Suppose you are logged in machine A and you need passwordless access to an account on machine B.
(1) Create RSA keys:
ssh-keygen -t rsa -f B_key
This will create two files:
B_key.pub. The first is the private key and the second is the public key of the RSA protocol.
(2) Copy the contents of
B_key.pub into the file
authorized_keys in the
.ssh directory of the remote account:
cat B_key.pub | ssh B_user@B_machine 'cat >> .ssh/authorized_keys'
(3) Login to machine B:
ssh -i B_key B_user@B_machine