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RT2301: GetDIBits, not GetBitmapBits in rand_win

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

Reviewed-by: Tim Hudson <tjh@openssl.org>
(cherry picked from commit 99b00fd993)
This commit is contained in:
Jake Goulding 2014-09-05 11:13:23 -04:00 committed by Rich Salz
parent 478b3470ff
commit 5015a93ded
1 changed files with 19 additions and 18 deletions
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37
crypto/rand/rand_win.c
View file

@ -739,9 +739,7 @@ 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 */
@ -749,13 +747,13 @@ 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);
@ -764,13 +762,22 @@ 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 */
@ -778,11 +785,9 @@ 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);
@ -794,13 +799,9 @@ 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 */
}