The problem is that (Libre|Open)SSL doesn't use /dev/urandom directly and instead implements a CSPRNG in user-space (seeded from /dev/urandom). And then you nee

The problem is that (Libre|Open)SSL doesn't use /dev/urandom directly and instead implements a CSPRNG in user-space (seeded from /dev/urandom). And then you need to be careful to reseed the CSPRNG after fork or you'll generate the same random number that the other process did. You could mix in the parent's PID too, but that would only delay the problem (you'd need more layers of fork before triggering the shared-state bug again). Why can't LibreSSL just open /dev/urandom once, on first call to RAND_poll/RAND_bytes/some-other-init-function, etc. and then always read from it directly. If that first open fails then you return an error from RAND_poll/RAND_bytes.