Question

I am having a really hard time with some API calls to the Wininet dll. I am trying to read cookies client side set by IE 9. Here’s the code.

     #include "stdafx.h"
     #include <Windows.h>
    #include <WinInet.h>
    #include <iostream>
    int _tmain(int argc, _TCHAR* argv[])
    {

LPTSTR lpData = NULL;
DWORD dwSz = 500; 
std::cout << "Hello Chris" << std::endl;
lpData = new TCHAR[dwSz];

std::wcout << "Arg 0: " << argv[1] << std::endl;


bool val = InternetGetCookieEx(argv[1], argv[2], lpData, &dwSz,  INTERNET_COOKIE_THIRD_PARTY | INTERNET_FLAG_RESTRICTED_ZONE, NULL);

    if (!val)
    {

        if (GetLastError() == ERROR_INSUFFICIENT_BUFFER)
        {
            std::cout << "Insufficent Buffer size" << std::endl;
            lpData = new TCHAR[dwSz];
            val = InternetGetCookieEx(argv[1], argv[2], lpData, &dwSz, INTERNET_COOKIE_THIRD_PARTY | INTERNET_FLAG_RESTRICTED_ZONE, NULL);
            if (val)
            {
                std::cout << "Cookie Data: " << lpData << std::endl;
            }
            else
            {
                std::cout << "ERROR Code: " << GetLastError() << std::endl;
            }
        }
        else 
        {
            int err = GetLastError();
            std::cout << "ERROR Code: " << err << std::endl;
        }
    }
    else
    {
                        std::cout << "Cookie Data: " << lpData << std::endl;
    }
//}


return 0;

}

The problem that I am having is that when I call InternetGetCookeEx I always return false and get an error code of 259, which means no more data available. When you consult the API essentially what that means is that it couldn’t find my cookie.

Because I am using IE 9 the names for files that the cookie is being stored in are obviously mangled , which is why I am trying to read my cookie data that way.

I have removed the company name to protect the company. Essentially what I am trying to do is. Find the lUsrCtxPersist cookie value. Therefore I am calling the code as such CookieReader.ext http://[CompanyDomain].com lUsrCtxPersist.

However I always get a false and an error code of 259. Any light you might be able to shed on this would be greatly appreciated.

Answer 1

Assuming the cookie name is correct, then try removing the INTERNET_COOKIE_THIRD_PARTY and/or INTERNET_FLAG_RESTRICTED_ZONE flags and see what happens. Or try calling InternetGetCookie() instead, which has no such flags available.

On a separate note, when InternetGetCookieEx() returns ERROR_INSUFFICIENT_BUFFER, you are leaking memory. You need to delete[] your existing buffer before then calling new[] to allocate a new buffer.