Can you import an existing certificate using ACM to be used by your LoadBalancerListener via CloudFormation?
On ACM FAQ, it does not tell it can be done on cloudformation concerning the importing of SSL.
Q: Can I import a third party certificate and use it with AWS services?
Yes. If you want to use a third-party certificate with Amazon CloudFront or Elastic Load Balancing, you may import it into ACM using the AWS Management Console, AWS CLI, or AWS Certificate Manager APIs. ACM does not manage the renewal process for imported certificates. You can use the AWS Management Console to monitor the expiration dates of an imported certificates and import a new third-party certificate to replace an expiring one.
As for the cloudformation documentation concerning the ACM. It doesn't provide properties to import an existing certificate to be used on my stack based on the below properties
Type: "AWS::CertificateManager::Certificate" Properties: DomainName: String DomainValidationOptions: - DomainValidationOptions SubjectAlternativeNames: - String Tags: - Resource Tag