Commit da4b5b7d authored by David Parks's avatar David Parks Committed by Pier Angelo Vendrame
Browse files

Bug 2038868: Set Zone.Identifier for dragged URLs r=win-reviewers,gstoll 

An (AFAICT undocumented) long-standing feature in Windows is the ability to
set the Zone.Identifier ADS on a file by writing to a file named
"${filename}:Zone.Identifier".  In DND, this patch exports this alongside
the ${filename} that will be used for the shortcut, so explorer writes both.
This causes the UAC to kick in when the shortcut is launched.

Differential Revision: https://phabricator.services.mozilla.com/D301935
parent a6e17cd0

widget/windows/nsDataObj.cpp

+80 −8
Original line number Diff line number Diff line
@@ -1230,8 +1230,13 @@ nsDataObj ::GetFileDescriptorInternetShortcutA(FORMATETC& aFE, 
  nsAutoString title;

  if (NS_FAILED(ExtractShortcutTitle(title))) return E_OUTOFMEMORY;



  // Allocate space for two FILEDESCRIPTOR entries: the .url file plus a

  // ":Zone.Identifier" ADS so the dropped shortcut is marked Internet-zone

  // (untrusted).

  size_t const allocSize =

      sizeof(FILEGROUPDESCRIPTORA) + sizeof(FILEDESCRIPTORA);

  HGLOBAL fileGroupDescHandle =

      ::GlobalAlloc(GMEM_ZEROINIT | GMEM_SHARE, sizeof(FILEGROUPDESCRIPTORA));

      ::GlobalAlloc(GMEM_ZEROINIT | GMEM_SHARE, allocSize);

  if (!fileGroupDescHandle) return E_OUTOFMEMORY;



  LPFILEGROUPDESCRIPTORA fileGroupDescA =
@@ -1252,11 +1257,24 @@ nsDataObj ::GetFileDescriptorInternetShortcutA(FORMATETC& aFE, 
      strcpy(fileGroupDescA->fgd[0].cFileName, "Untitled.url");

    }

  }



  // one file in the file block

  fileGroupDescA->cItems = 1;

  fileGroupDescA->fgd[0].dwFlags = FD_LINKUI;



  // Build the ":Zone.Identifier" ADS entry.

  // If appending the suffix would overflow, refuse the entire descriptor.

  constexpr char kAdsSuffix[] = ":Zone.Identifier";

  constexpr size_t kAdsSuffixSize = sizeof(kAdsSuffix);  // includes terminator

  size_t const mainLen = strnlen(fileGroupDescA->fgd[0].cFileName, MAX_PATH);

  if (mainLen + kAdsSuffixSize > MAX_PATH) {

    ::GlobalUnlock(fileGroupDescHandle);

    ::GlobalFree(fileGroupDescHandle);

    return HRESULT_FROM_WIN32(ERROR_PATH_NOT_FOUND);

  }

  memcpy(fileGroupDescA->fgd[1].cFileName, fileGroupDescA->fgd[0].cFileName,

         mainLen);

  memcpy(fileGroupDescA->fgd[1].cFileName + mainLen, kAdsSuffix,

         kAdsSuffixSize);

  fileGroupDescA->cItems = 2;



  ::GlobalUnlock(fileGroupDescHandle);

  aSTG.hGlobal = fileGroupDescHandle;

  aSTG.tymed = TYMED_HGLOBAL;
@@ -1271,8 +1289,13 @@ nsDataObj ::GetFileDescriptorInternetShortcutW(FORMATETC& aFE, 
  nsAutoString title;

  if (NS_FAILED(ExtractShortcutTitle(title))) return E_OUTOFMEMORY;



  // Allocate space for two FILEDESCRIPTOR entries: the .url file plus a

  // ":Zone.Identifier" ADS so the dropped shortcut is marked Internet-zone

  // (untrusted).

  size_t const allocSize =

      sizeof(FILEGROUPDESCRIPTORW) + sizeof(FILEDESCRIPTORW);

  HGLOBAL fileGroupDescHandle =

      ::GlobalAlloc(GMEM_ZEROINIT | GMEM_SHARE, sizeof(FILEGROUPDESCRIPTORW));

      ::GlobalAlloc(GMEM_ZEROINIT | GMEM_SHARE, allocSize);

  if (!fileGroupDescHandle) return E_OUTOFMEMORY;



  LPFILEGROUPDESCRIPTORW fileGroupDescW =
@@ -1293,11 +1316,25 @@ nsDataObj ::GetFileDescriptorInternetShortcutW(FORMATETC& aFE, 
      wcscpy(fileGroupDescW->fgd[0].cFileName, L"Untitled.url");

    }

  }



  // one file in the file block

  fileGroupDescW->cItems = 1;

  fileGroupDescW->fgd[0].dwFlags = FD_LINKUI;



  // Build the ":Zone.Identifier" ADS entry.

  // If appending the suffix would overflow, refuse the entire descriptor.

  constexpr WCHAR kAdsSuffix[] = L":Zone.Identifier";

  constexpr size_t kAdsSuffixLen =

      (sizeof(kAdsSuffix) / sizeof(WCHAR));  // includes terminator

  size_t const mainLen = wcsnlen(fileGroupDescW->fgd[0].cFileName, MAX_PATH);

  if (mainLen + kAdsSuffixLen > MAX_PATH) {

    ::GlobalUnlock(fileGroupDescHandle);

    ::GlobalFree(fileGroupDescHandle);

    return HRESULT_FROM_WIN32(ERROR_PATH_NOT_FOUND);

  }

  wmemcpy(fileGroupDescW->fgd[1].cFileName, fileGroupDescW->fgd[0].cFileName,

          mainLen);

  wmemcpy(fileGroupDescW->fgd[1].cFileName + mainLen, kAdsSuffix,

          kAdsSuffixLen);

  fileGroupDescW->cItems = 2;



  ::GlobalUnlock(fileGroupDescHandle);

  aSTG.hGlobal = fileGroupDescHandle;

  aSTG.tymed = TYMED_HGLOBAL;
@@ -1313,6 +1350,41 @@ nsDataObj ::GetFileDescriptorInternetShortcutW(FORMATETC& aFE, 
//

HRESULT

nsDataObj ::GetFileContentsInternetShortcut(FORMATETC& aFE, STGMEDIUM& aSTG) {

  // The descriptor advertises two entries: the .url content (lindex 0) and

  // the ":Zone.Identifier" ADS that marks it as Internet-zone (lindex 1).

  if (aFE.lindex == 1) {

    constexpr char kZoneIdContent[] = "[ZoneTransfer]\r\nZoneId=3\r\n";

    constexpr size_t kZoneIdLen = sizeof(kZoneIdContent) - 1;



    nsAutoGlobalMem globalMem(nsHGLOBAL(::GlobalAlloc(GMEM_SHARE, kZoneIdLen)));

    if (!globalMem) {

      return E_OUTOFMEMORY;

    }

    char* contents = reinterpret_cast<char*>(::GlobalLock(globalMem.get()));

    if (!contents) {

      return E_OUTOFMEMORY;

    }

    memcpy(contents, kZoneIdContent, kZoneIdLen);

    ::GlobalUnlock(globalMem.get());



    if (aFE.tymed & TYMED_ISTREAM) {

      RefPtr<IStream> stream = new CMemStream(

          globalMem.disown(), kZoneIdLen, already_AddRefed<AutoCloseEvent>());

      stream.forget(&aSTG.pstm);

      aSTG.tymed = TYMED_ISTREAM;

    } else {

      aSTG.hGlobal = globalMem.disown();

      aSTG.tymed = TYMED_HGLOBAL;

    }

    return S_OK;

  }



  // Treat aFE.lindex = 0 or -1 as requests for the URL file.  Anything else is

  // invalid.

  if (aFE.lindex != 0 && aFE.lindex != -1) {

    return DV_E_LINDEX;

  }



  static const char* kShellIconPref = "browser.shell.shortcutFavicons";

  nsAutoString url;

  if (NS_FAILED(ExtractShortcutURL(url))) return E_OUTOFMEMORY;