Quickstart: Provision an X.509 simulated device using the Azure IoT C SDK

In this quickstart, you will learn how to create and run an X.509 device simulator on a Windows development machine. You will configure this simulated device to be assigned to an IoT hub using an enrollment with a Device Provisioning Service instance. Sample code from the Azure IoT C SDK will be used to simulate a boot sequence for the device. The device will be recognized based on the enrollment with the provisioning service and assigned to the IoT hub.

If you're unfamiliar with the process of autoprovisioning, review Auto-provisioning concepts. Also, make sure you've completed the steps in Set up IoT Hub Device Provisioning Service with the Azure portal before continuing with this quickstart.

The Azure IoT Device Provisioning Service supports two types of enrollments:

This article will demonstrate individual enrollments.

If you don't have an Azure subscription, create a free account before you begin.


The following prerequisites are for a Windows development environment. For Linux or macOS, see the appropriate section in Prepare your development environment in the SDK documentation.

Prepare a development environment for the Azure IoT C SDK

In this section, you will prepare a development environment used to build the Azure IoT C SDK, which includeS the sample code for the X.509 boot sequence.

  1. Download the CMake build system.

    It is important that the Visual Studio prerequisites (Visual Studio and the 'Desktop development with C++' workload) are installed on your machine, before starting the CMake installation. Once the prerequisites are in place, and the download is verified, install the CMake build system.

  2. Find the tag name for the latest release of the SDK.

  3. Open a command prompt or Git Bash shell. Run the following commands to clone the latest release of the Azure IoT C SDK GitHub repository. Use the tag you found in the previous step as the value for the -b parameter:

    git clone -b <release-tag> https://github.com/Azure/azure-iot-sdk-c.git
    cd azure-iot-sdk-c
    git submodule update --init

    You should expect this operation to take several minutes to complete.

  4. Create a cmake subdirectory in the root directory of the git repository, and navigate to that folder. Run the following commands from the azure-iot-sdk-c directory:

    mkdir cmake
    cd cmake
  5. The code sample uses an X.509 certificate to provide attestation via X.509 authentication. Run the following command to build a version of the SDK specific to your development platform that includes the device provisioning client. A Visual Studio solution for the simulated device is generated in the cmake directory.

    cmake -Duse_prov_client:BOOL=ON ..

    If cmake does not find your C++ compiler, you might get build errors while running the above command. If that happens, try running this command in the Visual Studio command prompt.

    Once the build succeeds, the last few output lines look similar to the following output:

    $ cmake -Duse_prov_client:BOOL=ON ..
    -- Building for: Visual Studio 16 2019
    -- The C compiler identification is MSVC 19.23.28107.0
    -- The CXX compiler identification is MSVC 19.23.28107.0
    -- Configuring done
    -- Generating done
    -- Build files have been written to: C:/code/azure-iot-sdk-c/cmake

Create a self-signed X.509 device certificate

In this section you, will use a self-signed X.509 certificate, it is important to keep in mind the following points:

  • Self-signed certificates are for testing only, and should not be used in production.
  • The default expiration date for a self-signed certificate is one year.

You will use sample code from the Azure IoT C SDK to create the certificate to be used with the individual enrollment entry for the simulated device.

  1. Launch Visual Studio and open the new solution file named azure_iot_sdks.sln. This solution file is located in the cmake folder you previously created in the root of the azure-iot-sdk-c git repository.

  2. On the Visual Studio menu, select Build > Build Solution to build all projects in the solution.

  3. In Visual Studio's Solution Explorer window, navigate to the Provision_Tools folder. Right-click the dice_device_enrollment project and select Set as Startup Project.

  4. On the Visual Studio menu, select Debug > Start without debugging to run the solution. In the output window, enter i for individual enrollment when prompted.

    The output window displays a locally generated self-signed X.509 certificate for your simulated device. Copy the output to clipboard, starting from -----BEGIN CERTIFICATE----- and ending with the first -----END CERTIFICATE-----, making sure to include both of these lines as well. You need only the first certificate from the output window.

  5. Using a text editor, save the certificate to a new file named X509testcert.pem.

Create a device enrollment entry in the portal

  1. Sign in to the Azure portal, select the All resources button on the left-hand menu and open your Device Provisioning service.

  2. Select the Manage enrollments tab, then select the Add individual enrollment button at the top.

  3. In the Add Enrollment panel, enter the following information, then press the Save button.

    • Mechanism: Select X.509 as the identity attestation Mechanism.

    • Primary certificate .pem or .cer file: Choose Select a file to select the certificate file, X509testcert.pem, you created earlier.

    • IoT Hub Device ID: Enter test-docs-cert-device to give the device an ID.

      Add individual enrollment for X.509 attestation in the portal

      On successful enrollment, your X.509 device appears as riot-device-cert under the Registration ID column in the Individual Enrollments tab.

Simulate first boot sequence for the device

In this section, update the sample code to send the device's boot sequence to your Device Provisioning Service instance. This boot sequence will cause the device to be recognized and assigned to an IoT hub linked to the Device Provisioning Service instance.

  1. In the Azure portal, select the Overview tab for your Device Provisioning service and note the ID Scope value.

    Extract Device Provisioning Service endpoint information from the portal blade

  2. In Visual Studio's Solution Explorer window, navigate to the Provision_Samples folder. Expand the sample project named prov_dev_client_sample. Expand Source Files, and open prov_dev_client_sample.c.

  3. Find the id_scope constant, and replace the value with your ID Scope value that you copied earlier.

    static const char* id_scope = "0ne00002193";
  4. Find the definition for the main() function in the same file. Make sure the hsm_type variable is set to SECURE_DEVICE_TYPE_X509 instead of SECURE_DEVICE_TYPE_TPM as shown below.

    SECURE_DEVICE_TYPE hsm_type;
    //hsm_type = SECURE_DEVICE_TYPE_TPM;
    hsm_type = SECURE_DEVICE_TYPE_X509;
  5. Right-click the prov_dev_client_sample project and select Set as Startup Project.

  6. On the Visual Studio menu, select Debug > Start without debugging to run the solution. In the prompt to rebuild the project, select Yes to rebuild the project before running.

    The following output is an example of the provisioning device client sample successfully booting up, and connecting to the provisioning Service instance to get IoT hub information and registering:

    Provisioning API Version: 1.2.7
    Registering... Press enter key to interrupt.
    Registration Information received from service:
    test-docs-hub.azure-devices.net, deviceId: test-docs-cert-device
  7. In the portal, navigate to the IoT hub linked to your provisioning service and select the IoT devices tab. On successful provisioning of the simulated X.509 device to the hub, its device ID appears on the IoT devices blade, with STATUS as enabled. You might need to press the Refresh button at the top.

    Device is registered with the IoT hub

Clean up resources

If you plan to continue working on and exploring the device client sample, do not clean up the resources created in this quickstart. If you do not plan to continue, use the following steps to delete all resources created by this quickstart.

  1. Close the device client sample output window on your machine.
  2. From the left-hand menu in the Azure portal, select All resources and then select your Device Provisioning service. Open Manage Enrollments for your service, and then select the Individual Enrollments tab. Select the check box next to the REGISTRATION ID of the device you enrolled in this quickstart, and press the Delete button at the top of the pane.
  3. From the left-hand menu in the Azure portal, select All resources and then select your IoT hub. Open IoT devices for your hub, select the check box next to the DEVICE ID of the device you registered in this quickstart, and then press the Delete button at the top of the pane.

Next steps

In this quickstart, you’ve created a simulated X.509 device on your Windows machine and provisioned it to your IoT hub using the Azure IoT Hub Device Provisioning Service on the portal. To learn how to enroll your X.509 device programmatically, continue to the quickstart for programmatic enrollment of X.509 devices.