Win32API實現的第一個CrackMe

程序界面

已實現功能
整個窗口居中顯示，灰化最大化按鈕，空白處添加了消息回調，最後就是獲取輸入運算後判斷是否和預期相同，從而決定彈窗內容！這就是一般的 CrackMe 的套路

完整源碼

#include <windows.h>
#include <string.h>

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam);
BOOL Check(char *Name, char *Flag);
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR lpCmdLine, int nCmdShow)
{
    char *lpClassName = "FirstWin", *lpWindowName = "CrackMe0";
    HWND hwnd;
    MSG msg;
    WNDCLASSEX wndclass;

    wndclass.cbSize = sizeof(wndclass);       // 指定該結構體的大小
    wndclass.style = CS_HREDRAW | CS_VREDRAW; // 寬度高度變化時重繪
    wndclass.lpfnWndProc = WndProc;           // 窗口回調函數
    wndclass.cbClsExtra = 0;
    wndclass.cbWndExtra = 0;
    wndclass.hInstance = hInstance;
    wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);    // NULL表示系統圖標，默認圖標
    wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);      // 默認光標
    wndclass.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1); // 使用畫刷填充背景色，還可以(HBRUSH)GetStockObject(BLACK_BRUSH)
    wndclass.lpszMenuName = NULL;
    wndclass.lpszClassName = lpClassName;
    wndclass.hIconSm = NULL;

    if (!RegisterClassEx(&wndclass))
    {
        MessageBox(NULL, "Register Failed", "Tips", MB_ICONERROR);
        return 0;
    }

    hwnd = CreateWindow(lpClassName,
                        lpWindowName,
                        WS_OVERLAPPED | WS_CAPTION | WS_SYSMENU | WS_MINIMIZEBOX, //style，WS_OVERLAPPEDWINDOW包括了最大化最小化以及關閉
                        0,                                                        // x
                        0,                                                        // y
                        400,                                                      // width
                        300,                                                      // height
                        NULL,                                                     // hWndParent
                        NULL,                                                     // hMenu
                        hInstance,                                                // hInstance
                        NULL);
    ShowWindow(hwnd, nCmdShow);
    UpdateWindow(hwnd); /* 發送 WM_PAINT，保證窗口一定可以刷新顯示 */

    while (GetMessage(&msg, NULL, 0, 0))
    {
        /* 用於Tab切換輸入框，IsDialogMessage會調用user32.dll處理某些按鍵消息，其餘的交給我們定義的窗口回調函數*/
        if (!IsDialogMessage(hwnd, &msg))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }
    return msg.wParam;
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    HDC hdc;
    int screenWidth, screenHeight;
    int clientWidth, clientHeight;
    int id, event;
    PAINTSTRUCT ps;
    CHAR Name[32], Flag[32];
    RECT rect;
    RECT crect;

    switch (message)
    {
    case WM_CREATE:
        /* 設置居中顯示主窗口 */
        screenWidth = GetSystemMetrics(SM_CXSCREEN);
        screenHeight = GetSystemMetrics(SM_CYSCREEN);
        GetClientRect(hwnd, &crect);
        GetWindowRect(hwnd, &rect); // 區別於GetClientRect
        rect.left = (screenWidth - rect.right) / 2;
        rect.top = (screenHeight - rect.bottom) / 2;
        SetWindowPos(hwnd, HWND_TOP, rect.left, rect.top, rect.right, rect.bottom, SWP_SHOWWINDOW);
        /* MoveWindow(hwnd, rect.left, rect.top, rect.right, rect.bottom, 1); 效果同上 */
        CreateWindow("static",
                     "Name:",
                     WS_CHILD | WS_VISIBLE | SS_CENTERIMAGE | SS_RIGHT,
                     crect.right / 12, // 用比例保證兼容性
                     crect.bottom / 5,
                     90,
                     40,
                     hwnd,
                     (HMENU)1,
                     (HINSTANCE)GetWindowLong(hwnd, -6), // # define GWL_HINSTANCE -6
                     NULL);
        CreateWindow("static",
                     "Flag:",
                     WS_CHILD | WS_VISIBLE | SS_CENTERIMAGE | SS_RIGHT,
                     crect.right / 12,
                     crect.bottom * 2 / 5,
                     90,
                     40,
                     hwnd,
                     (HMENU)2,
                     (HINSTANCE)GetWindowLong(hwnd, -6),
                     NULL);
        CreateWindow("edit",
                     "",
                     WS_CHILD | WS_VISIBLE | WS_BORDER | WS_TABSTOP | ES_AUTOHSCROLL,
                     crect.right / 3,
                     crect.bottom / 5,
                     200,
                     35,
                     hwnd,
                     (HMENU)3,
                     (HINSTANCE)GetWindowLong(hwnd, -6),
                     NULL);
        CreateWindow("edit",
                     "",
                     WS_CHILD | WS_VISIBLE | WS_BORDER | WS_TABSTOP | ES_AUTOHSCROLL,
                     crect.right / 3,
                     crect.bottom * 2 / 5,
                     200,
                     35,
                     hwnd,
                     (HMENU)4,
                     (HINSTANCE)GetWindowLong(hwnd, -6),
                     NULL);
        CreateWindow("button",
                     "Submit",
                     WS_CHILD | WS_VISIBLE | WS_BORDER | BS_FLAT,
                     crect.right * 2 / 5,
                     crect.bottom * 16 / 25,
                     100,
                     35,
                     hwnd,
                     (HMENU)5,
                     (HINSTANCE)GetWindowLong(hwnd, -6),
                     NULL);
        break;
    case WM_CTLCOLORSTATIC:
        if ((HWND)lParam == GetDlgItem(hwnd, 1) || (HWND)lParam == GetDlgItem(hwnd, 2))
        {
            SetTextColor((HDC)wParam, RGB(0, 0, 0));
            SetBkMode((HDC)wParam, TRANSPARENT);
        }
        return (BOOL)(HBRUSH)GetStockObject(NULL_BRUSH);
        break;
    case WM_PAINT:
        hdc = BeginPaint(hwnd, &ps);
        EndPaint(hwnd, &ps);
        break;
    case WM_LBUTTONDOWN:
        MessageBox(hwnd, "Don't click here!", "Error", MB_OK);
        break;
    case WM_COMMAND:
        /* 當點擊菜單、按鈕、下拉列表框等控件時候,會觸發WM_COMMAND */
        id = LOWORD(wParam);
        event = HIWORD(wParam);
        switch (id)
        {
        case 5:
            GetWindowText(GetDlgItem(hwnd, 3), Name, 32);
            GetWindowText(GetDlgItem(hwnd, 4), Flag, 32);
            if (*Name != 0 && *Flag != 0) // 字符判斷時要加*，還可以用長度判斷是否爲空字符串；空字符串或者字符串結束就是內存中的00
            {
                if (Check(Name, Flag)) // 字符串判斷要用strcmp；格式化輸出的%s是個特例需要傳地址
                {
                    MessageBox(hwnd, "Hi,admin!Your flag is right!", "Right", MB_OK);
                    DestroyWindow(hwnd);
                }
                else
                {
                    MessageBox(hwnd, "Your name or flag is wrong!", "Wrong", MB_OK);
                    DestroyWindow(hwnd);
                }
            }
            else
            {
                MessageBox(hwnd, "Please input your name and flag!", "Tips", MB_OK);
            }
            break;
        default:
            return DefWindowProc(hwnd, message, wParam, lParam);
        }
        break;
    case WM_CLOSE:
        DestroyWindow(hwnd);
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    }
    return DefWindowProc(hwnd, message, wParam, lParam);
}

BOOL Check(char *Name, char *Flag)
{
    int i, len;
    char x;
    char *key = "You_are_a_pig!2333";
    char flag_enc[] = {0x3f, 0x03, 0x14, 0x38, 0x1a, 0x26, 0x0d, 0x36, 0x54, 0x00, 0x41, 0x1a, 0x38, 0x47, 0x5e, 0x52, 0x0a, 0x4e};
    if (!strcmp(Name, "admin") && strlen(Flag) == 18)
    {
        for (i = 0; i < len; i++)
        {
            x = Flag[i] ^ key[i];
            if (x != flag_enc[i])
            {
                return 0;
            }
            else
            {
                continue;
            }
        }
    }
    else
    {
        return 0;
    }
    return 1;
}

很簡單的 CrackMe，主要是爲了學習 Windows 消息機制，程序調用gcc -m32 -mwindows編譯的

END