examples/mqttc: add subscriber client implementation example

examples/mqttc/CMakeLists.txt

@@ -23,11 +23,23 @@
 if(CONFIG_EXAMPLES_MQTTC)
   nuttx_add_application(
     NAME
-    ${CONFIG_EXAMPLES_MQTTC_PROGNAME}
+    ${CONFIG_EXAMPLES_MQTTC_PUB_PROGNAME}
     STACKSIZE
     ${CONFIG_EXAMPLES_MQTTC_STACKSIZE}
     MODULE
     ${CONFIG_EXAMPLES_MQTTC}
     SRCS
     mqttc_pub.c)
+
+  if(CONFIG_EXAMPLES_MQTTC_SUB)
+    nuttx_add_application(
+      NAME
+      ${CONFIG_EXAMPLES_MQTTC_SUB_PROGNAME}
+      STACKSIZE
+      ${CONFIG_EXAMPLES_MQTTC_STACKSIZE}
+      MODULE
+      ${CONFIG_EXAMPLES_MQTTC}
+      SRCS
+      mqttc_sub.c)
+  endif()
 endif()

examples/mqttc/Kconfig

@@ -16,6 +16,17 @@ config EXAMPLES_MQTTC_PROGNAME
 	string "Program name"
 	default "mqttc_pub"
 
+config EXAMPLES_MQTTC_SUB
+	bool "Enable MQTT-C Subscriber Client"
+	default n
+	---help---
+		Enable a simple MQTT-C subscriber example alongside publisher
+
+config EXAMPLES_MQTTC_SUB_PROGNAME
+	string "Subscriber program name"
+	default "mqttc_sub"
+	depends on EXAMPLES_MQTTC_SUB
+
 config EXAMPLES_MQTTC_STACKSIZE
 	int "Task's stack size"
 	default 8192
@@ -28,6 +39,19 @@ config EXAMPLES_MQTTC_RXSIZE
 	int "RX Buffer size"
 	default 256
 
+config MQTT_USE_MBEDTLS
+	bool
+	default n
+
+config EXAMPLES_MQTTC_MBEDTLS
+	bool "Enable MQTT over TLS (mbedTLS)"
+	default n
+	depends on NETUTILS_MQTTC_WITH_MBEDTLS
+	select MQTT_USE_MBEDTLS
+	---help---
+		Enable TLS/SSL support for MQTT connections using mbedTLS.
+		Requires NETUTILS_MQTTC_WITH_MBEDTLS to be enabled.
+
 config EXAMPLES_MQTTC_ALLOW_UNVERIFIED_TLS
 	bool "Allow unverified TLS"
 	default n

examples/mqttc/Makefile

@@ -25,10 +25,20 @@ include $(APPDIR)/Make.defs
 PROGNAME = $(CONFIG_EXAMPLES_MQTTC_PROGNAME)
 PRIORITY = SCHED_PRIORITY_DEFAULT
 STACKSIZE = $(CONFIG_EXAMPLES_MQTTC_STACKSIZE)
+
+ifeq ($(CONFIG_EXAMPLES_MQTTC_SUB),y)
+    PROGNAME  += $(CONFIG_EXAMPLES_MQTTC_SUB_PROGNAME)
+    PRIORITY  += SCHED_PRIORITY_DEFAULT
+    STACKSIZE += $(CONFIG_EXAMPLES_MQTTC_STACKSIZE)
+endif
+
 MODULE = $(CONFIG_EXAMPLES_MQTTC)
 
 # MQTT-C example source code
 
 MAINSRC = mqttc_pub.c
+ifeq ($(CONFIG_EXAMPLES_MQTTC_SUB), y)
+    MAINSRC += mqttc_sub.c
+endif
 
 include $(APPDIR)/Application.mk

examples/mqttc/cert.inc

@@ -0,0 +1,30 @@
+/* Broker CA certificate (PEM), embedded in the firmware so the subscriber
+ * can authenticate the broker without copying a certificate file onto the
+ * board.
+ * Replace the body below if the broker's CA changes; init_conn() parses
+ * it whenever no CA file is supplied on the command line via -c.
+ */
+
+#  define TEST_CA_CRT_RSA_SHA256_PEM                                       \
+    "-----BEGIN CERTIFICATE-----\r\n"                                      \
+    "MIIDYTCCAkmgAwIBAgIUAk1VwJ7il2775wUnEgBZSvW77dUwDQYJKoZIhvcNAQEL\r\n" \
+    "BQAwQDELMAkGA1UEBhMCUk8xEjAQBgNVBAgMCUJ1Y2hhcmVzdDEOMAwGA1UECgwF\r\n" \
+    "TXlPcmcxDTALBgNVBAMMBE15Q0EwHhcNMjYwNjA5MDA0MjExWhcNMzYwNjA2MDA0\r\n" \
+    "MjExWjBAMQswCQYDVQQGEwJSTzESMBAGA1UECAwJQnVjaGFyZXN0MQ4wDAYDVQQK\r\n" \
+    "DAVNeU9yZzENMAsGA1UEAwwETXlDQTCCASIwDQYJKoZIhvcNAQEBBQADggEPADCC\r\n" \
+    "AQoCggEBAMGfLamBuio0mYqL8TDLqcxqCDhELmrmYxccz8/BAJ3xG0bbqAg0o2CM\r\n" \
+    "2nUcDWeDTTOFTEAOVKhqqbu7jzQA+/XRQaptYAzt13N0pMUFlKZQ0QVefAH11mph\r\n" \
+    "M2u0exWZObRQxUyfzzJG1UZQ4xGqXUekg+2LMSS09g/QAsCreu8O+xzAK9XUA6np\r\n" \
+    "8lebaIqxFHabrjlbHgan5qKP0+EncMRN/5Lb11MDzfjyIusoFWPZF8rF2x9D+UFv\r\n" \
+    "hZuL9Z40jz3cRlVUxuVtUq1tna2CCwWhwl5gwAQ/b0rkhe+5/b3cgSs3VbIdWHic\r\n" \
+    "nwM4Yq4K/nAetYiOxtjKY5zLIvRopd0CAwEAAaNTMFEwHQYDVR0OBBYEFFR43w+x\r\n" \
+    "ri1ssaAyJzQGDH/dP2e0MB8GA1UdIwQYMBaAFFR43w+xri1ssaAyJzQGDH/dP2e0\r\n" \
+    "MA8GA1UdEwEB/wQFMAMBAf8wDQYJKoZIhvcNAQELBQADggEBADU/lBjTGb7RlgGq\r\n" \
+    "HYCktoWZBNkJFPVTPrC1mwzJX/vSaz9QUpRA5dpprSl84QKvWNxO5fPEMmwK2Wrw\r\n" \
+    "x6tdE2aWb5x+3W0302JnaUPNhDF26Z5+LK4CoRHjbT2J3FrDg2u6/3Si+RpNSHYh\r\n" \
+    "0OCdApzCyzqWdmvb7VD+u+isSh9CEUcaBOCq/72GNqdIjnSsgMGNHp9Ld6+ctwJO\r\n" \
+    "sQkj0M3MaciNSPZ3y0w/GqeWNQaK3Rk5pSaqrc9RQS42KtJuGOqMiBMG1Ib6b7D4\r\n" \
+    "bJSEDBzhO1M0o9vwr9xYaCUfbQzuuYJ3al4weRl0E4B63o2OFUjMOILIO3LeuuRD\r\n" \
+    "+HXdOE0=\r\n"                                                         \
+    "-----END CERTIFICATE-----\r\n"
+/* END FILE */

examples/mqttc/mqttc_pub.c

@@ -24,6 +24,7 @@
  * Included Files
  ****************************************************************************/
 
+#include <nuttx/compiler.h>
 #include <unistd.h>
 #include <stdlib.h>
 #include <stdio.h>
@@ -42,39 +43,12 @@
 #  include <mbedtls/net_sockets.h>
 #  include <mbedtls/ssl.h>
 
+#include "cert.inc"
+
 /****************************************************************************
  * Pre-processor Definitions
  ****************************************************************************/
 
-/* This is taken from mbedtls/tests/data_files/test-ca-sha256.crt. */
-
-/* BEGIN FILE string macro TEST_CA_CRT_RSA_SHA256_PEM
- * mbedtls/tests/data_files/test-ca-sha256.crt
- */
-
-#  define TEST_CA_CRT_RSA_SHA256_PEM                                       \
-    "-----BEGIN CERTIFICATE-----\r\n"                                      \
-    "MIIDQTCCAimgAwIBAgIBAzANBgkqhkiG9w0BAQsFADA7MQswCQYDVQQGEwJOTDER\r\n" \
-    "MA8GA1UECgwIUG9sYXJTU0wxGTAXBgNVBAMMEFBvbGFyU1NMIFRlc3QgQ0EwHhcN\r\n" \
-    "MTkwMjEwMTQ0NDAwWhcNMjkwMjEwMTQ0NDAwWjA7MQswCQYDVQQGEwJOTDERMA8G\r\n" \
-    "A1UECgwIUG9sYXJTU0wxGTAXBgNVBAMMEFBvbGFyU1NMIFRlc3QgQ0EwggEiMA0G\r\n" \
-    "CSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQDA3zf8F7vglp0/ht6WMn1EpRagzSHx\r\n" \
-    "mdTs6st8GFgIlKXsm8WL3xoemTiZhx57wI053zhdcHgH057Zk+i5clHFzqMwUqny\r\n" \
-    "50BwFMtEonILwuVA+T7lpg6z+exKY8C4KQB0nFc7qKUEkHHxvYPZP9al4jwqj+8n\r\n" \
-    "YMPGn8u67GB9t+aEMr5P+1gmIgNb1LTV+/Xjli5wwOQuvfwu7uJBVcA0Ln0kcmnL\r\n" \
-    "R7EUQIN9Z/SG9jGr8XmksrUuEvmEF/Bibyc+E1ixVA0hmnM3oTDPb5Lc9un8rNsu\r\n" \
-    "KNF+AksjoBXyOGVkCeoMbo4bF6BxyLObyavpw/LPh5aPgAIynplYb6LVAgMBAAGj\r\n" \
-    "UDBOMAwGA1UdEwQFMAMBAf8wHQYDVR0OBBYEFLRa5KWz3tJS9rnVppUP6z68x/3/\r\n" \
-    "MB8GA1UdIwQYMBaAFLRa5KWz3tJS9rnVppUP6z68x/3/MA0GCSqGSIb3DQEBCwUA\r\n" \
-    "A4IBAQA4qFSCth2q22uJIdE4KGHJsJjVEfw2/xn+MkTvCMfxVrvmRvqCtjE4tKDl\r\n" \
-    "oK4MxFOek07oDZwvtAT9ijn1hHftTNS7RH9zd/fxNpfcHnMZXVC4w4DNA1fSANtW\r\n" \
-    "5sY1JB5Je9jScrsLSS+mAjyv0Ow3Hb2Bix8wu7xNNrV5fIf7Ubm+wt6SqEBxu3Kb\r\n" \
-    "+EfObAT4huf3czznhH3C17ed6NSbXwoXfby7stWUDeRJv08RaFOykf/Aae7bY5PL\r\n" \
-    "yTVrkAnikMntJ9YI+hNNYt3inqq11A5cN0+rVTst8UKCxzQ4GpvroSwPKTFkbMw4\r\n" \
-    "/anT1dVxr/BtwJfiESoK3/4CeXR1\r\n"                                     \
-    "-----END CERTIFICATE-----\r\n"
-/* END FILE */
-
 #  define EXTRA_OPT "c:"
 #else
 #  define EXTRA_OPT ""