How to add a custom CA certificate in Azure API Management

  • 06/13/2025

Azure API Management allows you to install CA certificates on the machine inside the trusted root and intermediate certificate stores. You should use this functionality if your services require a custom CA certificate.

This article shows how to manage CA certificates of an API Management instance in the Azure portal. For example, if you use self-signed client certificates, you can upload custom trusted root certificates to API Management.

CA certificates uploaded to API Management can be used for certificate validation only by the managed API Management gateway. If you use the self-hosted gateway, you can learn how to create a custom CA for self-hosted gateway later in this article.

Note

We recommend that you use the Azure Az PowerShell module to interact with Azure. See Install Azure PowerShell to get started. To learn how to migrate to the Az PowerShell module, see Migrate Azure PowerShell from AzureRM to Az.

Upload a CA certificate

Complete the following steps to upload a new CA certificate. If you haven't created an API Management instance yet, see Create an API Management service instance.

  1. Go to your Azure API Management instance in the Azure portal.

  2. In the left menu, under Security, select Certificates. On the Certificates page, select CA certificates > + Add.

  3. In the Upload CA certificate window, select the file icon and browse for the certificate .cer file. In the Store box, select a certificate store. Only the public key is needed, so the password is optional.

    Screenshot that shows the steps for adding a CA certificate in the Azure portal.

  4. Select the Add button at the bottom of the window, and then select Save. This operation might take a few minutes.

Note

You can also upload a CA certificate by using the New-AzApiManagementSystemCertificate PowerShell command.

Delete a CA certificate

Select the certificate, and then select Delete in the ... menu.

Create custom CA for a self-hosted gateway

If you use a self-hosted gateway, validation of server and client certificates via CA root certificates uploaded to API Management service isn't supported. To establish trust, configure a specific client certificate so that it's trusted by the gateway as a custom certificate authority.

Use the Gateway Certificate Authority REST APIs to create and manage custom CAs for a self-hosted gateway. To create a custom CA:

  1. Add a certificate .pfx file to your API Management instance.
  2. Use the Gateway Certificate Authority - Create Or Update REST API to associate the certificate with the self-managed gateway.