# ESP-MQTT SSL example with PSK verification (See the README.md file in the upper level 'examples' directory for more information about examples.) This example connects to a local broker configured to PSK authentication ## How to use example ### Hardware Required This example can be executed on any ESP32 board, the only required interface is WiFi (or ethernet) to connect to a MQTT broker with preconfigured PSK verification method. #### Mosquitto settings In case of using mosquitto broker, here is how to enable PSK authentication in `mosquitto.config`, ``` psk_hint hint psk_file path_to_your_psk_file allow_anonymous true ``` Note: Last line enables anonymous mode, as this example does not use mqtt username and password. PSK file then has to contain pairs of hints and keys, as shown below: ``` hint:BAD123 ``` Important note: Keys are stored as text hexadecimal values in PSK file, while the example code stores key as plain binary as required by MQTT API. (See the example source for details: `"BAD123" -> 0xBA, 0xD1, 0x23`) ### Configure the project * Run `idf.py menuconfig` * Configure Wi-Fi or Ethernet under "Example Connection Configuration" menu. See "Establishing Wi-Fi or Ethernet Connection" section in [examples/protocols/README.md](../../README.md) for more details. ### Build and Flash (To exit the serial monitor, type ``Ctrl-]``.) See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects. ## Example Output ``` I (2160) example_connect: Ethernet Link Up I (4650) example_connect: Connected to Ethernet I (4650) example_connect: IPv4 address: 192.168.0.1 I (4650) MQTTS_EXAMPLE: [APP] Free memory: 244792 bytes I (4660) system_api: Base MAC address is not set, read default base MAC address from BLK0 of EFUSE D (4670) MQTT_CLIENT: MQTT client_id=ESP32_c6B4F8 D (4680) MQTT_CLIENT: Core selection disabled I (4680) MQTTS_EXAMPLE: Other event id:7 D (4680) esp-tls: host:192.168.0.2: strlen 13 D (4700) esp-tls: ssl psk authentication D (4700) esp-tls: handshake in progress... D (4720) MQTT_CLIENT: Transport connected to mqtts://192.168.0.2:8883 I (4720) MQTT_CLIENT: Sending MQTT CONNECT message, type: 1, id: 0000 D (4720) MQTT_CLIENT: mqtt_message_receive: first byte: 0x20 D (4730) MQTT_CLIENT: mqtt_message_receive: read "remaining length" byte: 0x2 D (4730) MQTT_CLIENT: mqtt_message_receive: total message length: 4 (already read: 2) D (4740) MQTT_CLIENT: mqtt_message_receive: read_len=2 D (4750) MQTT_CLIENT: mqtt_message_receive: transport_read():4 4 D (4750) MQTT_CLIENT: Connected I (4760) MQTTS_EXAMPLE: MQTT_EVENT_CONNECTED D (4760) MQTT_CLIENT: mqtt_enqueue id: 4837, type=8 successful D (4770) OUTBOX: ENQUEUE msgid=4837, msg_type=8, len=18, size=18 D (4770) MQTT_CLIENT: Sent subscribe topic=/topic/qos0, id: 4837, type=8 successful I (4780) MQTTS_EXAMPLE: sent subscribe successful, msg_id=4837 D (4790) MQTT_CLIENT: mqtt_enqueue id: 58982, type=8 successful D (4790) OUTBOX: ENQUEUE msgid=58982, msg_type=8, len=18, size=36 D (4800) MQTT_CLIENT: Sent subscribe topic=/topic/qos1, id: 58982, type=8 successful I (4810) MQTTS_EXAMPLE: sent subscribe successful, msg_id=58982 ```