User:Alef/nocdkey

nocdkey here doesn't mean you can play illegal copies with this plugin!

What is this?

This is a plugin to avoid the problems described here.

Solution

The CD key check will be skipped at least if the name for the gamespy servers are not found, or resolved. It doesn't simply mean you can force a different IP, like 127.0.0.1, editing your c:\windows\system32\drivers\etc\hosts.

ws2_32.dll

To connect to the Internet, like all the other programs on Windows, ArmA uses a DLL called ws2_32.dll, that is a file installed in c:\windows\system32. If you put another file with the same name in the ArmA installation directory, ArmA will use that instead of the Windows one. It is the same like Armalib from Kegetys, which uses dsound.dll to inject custom code in the ArmA process address space. I've modified a program found online (see the links below), that intercept the functions ArmA does to connect other computers. One of these functions is gethostbyname, which is used to obtain an internet address given a name, like www.ofpec.com returns 85.17.58.182. Now, if ArmA asks for hosts in gamespy.com domain, to check for duplicated CD keys, if the address it's found and valid, the check will happens. This function is enables only if you use -host and -nocdkey. The server will get the message "No challenge value was received from the master server." when attempting to check for duplicated CD keys. The DLL will intercept all of the network functions. All of them, apart the one above, add an overhead for this to work. This overhead consists of a single jmp instruction without stack management (nacked), which I suppose should at least be long as a single CPU cycle, or less. So if you run a 3GHz CPU, the added delay should be 0,33 ns (nanosecond, a billionth of second).

Legal

I suppose this is something legally doable, because BI already provided the way to work without checking for duplicated CD keys. If BI doesn't want this, I'll remove any reference to this work and notify the reachable forums and mirrors.

Links

• Download nocdkey.zip
• OFPEC beta request
• Xfire video showing the procedure
• Original code: koaxia.com
• Original code: codeguru.com

Source

You get the full source in the distributed archive. This is the working code extracted from there:

struct hostent* FAR(__stdcall h_gethostbyname)(__in const char *name) {
    using namespace std;
    static const string master("armedass.master.gamespy.com"), available("armedass.available.gamespy.com");
    static const wstring mhost(L"-host"), mnocdkey(L"-nocdkey");
    static bool host=false, nocdkey=false, argschecked=false;
    struct hostent* FAR rc = 0;
    if (!argschecked) {
	argschecked=true; LPWSTR *szArglist; int nArgs;
	szArglist = CommandLineToArgvW(GetCommandLineW(), &nArgs);
	if( NULL != szArglist ) for(int i=0; i<nArgs ; ++i) {
		if (!host)    host=(mhost.compare(szArglist[i]) == 0); 
		if (!nocdkey) nocdkey=(mnocdkey.compare(szArglist[i]) == 0);
	}
	LocalFree(szArglist);
    }
    if (host && nocdkey && name && (master.compare(name) == 0 || available.compare(name) == 0) ) {
	p_WSASetLastError(WSAHOST_NOT_FOUND);
    } else {
	rc=p_gethostbyname(name);
    }
    return rc;
}

Where p_ is the original DLL function entry point and h_ the overloaded one.