#include <windows.h>

#ifndef MAXNAME
#define MAXNAME 12
#endif

#ifndef MAXSERIAL
#define MAXSERIAL 12
#endif

int KeyGen(LPCTSTR cszName, LPTSTR szSerial);

LRESULT CALLBACK MainWnd(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
	switch(uMsg)
	{
	case WM_CREATE:
		CreateWindow(TEXT("STATIC"), TEXT("Name:"), WS_CHILD | WS_VISIBLE, 10, 10, 100, 20, hWnd, (HMENU)-1, NULL, NULL);
		CreateWindow(TEXT("EDIT"), NULL, WS_CHILD | WS_VISIBLE | WS_BORDER | ES_AUTOHSCROLL, 120, 10, 100, 20, hWnd, (HMENU)101, NULL, NULL);
		CreateWindow(TEXT("STATIC"), TEXT("Serial:"), WS_CHILD | WS_VISIBLE, 10, 40, 100, 20, hWnd, (HMENU)-1, NULL, NULL);
		CreateWindow(TEXT("EDIT"), NULL, WS_CHILD | WS_VISIBLE | WS_BORDER | ES_READONLY | ES_AUTOHSCROLL, 120, 40, 100, 20, hWnd, (HMENU)102, NULL, NULL);
		CreateWindow(TEXT("BUTTON"), TEXT("Get"), WS_CHILD | WS_VISIBLE, 20, 70, 80, 20, hWnd, (HMENU)IDOK, NULL, NULL);
		CreateWindow(TEXT("BUTTON"), TEXT("Exit"), WS_CHILD | WS_VISIBLE, 130, 70, 80, 20, hWnd, (HMENU)IDCANCEL, NULL, NULL);
		SetFocus(GetDlgItem(hWnd, 101));
		break;
	case WM_COMMAND:
		switch(wParam)
		{
		case IDOK:
			{
				TCHAR name[MAXNAME];
				TCHAR serial[MAXSERIAL] = {0, };
				GetDlgItemText(hWnd, 101, name, MAXNAME);
				if(!KeyGen(name, serial))
				{
					MessageBox(hWnd, TEXT("Cannot generate serial!"), NULL, MB_ICONERROR + MB_OK);
				}
				else
				{
					SetDlgItemText(hWnd, 102, serial);
				}
			}
			break;
		case IDCANCEL:
			SendMessage(hWnd, WM_CLOSE, 0, 0);
			break;
		}
		break;
	case WM_DESTROY:
		PostQuitMessage(0);
		break;
	}
	return DefWindowProc(hWnd, uMsg, wParam, lParam);
}

INT WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR szCmdLine, int nCmdShow)
{
	WNDCLASS wndclass;
	HWND hWnd;
	MSG msg;

	ZeroMemory(&wndclass, sizeof(wndclass));
	wndclass.style = CS_VREDRAW | CS_HREDRAW;
	wndclass.lpfnWndProc = MainWnd;
	wndclass.hInstance = hInstance;
	wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
	wndclass.hbrBackground = CreateSolidBrush(GetSysColor(COLOR_3DFACE));
	wndclass.lpszClassName = TEXT("KEYGEN");

	RegisterClass(&wndclass);

	hWnd = CreateWindow(TEXT("KEYGEN"), TEXT("Keygen"), WS_POPUP | WS_CAPTION | WS_VISIBLE, CW_USEDEFAULT, CW_USEDEFAULT, 250, 150, NULL, NULL, hInstance, NULL);
	UpdateWindow(hWnd);

	while(GetMessage(&msg, NULL, 0, 0))
	{
		TranslateMessage(&msg);
		DispatchMessage(&msg);
	}

	DeleteObject(wndclass.hbrBackground);

	return (int)msg.wParam;
}

#include <windows.h>

#ifndef UNICODE
#error This keygen must be Unicode program
#endif

#ifndef MAXSERIAL
#define MAXSEIRAL 17
#endif

int KeyGen(LPCWSTR cszName, LPWSTR szSerial)
{
	int i;
	unsigned char name[3];
	unsigned short tmp[5];
	if(wcslen(cszName) < 4) return 0;
	for(i = 0; i < 4; i++)
	{
		name[1] = name[2] = 0;
		WideCharToMultiByte(CP_ACP, 0, &cszName[i], 1, (LPSTR)name, 3, NULL, NULL);
		if(name[1] != 0)
		{
			name[2] = name[0]; name[0] = name[1]; name[1] = name[2]; name[2] = 0;
		}
		wsprintf(tmp, TEXT("%02X"), *((unsigned short *)name) + 0x64);
		wcscat_s(szSerial, MAXSERIAL, tmp);
	}
	return 1;
}