If there are adversaries on the machine right now that can exploit this order, then touch+chmod is not enough. If somebody opens the file between those two oper

If there are adversaries on the machine right now that can exploit this order, then touch+chmod is not enough. If somebody opens the file between those two operations, they can still read the file contents written to it later. It only makes a bit harder by shortening that time. Use e.g. a current version of `install` to create files atomically with the correct permissions.