108 lines
2.7 KiB
C
108 lines
2.7 KiB
C
/* $OpenBSD: arc4random.h,v 1.4 2015/01/15 06:57:18 deraadt Exp $ */
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/*
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* Copyright (c) 1996, David Mazieres <dm@uun.org>
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* Copyright (c) 2008, Damien Miller <djm@openbsd.org>
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* Copyright (c) 2013, Markus Friedl <markus@openbsd.org>
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* Copyright (c) 2014, Theo de Raadt <deraadt@openbsd.org>
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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/*
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* Stub functions for portability.
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*/
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#include <sys/mman.h>
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#include <signal.h>
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#ifdef HAVE_PTHREAD_H
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#include <pthread.h>
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static pthread_mutex_t arc4random_mtx = PTHREAD_MUTEX_INITIALIZER;
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#define _ARC4_LOCK() pthread_mutex_lock(&arc4random_mtx)
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#define _ARC4_UNLOCK() pthread_mutex_unlock(&arc4random_mtx)
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#else
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#define _ARC4_LOCK()
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#define _ARC4_UNLOCK()
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#endif /* HAVE_PTHREAD_H */
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#ifdef HAVE_PTHREAD_ATFORK
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# define _ARC4_ATFORK(f) pthread_atfork(NULL, NULL, (f))
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# else
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# define _ARC4_ATFORK(f)
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#endif
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#if !defined(MAP_ANON) && defined(MAP_ANONYMOUS)
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# define MAP_ANON MAP_ANONYMOUS
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#endif
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static inline void
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_getentropy_fail(void)
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{
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raise(SIGKILL);
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}
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static volatile sig_atomic_t _rs_forked;
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#ifdef HAVE_PTHREAD_ATFORK
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static inline void
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_rs_forkhandler(void)
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{
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_rs_forked = 1;
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}
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#endif /* HAVE_PTHREAD_ATFORK */
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static int wipeonfork;
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static inline void
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_rs_forkdetect(void)
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{
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if (!wipeonfork) {
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static pid_t _rs_pid = 0;
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pid_t pid = getpid();
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if (_rs_pid == 0 || _rs_pid != pid || _rs_forked) {
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_rs_pid = pid;
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_rs_forked = 0;
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if (rs)
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memset(rs, 0, sizeof(*rs));
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}
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}
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}
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static inline int
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_rs_allocate(struct _rs **rsp, struct _rsx **rsxp)
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{
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if ((*rsp = (void *)mmap(NULL, sizeof(**rsp), PROT_READ|PROT_WRITE,
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MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED)
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return (-1);
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if ((*rsxp = (void *)mmap(NULL, sizeof(**rsxp), PROT_READ|PROT_WRITE,
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MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) {
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munmap((void *)*rsp, sizeof(**rsp));
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*rsp = NULL;
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return (-1);
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}
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#ifdef MADV_WIPEONFORK
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if (madvise (*rsp, sizeof(**rsp), MADV_WIPEONFORK) == 0 &&
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madvise (*rsxp, sizeof(**rsxp), MADV_WIPEONFORK) == 0) {
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wipeonfork = 1;
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}
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#endif
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_ARC4_ATFORK(_rs_forkhandler);
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return (0);
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}
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