ec2-instance-connect

EC2 Instance Connect is a service that publishes ssh keys for use by EC2
instances based on AWS Credentials. These keys are consumed by on-instance
configuration provided by this package. The ssh daemon will query EC2
Instance Metadata service for user-keys at ssh calltime, validate any if
present as well as validating their signature, and if all checks pass return
will include them in the authorized keys list.

In addition, there is an agent that harvests instance ssh host keys and
passes them back to the service. This is for authentication purposes by
the EC2 console to open an in-browser ssh terminal connection.