Here is a delphi code example which demonstrates how to brute force a hidden, custom crc check for a license key. One character from the custom crc calculation is used in an interesting calculation with the characters from which it was created.
The target for this example is Mayura Draw 4.5:
Code:
http://www.mayura.com/
If you have any questions regarding the functionality of the source, do not be afraid to ask. I am not here to criticize beginners, I am here to teach them.