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#include <Seeed_mbedtls.h>

#define KEY_SIZE 32  // 256 bits for HMAC-SHA256
#define OUTPUT_SIZE 32 // SHA-256 outputs 32 bytes

// Your 256-bit secret key (32 bytes)
String str = "DeviceSecret";
const uint8_t* deviceSecret = (const uint8_t*)str.c_str();

#include <WiFi.h>
WiFiClient wifiClient;

#include <time.h>     // include time library

// (utc+) TZ in hours

long timezone = 0; 

byte daysavetime = 0;

#include <PubSubClient.h>
PubSubClient client(wifiClient);

// Set up wifi
#define SSID "SSID"
#define WIFI_PWD "pwd"


// MQTT set up

//MQTT server
#define MQTT_BROKER "m1.tuyacn.com"
#define MQTT_PORT (8883)


String compute_hmac_sha256(const uint8_t *key, size_t key_len, const uint8_t *input, size_t input_len) {
    mbedtls_md_context_t ctx;
    const mbedtls_md_info_t *md_info;
    uint8_t hmac_output[32]; // SHA-256 outputs 32 bytes

mbedtls_md_init(&ctx);
md_info = mbedtls_md_info_from_type(MBEDTLS_MD_SHA256);

if (md_info == NULL) {
    Serial.println("Failed to get MD info for SHA256");
    mbedtls_md_free(&ctx);
    return String();
}

if (mbedtls_md_setup(&ctx, md_info, 1) != 0) {
    Serial.println("Failed to setup MD context");
    mbedtls_md_free(&ctx);
    return String();
}

if (mbedtls_md_hmac_starts(&ctx, key, key_len) != 0) {
    Serial.println("Failed to start HMAC");
    mbedtls_md_free(&ctx);
    return String();
}

if (mbedtls_md_hmac_update(&ctx, input, input_len) != 0) {
    Serial.println("Failed to update HMAC");
    mbedtls_md_free(&ctx);
    return String();
}

if (mbedtls_md_hmac_finish(&ctx, hmac_output) != 0) {
    Serial.println("Failed to finish HMAC");
    mbedtls_md_free(&ctx);
    return String();
}

mbedtls_md_free(&ctx);

// Convert the HMAC output to a hexadecimal string
String hmac_str;
for (int i = 0; i < sizeof(hmac_output); i++) {
    char buf[3];
    sprintf(buf, "%02x", hmac_output[i]);
    hmac_str += buf;
}

return hmac_str;
}

// the setup function runs once when you press reset or power the board
void setup() {
   Serial.begin(9600);
    Serial.print("Connecting to " SSID);
  WiFi.begin(SSID, WIFI_PWD); // attempt to connect to an existing wifi
  //Wait for wifi to connect
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(" . ");
    }
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());

  //Time Server Set up
  Serial.println("Contacting Time Server");
  configTime(3600*timezone, daysavetime*3600, "time.nist.gov", "0.pool.ntp.org", "1.pool.ntp.org");
  delay(1000);

  time_t now;
  time(&now); 

  //MQTT Credentials set up
  String MQTT_USERNAME = "deviceID|signMethod=hmacSha256,timestamp=" + String(now) +",secureMode=1,accessType=1";

  // Your original const char* message
const char *message = "deviceId=deviceID,timestamp=,secureMode=1,accessType=1";

// The String you want to insert
String additional = String(now);

// Convert the original message to a String
String messageString = String(message);

// Insert the additional String at the 43rd position
size_t insertPos = 42; // Position to insert
messageString = messageString.substring(0, insertPos) + additional + messageString.substring(insertPos);


// Convert the modified message back to const char*
const char* final_message = messageString.c_str();



  // Compute HMAC-SHA256
  String MQTT_PWD = compute_hmac_sha256(deviceSecret, KEY_SIZE, (const uint8_t *)final_message, strlen(final_message));
  Serial.println(now);

  Serial.print("MQTT_PWD: ");
  Serial.println(MQTT_PWD);

 Serial.println("init successfull");
 String tuyalink = "tuyalink_DeviceId";
    // Handle MQTT connection.
  client.setServer(MQTT_BROKER, MQTT_PORT); // set broker settings
  while (! client.connected()) { // check connected status
    if ( client.connect(tuyalink.c_str(),MQTT_USERNAME.c_str(),MQTT_PWD.c_str())){ // connect with random id
      Serial.println("MQTT connected."); // report success
      //client.subscribe("Test/ra542");
    } else {
      Serial. printf (" failed , rc=%d try again in 5 seconds", client.state ()); // report error
      delay(5000); // wait 5 seconds
    }
  }



}

// the loop function runs over and over again forever
void loop() {
Serial.println("Hello World!");
delay(5000);

        
}

Code: Select all

failed , rc=-4 try again in 5 seconds failed

Code: Select all

  uint16_t keepAlive = 60000;
  client.setKeepAlive(keepAlive);