content/browser/safe_util_win.cc

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include <shlobj.h>
   6 #include <shobjidl.h>
   7
   8 #include "content/browser/safe_util_win.h"
   9
  10 #include "base/files/file_path.h"
  11 #include "base/logging.h"
  12 #include "base/path_service.h"
  13 #include "base/strings/string_util.h"
  14 #include "base/strings/utf_string_conversions.h"
  15 #include "base/win/scoped_comptr.h"
  16 #include "ui/base/win/shell.h"
  17 #include "url/gurl.h"
  18
  19 namespace content {
  20 namespace {
  21
  22 // Sets the Zone Identifier on the file to "Internet" (3). Returns true if the
  23 // function succeeds, false otherwise. A failure is expected on system where
  24 // the Zone Identifier is not supported, like a machine with a FAT32 filesystem.
  25 // This function does not invoke Windows Attachment Execution Services.
  26 //
  27 // |full_path| is the path to the downloaded file.
  28 bool SetInternetZoneIdentifierDirectly(const base::FilePath& full_path) {
  29   const DWORD kShare = FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE;
  30   std::wstring path = full_path.value() + L":Zone.Identifier";
  31   HANDLE file = CreateFile(path.c_str(), GENERIC_WRITE, kShare, NULL,
  32                            OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
  33   if (INVALID_HANDLE_VALUE == file)
  34     return false;
  35
  36   static const char kIdentifier[] = "[ZoneTransfer]\r\nZoneId=3\r\n";
  37   // Don't include trailing null in data written.
  38   static const DWORD kIdentifierSize = arraysize(kIdentifier) - 1;
  39   DWORD written = 0;
  40   BOOL result = WriteFile(file, kIdentifier, kIdentifierSize, &written, NULL);
  41   BOOL flush_result = FlushFileBuffers(file);
  42   CloseHandle(file);
  43
  44   if (!result || !flush_result || written != kIdentifierSize) {
  45     NOTREACHED();
  46     return false;
  47   }
  48
  49   return true;
  50 }
  51
  52 }  // namespace
  53
  54 HRESULT AVScanFile(const base::FilePath& full_path,
  55                    const std::string& source_url,
  56                    const GUID& client_guid) {
  57   base::win::ScopedComPtr<IAttachmentExecute> attachment_services;
  58   HRESULT hr = attachment_services.CreateInstance(CLSID_AttachmentServices);
  59
  60   if (FAILED(hr)) {
  61     // The thread must have COM initialized.
  62     DCHECK_NE(CO_E_NOTINITIALIZED, hr);
  63
  64     // We don't have Attachment Execution Services, it must be a pre-XP.SP2
  65     // Windows installation, or the thread does not have COM initialized. Try to
  66     // set the zone information directly. Failure is not considered an error.
  67     SetInternetZoneIdentifierDirectly(full_path);
  68     return hr;
  69   }
  70
  71   if (!IsEqualGUID(client_guid, GUID_NULL)) {
  72     hr = attachment_services->SetClientGuid(client_guid);
  73     if (FAILED(hr))
  74       return hr;
  75   }
  76
  77   hr = attachment_services->SetLocalPath(full_path.value().c_str());
  78   if (FAILED(hr))
  79     return hr;
  80
  81   // Note: SetSource looks like it needs to be called, even if empty.
  82   // Docs say it is optional, but it appears not calling it at all sets
  83   // a zone that is too restrictive.
  84   hr = attachment_services->SetSource(UTF8ToWide(source_url).c_str());
  85   if (FAILED(hr))
  86     return hr;
  87
  88   // A failure in the Save() call below could result in the downloaded file
  89   // being deleted.
  90   return attachment_services->Save();
  91 }
  92
  93 }  // namespace content