The current NetBSD release, 6.1.5, fails to reseed arc4random fork. Work
around it by providing arc4random/getentropy shims. Revisit when NetBSD
7 is available.
tested on: HP-UX 11.31 ia64,
gcc 4.7.1(HP AllianceOne version)
gcc 4.2.3(http://hpux.connect.org.uk)
HP C/aC++
HP-UX defaults to use LP32 and it treats long as 32 bit (= 4 bytes).
This build forces LP64 for treating long as 64 bit.
The FreeBSD-native arc4random_buf implementation falls back to weak
sources of entropy if the sysctl fails. Remove these dangerous fallbacks
by overriding locally.
Unfortunately, pthread_atfork() is broken on FreeBSD (at least 9 and 10)
if a program does not link to -lthr. Callbacks registered with
pthread_atfork() simply fail silently. So, it is not always possible to
detect a PID wraparound. I wish we could do better.
This improves arc4random_buf's safety compared to the native FreeBSD
implementation. Tested on FreeBSD 9 and 10.
ok beck@ deraadt@
