| Endpoint |
- The endpoint of a public instance is
${YourProductKey}.iot-as-mqtt.${YourRegionId}.aliyuncs.com:1883. Parameters:
|
| Variable header: Keep Alive |
The CONNECT message must include a keep-alive period. Valid values of the keep-alive time: 30 to 1,200 seconds. We recommend that you set the keep-alive period to a value that is greater than 300 seconds. If the network connection is unstable, we recommend that you set the keep-alive period to a higher value. If the value of the Keep Alive parameter is not in this range, IoT Platform rejects the connection. For more information, see MQTT keep-alive. |
| Parameters in an MQTT CONNECT message |
- Unique-certificate-per-device authentication and pre-registration unique-certificate-per-product authentication: Use the device certificate (ProductKey, DeviceName, and DeviceSecret) to connect the device to IoT Platform.
mqttClientId: clientId+"|securemode=3,signmethod=hmacsha1,timestamp=132323232|"
mqttUsername: deviceName+"&"+productKey
mqttPassword: sign_hmac(deviceSecret,content)
- mqttClientId: Extended parameters are placed between vertical bars (
|).
- clientId: the ID of the client. You can specify a client ID based on your needs. The client ID cannot exceed 64 characters in length. We recommend that you use the MAC address or serial number (SN) of the device as the client ID.
- securemode: the current security mode. Valid values: 2 (direct TLS connection) and 3 (direct TCP connection).
- signmethod: the signature algorithm. Valid values: hmacmd5, hmacsha1, hmacsha256, and sha256. Default value: hmacmd5.
- timestamp: the current time, in milliseconds. This parameter is optional.
- mqttPassword: the password. Calculation method: Alphabetically sort the parameters that are submitted to the server and encrypt the parameters based on the specified signature algorithm. For more information about the signature calculation example, see Examples of signing MQTT connections.
- content: a concatenated string of the parameters that are submitted to the server. These parameters include productKey, deviceName, timestamp, and clientId. The parameters are sorted in alphabetical order and concatenated without delimiters.
Example: Assume that the following values are specified: clientId=12345, deviceName=device, productKey=pk, timestamp=789, signmethod=hmacsha1, deviceSecret=secret. The following code shows the parameters in an MQTT CONNECT message that is sent over TCP: mqttclientId=12345|securemode=3,signmethod=hmacsha1,timestamp=789|
mqttUsername=device&pk
mqttPassword=hmacsha1("secret","clientId12345deviceNamedeviceproductKeypktimestamp789").toHexString();
The encrypted password is a hexadecimal string that is converted from a binary string. The following code shows the result: FAFD82A3D602B37FB0FA8B7892F24A477F85****
- Preregistration-free unique-certificate-per-product authentication: Use ProductKey, DeviceName, ClientID, and DeviceToken to connect the device to IoT Platform.
mqttClientId: clientId+"|securemode=-2,authType=connwl|"
mqttUsername: deviceName+"&"+productKey
mqttPassword: deviceToken
- mqttClientId: Extended parameters are placed between vertical bars (
|).
- clientId, deviceToken: the ClientID and DeviceToken that are obtained when the device is dynamically registered. For more information, see MQTT-based dynamic registration.
- securemode: the current security mode. If you use preregistration-free unique-certificate-per-product authentication, set the value to -2.
- authType: the authentication method. If you use preregistration-free unique-certificate-per-product authentication, set the value to connwl.
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