Working on EC2 is a snap, you just download the .pem file, give it the right permissions, and you are ready to go, yet ... if you have the .pem file you have full access to the EC2 instance!!
What shall I do to limit people's access to the instance in a controllable way, e.g. people pass me their public key and add it to the instance a la Github
Follow the steps in this document: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/managing-users.html
There are 3 steps:
- You have to add a user account (adduser) for each user
- Make sure the user-home/.ssh dir has 600 permission (chmod)
- Add the user public key to user-home/.ssh/authorized_keys and make sure it has 700 permission (chmod)
来源：https://stackoverflow.com/questions/34250659/how-to-limit-people-access-to-my-ec2-with-their-public-key