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hotkey hooking

 
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Hi guys.
I want to write a keylogger which logs all strings I copy via <CTRL>+<C>
My problem is that I loose track of interessting links or code-snippets when overdoing it.

So I want a basic keylogger which notices every hotkey event and copies the content in the clipboard into a file.
The problem is that the clipboard doens't copy a string as I block the hotkey with my keyhook.
That means that the last copied string stays in the clipboard and as long as my programm runs I can't save new content with the hot key, as the event will not be passed to windows.
I have to pass the event to windows but I don't know how.

Here's the code, thanks for advice.

#include <windows.h>
#include <fstream>
#include <iostream>
/*  Declare Windows procedure  */
LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM);

#define MY_HOTKEYID     100

/*  Make the class name into a global variable  */
char szClassName[ ] = "kl";

char* GetClipBoard(void)
{
    HANDLE clip;
    if (OpenClipboard(NULL))
        clip = GetClipboardData(CF_TEXT);

    return (char*)clip;
}

HANDLE SetClipboard(std::string cpy)
{
    const char* output = cpy.c_str();

    const size_t len = strlen(output) + 1;
    HGLOBAL hMem =  GlobalAlloc(GMEM_MOVEABLE, len);
    memcpy(GlobalLock(hMem), output, len);
    GlobalUnlock(hMem);
    OpenClipboard(0);
    EmptyClipboard();
    SetClipboardData(CF_TEXT, hMem);
    CloseClipboard();

    return 0;

}

int WINAPI WinMain (HINSTANCE hThisInstance,
                     HINSTANCE hPrevInstance,
                     LPSTR lpszArgument,
                     int nCmdShow)
{

    HWND hwnd;               /* This is the handle for our window */
    MSG messages;            /* Here messages to the application are saved */
    WNDCLASSEX wincl;        /* Data structure for the windowclass */

    /* The Window structure */
    wincl.hInstance = hThisInstance;
    wincl.lpszClassName = szClassName;
    wincl.lpfnWndProc = WindowProcedure;      /* This function is called by windows */
    wincl.style = CS_DBLCLKS;                 /* Catch double-clicks */
    wincl.cbSize = sizeof (WNDCLASSEX);

    /* Use default icon and mouse-pointer */
    wincl.hIcon = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hCursor = LoadCursor (NULL, IDC_ARROW);
    wincl.lpszMenuName = NULL;                 /* No menu */
    wincl.cbClsExtra = 0;                      /* No extra bytes after the window class */
    wincl.cbWndExtra = 0;                      /* structure or the window instance */
    /* Use Windows's default colour as the background of the window */
    wincl.hbrBackground = (HBRUSH) COLOR_BACKGROUND;

    /* Register the window class, and if it fails quit the program */
    if (!RegisterClassEx (&wincl))
        return 0;

    /* The class is registered, let's create the program*/
    hwnd = CreateWindowEx (
           0,                   /* Extended possibilites for variation */
           szClassName,         /* Classname */
           "kl",       /* Title Text */
           WS_OVERLAPPEDWINDOW, /* default window */
           CW_USEDEFAULT,       /* Windows decides the position */
           CW_USEDEFAULT,       /* where the window ends up on the screen */
           544,                 /* The programs width */
           375,                 /* and height in pixels */
           HWND_DESKTOP,        /* The window is a child-window to desktop */
           NULL,                /* No menu */
           hThisInstance,       /* Program Instance handler */
           NULL                 /* No Window Creation data */
           );

    /* Make the window visible on the screen */
    //  ShowWindow (hwnd, nCmdShow);
    RegisterHotKey(hwnd,MY_HOTKEYID,MOD_CONTROL,0x44);
    /* Run the message loop. It will run until GetMessage() returns 0 */
    while (GetMessage (&messages, NULL, 0, 0))
    {
        /* Translate virtual-key messages into character messages */
        TranslateMessage(&messages);
        /* Send message to WindowProcedure */
        DispatchMessage(&messages);
    }

    UnregisterHotKey(hwnd,MY_HOTKEYID);

    /* The program return-value is 0 - The value that PostQuitMessage() gave */
    return messages.wParam;
}


/*  This function is called by the Windows function DispatchMessage()  */

LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)                  /* handle the messages */
    {
        case WM_DESTROY:
            PostQuitMessage (0);       /* send a WM_QUIT to the message queue */
            break;
        case WM_HOTKEY :
            {
                // Nope. Windows doesn't recieved any <Ctrl><c> hotkey, hence there is no new stuff in the clipboard
                // How to pass the event to windows then, before checking the clipboard again ?
                std::string help = GetClipBoard();

                std::cout << "Clip : " << help;

                if (help.size() < 100)
                {
                    std::ofstream tempfile("Records.txt", std::ios::app);

                    SYSTEMTIME time;
                    GetLocalTime(&time);

                    tempfile << "<" << help << ">";
                    tempfile << "Logging at " << time.wHour << ":" << time.wMinute << ":" << time.wSecond <<  " on " << time.wDay << "." << time.wMonth << "." <<  time.wYear << " (DD.MM.YYYY)\n\n";

                    tempfile.close();
                }
            }

        default:                      /* for messages that we don't deal with */
            return DefWindowProc (0, message, wParam, lParam);
    }

    return 0;
}
 
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Instead of hooking keystrokes why not use the clipboard api to get notifications when the clipboard changes? (clipboard)

 
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because that could be triggered by others application which modify the clipboard.
i cannot help you OP, sorry

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