50 lines
1.6 KiB
C
Executable file
50 lines
1.6 KiB
C
Executable file
/* $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);
|
|
}
|