Can anyone help me getting started with this? We have a current keygen for a set of our apps that's using des-ede2 in C++.
I need to make my vb.net app validate keys generated by that keygen. Anyone have any ideas where to start?
I'm googling like mad, but hoping someone can point me in the right direction.
Thank you!
There are two different aspects of a key you might want to check; wheter the key is a valid des key or if it's the key which some kind of data has been encrypted with.
A key can be used if the bit parity (http://en.wikipedia.org/wiki/Parity%5Fbit) of each key byte is odd.
As your title suggests you want to implement des in vb.net and then check if data has been encrypted with this key. This is only possible if you know some part of the original content (i.E. how it starts, chars that are likely or unlikely to occur, etc. the more unspecific, the more false-positives). If you really plan to implement des in vb.net i suggest reading the original standard document. IMO the best way to learn about how des works. http://csrc.nist.gov/publications/fips/fips46-3/fips46-3.pdf