The last time I had to do anything like this in a windows application, my code was all Borland Delphi and it was about 5 years ago.
The approach I took in that system was to allow users to download the system (packaged in an installer) FOC from the web and they could choose to use it forever without inputting a license key - in this mode the system was effctively feature limited running in demo mode (but it was never time limited).
The whole thing was based on a SourceForge project from Turbopower http://sourceforge.net/projects/tponguard/ and the general operation of this security mechanism was based on a local registration.dat file that contained license information for the system. If this registration information was missing or invalid, the system would run in demo feature limited mode.
The generation of this licensing information was from a unique key generated by the program running on the users computer - the algorithm that generated this unique key considered hardware factors in the users computer like hard disk descriptor, NIC mac address etc. If the user was willing to pay and wanted a license key they could just send their unique key and their unique unlock code could be generated and sent back to them for input.
I don't have any .NET code or anything recent but I do still have my Delphi code knocking around somewhere if you want to take a looksee..or perhaps the Turbopower stuff might give you some ideas and help if you can understand Delphi code.
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Reply to: Software registration codes
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Previously on "Software registration codes"
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Software registration codes
I need to implement a typical registration code system. So the customer can download a 30-day evaluation version, and hopefully then can go to the website and purchase an unlock code to use it properly.
I guess I need to find a way of encoding an evaluation timeout and a product code (there's two different levels of the same product) within the magic code. Cryptography really isn't my thing though
, so if anybody knows of an algorithm or free-ish library that I could use for this sort of thing that would be appreciated.
BTW the web server is Windows 2003, using sad old JavaScript ASP, so I could put a windows console app on the server and link that up with ASP to generate the code. And the actual software is of course Windows only.
I know this sort of thing isn't exactly secure, but more secure options come with potential support nightmares and that's the last thing we need.Tags: None
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