1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
|
/* $OpenBSD: getentropy_win.c,v 1.6 2020/11/11 10:41:24 bcook Exp $ */
/*
* Copyright (c) 2014, Theo de Raadt <deraadt@openbsd.org>
* Copyright (c) 2014, Bob Beck <beck@obtuse.com>
*
* 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 <windows.h>
#include <bcrypt.h>
#include <errno.h>
#include <stdint.h>
#include <sys/types.h>
int getentropy(void *buf, size_t len);
/*
* On Windows, BCryptGenRandom with BCRYPT_USE_SYSTEM_PREFERRED_RNG is supposed
* to be a well-seeded, cryptographically strong random number generator.
* https://docs.microsoft.com/en-us/windows/win32/api/bcrypt/nf-bcrypt-bcryptgenrandom
*/
int
getentropy(void *buf, size_t len)
{
if (len > 256) {
errno = EIO;
return (-1);
}
if (FAILED(BCryptGenRandom(NULL, buf, len, BCRYPT_USE_SYSTEM_PREFERRED_RNG))) {
errno = EIO;
return (-1);
}
return (0);
}
|
