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-rw-r--r--thirdparties/win32/include/directshow/checkbmi.h120
1 files changed, 120 insertions, 0 deletions
diff --git a/thirdparties/win32/include/directshow/checkbmi.h b/thirdparties/win32/include/directshow/checkbmi.h
new file mode 100644
index 0000000..9761dae
--- /dev/null
+++ b/thirdparties/win32/include/directshow/checkbmi.h
@@ -0,0 +1,120 @@
+// Copyright (c) 1992 - 1997 Microsoft Corporation. All Rights Reserved.
+
+#ifndef _CHECKBMI_H_
+#define _CHECKBMI_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Helper
+__inline BOOL MultiplyCheckOverflow(DWORD a, DWORD b, __deref_out_range(==, a * b) DWORD *pab) {
+ *pab = a * b;
+ if ((a == 0) || (((*pab) / a) == b)) {
+ return TRUE;
+ }
+ return FALSE;
+}
+
+
+// Checks if the fields in a BITMAPINFOHEADER won't generate
+// overlows and buffer overruns
+// This is not a complete check and does not guarantee code using this structure will be secure
+// from attack
+// Bugs this is guarding against:
+// 1. Total structure size calculation overflowing
+// 2. biClrUsed > 256 for 8-bit palettized content
+// 3. Total bitmap size in bytes overflowing
+// 4. biSize < size of the base structure leading to accessessing random memory
+// 5. Total structure size exceeding know size of data
+//
+
+__success(return != 0) __inline BOOL ValidateBitmapInfoHeader(
+ const BITMAPINFOHEADER *pbmi, // pointer to structure to check
+ __out_range(>=, sizeof(BITMAPINFOHEADER)) DWORD cbSize // size of memory block containing structure
+)
+{
+ DWORD dwWidthInBytes;
+ DWORD dwBpp;
+ DWORD dwWidthInBits;
+ DWORD dwHeight;
+ DWORD dwSizeImage;
+ DWORD dwClrUsed;
+
+ // Reject bad parameters - do the size check first to avoid reading bad memory
+ if (cbSize < sizeof(BITMAPINFOHEADER) ||
+ pbmi->biSize < sizeof(BITMAPINFOHEADER) ||
+ pbmi->biSize > 4096) {
+ return FALSE;
+ }
+
+ // Reject 0 size
+ if (pbmi->biWidth == 0 || pbmi->biHeight == 0) {
+ return FALSE;
+ }
+
+ // Use bpp of 200 for validating against further overflows if not set for compressed format
+ dwBpp = 200;
+
+ if (pbmi->biBitCount > dwBpp) {
+ return FALSE;
+ }
+
+ // Strictly speaking abs can overflow so cast explicitly to DWORD
+ dwHeight = (DWORD)abs(pbmi->biHeight);
+
+ if (!MultiplyCheckOverflow(dwBpp, (DWORD)pbmi->biWidth, &dwWidthInBits)) {
+ return FALSE;
+ }
+
+ // Compute correct width in bytes - rounding up to 4 bytes
+ dwWidthInBytes = (dwWidthInBits / 8 + 3) & ~3;
+
+ if (!MultiplyCheckOverflow(dwWidthInBytes, dwHeight, &dwSizeImage)) {
+ return FALSE;
+ }
+
+ // Fail if total size is 0 - this catches indivual quantities being 0
+ // Also don't allow huge values > 1GB which might cause arithmetic
+ // errors for users
+ if (dwSizeImage > 0x40000000 ||
+ pbmi->biSizeImage > 0x40000000) {
+ return FALSE;
+ }
+
+ // Fail if biClrUsed looks bad
+ if (pbmi->biClrUsed > 256) {
+ return FALSE;
+ }
+
+ if (pbmi->biClrUsed == 0 && pbmi->biBitCount <= 8 && pbmi->biBitCount > 0) {
+ dwClrUsed = (1 << pbmi->biBitCount);
+ } else {
+ dwClrUsed = pbmi->biClrUsed;
+ }
+
+ // Check total size
+ if (cbSize < pbmi->biSize + dwClrUsed * sizeof(RGBQUAD) +
+ (pbmi->biCompression == BI_BITFIELDS ? 3 * sizeof(DWORD) : 0)) {
+ return FALSE;
+ }
+
+ // If it is RGB validate biSizeImage - lots of code assumes the size is correct
+ if (pbmi->biCompression == BI_RGB || pbmi->biCompression == BI_BITFIELDS) {
+ if (pbmi->biSizeImage != 0) {
+ DWORD dwBits = (DWORD)pbmi->biWidth * (DWORD)pbmi->biBitCount;
+ DWORD dwWidthInBytes = ((DWORD)((dwBits+31) & (~31)) / 8);
+ DWORD dwTotalSize = (DWORD)abs(pbmi->biHeight) * dwWidthInBytes;
+ if (dwTotalSize > pbmi->biSizeImage) {
+ return FALSE;
+ }
+ }
+ }
+ return TRUE;
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // _CHECKBMI_H_
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