I have a public SSL certificate in Amazon Certificate Manager. I want to upload this certificate to an instance that is not hosted in amazon. How can i download the certificate from Amazon Certificate Manager. I need to download both certificate and private key
You cannot download the private key for an SSL certificate from ACM - ACM certificates are only for use on AWS ALBs, CloudFront, API gateway and other AWS infrastructure. ACM keep hold of the private key and will use it whereever the certificate is used.
You can download the certificate using awscli with aws acm get-certificate --certificate-arn arn:aws:acm:us-east-1:123456789012:certificate/12345678-1234-1234-1234-123456789012. This will get you Public certificate.
https://docs.aws.amazon.com/cli/latest/reference/acm/get-certificate.html