Time limited Demo
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RaymondM wrote:
Where should it be stored ?
It can be stored (encrypted) in either the registry or a
.inifile."Love people and use things, not love things and use people." - Unknown
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
David, Sometimes I think along those lines, but I wonder if the user can still 'get at' the data. I wondered also if the time could be stored in a private file in the server. Then whenever the program is run it would open the path to the server to check that file. What do commercial programmers do ? Raymond
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David, Sometimes I think along those lines, but I wonder if the user can still 'get at' the data. I wondered also if the time could be stored in a private file in the server. Then whenever the program is run it would open the path to the server to check that file. What do commercial programmers do ? Raymond
Key locked applications usually use an encryption algorithm that produces a large key and distributes the bits of the data source (in your case the expiry date) throughout the key. In this way it is impossible for the user to modify the date. Any attempt to modify the key to change the expiry date will invalidate the key completely and lock the application up. See this article[^] for details on how you may go about adding a product key to your application. Personally I don't like the "phone home" method of software validation, since I use a laptop and spend a fair bit of time developing disconnected from the internet (not always off a network, but that is a different matter).
Graham Librarians rule, Ook!
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David, Sometimes I think along those lines, but I wonder if the user can still 'get at' the data. I wondered also if the time could be stored in a private file in the server. Then whenever the program is run it would open the path to the server to check that file. What do commercial programmers do ? Raymond
RaymondM wrote:
I wondered also if the time could be stored in a private file in the server
Your application does not run "without" a server/network ?
RaymondM wrote:
What do commercial programmers do ?
We had (not now) a limited (not save/export and the like) features demo available for download (different than the paid application) We found that having a timed demo/application is not worth it, either they run it, or they don't; if with a limited feature demo they find that they like it, they will buy it. IN ANY CASES, if people want your application, they will find a way to get it ANYWAY.
This signature was proudly tested on animals.
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RaymondM wrote:
I wondered also if the time could be stored in a private file in the server
Your application does not run "without" a server/network ?
RaymondM wrote:
What do commercial programmers do ?
We had (not now) a limited (not save/export and the like) features demo available for download (different than the paid application) We found that having a timed demo/application is not worth it, either they run it, or they don't; if with a limited feature demo they find that they like it, they will buy it. IN ANY CASES, if people want your application, they will find a way to get it ANYWAY.
This signature was proudly tested on animals.
Thanks to all who have taken the trouble to reply, especially for the link to the AES code. I think now that the 'phone home' method is a bad idea. I had put out a limited feature demo, but did feel that it would be better to make it time limited. My experience is that either scheme can lead to a sale. Raymond
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Thanks to all who have taken the trouble to reply, especially for the link to the AES code. I think now that the 'phone home' method is a bad idea. I had put out a limited feature demo, but did feel that it would be better to make it time limited. My experience is that either scheme can lead to a sale. Raymond
The following post about registration systems/[^] is well worth a read
Graham Librarians rule, Ook!
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The following post about registration systems/[^] is well worth a read
Graham Librarians rule, Ook!
Graham, Going back to the aestest samples I see that I need various headers. #include "cryptlib.h" #include "aes.h" // AES #include "modes.h" // CBC_Mode< > #include "filters.h" // StringSource These are not given in that CodeProject page, but when I look around I find something under these names in http://www.koders.com/cpp/... but the headers I find there sre not right for aestest. So where or the correct headers ? I had more luck in compiling crypto50 etc, but the versions of cryptlib.h in those versions of crypto are clearly not right either for the aestest examples. Raymond
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Graham, Going back to the aestest samples I see that I need various headers. #include "cryptlib.h" #include "aes.h" // AES #include "modes.h" // CBC_Mode< > #include "filters.h" // StringSource These are not given in that CodeProject page, but when I look around I find something under these names in http://www.koders.com/cpp/... but the headers I find there sre not right for aestest. So where or the correct headers ? I had more luck in compiling crypto50 etc, but the versions of cryptlib.h in those versions of crypto are clearly not right either for the aestest examples. Raymond
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That is what I did, and was able to compile some of the various crypto programmes, but each one has a different cryptolib.h, and none of them seem to be right for the aestest programmes. Raymond
OK, and I see that you have also got previous version of the Crypto++ library as well. It may be that the example is using an earlier version of Crypto++ (the Sourceforge download pahe[^] has earlier versions. Other than posting a question to the author on the project page (or asking him if he has an update) I'm afraid that I cannot think what else to suggest. You may just have to try to update the aestest program to the latest version of Crypto++ yourself
Graham Librarians rule, Ook!
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That is what I did, and was able to compile some of the various crypto programmes, but each one has a different cryptolib.h, and none of them seem to be right for the aestest programmes. Raymond
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