Re: Protecting Software w/ Software License Keys...
Re: Protecting Software w/ Software License Keys...
- Subject: Re: Protecting Software w/ Software License Keys...
- From: Kyle Moffett <email@hidden>
- Date: Mon, 17 Jun 2002 18:42:17 -0400
On Monday, June 17, 2002, at 06:13 PM, Jason Harris wrote:
A cracker would completely ignore the whole public/private thing and
find
the spot where the function that checks 'em returns YES or NO. And
change
it so it always returns YES.
You could encrypt part of your code and when serialized, provide a value
that when hashed with the MAC gives the encryption key. But even
then, a
hacker would take a properly serialized version, let it unencrypt the
code,
and create a patch that replaces the encrypted code with the unencrypted
code.
It's just not worth the time you'd spend implementing this. Instead,
develop something that _can_ be cracked, but that will get the majority
of
people to pay.
Jason Harris
I am not very familiar with how to do this. If this is possible with C
code, then I
accept the validity of your argument. How would someone go about
changing
the function? Would it be done on disk? How would this be affected if
the code
was linked in statically vs. dynamically? Is there any way to protect
against this
kind of attack? Would inlining help at all? Could the processing
functions use
a macro that is compiled in, so the hacker would have to alter all of
the functions?
In any case, the goal is to prevent a simple serial from working on any
given system.
If a serious effort like this is required to crack it, then I'm
satisfied. I would rearrange
functions and memory addresses every release anyway, just to make it more
difficult to crack.
Thanks,
Kyle Moffett
_______________________________________________
cocoa-dev mailing list | email@hidden
Help/Unsubscribe/Archives:
http://www.lists.apple.com/mailman/listinfo/cocoa-dev
Do not post admin requests to the list. They will be ignored.