Note: Below tested on CentOS/RedHat 7x
1. In source system generate keys for specific user:
ssh-keygen -t rsa -C "user@source-machine-name"
Enter file in which to save the key (/root/.ssh/id_rsa): filename_rsa
No Passprase Enter passphrase (empty for no passphrase): passphrase
Enter same passphrase again: passphrase
2. In destination system under /home/user create .ssh folder (owner user and rights 700), and after create FILE authorized_keys (inside .ssh folder) (chmod 644 chown user) and copy Public key from source system into this file.
3. In destination system:
service sshd restart
4. SSH from source to destination
ssh -i id_rsa_user user@destination-machine-ip
5. SCP files from source to destination
scp -i id_rsa_user /path/test.txt user@destination-machine-ip:/destination-folder/
