| // Copyright (c) 2011 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 "sandbox/win/src/window.h" |
| |
| #include <aclapi.h> |
| |
| #include "base/logging.h" |
| #include "base/memory/scoped_ptr.h" |
| |
| namespace { |
| |
| // Gets the security attributes of a window object referenced by |handle|. The |
| // lpSecurityDescriptor member of the SECURITY_ATTRIBUTES parameter returned |
| // must be freed using LocalFree by the caller. |
| bool GetSecurityAttributes(HANDLE handle, SECURITY_ATTRIBUTES* attributes) { |
| attributes->bInheritHandle = FALSE; |
| attributes->nLength = sizeof(SECURITY_ATTRIBUTES); |
| |
| PACL dacl = NULL; |
| DWORD result = ::GetSecurityInfo(handle, SE_WINDOW_OBJECT, |
| DACL_SECURITY_INFORMATION, NULL, NULL, &dacl, |
| NULL, &attributes->lpSecurityDescriptor); |
| if (ERROR_SUCCESS == result) |
| return true; |
| |
| return false; |
| } |
| |
| } |
| |
| namespace sandbox { |
| |
| ResultCode CreateAltWindowStation(HWINSTA* winsta) { |
| // Get the security attributes from the current window station; we will |
| // use this as the base security attributes for the new window station. |
| SECURITY_ATTRIBUTES attributes = {0}; |
| if (!GetSecurityAttributes(::GetProcessWindowStation(), &attributes)) { |
| return SBOX_ERROR_CANNOT_CREATE_WINSTATION; |
| } |
| |
| // Create the window station using NULL for the name to ask the os to |
| // generate it. |
| // TODO(nsylvain): don't ask for WINSTA_ALL_ACCESS if we don't need to. |
| *winsta = ::CreateWindowStationW(NULL, 0, WINSTA_ALL_ACCESS, &attributes); |
| LocalFree(attributes.lpSecurityDescriptor); |
| |
| if (*winsta) |
| return SBOX_ALL_OK; |
| |
| return SBOX_ERROR_CANNOT_CREATE_WINSTATION; |
| } |
| |
| ResultCode CreateAltDesktop(HWINSTA winsta, HDESK* desktop) { |
| base::string16 desktop_name = L"sbox_alternate_desktop_"; |
| |
| // Append the current PID to the desktop name. |
| wchar_t buffer[16]; |
| _snwprintf_s(buffer, sizeof(buffer) / sizeof(wchar_t), L"0x%X", |
| ::GetCurrentProcessId()); |
| desktop_name += buffer; |
| |
| // Get the security attributes from the current desktop, we will use this as |
| // the base security attributes for the new desktop. |
| SECURITY_ATTRIBUTES attributes = {0}; |
| if (!GetSecurityAttributes(GetThreadDesktop(GetCurrentThreadId()), |
| &attributes)) { |
| return SBOX_ERROR_CANNOT_CREATE_DESKTOP; |
| } |
| |
| // Back up the current window station, in case we need to switch it. |
| HWINSTA current_winsta = ::GetProcessWindowStation(); |
| |
| if (winsta) { |
| // We need to switch to the alternate window station before creating the |
| // desktop. |
| if (!::SetProcessWindowStation(winsta)) { |
| ::LocalFree(attributes.lpSecurityDescriptor); |
| return SBOX_ERROR_CANNOT_CREATE_DESKTOP; |
| } |
| } |
| |
| // Create the destkop. |
| // TODO(nsylvain): don't ask for GENERIC_ALL if we don't need to. |
| *desktop = ::CreateDesktop(desktop_name.c_str(), NULL, NULL, 0, GENERIC_ALL, |
| &attributes); |
| ::LocalFree(attributes.lpSecurityDescriptor); |
| |
| if (winsta) { |
| // Revert to the right window station. |
| if (!::SetProcessWindowStation(current_winsta)) { |
| return SBOX_ERROR_FAILED_TO_SWITCH_BACK_WINSTATION; |
| } |
| } |
| |
| if (*desktop) |
| return SBOX_ALL_OK; |
| |
| return SBOX_ERROR_CANNOT_CREATE_DESKTOP; |
| } |
| |
| base::string16 GetWindowObjectName(HANDLE handle) { |
| // Get the size of the name. |
| DWORD size = 0; |
| ::GetUserObjectInformation(handle, UOI_NAME, NULL, 0, &size); |
| |
| if (!size) { |
| NOTREACHED(); |
| return base::string16(); |
| } |
| |
| // Create the buffer that will hold the name. |
| scoped_ptr<wchar_t[]> name_buffer(new wchar_t[size]); |
| |
| // Query the name of the object. |
| if (!::GetUserObjectInformation(handle, UOI_NAME, name_buffer.get(), size, |
| &size)) { |
| NOTREACHED(); |
| return base::string16(); |
| } |
| |
| return base::string16(name_buffer.get()); |
| } |
| |
| base::string16 GetFullDesktopName(HWINSTA winsta, HDESK desktop) { |
| if (!desktop) { |
| NOTREACHED(); |
| return base::string16(); |
| } |
| |
| base::string16 name; |
| if (winsta) { |
| name = GetWindowObjectName(winsta); |
| name += L'\\'; |
| } |
| |
| name += GetWindowObjectName(desktop); |
| return name; |
| } |
| |
| } // namespace sandbox |