rand_win.c

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			 * 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;
		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");
		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))
			!= NULL)
			{
			/* 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 = 50;
						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));

			CloseHandle(handle);
			}

		FreeLibrary(kernel);
		}

#ifdef DEBUG
	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;
#ifndef __GNUC__
	static int have_tsc = 1;
	DWORD cyclecount;

	if (have_tsc) {
	  __try {
	    __asm {
	      rdtsc
	      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, [e-mail], West Consulting B.V.
 *
 * Code adapted from
 * <URL:http://www.microsoft.com/kb/developr/win_dk/q97193.htm>;
 * 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)
{
  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("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);
}

#else /* Unix version */

#include <time.h>

int RAND_poll(void)
{
	unsigned long l;
	pid_t curr_pid = getpid();
#ifdef DEVRANDOM
	FILE *fh;
#endif

#ifdef DEVRANDOM
	/* Use a random entropy pool device. Linux, FreeBSD and OpenBSD
	 * have this. Use /dev/urandom if you can as /dev/random may block
	 * if it runs out of random entries.  */

	if ((fh = fopen(DEVRANDOM, "r")) != NULL)
		{
		unsigned char tmpbuf[ENTROPY_NEEDED];
		int n;
		
		setvbuf(fh, NULL, _IONBF, 0);
		n=fread((unsigned char *)tmpbuf,1,ENTROPY_NEEDED,fh);
		fclose(fh);
		RAND_add(tmpbuf,sizeof tmpbuf,n);
		memset(tmpbuf,0,n);
		}
#endif

	/* put in some default random data, we need more than just this */
	l=curr_pid;
	RAND_add(&l,sizeof(l),0);
	l=getuid();
	RAND_add(&l,sizeof(l),0);

	l=time(NULL);
	RAND_add(&l,sizeof(l),0);

#ifdef DEVRANDOM
	return 1;
#endif
	return 0;
}

#endif