1 /*	$OpenBSD: arc4random_win.h,v 1.6 2016/06/30 12:17:29 bcook Exp $	*/
2 
3 /*
4  * Copyright (c) 1996, David Mazieres <dm@uun.org>
5  * Copyright (c) 2008, Damien Miller <djm@openbsd.org>
6  * Copyright (c) 2013, Markus Friedl <markus@openbsd.org>
7  * Copyright (c) 2014, Theo de Raadt <deraadt@openbsd.org>
8  *
9  * Permission to use, copy, modify, and distribute this software for any
10  * purpose with or without fee is hereby granted, provided that the above
11  * copyright notice and this permission notice appear in all copies.
12  *
13  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
14  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
15  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
16  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
17  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
18  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
19  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
20  */
21 
22 /*
23  * Stub functions for portability.
24  */
25 
26 #include <windows.h>
27 
28 static volatile HANDLE arc4random_mtx = NULL;
29 
30 /*
31  * Initialize the mutex on the first lock attempt. On collision, each thread
32  * will attempt to allocate a mutex and compare-and-swap it into place as the
33  * global mutex. On failure to swap in the global mutex, the mutex is closed.
34  */
35 #define _ARC4_LOCK() { \
36 	if (!arc4random_mtx) { \
37 		HANDLE p = CreateMutex(NULL, FALSE, NULL); \
38 		if (InterlockedCompareExchangePointer((void **)&arc4random_mtx, (void *)p, NULL)) \
39 			CloseHandle(p); \
40 	} \
41 	WaitForSingleObject(arc4random_mtx, INFINITE); \
42 } \
43 
44 #define _ARC4_UNLOCK() ReleaseMutex(arc4random_mtx)
45 
46 static inline void
47 _getentropy_fail(void)
48 {
49 	TerminateProcess(GetCurrentProcess(), 0);
50 }
51 
52 static inline int
53 _rs_allocate(struct _rs **rsp, struct _rsx **rsxp)
54 {
55 	*rsp = VirtualAlloc(NULL, sizeof(**rsp),
56 	    MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
57 	if (*rsp == NULL)
58 		return (-1);
59 
60 	*rsxp = VirtualAlloc(NULL, sizeof(**rsxp),
61 	    MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
62 	if (*rsxp == NULL) {
63 		VirtualFree(*rsp, 0, MEM_RELEASE);
64 		*rsp = NULL;
65 		return (-1);
66 	}
67 	return (0);
68 }
69 
70 static inline void
71 _rs_forkhandler(void)
72 {
73 }
74 
75 static inline void
76 _rs_forkdetect(void)
77 {
78 }
79