61 lines
1.6 KiB
C
Executable File
61 lines
1.6 KiB
C
Executable File
/* $OpenBSD: getentropy_freebsd.c,v 1.4 2020/10/12 22:08:33 deraadt Exp $ */
|
|
|
|
/*
|
|
* Copyright (c) 2014 Pawel Jakub Dawidek <pjd@FreeBSD.org>
|
|
* Copyright (c) 2014 Brent Cook <bcook@openbsd.org>
|
|
*
|
|
* Permission to use, copy, modify, and distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
|
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
*
|
|
* Emulation of getentropy(2) as documented at:
|
|
* http://man.openbsd.org/getentropy.2
|
|
*/
|
|
|
|
#include <sys/types.h>
|
|
#include <sys/sysctl.h>
|
|
|
|
#include <errno.h>
|
|
#include <stddef.h>
|
|
|
|
/*
|
|
* Derived from lib/libc/gen/arc4random.c from FreeBSD.
|
|
*/
|
|
static size_t
|
|
getentropy_sysctl(u_char *buf, size_t size)
|
|
{
|
|
const int mib[2] = { CTL_KERN, KERN_ARND };
|
|
size_t len, done;
|
|
|
|
done = 0;
|
|
|
|
do {
|
|
len = size;
|
|
if (sysctl(mib, 2, buf, &len, NULL, 0) == -1)
|
|
return (done);
|
|
done += len;
|
|
buf += len;
|
|
size -= len;
|
|
} while (size > 0);
|
|
|
|
return (done);
|
|
}
|
|
|
|
int
|
|
getentropy(void *buf, size_t len)
|
|
{
|
|
if (len <= 256 && getentropy_sysctl(buf, len) == len)
|
|
return (0);
|
|
|
|
errno = EIO;
|
|
return (-1);
|
|
}
|