.k5login and only allow rcp

[Turbo Fredriksson]

I could not get AFBackup to work with multiple hosts, so I wrote
a little shellscript that uploads a tarball to the backupserver.

Using the user 'backup', I have managed to upload the files ok. But
the user can also LOGIN to the backupserver. I'd prefere not to allow
this. Is there some way to restrict (via .k5login or other way) logins
and only allow rcp?
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