@navi@social.vlhl.dev @lanodan@queer.hacktivis.me If you have one socket per service with an unpredictable name, I don't think you need to authenticate at all. Only the right service knows the socket name, if the name is in a large enough space, you're good; it's all collaborative, if someone is trying to be malicious you have already lost. (You could verify via SO_PEERCRED that the client is root, though, if you want to be really safe.) s6-notify-socket-from-fd uses an abstract socket with autobind. The autobind address space is 2^20; that should be enough for the kernel to make the socket address unpredictable, and if not, 🤷