Story: Many .pem files stored locally; many pem files on the AWS account.
Problem: How do you match them ?
* AWS - shows a fingerprint of the pem file
* linux / mac command to produce that from the pen file: (https://forums.aws.amazon.com/thread.jspa?messageID=386670)
openssl pkcs8 -in ~/.ssh/ec2/primary.pem -nocrypt -topk8 -outform DER | openssl sha1 -c