Cory, thanks for summing it up for us. I totally agree with you. In my opinion it is troublesome to have different behavior on platforms. We can implement a workaround for Linux, but not for BSD. Or would O_NONBLOCK cause read() to fail with EWOULDBLOCK on /dev/urandom device?

It might be secure enough to use srandom() / random() instead of /dev/urandom in some platforms. It still won't do any good on platforms like Raspberry Pie since the SoC has no RTC. Without a RTC the clock is not set yet. It happens much later in the boot phase when network is available.

I don't see a cross-platform solution that is able to handle this super-special case without opening a potential security issue for the majority of users.