diff options
Diffstat (limited to 'chrome_elf/create_file/chrome_create_file.cc')
| -rw-r--r-- | chrome_elf/create_file/chrome_create_file.cc | 237 |
1 files changed, 0 insertions, 237 deletions
diff --git a/chrome_elf/create_file/chrome_create_file.cc b/chrome_elf/create_file/chrome_create_file.cc deleted file mode 100644 index 529e014..0000000 --- a/chrome_elf/create_file/chrome_create_file.cc +++ /dev/null @@ -1,237 +0,0 @@ -// Copyright 2014 The Chromium Authors. All rights reserved. -// Use of this source code is governed by a BSD-style license that can be -// found in the LICENSE file. - -#include "chrome_elf/create_file/chrome_create_file.h" - -#include <string> - -#include "base/strings/string16.h" -#include "chrome_elf/chrome_elf_constants.h" -#include "chrome_elf/ntdll_cache.h" -#include "sandbox/win/src/nt_internals.h" - -namespace { - -// From ShlObj.h in the Windows SDK. -#define CSIDL_LOCAL_APPDATA 0x001c - -typedef BOOL (WINAPI *PathIsUNCFunction)( - IN LPCWSTR path); - -typedef BOOL (WINAPI *PathAppendFunction)( - IN LPWSTR path, - IN LPCWSTR more); - -typedef BOOL (WINAPI *PathIsPrefixFunction)( - IN LPCWSTR prefix, - IN LPCWSTR path); - -typedef HRESULT (WINAPI *SHGetFolderPathFunction)( - IN HWND hwnd_owner, - IN int folder, - IN HANDLE token, - IN DWORD flags, - OUT LPWSTR path); - -PathIsUNCFunction g_path_is_unc_func; -PathAppendFunction g_path_append_func; -PathIsPrefixFunction g_path_is_prefix_func; -SHGetFolderPathFunction g_get_folder_func; - -// Populates the g_*_func pointers to functions which will be used in -// ShouldBypass(). Chrome_elf cannot have a load-time dependency on shell32 or -// shlwapi as this would induce a load-time dependency on user32.dll. Instead, -// the addresses of the functions we need are retrieved the first time this -// method is called, and cached to avoid subsequent calls to GetProcAddress(). -// It is assumed that the host process will never unload these functions. -// Returns true if all the functions needed are present. -bool PopulateShellFunctions() { - // Early exit if functions have already been populated. - if (g_path_is_unc_func && g_path_append_func && - g_path_is_prefix_func && g_get_folder_func) { - return true; - } - - // Get the addresses of the functions we need and store them for future use. - // These handles are intentionally leaked to ensure that these modules do not - // get unloaded. - HMODULE shell32 = ::LoadLibrary(L"shell32.dll"); - HMODULE shlwapi = ::LoadLibrary(L"shlwapi.dll"); - - if (!shlwapi || !shell32) - return false; - - g_path_is_unc_func = reinterpret_cast<PathIsUNCFunction>( - ::GetProcAddress(shlwapi, "PathIsUNCW")); - g_path_append_func = reinterpret_cast<PathAppendFunction>( - ::GetProcAddress(shlwapi, "PathAppendW")); - g_path_is_prefix_func = reinterpret_cast<PathIsPrefixFunction>( - ::GetProcAddress(shlwapi, "PathIsPrefixW")); - g_get_folder_func = reinterpret_cast<SHGetFolderPathFunction>( - ::GetProcAddress(shell32, "SHGetFolderPathW")); - - return g_path_is_unc_func && g_path_append_func && - g_path_is_prefix_func && g_get_folder_func; -} - -} // namespace - -HANDLE WINAPI CreateFileWRedirect( - LPCWSTR file_name, - DWORD desired_access, - DWORD share_mode, - LPSECURITY_ATTRIBUTES security_attributes, - DWORD creation_disposition, - DWORD flags_and_attributes, - HANDLE template_file) { - if (ShouldBypass(file_name)) { - return CreateFileNTDLL(file_name, - desired_access, - share_mode, - security_attributes, - creation_disposition, - flags_and_attributes, - template_file); - } - return CreateFile(file_name, - desired_access, - share_mode, - security_attributes, - creation_disposition, - flags_and_attributes, - template_file); - -} - -HANDLE CreateFileNTDLL( - LPCWSTR file_name, - DWORD desired_access, - DWORD share_mode, - LPSECURITY_ATTRIBUTES security_attributes, - DWORD creation_disposition, - DWORD flags_and_attributes, - HANDLE template_file) { - HANDLE file_handle = INVALID_HANDLE_VALUE; - NTSTATUS result = STATUS_UNSUCCESSFUL; - IO_STATUS_BLOCK io_status_block = {}; - - // Convert from Win32 domain to to NT creation disposition values. - switch (creation_disposition) { - case CREATE_NEW: - creation_disposition = FILE_CREATE; - break; - case CREATE_ALWAYS: - creation_disposition = FILE_OVERWRITE_IF; - break; - case OPEN_EXISTING: - creation_disposition = FILE_OPEN; - break; - case OPEN_ALWAYS: - creation_disposition = FILE_OPEN_IF; - break; - case TRUNCATE_EXISTING: - creation_disposition = FILE_OVERWRITE; - break; - default: - SetLastError(ERROR_INVALID_PARAMETER); - return INVALID_HANDLE_VALUE; - } - - if (!g_ntdll_lookup["NtCreateFile"] || - !g_ntdll_lookup["RtlInitUnicodeString"]) { - return INVALID_HANDLE_VALUE; - } - - NtCreateFileFunction create_file = - reinterpret_cast<NtCreateFileFunction>(g_ntdll_lookup["NtCreateFile"]); - - RtlInitUnicodeStringFunction init_unicode_string = - reinterpret_cast<RtlInitUnicodeStringFunction>( - g_ntdll_lookup["RtlInitUnicodeString"]); - - UNICODE_STRING path_unicode_string; - - // Format the path into an NT path. Arguably this should be done with - // RtlDosPathNameToNtPathName_U, but afaict this is equivalent for - // local paths. Using this with a UNC path name will almost certainly - // break in interesting ways. - base::string16 filename_string(L"\\??\\"); - filename_string += file_name; - - init_unicode_string(&path_unicode_string, filename_string.c_str()); - - OBJECT_ATTRIBUTES path_attributes = {}; - InitializeObjectAttributes(&path_attributes, - &path_unicode_string, - OBJ_CASE_INSENSITIVE, - NULL, // No Root Directory - NULL); // No Security Descriptor - - // Set create_options, desired_access, and flags_and_attributes to match those - // set by kernel32!CreateFile. - ULONG create_options = FILE_ATTRIBUTE_DEVICE | FILE_ATTRIBUTE_ARCHIVE; - desired_access |= 0x100080; - flags_and_attributes &= 0x2FFA7; - - result = create_file(&file_handle, - desired_access, - &path_attributes, - &io_status_block, - 0, // Allocation size - flags_and_attributes, - share_mode, - creation_disposition, - create_options, - NULL, - 0); - - if (result != STATUS_SUCCESS) { - if (result == STATUS_OBJECT_NAME_COLLISION && - creation_disposition == FILE_CREATE) { - SetLastError(ERROR_FILE_EXISTS); - } - return INVALID_HANDLE_VALUE; - } - - if (creation_disposition == FILE_OPEN_IF) { - SetLastError(io_status_block.Information == FILE_OPENED ? - ERROR_ALREADY_EXISTS : ERROR_SUCCESS); - } else if (creation_disposition == FILE_OVERWRITE_IF) { - SetLastError(io_status_block.Information == FILE_OVERWRITTEN ? - ERROR_ALREADY_EXISTS : ERROR_SUCCESS); - } else { - SetLastError(ERROR_SUCCESS); - } - - return file_handle; -} - -bool ShouldBypass(LPCWSTR file_name) { - // If the shell functions are not present, forward the call to kernel32. - if (!PopulateShellFunctions()) - return false; - - // Forward all UNC filepaths to kernel32. - if (g_path_is_unc_func(file_name)) - return false; - - wchar_t local_appdata_path[MAX_PATH]; - - // Get the %LOCALAPPDATA% Path and append the location of our UserData - // directory to it. - HRESULT appdata_result = g_get_folder_func( - NULL, CSIDL_LOCAL_APPDATA, NULL, 0, local_appdata_path); - - // If getting the %LOCALAPPDATA% path or appending to it failed, then forward - // the call to kernel32. - if (!SUCCEEDED(appdata_result) || - !g_path_append_func(local_appdata_path, kAppDataDirName) || - !g_path_append_func(local_appdata_path, kUserDataDirName)) { - return false; - } - - // Check if we are trying to access something in the UserData dir. If so, - // then redirect the call to bypass kernel32. - return !!g_path_is_prefix_func(local_appdata_path, file_name); -} |