1*2b5e567dSriastradh /* $NetBSD: getentropy.c,v 1.3 2022/05/31 13:42:59 riastradh Exp $ */
2*2b5e567dSriastradh
3*2b5e567dSriastradh /*-
4*2b5e567dSriastradh * Copyright (c) 2020 The NetBSD Foundation, Inc.
5*2b5e567dSriastradh * All rights reserved.
6*2b5e567dSriastradh *
7*2b5e567dSriastradh * This code is derived from software contributed to The NetBSD Foundation
8*2b5e567dSriastradh * by Nia Alarie.
9*2b5e567dSriastradh *
10*2b5e567dSriastradh * Redistribution and use in source and binary forms, with or without
11*2b5e567dSriastradh * modification, are permitted provided that the following conditions
12*2b5e567dSriastradh * are met:
13*2b5e567dSriastradh * 1. Redistributions of source code must retain the above copyright
14*2b5e567dSriastradh * notice, this list of conditions and the following disclaimer.
15*2b5e567dSriastradh * 2. Redistributions in binary form must reproduce the above copyright
16*2b5e567dSriastradh * notice, this list of conditions and the following disclaimer in the
17*2b5e567dSriastradh * documentation and/or other materials provided with the distribution.
18*2b5e567dSriastradh *
19*2b5e567dSriastradh * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20*2b5e567dSriastradh * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21*2b5e567dSriastradh * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22*2b5e567dSriastradh * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23*2b5e567dSriastradh * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24*2b5e567dSriastradh * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25*2b5e567dSriastradh * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26*2b5e567dSriastradh * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27*2b5e567dSriastradh * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28*2b5e567dSriastradh * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29*2b5e567dSriastradh * POSSIBILITY OF SUCH DAMAGE.
30*2b5e567dSriastradh */
31*2b5e567dSriastradh
32*2b5e567dSriastradh #include <sys/cdefs.h>
33*2b5e567dSriastradh __RCSID("$NetBSD: getentropy.c,v 1.3 2022/05/31 13:42:59 riastradh Exp $");
34*2b5e567dSriastradh
35*2b5e567dSriastradh #include "namespace.h"
36*2b5e567dSriastradh
37*2b5e567dSriastradh #include <sys/param.h>
38*2b5e567dSriastradh #include <sys/sysctl.h>
39*2b5e567dSriastradh
40*2b5e567dSriastradh #include <errno.h>
41*2b5e567dSriastradh #include <limits.h>
42*2b5e567dSriastradh #include <unistd.h>
43*2b5e567dSriastradh
44*2b5e567dSriastradh #ifdef __weak_alias
45*2b5e567dSriastradh __weak_alias(getentropy,_getentropy)
46*2b5e567dSriastradh #endif
47*2b5e567dSriastradh
48*2b5e567dSriastradh __CTASSERT(GETENTROPY_MAX == 256);
49*2b5e567dSriastradh
50*2b5e567dSriastradh int
getentropy(void * buf,size_t buflen)51*2b5e567dSriastradh getentropy(void *buf, size_t buflen)
52*2b5e567dSriastradh {
53*2b5e567dSriastradh size_t len = buflen;
54*2b5e567dSriastradh int name[2] = { CTL_KERN, KERN_ARND };
55*2b5e567dSriastradh
56*2b5e567dSriastradh if (buf == NULL && buflen > 0) {
57*2b5e567dSriastradh errno = EFAULT;
58*2b5e567dSriastradh return -1;
59*2b5e567dSriastradh }
60*2b5e567dSriastradh
61*2b5e567dSriastradh if (buflen > 256) {
62*2b5e567dSriastradh errno = EINVAL;
63*2b5e567dSriastradh return -1;
64*2b5e567dSriastradh }
65*2b5e567dSriastradh
66*2b5e567dSriastradh return sysctl(name, 2, buf, &len, NULL, 0);
67*2b5e567dSriastradh }
68