iot-central-x509-javascript-code.md

author	ms.author	ms.service	ms.topic	ms.date
dominicbetts	dobett	iot-develop	include	12/17/2021

To modify the sample code to use the X.509 certificates:

1. Navigate to the azure-iot-sdk-node/device/samples/javascript folder that contains the pnp_temperature_controller.js application and run the following command to install the X.509 package:

   npm install azure-iot-security-x509 --save
   

2. Open the pnp_temperature_controller.js file in a text editor.

3. Edit the require statements to include the following code:

   const fs = require('fs');
   const X509Security = require('azure-iot-security-x509').X509Security;

4. Add the following four lines to the "DPS connection information" section to initialize the deviceCert variable:

   const deviceCert = {
     cert: fs.readFileSync(process.env.IOTHUB_DEVICE_X509_CERT).toString(),
     key: fs.readFileSync(process.env.IOTHUB_DEVICE_X509_KEY).toString()
   };

5. Edit the provisionDevice function that creates the client by replacing the first line with the following code:

   var provSecurityClient = new X509Security(registrationId, deviceCert);

6. In the same function, modify the line that sets the deviceConnectionString variable as follows:

   deviceConnectionString = 'HostName=' + result.assignedHub + ';DeviceId=' + result.deviceId + ';x509=true';

7. In the main function, add the following line after the line that calls Client.fromConnectionString:

   client.setOptions(deviceCert);

   Save the changes.