Scenario; set up ssh keys to machine so that you do not require a password for use with something like scp.
First you need a slave user. If you ‘adduser’ on both machines and pick a user name. Make sure they have a shell account but do not require authentication using a password.
On the remote machine you need to run ssh-keygen when you have logged in as that user. You can do something like – su username. Once you run that you will see in /home/username/.ssh/id_rsa.pub you now have a public key, which you need to copy onto the following file on the remote machine –
You then need to ensure permissions are set properly on all the files to the user you created. chmod -R username /home/username/.ssh
Do this on both machines.
You can then – su username on the local machine and try a scp command and it should not prompt you for the password.
You can either then run a script via the crontab as that user, or if you like something like this should work –
su username -c “scp -B remotehost:/etc/somefile /tmp”