AWS Certificate Manager will discontinue WHOIS lookup for email-validated certificates
AWS Certificate Manager (ACM) is a managed service that you can use to provision, manage, and deploy public and private TLS certificates for use with Amazon Web Services (AWS) and your internal connected resources. Today, we’re announcing that ACM will be discontinuing the use of WHOIS lookup for validating domain ownership when you request email-validated TLS certificates.
WHOIS lookup is commonly used to query registration information for a given domain name. This information includes details such as when the domain was originally registered, and contact information for the domain owner and the technical and administrative contacts. Domain owners create and maintain domain registration information outside of ACM in WHOIS, which is a publicly available directory that contains information about domains sponsored by domain registrars and registries. You can use WHOIS lookup to view information about domains that are registered with Amazon Route 53.
Starting June 2024, ACM will no longer send domain validation emails by using WHOIS lookup for new email-validated certificates that you request. Starting October 2024, ACM will no longer send domain validation emails to mailboxes associated with WHOIS lookup for renewal of existing email-validated certificates. ACM will continue to send validation emails to the five common system addresses for the requested domain—we provide a list of these common system addresses in the next section of this post.
In this blog post, we share important details about this change and how you can prepare. Note that if you currently use DNS validation for your certificates requested from ACM, this change doesn’t affect you. These changes only apply to certificates that use email validation.
When you request public certificates through ACM, you need to prove that you own or control the domain before ACM can issue the public certificate. ACM provides two options to validate ownership of a domain: DNS validation and email validation.
AWS recommends that you use DNS validation whenever possible so that ACM can automatically renew certificates that are requested from ACM without requiring action on your part. Email validation is another option that you can use to prove ownership of the domain, but you must manually validate ownership of the domain by using a link provided in an email. Figure 1 is a sample validation email from ACM for the AWS account 111122223333 and AWS US West (Oregon) Region (us-west-2) to validate ownership of the example.com domain.
How does ACM know where to send the validation email? Today, as part of the email validation process, ACM sends domain validation emails to the three contact addresses associated with the domain listed in the WHOIS database. These contact addresses are the domain registrant, technical contact, and administrative contact. You create and maintain domain registration information, including these contact addresses, outside of ACM—in the WHOIS database that your domain registrar provides.
Note: If you use Route53, see Updating contact information for a domain to update the contact information for your domain.
ACM also sends validation emails to the following five common system addresses for each domain:
To prove that you own the domain, you must select the validation link included in these emails. ACM also sends validation emails to these same addresses to renew the certificate when the certificate is 45 days from expiry.
If you currently use email validation for certificates requested from ACM, there are two important dates that you should be aware of:
- Starting June 2024, ACM will no longer send domain validation emails by using WHOIS lookup for new email-validated certificates that you request. ACM will continue to send validation emails to the three WHOIS lookup contact addresses for renewal of existing certificates, until October 2024.
- Starting October 2024, ACM will no longer send the validation emails to mailboxes associated with WHOIS lookup for existing certificates. After this date, ACM will not send validation emails to the three WHOIS lookup addresses for new or existing certificates.
ACM will continue to send validation emails to the five common system addresses that we listed in the previous section of this post.
Why are we making this change?
We’re making this change to mitigate a potential availability risk for ACM customers. A TLS certificate that ACM issues is valid for up to 395 days, and if you want to keep using it, you need to renew it prior to expiry. To renew an email-validated certificate, you must approve an email that ACM sends. ACM sends the first renewal email 45 days prior to certificate renewal, and if you don’t respond to this email, ACM sends additional reminders prior to expiry. If a certificate bound to one of your AWS resources—such as an Application Load Balancer—expires without being renewed, this could cause an outage for your application.
Some domain registrars that support WHOIS have made changes to the data that they publish to support their compliance with various privacy laws and recommended practices. Over the past several years, we’ve observed that the WHOIS lookup success rate has declined to less than 5 percent. If you rely on the contact addresses listed in the WHOIS database provided by your domain registrar to validate your domain ownership, this might create an availability risk. With a 5 percent success rate for WHOIS lookup, you might not receive validation emails for renewals of your certificates around 95 percent of the time. To provide a consistent mechanism for validating domain ownership when renewing certificates, ACM will only send validation emails to the five common system addresses that we listed in the Background section of this post.
What should you do to prepare?
If you currently monitor one of the five common system addresses (listed previously) for your domains, you don’t need to take any action. Otherwise, we strongly recommend that you create new DNS-validated certificates rather than creating and using email-validated certificates. ACM can automatically renew a DNS-validated certificate, without you taking any action, as long as the CNAME is accurately configured.
Alternatively, if you want to continue using email-validated certificates, we recommend that you monitor at least one of the five common email addresses listed previously. ACM sends the validation emails during certificate issuance for new ACM-issued certificates and during renewal of existing certificates. You can use the ACM describe-certificate API or check the certificate details on the ACM console to see if ACM previously sent validation emails to the relevant system addresses.
In addition, we strongly recommend that you use ACM Certificate Approaching Expiration events to monitor your certificates for expiry and help ensure that you’re notified about certificates that require an action from you to renew. For additional guidance, see How to manage certificate lifecycles using ACM event-driven workflows.
In this blog post, we outlined the changes coming to the email validation process when requesting and renewing certificates from ACM. We also shared the steps that you can take to prepare for this change, including monitoring at least one of the five relevant email addresses for your domains. Remember that these changes only apply to certificates that use email validation, not certificates that use DNS validation. For more information about certificate management on AWS, see the ACM documentation or get started using ACM today in the AWS Management Console.
If you have questions, contact AWS Support or your technical account manager (TAM), or start a new thread on the AWS re:Post ACM Forum. If you have feedback about this post, submit comments in the Comments section below.
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