Windows 10 Compatibility for Windows XP/2003 (WIP)

Update 2020/12/05: it seems that the Universal CRT libraries are not loading in Windows XP - working on getting that to work now

Purpose

This project is about adding Win32/WinAPI functions to the Windows XP SP1/2003 codebase that are only available in newer versions of Windows. By adding these functions using applications under Windows XP/2003 - that are only working under Windows 2003R2/Vista/2008/2008R2/7/8/8.1/2016/10/10H2/2019 - will become a reality.

The functions have to be added to the C-sources of several system libraries (DLL's typically available in the c:\windows\system32 folder), build into binary form (compiling/linking), and replaced with the standard ones to be available to applications.

Since the source code has become available this can be done, see Windows Server 2003 (NT 5.2.3790.0) build guide

However as the source for these missing functions is not publicly available, the best available source is the source code of the Wine project project (link to source of DLL's) or approximations of code that has been reverse-engineered with tools like Ghidra/IDA.

Documentation on them can be found on Microsoft's site at https://docs.microsoft.com/en-us/windows/win32/api/ like:

• the correct function signature, which usually differs in Wine's code
• a proper description of the input and output parameters
• purpose of the function
• sometimes a C-code usage example
• minimal supported version of Windows
• what C-header file (*.h) of the Windows 10 SDK (link to headers) defines the function declaration and (possible) custom datatypes

e.g. documentation for GetDpiForWindow

The latest status can be seen in the tables below.

This is not intended to be a secure implementation for now, it just intended to provide compatibility. Some functions are being tested now, as Python 3.9 and other applications do crash when starting, using a small program (WIP) calling the function with an input value, see TestHarness.

New C-source files that are implementing functions start with an _. Missing functions in applications can be found out by loading the executable into Dependency Walker.

Needs help as they are many functions to be back-ported!

Current major issue - Universal CRT

A message box shows an unfriendly 0xC0000142 NT status to the user (STATUS_DLL_INIT_FAILED).:
Further analysis in WinDbg for pythonw.exe 3.9 revealed:
LDR: LdrpInitializeProcess - Failed running initialization routines; status c0000142
and
[6a8,6b4] LDR: DLL_PROCESS_ATTACH for dll "downlevel\ucrtbase.dll" (InitRoutine: 0050B170) failed
This ucrtbase.dll is included in the ApiSet/downlevel package below and might require a fix...
This paper from 1999 goes deeper into how to debug these errors: https://manualzz.com/doc/19760582/loading-exe-and-dll-programs-matt-pietrek
Trying to load ucrtbase.dll using LoadLibary using the test program:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16

#include <stdio.h>

#define NOMINMAX
#include <Windows.h>

VOID
__cdecl main(USHORT argc, PCHAR *argv)
{
    HMODULE ucrtbase=LoadLibrary("ucrtbase.dll");
    if (!ucrtbase) {
        printf("ucrtbase.dll failed to load: %d\n", GetLastError());
    } else {
        printf("ucrtbase.dll loaded successfully\n");
    }
    return;
}

results in
ucrtbase.dll failed to load: 1114
1114 is ERROR_DLL_INIT_FAILED A dynamic link library (DLL) initialization routine failed.
On Windows 10, this program loads fine, so possibly due to installation of other components, changes to kernel, currently missing in Windows XP it does not load.
The UCRTBASE.DLL is part of Universal CRT, see https://docs.microsoft.com/en-us/cpp/windows/universal-crt-deployment?view=msvc-160
Here are more links.. http://www.geoffchappell.com/studies/windows/win32/apisetschema/index.htm?tx=3 https://ofekshilon.com/2016/03/27/on-api-ms-win-xxxxx-dll-and-other-dependency-walker-glitches/
After reading these it seems as if

• it is necessary to create a new UCRTBASE.DLL, as it seems to require things only available in the Windows 10 kernel - regarding loading of functions/ApiSets, so now building one from scratch with a few implemented is an idea
• there is a check in place looking for a 'valid' Windows version and then stopping the execution, that needs to be overridden

(Original reference to error found here: https://github.com/mtth-bfft/win32k-mitigation)

(Not yet) compatible applications

Currently trying to get following software to work.

Requirements

1. A x86 version of Windows 2003 / XP SP1 with source code available: see build-win2k3
2. Disable Windows File Protection when DLL's replacing after installation, see https://www.technipages.com/enable-disable-wfp
3. Ability to execute executables built for newer versions than Windows XP SP2 / Windows Server 2003 RTM (NT 5.2): https://rentry.co/kernel32-version-unlock
4. The changes in place in either source code and then installing the build or replacing the DLL's after installation
5. WinDbg/OllyDb/etc to debug

Missing functions in Windows XP/2003 - implemented

Existing functions in Windows XP/2003 - patched

Missing DLL's - ApiSets/downlevel

To get the above software to work some Windows 10 DLL's have to be copied, as these apps need it (except Hello World and Write.exe); the ones that do live in c:\windows\system32\downlevel (on 32-bit Windows version)

These are socalled ApiSets, see https://docs.microsoft.com/en-us/windows/win32/apiindex/windows-apisets

First this directory must be added to Windows XP/2003, then the path where they are stored needs to be added Windows XP's PATH environment variable. These are slightly patched, to match the import:
e.g. kernel32.dll.VirtualProtect to kernel32.VirtualProtect : see https://rentry.co/extras-downlevel

Other topics