A successful ssl upload command to cloudfront using a ssl certificate signed by comodo.
This is the cloudfront documentation: http://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/SecureConnections.html#CNAMEsAndHTTPS
Here's my successful command:
aws iam upload-server-certificate --server-certificate-name myServerCertificate --certificate-body file:///Users/..../from_comodo.pem --private-key file:///Users/.../server.key.pem --certificate-chain file:///Users/.../chain.pem --path=/cloudfront/production/
Replace /Users/.... with the path to those files. And yes keep the three three slashes in the beginning.