SSH key managment for many users

Hi,

I need to assign ssh key pairs to the EC2 instances for multiple IAM users. So what i want to have:

IAM users [user1,user2,user3], out of them [user1,user2] should have separate (each IAM user should have its own user in VM) SSH access to the [VM-1,VM-2] EC2 instances, and the [user3] should have access only to the [VM-3] instance.

Do i need to generate ssh key pairs, create users inside the EC2 instance, assign permissions for those users - manually, and then also manually add those SSH pub keys in the EC2 instances? Or AWS has service that can do it automatically for me?

Joann