/* 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 #include "rand_lcl.h" #if defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32) #include #ifndef _WIN32_WINNT # define _WIN32_WINNT 0x0400 #endif #include #include /* 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 */ 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, ULONG_PTR); 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 #ifndef OPENSSL_SYS_WINCE #include #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; int good = 0; /* 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) # 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... */ # ifndef CryptAcquireContext /* reserve for broken header... */ # define CryptAcquireContext CryptAcquireContextW # endif /* poll the CryptoAPI PRNG */ /* The CryptoAPI returns sizeof(buf) bytes of randomness */ if (CryptAcquireContext(&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; 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. */ /* Wolfgang Marczy 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, 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 ((osverinfo.dwPlatformId != VER_PLATFORM_WIN32_NT || !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 ( 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; DWORD stoptime = 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. */ hlist.dwSize = sizeof(HEAPLIST32); if (good) stoptime = GetTickCount() + MAXDELAY; 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) && GetTickCount() < stoptime); /* 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) stoptime = GetTickCount() + MAXDELAY; if (process_first(handle, &p)) do RAND_add(&p, p.dwSize, 9); while (process_next(handle, &p) && GetTickCount() < stoptime); /* 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) stoptime = GetTickCount() + MAXDELAY; if (thread_first(handle, &t)) do RAND_add(&t, t.dwSize, 6); while (thread_next(handle, &t) && GetTickCount() < stoptime); /* 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) stoptime = GetTickCount() + MAXDELAY; if (module_first(handle, &m)) do RAND_add(&m, m.dwSize, 9); while (module_next(handle, &m) && (GetTickCount() < stoptime)); 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 * ; * 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 */ if (GetVersion() >= 0x80000000 || !OPENSSL_isservice()) return; /* 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