Brent Cook 0aeb93b9fc override native arc4random_buf on FreeBSD
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@
2014-11-03 01:19:36 -06:00

27 lines
451 B
C

#ifndef LIBCRYPTOCOMPAT_ARC4RANDOM_H
#define LIBCRYPTOCOMPAT_ARC4RANDOM_H
#include <sys/param.h>
#if defined(__FreeBSD__)
#include "arc4random_freebsd.h"
#elif defined(__linux__)
#include "arc4random_linux.h"
#elif defined(__APPLE__)
#include "arc4random_osx.h"
#elif defined(__sun)
#include "arc4random_solaris.h"
#elif defined(__WIN32)
#include "arc4random_win.h"
#else
#error "No arc4random hooks defined for this platform."
#endif
#endif