I am trying to make a nice licensing method to use with my C-programs.
I have implemented a simple method like the following:
* KeyFile.cfg - contains the following
- Expiration Date
* Program contains
Now for input in the program I use the following:
* Input into program
- Expiration Date (from KeyFile.cfg)
- Activation Key (from KeyFile.cfg)
I use Crypt mechanism to crypt the input data and verify that against the Activation Key. Those have to be the same.
I am looking for a method of checking the date, to see if the key is still valid without entering an Expiration Date manually into the KeyFile.cfg
I have searched and searched for such a mechanism but have failed to find anything that comes even close.
Does anyone have any experience in this matter, or have some good reference sites where I can start from?
Any help is appreciated, also C++.
Thank you in advance,
Kind regards, Tom.