openssl1.0/crypto/rand/rand_win.c
2019-08-09 10:00:55 +02:00

748 lines
28 KiB
C

/* crypto/rand/rand_win.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
/* ====================================================================
* Copyright (c) 1998-2000 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* openssl-core@openssl.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com).
*
*/
#include "cryptlib.h"
#include <openssl/rand.h>
#include "rand_lcl.h"
#if defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32)
# include <windows.h>
# ifndef _WIN32_WINNT
# define _WIN32_WINNT 0x0400
# endif
# include <wincrypt.h>
# include <tlhelp32.h>
/*
* Limit the time spent walking through the heap, processes, threads and
* modules to a maximum of 1000 miliseconds each, unless CryptoGenRandom
* failed
*/
# define MAXDELAY 1000
/*
* Intel hardware RNG CSP -- available from
* http://developer.intel.com/design/security/rng/redist_license.htm
*/
# define PROV_INTEL_SEC 22
# define INTEL_DEF_PROV L"Intel Hardware Cryptographic Service Provider"
static void readtimer(void);
static void readscreen(void);
/*
* It appears like CURSORINFO, PCURSORINFO and LPCURSORINFO are only defined
* when WINVER is 0x0500 and up, which currently only happens on Win2000.
* Unfortunately, those are typedefs, so they're a little bit difficult to
* detect properly. On the other hand, the macro CURSOR_SHOWING is defined
* within the same conditional, so it can be use to detect the absence of
* said typedefs.
*/
# ifndef CURSOR_SHOWING
/*
* Information about the global cursor.
*/
typedef struct tagCURSORINFO {
DWORD cbSize;
DWORD flags;
HCURSOR hCursor;
POINT ptScreenPos;
} CURSORINFO, *PCURSORINFO, *LPCURSORINFO;
# define CURSOR_SHOWING 0x00000001
# endif /* CURSOR_SHOWING */
# if !defined(OPENSSL_SYS_WINCE)
typedef BOOL(WINAPI *CRYPTACQUIRECONTEXTW) (HCRYPTPROV *, LPCWSTR, LPCWSTR,
DWORD, DWORD);
typedef BOOL(WINAPI *CRYPTGENRANDOM) (HCRYPTPROV, DWORD, BYTE *);
typedef BOOL(WINAPI *CRYPTRELEASECONTEXT) (HCRYPTPROV, DWORD);
typedef HWND(WINAPI *GETFOREGROUNDWINDOW) (VOID);
typedef BOOL(WINAPI *GETCURSORINFO) (PCURSORINFO);
typedef DWORD(WINAPI *GETQUEUESTATUS) (UINT);
typedef HANDLE(WINAPI *CREATETOOLHELP32SNAPSHOT) (DWORD, DWORD);
typedef BOOL(WINAPI *CLOSETOOLHELP32SNAPSHOT) (HANDLE);
typedef BOOL(WINAPI *HEAP32FIRST) (LPHEAPENTRY32, DWORD, size_t);
typedef BOOL(WINAPI *HEAP32NEXT) (LPHEAPENTRY32);
typedef BOOL(WINAPI *HEAP32LIST) (HANDLE, LPHEAPLIST32);
typedef BOOL(WINAPI *PROCESS32) (HANDLE, LPPROCESSENTRY32);
typedef BOOL(WINAPI *THREAD32) (HANDLE, LPTHREADENTRY32);
typedef BOOL(WINAPI *MODULE32) (HANDLE, LPMODULEENTRY32);
# include <lmcons.h>
# include <lmstats.h>
# if 1
/*
* The NET API is Unicode only. It requires the use of the UNICODE macro.
* When UNICODE is defined LPTSTR becomes LPWSTR. LMSTR was was added to the
* Platform SDK to allow the NET API to be used in non-Unicode applications
* provided that Unicode strings were still used for input. LMSTR is defined
* as LPWSTR.
*/
typedef NET_API_STATUS(NET_API_FUNCTION *NETSTATGET)
(LPWSTR, LPWSTR, DWORD, DWORD, LPBYTE *);
typedef NET_API_STATUS(NET_API_FUNCTION *NETFREE) (LPBYTE);
# endif /* 1 */
# endif /* !OPENSSL_SYS_WINCE */
#define NOTTOOLONG(start) ((GetTickCount() - (start)) < MAXDELAY)
int RAND_poll(void)
{
MEMORYSTATUS m;
HCRYPTPROV hProvider = 0;
DWORD w;
int good = 0;
# if defined(OPENSSL_SYS_WINCE)
# if defined(_WIN32_WCE) && _WIN32_WCE>=300
/*
* Even though MSDN says _WIN32_WCE>=210, it doesn't seem to be available
* in commonly available implementations prior 300...
*/
{
BYTE buf[64];
/* poll the CryptoAPI PRNG */
/* The CryptoAPI returns sizeof(buf) bytes of randomness */
if (CryptAcquireContextW(&hProvider, NULL, NULL, PROV_RSA_FULL,
CRYPT_VERIFYCONTEXT)) {
if (CryptGenRandom(hProvider, sizeof(buf), buf))
RAND_add(buf, sizeof(buf), sizeof(buf));
CryptReleaseContext(hProvider, 0);
}
}
# endif
# else /* OPENSSL_SYS_WINCE */
/*
* None of below libraries are present on Windows CE, which is
* why we #ifndef the whole section. This also excuses us from
* handling the GetProcAddress issue. The trouble is that in
* real Win32 API GetProcAddress is available in ANSI flavor
* only. In WinCE on the other hand GetProcAddress is a macro
* most commonly defined as GetProcAddressW, which accepts
* Unicode argument. If we were to call GetProcAddress under
* WinCE, I'd recommend to either redefine GetProcAddress as
* GetProcAddressA (there seem to be one in common CE spec) or
* implement own shim routine, which would accept ANSI argument
* and expand it to Unicode.
*/
{
/* load functions dynamically - not available on all systems */
HMODULE advapi = LoadLibrary(TEXT("ADVAPI32.DLL"));
HMODULE kernel = LoadLibrary(TEXT("KERNEL32.DLL"));
HMODULE user = NULL;
HMODULE netapi = LoadLibrary(TEXT("NETAPI32.DLL"));
CRYPTACQUIRECONTEXTW acquire = NULL;
CRYPTGENRANDOM gen = NULL;
CRYPTRELEASECONTEXT release = NULL;
NETSTATGET netstatget = NULL;
NETFREE netfree = NULL;
BYTE buf[64];
if (netapi) {
netstatget =
(NETSTATGET) GetProcAddress(netapi, "NetStatisticsGet");
netfree = (NETFREE) GetProcAddress(netapi, "NetApiBufferFree");
}
if (netstatget && netfree) {
LPBYTE outbuf;
/*
* NetStatisticsGet() is a Unicode only function
* STAT_WORKSTATION_0 contains 45 fields and STAT_SERVER_0
* contains 17 fields. We treat each field as a source of one
* byte of entropy.
*/
if (netstatget(NULL, L"LanmanWorkstation", 0, 0, &outbuf) == 0) {
RAND_add(outbuf, sizeof(STAT_WORKSTATION_0), 45);
netfree(outbuf);
}
if (netstatget(NULL, L"LanmanServer", 0, 0, &outbuf) == 0) {
RAND_add(outbuf, sizeof(STAT_SERVER_0), 17);
netfree(outbuf);
}
}
if (netapi)
FreeLibrary(netapi);
/*
* It appears like this can cause an exception deep within
* ADVAPI32.DLL at random times on Windows 2000. Reported by Jeffrey
* Altman. Only use it on NT.
*/
if (advapi) {
/*
* If it's available, then it's available in both ANSI
* and UNICODE flavors even in Win9x, documentation says.
* We favor Unicode...
*/
acquire = (CRYPTACQUIRECONTEXTW) GetProcAddress(advapi,
"CryptAcquireContextW");
gen = (CRYPTGENRANDOM) GetProcAddress(advapi, "CryptGenRandom");
release = (CRYPTRELEASECONTEXT) GetProcAddress(advapi,
"CryptReleaseContext");
}
if (acquire && gen && release) {
/* poll the CryptoAPI PRNG */
/* The CryptoAPI returns sizeof(buf) bytes of randomness */
if (acquire(&hProvider, NULL, NULL, PROV_RSA_FULL,
CRYPT_VERIFYCONTEXT)) {
if (gen(hProvider, sizeof(buf), buf) != 0) {
RAND_add(buf, sizeof(buf), 0);
good = 1;
# if 0
printf("randomness from PROV_RSA_FULL\n");
# endif
}
release(hProvider, 0);
}
/* poll the Pentium PRG with CryptoAPI */
if (acquire(&hProvider, 0, INTEL_DEF_PROV, PROV_INTEL_SEC, 0)) {
if (gen(hProvider, sizeof(buf), buf) != 0) {
RAND_add(buf, sizeof(buf), sizeof(buf));
good = 1;
# if 0
printf("randomness from PROV_INTEL_SEC\n");
# endif
}
release(hProvider, 0);
}
}
if (advapi)
FreeLibrary(advapi);
if ((!check_winnt() ||
!OPENSSL_isservice()) &&
(user = LoadLibrary(TEXT("USER32.DLL")))) {
GETCURSORINFO cursor;
GETFOREGROUNDWINDOW win;
GETQUEUESTATUS queue;
win =
(GETFOREGROUNDWINDOW) GetProcAddress(user,
"GetForegroundWindow");
cursor = (GETCURSORINFO) GetProcAddress(user, "GetCursorInfo");
queue = (GETQUEUESTATUS) GetProcAddress(user, "GetQueueStatus");
if (win) {
/* window handle */
HWND h = win();
RAND_add(&h, sizeof(h), 0);
}
if (cursor) {
/*
* unfortunately, its not safe to call GetCursorInfo() on NT4
* even though it exists in SP3 (or SP6) and higher.
*/
if (check_winnt() && !check_win_minplat(5))
cursor = 0;
}
if (cursor) {
/* cursor position */
/* assume 2 bytes of entropy */
CURSORINFO ci;
ci.cbSize = sizeof(CURSORINFO);
if (cursor(&ci))
RAND_add(&ci, ci.cbSize, 2);
}
if (queue) {
/* message queue status */
/* assume 1 byte of entropy */
w = queue(QS_ALLEVENTS);
RAND_add(&w, sizeof(w), 1);
}
FreeLibrary(user);
}
/*-
* Toolhelp32 snapshot: enumerate processes, threads, modules and heap
* http://msdn.microsoft.com/library/psdk/winbase/toolhelp_5pfd.htm
* (Win 9x and 2000 only, not available on NT)
*
* This seeding method was proposed in Peter Gutmann, Software
* Generation of Practically Strong Random Numbers,
* http://www.usenix.org/publications/library/proceedings/sec98/gutmann.html
* revised version at http://www.cryptoengines.com/~peter/06_random.pdf
* (The assignment of entropy estimates below is arbitrary, but based
* on Peter's analysis the full poll appears to be safe. Additional
* interactive seeding is encouraged.)
*/
if (kernel) {
CREATETOOLHELP32SNAPSHOT snap;
CLOSETOOLHELP32SNAPSHOT close_snap;
HANDLE handle;
HEAP32FIRST heap_first;
HEAP32NEXT heap_next;
HEAP32LIST heaplist_first, heaplist_next;
PROCESS32 process_first, process_next;
THREAD32 thread_first, thread_next;
MODULE32 module_first, module_next;
HEAPLIST32 hlist;
HEAPENTRY32 hentry;
PROCESSENTRY32 p;
THREADENTRY32 t;
MODULEENTRY32 m;
DWORD starttime = 0;
snap = (CREATETOOLHELP32SNAPSHOT)
GetProcAddress(kernel, "CreateToolhelp32Snapshot");
close_snap = (CLOSETOOLHELP32SNAPSHOT)
GetProcAddress(kernel, "CloseToolhelp32Snapshot");
heap_first = (HEAP32FIRST) GetProcAddress(kernel, "Heap32First");
heap_next = (HEAP32NEXT) GetProcAddress(kernel, "Heap32Next");
heaplist_first =
(HEAP32LIST) GetProcAddress(kernel, "Heap32ListFirst");
heaplist_next =
(HEAP32LIST) GetProcAddress(kernel, "Heap32ListNext");
process_first =
(PROCESS32) GetProcAddress(kernel, "Process32First");
process_next =
(PROCESS32) GetProcAddress(kernel, "Process32Next");
thread_first = (THREAD32) GetProcAddress(kernel, "Thread32First");
thread_next = (THREAD32) GetProcAddress(kernel, "Thread32Next");
module_first = (MODULE32) GetProcAddress(kernel, "Module32First");
module_next = (MODULE32) GetProcAddress(kernel, "Module32Next");
if (snap && heap_first && heap_next && heaplist_first &&
heaplist_next && process_first && process_next &&
thread_first && thread_next && module_first &&
module_next && (handle = snap(TH32CS_SNAPALL, 0))
!= INVALID_HANDLE_VALUE) {
/* heap list and heap walking */
/*
* HEAPLIST32 contains 3 fields that will change with each
* entry. Consider each field a source of 1 byte of entropy.
* HEAPENTRY32 contains 5 fields that will change with each
* entry. Consider each field a source of 1 byte of entropy.
*/
ZeroMemory(&hlist, sizeof(HEAPLIST32));
hlist.dwSize = sizeof(HEAPLIST32);
if (good)
starttime = GetTickCount();
# ifdef _MSC_VER
if (heaplist_first(handle, &hlist)) {
/*
* following discussion on dev ML, exception on WinCE (or
* other Win platform) is theoretically of unknown
* origin; prevent infinite loop here when this
* theoretical case occurs; otherwise cope with the
* expected (MSDN documented) exception-throwing
* behaviour of Heap32Next() on WinCE.
*
* based on patch in original message by Tanguy Fautré
* (2009/03/02) Subject: RAND_poll() and
* CreateToolhelp32Snapshot() stability
*/
int ex_cnt_limit = 42;
do {
RAND_add(&hlist, hlist.dwSize, 3);
__try {
ZeroMemory(&hentry, sizeof(HEAPENTRY32));
hentry.dwSize = sizeof(HEAPENTRY32);
if (heap_first(&hentry,
hlist.th32ProcessID,
hlist.th32HeapID)) {
int entrycnt = 80;
do
RAND_add(&hentry, hentry.dwSize, 5);
while (heap_next(&hentry)
&& (!good || NOTTOOLONG(starttime))
&& --entrycnt > 0);
}
}
__except(EXCEPTION_EXECUTE_HANDLER) {
/*
* ignore access violations when walking the heap
* list
*/
ex_cnt_limit--;
}
} while (heaplist_next(handle, &hlist)
&& (!good || NOTTOOLONG(starttime))
&& ex_cnt_limit > 0);
}
# else
if (heaplist_first(handle, &hlist)) {
do {
RAND_add(&hlist, hlist.dwSize, 3);
hentry.dwSize = sizeof(HEAPENTRY32);
if (heap_first(&hentry,
hlist.th32ProcessID,
hlist.th32HeapID)) {
int entrycnt = 80;
do
RAND_add(&hentry, hentry.dwSize, 5);
while (heap_next(&hentry)
&& (!good || NOTTOOLONG(starttime))
&& --entrycnt > 0);
}
} while (heaplist_next(handle, &hlist)
&& (!good || NOTTOOLONG(starttime)));
}
# endif
/* process walking */
/*
* PROCESSENTRY32 contains 9 fields that will change with
* each entry. Consider each field a source of 1 byte of
* entropy.
*/
p.dwSize = sizeof(PROCESSENTRY32);
if (good)
starttime = GetTickCount();
if (process_first(handle, &p))
do
RAND_add(&p, p.dwSize, 9);
while (process_next(handle, &p)
&& (!good || NOTTOOLONG(starttime)));
/* thread walking */
/*
* THREADENTRY32 contains 6 fields that will change with each
* entry. Consider each field a source of 1 byte of entropy.
*/
t.dwSize = sizeof(THREADENTRY32);
if (good)
starttime = GetTickCount();
if (thread_first(handle, &t))
do
RAND_add(&t, t.dwSize, 6);
while (thread_next(handle, &t)
&& (!good || NOTTOOLONG(starttime)));
/* module walking */
/*
* MODULEENTRY32 contains 9 fields that will change with each
* entry. Consider each field a source of 1 byte of entropy.
*/
m.dwSize = sizeof(MODULEENTRY32);
if (good)
starttime = GetTickCount();
if (module_first(handle, &m))
do
RAND_add(&m, m.dwSize, 9);
while (module_next(handle, &m)
&& (!good || NOTTOOLONG(starttime)));
if (close_snap)
close_snap(handle);
else
CloseHandle(handle);
}
FreeLibrary(kernel);
}
}
# endif /* !OPENSSL_SYS_WINCE */
/* timer data */
readtimer();
/* memory usage statistics */
GlobalMemoryStatus(&m);
RAND_add(&m, sizeof(m), 1);
/* process ID */
w = GetCurrentProcessId();
RAND_add(&w, sizeof(w), 1);
# if 0
printf("Exiting RAND_poll\n");
# endif
return (1);
}
int RAND_event(UINT iMsg, WPARAM wParam, LPARAM lParam)
{
double add_entropy = 0;
switch (iMsg) {
case WM_KEYDOWN:
{
static WPARAM key;
if (key != wParam)
add_entropy = 0.05;
key = wParam;
}
break;
case WM_MOUSEMOVE:
{
static int lastx, lasty, lastdx, lastdy;
int x, y, dx, dy;
x = LOWORD(lParam);
y = HIWORD(lParam);
dx = lastx - x;
dy = lasty - y;
if (dx != 0 && dy != 0 && dx - lastdx != 0 && dy - lastdy != 0)
add_entropy = .2;
lastx = x, lasty = y;
lastdx = dx, lastdy = dy;
}
break;
}
readtimer();
RAND_add(&iMsg, sizeof(iMsg), add_entropy);
RAND_add(&wParam, sizeof(wParam), 0);
RAND_add(&lParam, sizeof(lParam), 0);
return (RAND_status());
}
void RAND_screen(void)
{ /* function available for backward
* compatibility */
RAND_poll();
readscreen();
}
/* feed timing information to the PRNG */
static void readtimer(void)
{
DWORD w;
LARGE_INTEGER l;
static int have_perfc = 1;
# if defined(_MSC_VER) && defined(_M_X86)
static int have_tsc = 1;
DWORD cyclecount;
if (have_tsc) {
__try {
__asm {
_emit 0x0f _emit 0x31 mov cyclecount, eax}
RAND_add(&cyclecount, sizeof(cyclecount), 1);
}
__except(EXCEPTION_EXECUTE_HANDLER) {
have_tsc = 0;
}
}
# else
# define have_tsc 0
# endif
if (have_perfc) {
if (QueryPerformanceCounter(&l) == 0)
have_perfc = 0;
else
RAND_add(&l, sizeof(l), 0);
}
if (!have_tsc && !have_perfc) {
w = GetTickCount();
RAND_add(&w, sizeof(w), 0);
}
}
/* feed screen contents to PRNG */
/*****************************************************************************
*
* Created 960901 by Gertjan van Oosten, gertjan@West.NL, West Consulting B.V.
*
* Code adapted from
* <URL:http://support.microsoft.com/default.aspx?scid=kb;[LN];97193>;
* the original copyright message is:
*
* (C) Copyright Microsoft Corp. 1993. All rights reserved.
*
* You have a royalty-free right to use, modify, reproduce and
* distribute the Sample Files (and/or any modified version) in
* any way you find useful, provided that you agree that
* Microsoft has no warranty obligations or liability for any
* Sample Application Files which are modified.
*/
static void readscreen(void)
{
# if !defined(OPENSSL_SYS_WINCE) && !defined(OPENSSL_SYS_WIN32_CYGWIN)
HDC hScrDC; /* screen DC */
HBITMAP hBitmap; /* handle for our bitmap */
BITMAP bm; /* bitmap properties */
unsigned int size; /* size of bitmap */
char *bmbits; /* contents of bitmap */
int w; /* screen width */
int h; /* screen height */
int y; /* y-coordinate of screen lines to grab */
int n = 16; /* number of screen lines to grab at a time */
BITMAPINFOHEADER bi; /* info about the bitmap */
if (check_winnt() && OPENSSL_isservice() > 0)
return;
/* Get a reference to the screen DC */
hScrDC = GetDC(NULL);
/* Get screen resolution */
w = GetDeviceCaps(hScrDC, HORZRES);
h = GetDeviceCaps(hScrDC, VERTRES);
/* Create a bitmap compatible with the screen DC */
hBitmap = CreateCompatibleBitmap(hScrDC, w, n);
/* Get bitmap properties */
GetObject(hBitmap, sizeof(bm), (LPSTR)&bm);
size = (unsigned int)4 * bm.bmHeight * bm.bmWidth;
bi.biSize = sizeof(bi);
bi.biWidth = bm.bmWidth;
bi.biHeight = bm.bmHeight;
bi.biPlanes = 1;
bi.biBitCount = 32;
bi.biCompression = BI_RGB;
bi.biSizeImage = 0;
bi.biXPelsPerMeter = 0;
bi.biYPelsPerMeter = 0;
bi.biClrUsed = 0;
bi.biClrImportant = 0;
bmbits = OPENSSL_malloc(size);
if (bmbits) {
/* Now go through the whole screen, repeatedly grabbing n lines */
for (y = 0; y < h - n; y += n) {
unsigned char md[MD_DIGEST_LENGTH];
/* Copy the bits of the current line range into the buffer */
GetDIBits(hScrDC, hBitmap, y, n,
bmbits, (LPBITMAPINFO)&bi, DIB_RGB_COLORS);
/* Get the hash of the bitmap */
MD(bmbits, size, md);
/* Seed the random generator with the hash value */
RAND_add(md, MD_DIGEST_LENGTH, 0);
}
OPENSSL_free(bmbits);
}
/* Clean up */
DeleteObject(hBitmap);
ReleaseDC(NULL, hScrDC);
# endif /* !OPENSSL_SYS_WINCE */
}
#endif