Let us say, there are two servers, server-A and server-B. The objective is to setup password less from server-A toward server-B using RSA Key.
Here are step by step to follow:
Step#1: Create .ssh directory in server-A if it’s not exist.
server-A# mkdir ~/.ssh
Step#2: Go to inside .ssh directory
server-A# cd ~/.ssh
Step#3: Generate both RSA private and public keys
server-A# ssh-keygen -t rsa
Step#4: Transfer generated RSA public key from server-A to server-B
server-A# scp ~/.ssh/id_rsa.pub <server-B>:/<home>/id_rsa.server-A.pub
Step#5: Go to server-B
server-A# ssh <server-B> Password:
Step#6: Create .ssh directory in server-B if it’s not exist.
server-B# mkdir .ssh
Step#7: Change directory permission to be readable, writable and executable by the owner
server-B# chmod 700 .ssh
Step#8: Append transferred RSA public key of server-A to authorized_keys file inside .ssh directory of server-B
server-B# cat id_rsa.server-A.pub >> .ssh/authorized_keys
Step#9: Change authorized_keys file as following
server-B# chmod 644 .ssh/authorized_keys
Step#10: Logoff from server-A and test RSA password less setup from server-A toward server-B
server-B# exit server-A# ssh <server-B>
1- Above steps were tried between two Unix Solaris based Servers.
2- If DSA Key is preferred, just replace ‘rsa’ with ‘dsa’ in above steps