Function receive 

pub fn receive(names: &[String], files: &[SecretFile]) -> String

The script the runner runs as root on the machine. Its standard input holds one line per secret of names, in that order, each value in base64 (so any text fits on one line); the script keeps each one, marks the delivery, then puts files in place (so a run again refreshes them). Nothing of a value reaches its command line or its output.