This is all fine and dandy for seeding a CSPRNG, but we still don't actually have a CSPRNG in the C stdlib or glibc. getrandom(2) seems to target exclusively ge

This is all fine and dandy for seeding a CSPRNG, but we still don't actually have a CSPRNG in the C stdlib or glibc. getrandom(2) seems to target exclusively getting entropy for seeding, looking at the man page ("These bytes can be used to seed userspace random number generators or for cryptographic purposes."). And of course, the syscall is very recent, introduced in Linux 3.17, coming after the kernels in Debian stable (jessie), which features 3.16, and CentOS/RHEL7, which features 3.10. OpenBSD and NetBSD feature a ChaCha-based arc4random; FreeBSD and libbsd still seem stuck with RC4-based arc4random[1]. An equivalent for that is sorely missing on Linux. /dev/urandom requires messing with file descriptors, which you may run out of and may require error handling, plus all kinds of security precautions to make sure you're actually looking at the right /dev/urandom[2]. [1] https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=182610 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=182610 and https://bugs.freedesktop.org/show_bug.cgi?id=85827 https://bugs.freedesktop.org/show_bug.cgi?id=85827 [2] http://insanecoding.blogspot.ch/2014/05/a-good-idea-with-bad-usage-devurandom.html http://insanecoding.blogspot.ch/2014/05/a-good-idea-with-bad...