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openssl/crypto/rand/rand_win.c
Ulf Möller 6d2a7098d6 Cygwin randomness
2005-03-19 11:40:41 +00:00

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/* 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) || defined(OPENSSL_SYS_WIN32_CYGWIN)
#include <windows.h>
#ifndef _WIN32_WINNT
# define _WIN32_WINNT 0x0400
#endif
#include <wincrypt.h>
#include <tlhelp32.h>
/* 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 */
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, DWORD);
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>
#ifndef OPENSSL_SYS_WINCE
#include <lmstats.h>
#endif
#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 */
int RAND_poll(void)
{
MEMORYSTATUS m;
HCRYPTPROV hProvider = 0;
BYTE buf[64];
DWORD w;
HWND h;
HMODULE advapi, kernel, user, netapi;
CRYPTACQUIRECONTEXTW acquire = 0;
CRYPTGENRANDOM gen = 0;
CRYPTRELEASECONTEXT release = 0;
#if 1 /* There was previously a problem with NETSTATGET. Currently, this
* section is still experimental, but if all goes well, this conditional
* will be removed
*/
NETSTATGET netstatget = 0;
NETFREE netfree = 0;
#endif /* 1 */
/* Determine the OS version we are on so we can turn off things
* that do not work properly.
*/
OSVERSIONINFO osverinfo ;
osverinfo.dwOSVersionInfoSize = sizeof(OSVERSIONINFO) ;
GetVersionEx( &osverinfo ) ;
#if defined(OPENSSL_SYS_WINCE) && WCEPLATFORM!=MS_HPC_PRO
#ifndef CryptAcquireContext
#define CryptAcquireContext CryptAcquireContextW
#endif
/* poll the CryptoAPI PRNG */
/* The CryptoAPI returns sizeof(buf) bytes of randomness */
if (CryptAcquireContext(&hProvider, 0, 0, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT))
{
if (CryptGenRandom(hProvider, sizeof(buf), buf))
RAND_add(buf, sizeof(buf), sizeof(buf));
CryptReleaseContext(hProvider, 0);
}
#endif
#ifndef 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 */
advapi = LoadLibrary(TEXT("ADVAPI32.DLL"));
kernel = LoadLibrary(TEXT("KERNEL32.DLL"));
user = LoadLibrary(TEXT("USER32.DLL"));
netapi = LoadLibrary(TEXT("NETAPI32.DLL"));
#if 1 /* There was previously a problem with NETSTATGET. Currently, this
* section is still experimental, but if all goes well, this conditional
* will be removed
*/
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);
#endif /* 1 */
/* 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.
*/
/* Wolfgang Marczy <WMarczy@topcall.co.at> reports that
* the RegQueryValueEx call below can hang on NT4.0 (SP6).
* So we don't use this at all for now. */
#if 0
if ( osverinfo.dwPlatformId == VER_PLATFORM_WIN32_NT &&
osverinfo.dwMajorVersion < 5)
{
/* Read Performance Statistics from NT/2000 registry
* The size of the performance data can vary from call
* to call so we must guess the size of the buffer to use
* and increase its size if we get an ERROR_MORE_DATA
* return instead of ERROR_SUCCESS.
*/
LONG rc=ERROR_MORE_DATA;
char * buf=NULL;
DWORD bufsz=0;
DWORD length;
while (rc == ERROR_MORE_DATA)
{
buf = realloc(buf,bufsz+8192);
if (!buf)
break;
bufsz += 8192;
length = bufsz;
rc = RegQueryValueEx(HKEY_PERFORMANCE_DATA, TEXT("Global"),
NULL, NULL, buf, &length);
}
if (rc == ERROR_SUCCESS)
{
/* For entropy count assume only least significant
* byte of each DWORD is random.
*/
RAND_add(&length, sizeof(length), 0);
RAND_add(buf, length, length / 4.0);
/* Close the Registry Key to allow Windows to cleanup/close
* the open handle
* Note: The 'HKEY_PERFORMANCE_DATA' key is implicitly opened
* when the RegQueryValueEx above is done. However, if
* it is not explicitly closed, it can cause disk
* partition manipulation problems.
*/
RegCloseKey(HKEY_PERFORMANCE_DATA);
}
if (buf)
free(buf);
}
#endif
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, 0, 0, PROV_RSA_FULL,
CRYPT_VERIFYCONTEXT))
{
if (gen(hProvider, sizeof(buf), buf) != 0)
{
RAND_add(buf, sizeof(buf), 0);
#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));
#if 0
printf("randomness from PROV_INTEL_SEC\n");
#endif
}
release(hProvider, 0);
}
}
if (advapi)
FreeLibrary(advapi);
if (user)
{
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 */
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 ( osverinfo.dwPlatformId == VER_PLATFORM_WIN32_NT &&
osverinfo.dwMajorVersion < 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;
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.
*/
hlist.dwSize = sizeof(HEAPLIST32);
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)
&& --entrycnt > 0);
}
} while (heaplist_next(handle,
&hlist));
/* 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 (process_first(handle, &p))
do
RAND_add(&p, p.dwSize, 9);
while (process_next(handle, &p));
/* 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 (thread_first(handle, &t))
do
RAND_add(&t, t.dwSize, 6);
while (thread_next(handle, &t));
/* 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 (module_first(handle, &m))
do
RAND_add(&m, m.dwSize, 9);
while (module_next(handle, &m));
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 */
HDC hMemDC; /* memory DC */
HBITMAP hBitmap; /* handle for our bitmap */
HBITMAP hOldBitmap; /* handle for previous 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 */
/* Create a screen DC and a memory DC compatible to screen DC */
hScrDC = CreateDC(TEXT("DISPLAY"), NULL, NULL, NULL);
hMemDC = CreateCompatibleDC(hScrDC);
/* Get screen resolution */
w = GetDeviceCaps(hScrDC, HORZRES);
h = GetDeviceCaps(hScrDC, VERTRES);
/* Create a bitmap compatible with the screen DC */
hBitmap = CreateCompatibleBitmap(hScrDC, w, n);
/* Select new bitmap into memory DC */
hOldBitmap = SelectObject(hMemDC, hBitmap);
/* Get bitmap properties */
GetObject(hBitmap, sizeof(BITMAP), (LPSTR)&bm);
size = (unsigned int)bm.bmWidthBytes * bm.bmHeight * bm.bmPlanes;
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];
/* Bitblt screen DC to memory DC */
BitBlt(hMemDC, 0, 0, w, n, hScrDC, 0, y, SRCCOPY);
/* Copy bitmap bits from memory DC to bmbits */
GetBitmapBits(hBitmap, size, bmbits);
/* 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);
}
/* Select old bitmap back into memory DC */
hBitmap = SelectObject(hMemDC, hOldBitmap);
/* Clean up */
DeleteObject(hBitmap);
DeleteDC(hMemDC);
DeleteDC(hScrDC);
#endif /* !OPENSSL_SYS_WINCE */
}
#endif
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