[Keat]

I am trying to use CreateProcessW() to run cmd.exe and run commands. I am then trying to get unicode back so I can support all languages.

I have working code that does what I need it to. The issue I am running into is only built in command prompt commands will output unicode with the "/u" argument given.

Code

WCHAR works[] = L"cmd.exe /u /c dir C:\\windows";
WCHAR dont[] = L"cmd.exe /u /c ipconfig";

BOOL fSuccess = CreateProcessW(NULL, dont, NULL, NULL, TRUE, CREATE_NEW_CONSOLE, NULL, NULL, &si, &pi);

Works - will give me back unicode.
don't - will not give me unicode

I have taken a picture of the bytes it returns back to me.


This is "works". It shows that I am getting unicode back.
https://i.imgur.com/KQepszB.png


This is "dont. Showing it only gives me ANSI.
https://i.imgur.com/YKpSqru.png

Does anyone know of a better way to go about what I am trying to accomplish. I am basically going to end up building a pseudo remote shell. I want the user to be able to send commands and get the output, but support on non English computers as well.




Full test code that is handling this:

Code

#include <Windows.h>

void main() {
    HANDLE hPipeRead, hPipeWrite;

    SECURITY_ATTRIBUTES saAttr = { sizeof(SECURITY_ATTRIBUTES) };
    saAttr.bInheritHandle = TRUE;
    saAttr.lpSecurityDescriptor = NULL;

    if (!CreatePipe(&hPipeRead, &hPipeWrite, &saAttr, 0))
        return;

    STARTUPINFO si = { sizeof(STARTUPINFO) };
    si.dwFlags = STARTF_USESHOWWINDOW | STARTF_USESTDHANDLES;
    si.hStdOutput = hPipeWrite;
    si.hStdError = hPipeWrite;
    si.wShowWindow = SW_HIDE;

    PROCESS_INFORMATION pi = { 0 };

    WCHAR works[] = L"cmd.exe /u /c dir C:\\windows";
    WCHAR dont[] = L"cmd.exe /u /c ipconfig";

    BOOL fSuccess = CreateProcessW(NULL, dont, NULL, NULL, TRUE, CREATE_NEW_CONSOLE, NULL, NULL, &si, &pi);
    if (!fSuccess) {
        CloseHandle(hPipeWrite);
        CloseHandle(hPipeRead);
        return;
    }

    BOOL bProcessEnded = FALSE;
    for (; !bProcessEnded;) {

        bProcessEnded = WaitForSingleObject(pi.hProcess, 50) == WAIT_OBJECT_0;

        while (TRUE) {
            CHAR *buf = NULL;
            DWORD dwRead = 0;
            DWORD dwAvail = 0;

            if (!PeekNamedPipe(hPipeRead, NULL, 0, NULL, &dwAvail, NULL))
                break;

            if (!dwAvail)
                break;
            buf = HeapAlloc(GetProcessHeap(), 0, dwAvail);
            if (buf == NULL) {
                return;
            }

            if (!ReadFile(hPipeRead, buf, dwAvail, &dwRead, NULL) || !dwRead)
                break;


        }
    }

    CloseHandle(hPipeWrite);
    CloseHandle(hPipeRead);
    CloseHandle(pi.hProcess);
    CloseHandle(pi.hThread);
    return;
}

[0xDEAD10CC]

First, why are you using void main()???

Here's what the help says about the /U flag:

Code

/U      Causes the output of internal commands to a pipe or file to be
        Unicode

You're also using File I/O rather than Console I/O API's to deal with the data. This is a point of failure. Read what Python does: https://www.python.org/dev/peps/pep-0528/

And programs like ConEmu (which is what I use) tend to do a lot more with intercepting such calls, but they also implement this properly.

You'll see notes about ReadConsoleW/WriteConsoleW. The flag only works really on internal programs because you can tell the program to format it in such a way while you can't really do the same for external programs. There's lots of information on tricks people have used though.

[Keat]

First, why are you using void main()???

Here's what the help says about the /U flag:

Code

/U      Causes the output of internal commands to a pipe or file to be
       Unicode

You're also using File I/O rather than Console I/O API's to deal with the data. This is a point of failure. Read what Python does: https://www.python.org/dev/peps/pep-0528/

And programs like ConEmu (which is what I use) tend to do a lot more with intercepting such calls, but they also implement this properly.

You'll see notes about ReadConsoleW/WriteConsoleW. The flag only works really on internal programs because you can tell the program to format it in such a way while you can't really do the same for external programs. There's lots of information on tricks people have used though.

I am using void main() because this was originally in another function but I just renamed it to main to just test. This isn't actual full code.

And I am trying to do this without ConEmu or any external stuff.

[0xDEAD10CC]

I am using void main() because this was originally in another function but I just renamed it to main to just test. This isn't actual full code.

And I am trying to do this without ConEmu or any external stuff.

You didn't understand what I was saying about using ConEmu though. You could use ComEmu as a resource to understand how some of these things can be done.