AWS Security Blog

Options for AWS customers who use Entrust-issued certificates

Multiple popular browsers have announced that they will no longer trust public certificates issued by Entrust later this year. Certificates that are issued by Entrust on dates up to and including November 11, 2024 will continue to be trusted until they expire, according to current information from browser makers. Certificates issued by Entrust after that date will not be trusted.

If you’ve imported Entrust certificates into AWS Certificate Manager (ACM) for use with integrated services such as Amazon CloudFront or Elastic Load Balancing, consider reissuing these certificates through Entrust before November 12, 2024, and re-importing them. This will provide you with a longer timeline to evaluate your alternatives. In this blog post, we discuss how you can determine whether certificates you imported to ACM will be affected, and suggest potential alternatives, including public certificates issued by Amazon Trust Services.

How to tell if you’ve imported Entrust certificates to ACM

If you’re unsure whether you’ve imported certificates to ACM, there are a few different ways to verify. You can use the ACM console to view your certificates for that AWS account. Certificates that are imported to ACM have the type Imported, as shown in Figure 1.

Figure 1: Viewing certificates in AWS Certificate Manager

Figure 1: Viewing certificates in AWS Certificate Manager

You can also list the certificates in your AWS account by using the AWS CLI or APIs. You can use the list-certificates command with the AWS CLI:

aws acm list-certificates

You can then filter the response to only show the certificate ARN of certificates that are imported into ACM by using the following command:

aws acm list-certificates --query 'CertificateSummaryList[?Type==`IMPORTED`].CertificateArn'

After you’ve identified the ARNs of imported certificates, you can use the describe-certificate CLI command to get more information about each of the imported certificates. One of the returned fields is Issuer—this field indicates who originally issued the certificate in question. See the following example command and output, where in this case the issuer is Amazon:

aws acm describe-certificate --certificate-arn arn:aws:acm:region:account:certificate/12345678-1234-1234-1234-123456789012

{
"Certificate": {
"CertificateArn": "arn:aws:acm:region:account:certificate/12345678-1234-1234-1234-123456789012",
"CreatedAt": 1446835267.0,
"DomainName": "www.example.com",
"DomainValidationOptions": [
{
"DomainName": "www.example.com",
"ValidationDomain": "www.example.com",
"ValidationEmails": [
"hostmaster@example.com",
"admin@example.com",
"owner@example.com.whoisprivacyservice.org",
"tech@example.com.whoisprivacyservice.org",
"admin@example.com.whoisprivacyservice.org",
"postmaster@example.com",
"webmaster@example.com",
"administrator@example.com"
]
},
{
"DomainName": "www.example.net",
"ValidationDomain": "www.example.net",
"ValidationEmails": [
"postmaster@example.net",
"admin@example.net",
"owner@example.net.whoisprivacyservice.org",
"tech@example.net.whoisprivacyservice.org",
"admin@example.net.whoisprivacyservice.org",
"hostmaster@example.net",
"administrator@example.net",
"webmaster@example.net"
]
}
],
"InUseBy": [],
"IssuedAt": 1446835815.0,
"Issuer": "Amazon",
"KeyAlgorithm": "RSA-2048",
"NotAfter": 1478433600.0,
"NotBefore": 1446768000.0,
"Serial": "0f:ac:b0:a3:8d:ea:65:52:2d:7d:01:3a:39:36:db:d6",
"SignatureAlgorithm": "SHA256WITHRSA",
"Status": "ISSUED",
"Subject": "CN=www.example.com",
"SubjectAlternativeNames": [
"www.example.com",
"www.example.net"
]
}
}

You can use one of these methods to determine whether you’ve imported certificates to ACM, and use the Issuer field of the DescribeCertificate response to check whether any of your imported certificates were issued by Entrust and will be affected by the coming changes in popular browsers.

Lastly, you can also use this sample code from our GitHub repository to discover imported certificates that were issued by a certain CA or issuer. The project evaluates the ACM certificates for a given AWS account, flagging certificates with an Issuer value that matches against a specific, customizable list of CAs. This can be run as a Python script, an AWS Config query, or a custom rule in AWS Config.

Consider replacing Entrust certificates with public certificates issued through ACM

If you’re using Extended Validation (EV) or Organization Validation (OV) certificates, we recommend that you use Domain Validated (DV) certificates from ACM instead. Popular browsers do not differentiate between EV/OV and DV certificates when indicating whether a site is trusted. Additionally, EV/OV certificate issuance and renewals cannot be automated and require manual effort, unlike DV certificates.

You can use ACM to get DV certificates at no additional cost for use with Amazon CloudFront, Elastic Load Balancing, or Amazon API Gateway. Our public certificates are issued by Amazon Trust Services and are trusted by popular browsers and operating systems. When you issue certificates through ACM, you get the benefit of fully managed certificate renewal, where ACM automatically renews and redeploys the certificate when it is 60 days from expiration.

Evaluate use of private certificates for internal-facing use cases

We also recommend that you re-evaluate your use of certificates to reconsider whether you need private or public certificates for your use cases. For internal-facing workloads, you should consider using private certificates. This will allow you to control the certificate parameters, such as the certificate type or the validity period, to align with your specific TLS requirements. For example, ACM issued public certificates are valid for 395 days, but you might have use cases in which certificates with a longer validity period make more sense, and in such cases you can issue private certificates from AWS Private Certificate Authority (AWS Private CA).

Conclusion

In summary, if you are importing Entrust-issued certificates to ACM, evaluate whether you need public or private certificates, especially for internal-facing workloads—for which private certificates are typically better suited. For public certificates, take this opportunity to re-evaluate your usage of EV and OV certificates, and whether they could be replaced with DV certificates. If you want to use public certificates with services such as Amazon CloudFront, Elastic Load Balancing, or Amazon API Gateway, issue the certificates directly from ACM. Lastly, if you need more time to evaluate your options before making a decision, consider re-issuing and re-importing your certificates from Entrust before November 12, 2024. Popular browsers stated their intention to trust certificates issued by Entrust prior to November 12, 2024 until these certificates expire, giving you until the next certificate renewal to make an informed decision. You can learn more about ACM by reviewing the AWS documentation, and get started issuing certificates from ACM in the AWS Management Console.

 
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Zach Miller Zach Miller
Zach is a Principal Security Specialist Solutions Architect at AWS. His background is in data protection and security architecture, focused on a variety of security domains, including applied cryptography and secrets management. Today, he focuses on helping enterprise AWS customers adopt and operationalize AWS security services to increase security effectiveness and reduce risk.
Chandan Kundapur Chandan Kundapur
Chandan is a Principal Technical Product Manager on the AWS Certificate Manager (ACM) team. With close to 20 years of cybersecurity experience, he has a passion for driving the ACM team’s product strategy to help AWS customers identify and secure their resources and endpoints with public and private certificates.
Ian Olson Ian Olson
Ian is a Senior Security Specialist Solutions Architect at Amazon Web Services. He helps customers automate security services to safeguard against threats like DDoS attacks and web exploitations. Through intelligent automation, he delivers security solutions tailored to organizations of any scale. When he’s not working, Ian enjoys spending quality time with his two young children.