Connect to weblogin, how to set cookies?

Question

I want to log in onto my works' webpage with WinINet.

int main()
{
    HINTERNET hInet = InternetOpenA("UserAgent/1.0", INTERNET_OPEN_TYPE_PRECONFIG,0, 0, 0 );
    if(!hInet)
    {
        printf("hInet Failed!\n");
        return -1;
    }

    HINTERNET hConnection = InternetConnectA( hInet,"app.tamigo.com",INTERNET_DEFAULT_HTTPS_PORT,"","", INTERNET_SERVICE_HTTP,0,0);
    if (!hConnection)
    {
        InternetCloseHandle(hInet);
        printf("InternetConnectA failed!\n");
        return -1;
    }

    HINTERNET hRequest = HttpOpenRequestA( hConnection, "Accept","text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",NULL,"https://app.tamigo.com/Home/Pages/Login.aspx", NULL, INTERNET_FLAG_KEEP_CONNECTION, 0 );
    if (!hRequest)
    {
        printf("BuildRequestHeader failed %d!\n",GetLastError());
        InternetCloseHandle(hConnection);
        InternetCloseHandle(hInet);
        return -1;
    }

    HttpSendRequestA(hRequest, NULL, 0, NULL, 0);

    DWORD dwInfoLevel = HTTP_QUERY_RAW_HEADERS_CRLF;
    DWORD dwInfoBufferLength = 10;
    BYTE *pInfoBuffer = (BYTE *)malloc(dwInfoBufferLength+1);
    while (!HttpQueryInfo(hRequest, dwInfoLevel, pInfoBuffer, &dwInfoBufferLength, NULL))
    {
        DWORD dwError = GetLastError();
        if (dwError == ERROR_INSUFFICIENT_BUFFER)
        {
            free(pInfoBuffer);
            pInfoBuffer = (BYTE *)malloc(dwInfoBufferLength+1);
        }
        else
        {
            fprintf(stderr, "HttpQueryInfo failed, error = %d (0x%x)\n",
            GetLastError(), GetLastError());
            break;
        }
    }
    pInfoBuffer[dwInfoBufferLength] = '\0';
    printf("%s", pInfoBuffer);
    free(pInfoBuffer);

    cin.get();
    return 1;
}

If this code is right, I have to log in with my username and password, I got a cookie using "Firefox plugin Tamper Data".

How can I set this cookie with WinINet?

Answer 1

If the cookie already exists from a previous WinInet request, then WinInet will send it automatically. However, if the cookie does not exist in WinInet's cookie cache (if instance, if you got the cookie from another source), then you will have to use HttpAddRequestHeaders() to provide your own Cookie: request header before calling HttpSendRequest().

Answer 2

This is based of @vishalb (I think incorrectly) removed answer. Reposting with more detail because that is the correct answer!

If the default cookie behavior is used, you cannot manually set a cookie. Using default behavior you can pass a Cookie header into lpzHeaders in SendRequest() or call HttpAddRequestHeaders() but the manual Cookie header is simply ignored, because by default automatic cookie handling is enabled. Automatic cookie handling uses a cookie cache that captures system and previously captured session cookies and provides them to the current request. AFAIK there's no way to mix automatic cookie handline and add manual cookies.

You can turn off automatic cookie handling by using setting the INTERNET_FLAG_NO_COOKIES flag. If applied you can manually set your own Cookie headers, but at that point no cached cookies are used and any new cookies set are not captured for use in subsequent requests.

IOW, you can have either automatic cookie handling that picks up cookies from the system and your previous requests and passes them forward in the same way a browser does, or you manually set the Cookie headers explicitly. But you can't mix and match the two.