Mayhaps I am slow, but this is how I was finally able to give access to my AWS server to another person:
1. Generate public/private key pair (ex: GitHub)
2. Admin: log into your EC2 instance and add the public key to “~/.ssh/authorized_keys” (StackOverflow)
3. Generate Putty Key using (PuttyGen)
4. Add KeyPair under AWS Management Console –> Network & Security –> Key Pairs
5. Use the private key to log in.
I’m still confused on how to use AMI to control user-based access… if someone knows how to do this, please shed light.