def copySshKeys(self, keyName):
        """ Copy authorized_keys file to the core user from the keyName user."""
        if keyName == 'core':
            return # No point.

        # Make sure that keys are there.
        self._waitForSSHKeys(keyName=keyName)

        # copy keys to core user so that the ssh calls will work
        # - normal mechanism failed unless public key was in the google-ssh format
        # - even so, the key wasn't copied correctly to the core account
        keyFile = '/home/%s/.ssh/authorized_keys' % keyName
        self.sshInstance('/usr/bin/sudo', '/usr/bin/cp', keyFile, '/home/core/.ssh', user=keyName)
        self.sshInstance('/usr/bin/sudo', '/usr/bin/chown', 'core',
                         '/home/core/.ssh/authorized_keys', user=keyName)
Copy authorized_keys file to the core user from the keyName user.