Commit 99b00fd9 authored by Jake Goulding's avatar Jake Goulding Committed by Rich Salz
Browse files

RT2301: GetDIBits, not GetBitmapBits in rand_win 



GetDIBits has been around since Windows2000 and
BitBitmapBits is an old Win16 compatibility function
that is much slower.

Reviewed-by: default avatarTim Hudson <tjh@openssl.org>
parent 569e2d12

crypto/rand/rand_win.c

+19 −18
Original line number Diff line number Diff line
@@ -741,9 +741,7 @@ 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 */
@@ -751,13 +749,13 @@ static void readscreen(void) 
  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;



  /* Create a screen DC and a memory DC compatible to screen DC */

  hScrDC = CreateDC(TEXT("DISPLAY"), NULL, NULL, NULL);

  hMemDC = CreateCompatibleDC(hScrDC);

  /* Get a reference to the screen DC */

  hScrDC = GetDC(NULL);



  /* Get screen resolution */

  w = GetDeviceCaps(hScrDC, HORZRES);
@@ -766,13 +764,22 @@ static void readscreen(void) 
  /* 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;



  bi.biSize = sizeof(BITMAPINFOHEADER);

  bi.biWidth = bm.bmWidth;

  bi.biHeight = bm.bmHeight;

  bi.biPlanes = bm.bmPlanes;

  bi.biBitCount = bm.bmBitsPixel;

  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 */
@@ -780,11 +787,9 @@ static void readscreen(void) 
    	{

	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);

	/* Copy the bits of the current line range into the buffer */

	GetDIBits(hScrDC, hBitmap, y, n,

		  bmbits, (BITMAPINFO *)&bi, DIB_RGB_COLORS);



	/* Get the hash of the bitmap */

	MD(bmbits,size,md);
@@ -796,13 +801,9 @@ static void readscreen(void) 
    OPENSSL_free(bmbits);

  }



  /* Select old bitmap back into memory DC */

  hBitmap = SelectObject(hMemDC, hOldBitmap);



  /* Clean up */

  DeleteObject(hBitmap);

  DeleteDC(hMemDC);

  DeleteDC(hScrDC);

  ReleaseDC(NULL, hScrDC);

#endif /* !OPENSSL_SYS_WINCE */

}