Application Licensing

[Guest]

Hi!

What's the easiest/best way to provide a licensing feature to an application?

We've developed an application that defaults to evaluation mode, but now need to achieve a method of licensing the application, preferably by entering some kind of unique string.

What are the options and products we should be looking at?

Thanks!

 

[Lucas Tam]

What are the options and products we should be looking at?

Make sure you obfusticate your .NET code as it can be easily decompiled.

 

[Herfried K. Wagner [MVP]]

What's the easiest/best way to provide a licensing feature to an application?

<URL:http://msdn.microsoft.com/library/en-us/cpguide/html/cpconlicensingcomponentscontrols.asp>
<URL:http://windowsforms.net/articles/Licensing.aspx>

 

[Paul Bromley]

Hi Phil,

I wanted something relatively simple for me to do on the same lines. My
application was in a vertical market where the product was likely to be
passed around. I decided to go for MD5 encryption based on a number of
paramters incluidng the server name that the user supplied to me. I would
then generate a key that would match up to a key geneerated by my
application after looking for the relevant server name and other
information. This locked my application to the server, which is what I
wanted. I knew that my user base could not cahnge their server name due to
the main application that was running on it - this needed a set server name.
Hope that this helps.

Best wishes

Paul Bromley

Hi!

What's the easiest/best way to provide a licensing feature to an application?

We've developed an application that defaults to evaluation mode, but now

need to achieve a method of licensing the application, preferably by
entering some kind of unique string.

 

[Guest]

We, www.pinroe.com, will have a license generator online sometime this weekend.

Basically this is how it works. We generate a public/private key pair. If you are not familiar with this you can create a signature with the private key and verify the signature with the public key but not visa-versa. We generate the license in xml with the signature in plain sight because the public key is embeded into a assembly level custom attribute in your assembly. At run time the license tool verifies the signature contained in the xml file, which only you can generate because only you have the private key, against the public key in the assembly. The signature is based on the actual xml. So if the xml changes the signature does not match and thus the user is out of luck.

As long as you obsfucate your assembly your component is safe. Well...as safe as your private key! (If you do not obsfucate then it is possible for someone to decompile and either take out the licensing stuff totally or to embed their own public key).

Source code will be available for this tool. We have one more tool, a CSLA builder, on line now and are in the process of putting more online.

jason.

 

[LogicNP]

Have you tried a tool like CryptoLicensing ? The easiest and the most advisable way is to use 3rd party licensing tools like the one mentioned before. It will allow you to send out trial licenses to evaluators and full licenses to customers.