Tutorial: Configure HTTPS on an Azure CDN custom domain

Important

This feature is not available with Azure CDN Standard from Akamai products. For a comparison of Azure Content Delivery Network (CDN) features, see Compare Azure CDN product features.

This tutorial shows how to enable the HTTPS protocol for a custom domain that's associated with an Azure CDN endpoint. By using the HTTPS protocol on your custom domain (for example, https://www.contoso.com), you ensure that your sensitive data is delivered securely via TLS/SSL encryption when it is sent across the internet. When your web browser is connected to a web site via HTTPS, it validates the web site’s security certificate and verifies it’s issued by a legitimate certificate authority. This process provides security and protects your web applications from attacks.

Azure CDN supports HTTPS on a CDN endpoint hostname, by default. For example, if you create a CDN endpoint (such as https://contoso.azureedge.net), HTTPS is automatically enabled.

Some of the key attributes of the custom HTTPS feature are:

  • No additional cost: There are no costs for certificate acquisition or renewal and no additional cost for HTTPS traffic. You pay only for GB egress from the CDN.

  • Simple enablement: One-click provisioning is available from the Azure portal. You can also use REST API or other developer tools to enable the feature.

  • Complete certificate management is available: All certificate procurement and management is handled for you. Certificates are automatically provisioned and renewed prior to expiration, which removes the risks of service interruption due to a certificate expiring.

In this tutorial, you learn how to:

  • Enable the HTTPS protocol on your custom domain.
  • Use a CDN-managed certificate
  • Use your own certificate
  • Validate the domain
  • Disable the HTTPS protocol on your custom domain.

Prerequisites

Before you can complete the steps in this tutorial, you must first create a CDN profile and at least one CDN endpoint. For more information, see Quickstart: Create an Azure CDN profile and endpoint.

In addition, you must associate an Azure CDN custom domain on your CDN endpoint. For more information, see Tutorial: Add a custom domain to your Azure CDN endpoint


SSL certificates

To enable the HTTPS protocol for securely delivering content on an Azure CDN custom domain, you must use an SSL certificate. You can choose to use a certificate that is managed by Azure CDN or use your own certificate.

When you use a CDN-managed certificate, the HTTPS feature can be turned on with just a few clicks. Azure CDN completely handles certificate management tasks such as procurement and renewal. After you enable the feature, the process starts immediately. If the custom domain is already mapped to the CDN endpoint, no further action is required. Azure CDN will process the steps and complete your request automatically. However, if your custom domain is mapped elsewhere, you must use email to validate your domain ownership.

To enable HTTPS on a custom domain, follow these steps:

  1. In the Azure portal, browse to your Azure CDN Standard from Microsoft, Azure CDN Standard from Verizon or Azure CDN Premium from Verizon profile.

  2. In the list of CDN endpoints, select the endpoint containing your custom domain.

    Endpoints list

    The Endpoint page appears.

  3. In the list of custom domains, select the custom domain for which you want to enable HTTPS.

    Custom domains list

    The Custom domain page appears.

  4. Under Certificate management type, select CDN managed.

  5. Select On to enable HTTPS.

    Custom domain HTTPS status

  6. Proceed to Validate the domain.

Validate the domain

If you already have a custom domain in use that is mapped to your custom endpoint with a CNAME record or you're using your own certificate, proceed to
Custom domain is mapped to your CDN endpoint. Otherwise, if the CNAME record entry for your endpoint no longer exists or it contains the cdnverify subdomain, proceed to Custom domain is not mapped to your CDN endpoint.

Custom domain is mapped to your CDN endpoint by a CNAME record

When you added a custom domain to your endpoint, you created a CNAME record in the DNS table of your domain registrar to map it to your CDN endpoint hostname. If that CNAME record still exists and does not contain the cdnverify subdomain, the DigiCert CA uses it to automatically validate ownership of your custom domain.

If you're using your own certificate, domain validation is not required.

Your CNAME record should be in the following format, where Name is your custom domain name and Value is your CDN endpoint hostname:

Name Type Value
www.contoso.com CNAME contoso.azureedge.net

For more information about CNAME records, see Create the CNAME DNS record.

If your CNAME record is in the correct format, DigiCert automatically verifies your custom domain name and adds it to the Subject Alternative Names (SAN) certificate. DigitCert won't send you a verification email and you won't need to approve your request. The certificate is valid for one year and will be auto-renewed before it expires. Proceed to Wait for propagation.

Automatic validation typically takes a few mins. If you don’t see your domain validated within an hour, open a support ticket.

Note

If you have a Certificate Authority Authorization (CAA) record with your DNS provider, it must include DigiCert as a valid CA. A CAA record allows domain owners to specify with their DNS providers which CAs are authorized to issue certificates for their domain. If a CA receives an order for a certificate for a domain that has a CAA record and that CA is not listed as an authorized issuer, it is prohibited from issuing the certificate to that domain or subdomain. For information about managing CAA records, see Manage CAA records. For a CAA record tool, see CAA Record Helper.

Custom domain is not mapped to your CDN endpoint

If the CNAME record entry for your endpoint no longer exists or it contains the cdnverify subdomain, follow the rest of the instructions in this step.

After you enable HTTPS on your custom domain, the DigiCert CA validates ownership of your domain by contacting its registrant, according to the domain's WHOIS registrant information. Contact is made via the email address (by default) or the phone number listed in the WHOIS registration. You must complete domain validation before HTTPS will be active on your custom domain. You have six business days to approve the domain. Requests that are not approved within six business days are automatically canceled.

WHOIS record

DigiCert also sends a verification email to additional email addresses. If the WHOIS registrant information is private, verify that you can approve directly from one of the following addresses:

admin@<your-domain-name.com>
administrator@<your-domain-name.com>
webmaster@<your-domain-name.com>
hostmaster@<your-domain-name.com>
postmaster@<your-domain-name.com>

You should receive an email in a few minutes, similar to the following example, asking you to approve the request. If you are using a spam filter, add admin@digicert.com to its whitelist. If you don't receive an email within 24 hours, contact Microsoft support.

Domain validation email

When you click on the approval link, you are directed to the following online approval form:

Domain validation form

Follow the instructions on the form; you have two verification options:

  • You can approve all future orders placed through the same account for the same root domain; for example, contoso.com. This approach is recommended if you plan to add additional custom domains for the same root domain.

  • You can approve just the specific host name used in this request. Additional approval is required for subsequent requests.

After approval, DigiCert adds your custom domain name to the SAN certificate. The certificate is valid for one year and will be auto-renewed before it's expired.

Wait for propagation

After the domain name is validated, it can take up to 6-8 hours for the custom domain HTTPS feature to be activated. When the process is complete, the custom HTTPS status in the Azure portal is set to Enabled and the four operation steps in the custom domain dialog are marked as complete. Your custom domain is now ready to use HTTPS.

Enable HTTPS dialog

Operation progress

The following table shows the operation progress that occurs when you enable HTTPS. After you enable HTTPS, four operation steps appear in the custom domain dialog. As each step becomes active, additional substep details appear under the step as it progresses. Not all of these substeps will occur. After a step successfully completes, a green check mark appears next to it.

Operation step Operation substep details
1 Submitting request Submitting request
Your HTTPS request is being submitted.
Your HTTPS request has been submitted successfully.
2 Domain validation Domain is automatically validated if it is CNAME mapped to the CDN Endpoint. Otherwise, a verification request will be sent to the email listed in your domain’s registration record (WHOIS registrant). Please verify the domain as soon as possible.
Your domain ownership has been successfully validated.
Domain ownership validation request expired (customer likely didn't respond within 6 days). HTTPS will not be enabled on your domain. *
Domain ownership validation request was rejected by the customer. HTTPS will not be enabled on your domain. *
3 Certificate provisioning The certificate authority is currently issuing the certificate needed to enable HTTPS on your domain.
The certificate has been issued and is currently being deployed to CDN network. This could take up to 6 hours.
The certificate has been successfully deployed to CDN network.
4 Complete HTTPS has been successfully enabled on your domain.

* This message doesn't appear unless an error has occurred.

If an error occurs before the request is submitted, the following error message is displayed:

We encountered an unexpected error while processing your HTTPS request. Please try again and contact support if the issue persists.

Clean up resources - disable HTTPS

In the preceding steps, you enabled the HTTPS protocol on your custom domain. If you no longer want to use your custom domain with HTTPS, you can disable HTTPS by performing theses steps:

Disable the HTTPS feature

  1. In the Azure portal, browse to your Azure CDN Standard from Microsoft, Azure CDN Standard from Verizon or Azure CDN Premium from Verizon profile.

  2. In the list of endpoints, click the endpoint containing your custom domain.

  3. Click the custom domain for which you want to disable HTTPS.

    Custom domains list

  4. Click Off to disable HTTPS, then click Apply.

    Custom HTTPS dialog

Wait for propagation

After the custom domain HTTPS feature is disabled, it can take up to 6-8 hours for it to take effect. When the process is complete, the custom HTTPS status in the Azure portal is set to Disabled and the three operation steps in the custom domain dialog are marked as complete. Your custom domain can no longer use HTTPS.

Disable HTTPS dialog

Operation progress

The following table shows the operation progress that occurs when you disable HTTPS. After you disable HTTPS, three operation steps appear in the Custom domain dialog. As each step becomes active, additional details appear under the step. After a step successfully completes, a green check mark appears next to it.

Operation progress Operation details
1 Submitting request Submitting your request
2 Certificate deprovisioning Deleting certificate
3 Complete Certificate deleted

Frequently asked questions

  1. Who is the certificate provider and what type of certificate is used?

    With Azure CDN from Verizon, a Subject Alternative Names (SAN) certificate provided by DigiCert is used. A SAN certificate can secure multiple fully qualified domain names with one certificate. With Azure CDN Standard from Microsoft, a single certificate provided by DigiCert is used.

  2. Do you use IP-based or SNI TLS/SSL?

    Azure CDN from Verizon uses IP-based TLS/SSL. Azure CDN Standard from Microsoft uses SNI TLS/SSL.

  3. What if I don't receive the domain verification email from DigiCert?

    If you have a CNAME entry for your custom domain that points directly to your endpoint hostname (and you are not using the cdnverify subdomain name), you won't receive a domain verification email. Validation occurs automatically. Otherwise, if you don't have a CNAME entry and you haven't received an email within 24 hours, contact Microsoft support.

  4. Is using a SAN certificate less secure than a dedicated certificate?

    A SAN certificate follows the same encryption and security standards as a dedicated certificate. All issued SSL certificates use SHA-256 for enhanced server security.

  5. Can I use a custom domain HTTPS with Azure CDN from Akamai?

    Currently, this feature is not available with Azure CDN Standard from Akamai profiles. Microsoft is working on supporting this feature in the coming months.

  6. Do I need a Certificate Authority Authorization record with my DNS provider?

    No, a Certificate Authority Authorization record is not currently required. However, if you do have one, it must include DigiCert as a valid CA.

Next steps

In this tutorial, you learned how to:

  • Enable the HTTPS protocol on your custom domain.
  • Use a CDN-managed certificate
  • Use your own certificate
  • Validate the domain.
  • Disable the HTTPS protocol on your custom domain.

Advance to the next tutorial to learn how to configure caching on your CDN endpoint.