aws_iot_mqtt_subscribe() fails with NETWORK_SSL_READ_ERROR (CA-203)

[sduddell]

Hi,

I'm trying to subscribe to an MQTT topic using aws_iot_mqtt_subscribe(), but it fails.

As shown in below code, trying to subscribe to topic "M5TimerCameraF1/pub" :

    string c2a_topic = "M5TimerCameraF1/pub";
    const int topic_len = c2a_topic.length();

    ESP_LOGI(AWS_IOT_TAG, "Subscribing...");
    result = aws_iot_mqtt_subscribe(&aws_client, c2a_topic.c_str(), topic_len, QOS0, iot_subscribe_callback_handler, NULL);
    if(SUCCESS != result) {
        ESP_LOGE(AWS_IOT_TAG, "Error subscribing : %d ", result);
        abort();
    } 

It fails as shown below:

␛[0;32mI (22295) AwsIoT: Subscribing...␛[0m
␛[0;31mE (22505) aws_iot: Failed
  ! mbedtls_ssl_read returned -0x7880

␛[0m
␛[0;31mE (22505) AwsIoT: Error subscribing : -12 ␛[0m

It connected properly to AWS IOT before subscribing though. Are there any pre-requisites to be done before subscription? Any suggestions/solutions would help.

Thanks!

[shahpiyushv]

@sduddell , does your AWS IoT Policy allow the client to subscribe to this topic?

[sduddell]

Hi Piyush,

Thanks for quick reply. Yes, AWS IoT policy is allowing, still this error is seen.

[MaazSk]

Hi @sduddell, did you found the solution as I am facing the same issue.

[sduddell]

In my case, certificate in the device was different from policy where I'm allowing it to connect. You can also check the cloudwatch logs to understand the error from AWS IoT perspective.