+#persistent_client_expiration
+
+# If a client is subscribed to multiple subscriptions that overlap, e.g. foo/#
+# and foo/+/baz , then MQTT expects that when the broker receives a message on
+# a topic that matches both subscriptions, such as foo/bar/baz, then the client
+# should only receive the message once.
+# Mosquitto keeps track of which clients a message has been sent to in order to
+# meet this requirement. The allow_duplicate_messages option allows this
+# behaviour to be disabled, which may be useful if you have a large number of
+# clients subscribed to the same set of topics and are very concerned about
+# minimising memory usage.
+# It can be safely set to true if you know in advance that your clients will
+# never have overlapping subscriptions, otherwise your clients must be able to
+# correctly deal with duplicate messages even when then have QoS=2.
+#allow_duplicate_messages false
+
+# The MQTT specification requires that the QoS of a message delivered to a
+# subscriber is never upgraded to match the QoS of the subscription. Enabling
+# this option changes this behaviour. If upgrade_outgoing_qos is set true,
+# messages sent to a subscriber will always match the QoS of its subscription.
+# This is a non-standard option explicitly disallowed by the spec.
+#upgrade_outgoing_qos false
+
+# =================================================================
+# Default listener
+# =================================================================
+
+# IP address/hostname to bind the default listener to. If not
+# given, the default listener will not be bound to a specific 
+# address and so will be accessible to all network interfaces.
+# bind_address ip-address/host name
+#bind_address
+
+# Port to use for the default listener.
+#port 1883
+listener 8884
+
+# The maximum number of client connections to allow. This is 
+# a per listener setting.
+# Default is -1, which means unlimited connections.
+# Note that other process limits mean that unlimited connections 
+# are not really possible. Typically the default maximum number of 
+# connections possible is around 1024.
+#max_connections -1
+
+# Choose the protocol to use when listening.
+# This can be either mqtt or websockets.
+# Websockets support is currently disabled by default at compile time.
+# Certificate based TLS may be used with websockets, except that
+# only the cafile, certfile, keyfile and ciphers options are supported.
+#protocol mqtt
+
+# When a listener is using the websockets protocol, it is possible to serve
+# http data as well. Set http_dir to a directory which contains the files you
+# wish to serve. If this option is not specified, then no normal http
+# connections will be possible.
+#http_dir
+
+# Set use_username_as_clientid to true to replace the clientid that a client
+# connected with with its username. This allows authentication to be tied to
+# the clientid, which means that it is possible to prevent one client
+# disconnecting another by using the same clientid.
+# If a client connects with no username it will be disconnected as not
+# authorised when this option is set to true.
+# Do not use in conjunction with clientid_prefixes.
+# See also use_identity_as_username.
+#use_username_as_clientid
+
+# -----------------------------------------------------------------
+# Certificate based SSL/TLS support
+# -----------------------------------------------------------------
+# The following options can be used to enable SSL/TLS support for 
+# this listener. Note that the recommended port for MQTT over TLS
+# is 8883, but this must be set manually.
+#
+# See also the mosquitto-tls man page.
+
+# At least one of cafile or capath must be defined. They both 
+# define methods of accessing the PEM encoded Certificate 
+# Authority certificates that have signed your server certificate 
+# and that you wish to trust.
+# cafile defines the path to a file containing the CA certificates.
+# capath defines a directory that will be searched for files
+# containing the CA certificates. For capath to work correctly, the
+# certificate files must have ".crt" as the file ending and you must run
+# "c_rehash <path to capath>" each time you add/remove a certificate.
+#cafile CA/ca/ca.crt
+#capath
+
+# Path to the PEM encoded server certificate.
+#certfile ./cert.pem
+#certfile CA/certs/broker.server.crt
+
+
+# Path to the PEM encoded keyfile.
+#keyfile ./keyout.pem
+#keyfile CA/private/broker.server.key
+
+# This option defines the version of the TLS protocol to use for this listener.
+# The default value allows v1.2, v1.1 and v1.0, if they are all supported by
+# the version of openssl that the broker was compiled against. For openssl >=
+# 1.0.1 the valid values are tlsv1.2 tlsv1.1 and tlsv1. For openssl < 1.0.1 the
+# valid values are tlsv1.
+#tls_version tlsv1.2
+
+# By default a TLS enabled listener will operate in a similar fashion to a
+# https enabled web server, in that the server has a certificate signed by a CA
+# and the client will verify that it is a trusted certificate. The overall aim
+# is encryption of the network traffic. By setting require_certificate to true,
+# the client must provide a valid certificate in order for the network
+# connection to proceed. This allows access to the broker to be controlled
+# outside of the mechanisms provided by MQTT.
+#require_certificate true
+
+# If require_certificate is true, you may set use_identity_as_username to true
+# to use the CN value from the client certificate as a username. If this is
+# true, the password_file option will not be used for this listener.
+#use_identity_as_username false
+
+# If you have require_certificate set to true, you can create a certificate
+# revocation list file to revoke access to particular client certificates. If
+# you have done this, use crlfile to point to the PEM encoded revocation file.
+#crlfile
+
+# If you wish to control which encryption ciphers are used, use the ciphers
+# option. The list of available ciphers can be optained using the "openssl
+# ciphers" command and should be provided in the same format as the output of
+# that command.
+# If unset defaults to DEFAULT:!aNULL:!eNULL:!LOW:!EXPORT:!SSLv2:@STRENGTH
+#ciphers DEFAULT:!aNULL:!eNULL:!LOW:!EXPORT:!SSLv2:@STRENGTH
+
+# -----------------------------------------------------------------
+# Pre-shared-key based SSL/TLS support
+# -----------------------------------------------------------------
+# The following options can be used to enable PSK based SSL/TLS support for
+# this listener. Note that the recommended port for MQTT over TLS is 8883, but
+# this must be set manually.
+#
+# See also the mosquitto-tls man page and the "Certificate based SSL/TLS
+# support" section. Only one of certificate or PSK encryption support can be
+# enabled for any listener.
+
+# The psk_hint option enables pre-shared-key support for this listener and also
+# acts as an identifier for this listener. The hint is sent to clients and may
+# be used locally to aid authentication. The hint is a free form string that
+# doesn't have much meaning in itself, so feel free to be creative.
+# If this option is provided, see psk_file to define the pre-shared keys to be
+# used or create a security plugin to handle them.
+#psk_hint Client_identity
+
+# Set use_identity_as_username to have the psk identity sent by the client used
+# as its username. Authentication will be carried out using the PSK rather than
+# the MQTT username/password and so password_file will not be used for this
+# listener.
+#use_identity_as_username true
+
+# When using PSK, the encryption ciphers used will be chosen from the list of
+# available PSK ciphers. If you want to control which ciphers are available,
+# use the "ciphers" option.  The list of available ciphers can be optained
+# using the "openssl ciphers" command and should be provided in the same format
+# as the output of that command.
+#ciphers
+
+# =================================================================
+# Persistence
+# =================================================================
+
+# If persistence is enabled, save the in-memory database to disk 
+# every autosave_interval seconds. If set to 0, the persistence 
+# database will only be written when mosquitto exits. See also
+# autosave_on_changes.
+# Note that writing of the persistence database can be forced by 
+# sending mosquitto a SIGUSR1 signal.
+#autosave_interval 1800
+
+# If true, mosquitto will count the number of subscription changes, retained
+# messages received and queued messages and if the total exceeds
+# autosave_interval then the in-memory database will be saved to disk.
+# If false, mosquitto will save the in-memory database to disk by treating
+# autosave_interval as a time in seconds.
+#autosave_on_changes false
+
+# Save persistent message data to disk (true/false).
+# This saves information about all messages, including 
+# subscriptions, currently in-flight messages and retained 
+# messages.
+# retained_persistence is a synonym for this option.
+#persistence false
+
+# The filename to use for the persistent database, not including 
+# the path.
+#persistence_file mosquitto.db
+
+# Location for persistent database. Must include trailing /
+# Default is an empty string (current directory).
+# Set to e.g. /var/lib/mosquitto/ if running as a proper service on Linux or
+# similar.
+#persistence_location
+
+# =================================================================
+# Logging
+# =================================================================
+
+# Places to log to. Use multiple log_dest lines for multiple 
+# logging destinations.
+# Possible destinations are: stdout stderr syslog topic file
+#
+# stdout and stderr log to the console on the named output.
+#
+# syslog uses the userspace syslog facility which usually ends up 
+# in /var/log/messages or similar.
+#
+# topic logs to the broker topic '$SYS/broker/log/<severity>', 
+# where severity is one of D, E, W, N, I, M which are debug, error, 
+# warning, notice, information and message. Message type severity is used by
+# the subscribe/unsubscribe log_types and publishes log messages to
+# $SYS/broker/log/M/susbcribe or $SYS/broker/log/M/unsubscribe.
+#
+# The file destination requires an additional parameter which is the file to be
+# logged to, e.g. "log_dest file /var/log/mosquitto.log". The file will be
+# closed and reopened when the broker receives a HUP signal. Only a single file
+# destination may be configured.
+#
+# Note that if the broker is running as a Windows service it will default to
+# "log_dest none" and neither stdout nor stderr logging is available.
+# Use "log_dest none" if you wish to disable logging.
+#log_dest stderr
+
+# If using syslog logging (not on Windows), messages will be logged to the
+# "daemon" facility by default. Use the log_facility option to choose which of
+# local0 to local7 to log to instead. The option value should be an integer
+# value, e.g. "log_facility 5" to use local5.
+#log_facility
+
+# Types of messages to log. Use multiple log_type lines for logging
+# multiple types of messages.
+# Possible types are: debug, error, warning, notice, information, 
+# none, subscribe, unsubscribe, websockets, all.
+# Note that debug type messages are for decoding the incoming/outgoing
+# network packets. They are not logged in "topics".
+#log_type error
+#log_type warning
+#log_type notice
+#log_type information
+
+# Change the websockets logging level. This is a global option, it is not
+# possible to set per listener. This is an integer that is interpreted by
+# libwebsockets as a bit mask for its lws_log_levels enum. See the
+# libwebsockets documentation for more details. "log_type websockets" must also
+# be enabled.
+#websockets_log_level 0
+
+# If set to true, client connection and disconnection messages will be included
+# in the log.
+#connection_messages true
+
+# If set to true, add a timestamp value to each log message.
+#log_timestamp true
+
+# =================================================================
+# Security
+# =================================================================
+
+# If set, only clients that have a matching prefix on their 
+# clientid will be allowed to connect to the broker. By default, 
+# all clients may connect.
+# For example, setting "secure-" here would mean a client "secure-
+# client" could connect but another with clientid "mqtt" couldn't.
+#clientid_prefixes
+
+# Boolean value that determines whether clients that connect 
+# without providing a username are allowed to connect. If set to 
+# false then a password file should be created (see the 
+# password_file option) to control authenticated client access. 
+# Defaults to true.
+allow_anonymous true
+
+# In addition to the clientid_prefixes, allow_anonymous and TLS 
+# authentication options, username based authentication is also 
+# possible. The default support is described in "Default 
+# authentication and topic access control" below. The auth_plugin 
+# allows another authentication method to be used.
+# Specify the path to the loadable plugin and see the 
+# "Authentication and topic access plugin options" section below.
+#auth_plugin
+
+# -----------------------------------------------------------------
+# Default authentication and topic access control
+# -----------------------------------------------------------------
+
+# Control access to the broker using a password file. This file can be
+# generated using the mosquitto_passwd utility. If TLS support is not compiled
+# into mosquitto (it is recommended that TLS support should be included) then
+# plain text passwords are used, in which case the file should be a text file
+# with lines in the format:
+# username:password
+# The password (and colon) may be omitted if desired, although this 
+# offers very little in the way of security.
+# 
+# See the TLS client require_certificate and use_identity_as_username options
+# for alternative authentication options.
+#password_file
+
+# Access may also be controlled using a pre-shared-key file. This requires
+# TLS-PSK support and a listener configured to use it. The file should be text
+# lines in the format:
+# identity:key
+# The key should be in hexadecimal format without a leading "0x".
+#psk_file ./psk_file.txt
+
+# Control access to topics on the broker using an access control list
+# file. If this parameter is defined then only the topics listed will
+# have access.
+# If the first character of a line of the ACL file is a # it is treated as a
+# comment.
+# Topic access is added with lines of the format:
+#
+# topic [read|write|readwrite] <topic>
+# 
+# The access type is controlled using "read", "write" or "readwrite". This
+# parameter is optional (unless <topic> contains a space character) - if not
+# given then the access is read/write.  <topic> can contain the + or #
+# wildcards as in subscriptions.
+# 
+# The first set of topics are applied to anonymous clients, assuming
+# allow_anonymous is true. User specific topic ACLs are added after a 
+# user line as follows:
+#
+# user <username>
+#
+# The username referred to here is the same as in password_file. It is
+# not the clientid.
+#
+#
+# If is also possible to define ACLs based on pattern substitution within the
+# topic. The patterns available for substition are:
+#
+# %c to match the client id of the client
+# %u to match the username of the client
+#
+# The substitution pattern must be the only text for that level of hierarchy.
+#
+# The form is the same as for the topic keyword, but using pattern as the
+# keyword.
+# Pattern ACLs apply to all users even if the "user" keyword has previously
+# been given.
+#
+# If using bridges with usernames and ACLs, connection messages can be allowed
+# with the following pattern:
+# pattern write $SYS/broker/connection/%c/state
+#
+# pattern [read|write|readwrite] <topic>
+#
+# Example:
+#
+# pattern write sensor/%u/data
+#
+#acl_file
+
+# -----------------------------------------------------------------
+# Authentication and topic access plugin options
+# -----------------------------------------------------------------
+
+# If the auth_plugin option above is used, define options to pass to the
+# plugin here as described by the plugin instructions. All options named
+# using the format auth_opt_* will be passed to the plugin, for example:
+#
+# auth_opt_db_host
+# auth_opt_db_port 
+# auth_opt_db_username
+# auth_opt_db_password
+
+# =================================================================
+# External config files
+# =================================================================
+
+# External configuration files may be included by using the 
+# include_dir option. This defines a directory that will be searched
+# for config files. All files that end in '.conf' will be loaded as
+# a configuration file. It is best to have this as the last option
+# in the main file. This option will only be processed from the main
+# configuration file. The directory specified must not contain the 
+# main configuration file.
+#include_dir
+
+# =================================================================
+# rsmb options - unlikely to ever be supported
+# =================================================================
+
+#ffdc_output
+#max_log_entries
+#trace_level
+#trace_output
diff --git a/test/regression/interoperability_test/mqtt_test/test_scripts/no_tls_pub.sh b/test/regression/interoperability_test/mqtt_test/test_scripts/no_tls_pub.sh
new file mode 100755
index 00000000..34211a3e
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/test_scripts/no_tls_pub.sh
@@ -0,0 +1,5 @@
+#! /bin/sh
+dir=`dirname $0`
+dir=`realpath $dir`
+cd $dir
+mosquitto_pub $*
diff --git a/test/regression/interoperability_test/mqtt_test/test_scripts/no_tls_server.sh b/test/regression/interoperability_test/mqtt_test/test_scripts/no_tls_server.sh
new file mode 100755
index 00000000..b04593a5
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/test_scripts/no_tls_server.sh
@@ -0,0 +1,14 @@
+#! /bin/bash
+
+function kill_mqtt_server(){
+    kill $mqtt_server_pid
+    wait
+}
+
+dir=`dirname $0`
+dir=`realpath $dir`
+cd $dir
+mosquitto -c ./mosquitto_no_tls.conf -v $* &
+mqtt_server_pid=$!
+trap kill_mqtt_server TERM ALRM
+wait
diff --git a/test/regression/interoperability_test/mqtt_test/test_scripts/no_tls_sub.sh b/test/regression/interoperability_test/mqtt_test/test_scripts/no_tls_sub.sh
new file mode 100755
index 00000000..52be4a76
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/test_scripts/no_tls_sub.sh
@@ -0,0 +1,5 @@
+#! /bin/sh
+dir=`dirname $0`
+dir=`realpath $dir`
+cd $dir
+mosquitto_sub -p 8883 $*
diff --git a/test/regression/interoperability_test/mqtt_test/test_scripts/psk_server.sh b/test/regression/interoperability_test/mqtt_test/test_scripts/psk_server.sh
new file mode 100644
index 00000000..ce9691b8
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/test_scripts/psk_server.sh
@@ -0,0 +1 @@
+../mosquitto-1.4.10/src/mosquitto.exe -c ./mosquitto-psk.conf -v -p 8883
diff --git a/test/regression/interoperability_test/mqtt_test/test_scripts/pub.sh b/test/regression/interoperability_test/mqtt_test/test_scripts/pub.sh
new file mode 100755
index 00000000..8e0eae0a
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/test_scripts/pub.sh
@@ -0,0 +1,5 @@
+#! /bin/sh
+dir=`dirname $0`
+dir=`realpath $dir`
+cd $dir
+mosquitto_pub --cert CA/certs/ew2017.client.crt --key CA/private/ew2017.client.key --cafile CA/ca/ca.crt --insecure $*
diff --git a/test/regression/interoperability_test/mqtt_test/test_scripts/sub.sh b/test/regression/interoperability_test/mqtt_test/test_scripts/sub.sh
new file mode 100755
index 00000000..83b95e34
--- /dev/null
+++ b/test/regression/interoperability_test/mqtt_test/test_scripts/sub.sh
@@ -0,0 +1,5 @@
+#! /bin/sh
+dir=`dirname $0`
+dir=`realpath $dir`
+cd $dir
+mosquitto_sub --cert CA/certs/ew2017.client.crt --key CA/private/ew2017.client.key --cafile CA/ca/ca.crt -p 8883 --insecure $*