go1.21-over-win7

Make golang 1.21 or later run in Windows 7!

• This repository seeks to run golang 1.21 or later on Windows 7(which was dropped its support in golang 1.21), in a need of using golang compiled programs in Windows 7(in production environments).

Tested using go1.23.2 with test cases in src/cmd/internal/testdir in official golang repository.

How does it work?

The following two commits result in the panic in the image above.

• https://github.com/golang/go/commit/a17d959debdb04cd550016a3501dd09d50cd62e7

  This breaks in Windows 7 as an specific update(KB2533623) is required for LOAD_LIBRARY_SEARCH_SYSTEM32(0x800) flag to work.

• https://github.com/golang/go/commit/693def151adff1af707d82d28f55dba81ceb08e1

  This breaks as ProcessPrng function does not exist in BCryptPrimitives.dll(the dll itself exists in Windows 7).

To handle these, Microsoft Detours project(imported as submodule) is used to create DLL for hooking procedures that causes the panic.

1. Just remove the LOAD_LIBRARY_SEARCH_SYSTEM32 flag from LoadLibraryEx call.
2. Use BCryptGenRandom like this in a following format to replace ProcessPrng(this may not ideal as BCryptGenRandom can return error unlike ProcessPrng).

(void)BCryptGenRandom(NULL, (PUCHAR)pbData, (ULONG)cbData, BCRYPT_USE_SYSTEM_PREFERRED_RNG);

Requirements to build

• Visual Studio 2017 or later
• Windows SDK

How to build DLL

• After installing Visual Studio, open native tools command prompt for vs [your version] or x64 native tools command prompt for vs [your version] from start menu according to the architecture that you want to build dll.
• If haven't built Detours library before, run nmake in the opened command prompt after navigating into Detours/src directory. This should be done separately for x86 and x64 version in each command prompt to get the dll for each architecutre.
• Navigate into go121pluswin7 directory and then run

cl /LD /nologo /Zi /MT /Gm- /W4 /WX /we4777 /we4800 /Od /DDETOUR_DEBUG=0  /I ..\Detours\include\ /Fego121pluswin7.dll go121pluswin7.cpp  /link /release /incremental:no  /nodefaultlib:oldnames.lib /export:DetourFinishHelperProcess,@1,NONAME /export:HookedCreateProcessInternal  /export:HookedLoadLibraryEx  /export:HookedGetProcAddress ..\Detours\lib.X86\detours.lib kernel32.lib bcrypt.lib

for x86 architecture and

cl /LD /nologo /Zi /MT /Gm- /W4 /WX /we4777 /we4800 /Od /DDETOUR_DEBUG=0  /I ..\Detours\include\ /Fego121pluswin7_64.dll go121pluswin7.cpp  /link /release /incremental:no  /nodefaultlib:oldnames.lib /export:DetourFinishHelperProcess,@1,NONAME  /export:HookedCreateProcessInternal /export:HookedLoadLibraryEx  /export:HookedGetProcAddress ..\Detours\lib.X64\detours.lib kernel32.lib bcrypt.lib

for x64 architecture in a command prompt opened eariler.

• Copy the compiled dll into a path that the program can look for dll(%PATH% or the directory that the program exists).

(Referenced from Makefile in Simple sample from Detours Project)

To inject this dll into a binary you can use setdll.exe from Detours Project after building sample binaries by running nmake in a Detours/samples directory in as mentioned above.

Inject into subprocesses for testing

• To make debugging convenient, this code can be used to build a simple cmd wrapper to inject the produced dll into every subprocesses.

#ifndef _UNICODE
#define _UNICODE
#endif

#include <windows.h>
#include <stdio.h>
#include <stdlib.h>

int wmain()
{
	LoadLibraryW(L"go121pluswin7.dll"); // the path that dll exists

	STARTUPINFO si;
	PROCESS_INFORMATION pi;

	WCHAR cmdline[MAX_PATH] = L"cmd.exe";

	ZeroMemory(&si, sizeof(si));
	ZeroMemory(&pi, sizeof(pi));

	si.cb = sizeof(si);

	if (!CreateProcessW(NULL, cmdline, NULL, NULL, TRUE, CREATE_UNICODE_ENVIRONMENT, NULL, NULL, &si, &pi)) {
		fprintf(stderr, "FAILED: %d\n", GetLastError());
		return 1;
	}

	WaitForSingleObject(pi.hProcess, INFINITE);

	CloseHandle(pi.hProcess);
	CloseHandle(pi.hThread);

	return 0;
}

and build it from Visual studio.

Special thanks

Special thanks to @mrexodia for creating x64dbg project which helped me a lot with investigating the issue and other Windows program debugging!