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Re: project license [message #59971]

Thu, 24 April 2008 09:18

David Fanning is currently offline

David Fanning
Messages: 11724
Registered: August 2001

Senior Member

David Fanning writes:

> Rather, try smiling while someone pulls out their dog-eared
> photocopy of YOUR book and all you can think about is the
> year you spent without income while your marriage nearly
> disintegrated. It's harder than you think.

What!? No comments?

I'll have to check the revenues from the store. Money
from shamed IDL users must be pouring in today. :-)

Cheers,

David
--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming (www.dfanning.com)
Sepore ma de ni thui. ("Perhaps thou speakest truth.")

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Re: project license [message #59975 is a reply to message #59971]

Thu, 24 April 2008 06:47

David Fanning is currently offline

David Fanning
Messages: 11724
Registered: August 2001

Senior Member

David Fanning writes:

> Try writing a book. You will understand it a *lot* better!

Rather, try smiling while someone pulls out their dog-eared
photocopy of YOUR book and all you can think about is the
year you spent without income while your marriage nearly
disintegrated. It's harder than you think.

Cheers,

David
--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming: http://www.dfanning.com/
Sepore ma de ni thui. ("Perhaps thou speakest truth.")

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Re: project license [message #59976 is a reply to message #59975]

Thu, 24 April 2008 06:41

David Fanning is currently offline

David Fanning
Messages: 11724
Registered: August 2001

Senior Member

Vince Hradil writes:

> This immediately makes me ask the more philosophical question: "Is ANY
> software worth stealing?" But then, I've never understood the whole
> "copyright" thing...

Try writing a book. You will understand it a *lot* better!

Cheers,

David
--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming: http://www.dfanning.com/
Sepore ma de ni thui. ("Perhaps thou speakest truth.")

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Re: project license [message #59977 is a reply to message #59976]

Thu, 24 April 2008 06:35

Vince Hradil is currently offline

Vince Hradil
Messages: 574
Registered: December 1999

Senior Member

On Apr 23, 4:56 pm, David Fanning <n...@dfanning.com> wrote:
> nata writes:
>> Similarly I can store the date of the last time the software was used.
>> Also I could use another kind of "cryptgraphy" but I think this is
>> more dificult.
>
> The main thing is to make sure the software is *worth* stealing. :-)
>
> Cheers,
>
> David
>
> --
> David Fanning, Ph.D.
> Fanning Software Consulting, Inc.
> Coyote's Guide to IDL Programming (www.dfanning.com)
> Sepore ma de ni thui. ("Perhaps thou speakest truth.")

This immediately makes me ask the more philosophical question: "Is ANY
software worth stealing?" But then, I've never understood the whole
"copyright" thing...

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Re: project license [message #59989 is a reply to message #59977]

Wed, 23 April 2008 15:57

b_gom is currently offline

b_gom
Messages: 105
Registered: April 2003

Senior Member

On Apr 23, 1:57 pm, nata <bernat.puigdomen...@gmail.com> wrote:
> Hi gurus,
>
> Anybody knows how to put a license in a IDL project ? I want to write
> a license for my project (only available for X days). Is it possible?
>
> Thanks

I agree with David; the amount of work you put into the licensing
should be proportional to the risk that someone is going to steal the
program.

I've never really liked date-based licenses, but I've tried the
following approaches for this type of thing, each with their own set
of disadvantages:
-using a hardware ID, such as a MAC address or hard drive serial
number, and requesting permission to execute over the web. This can be
circumvented but at least you will be able to tell if it has by the
web server logs.
-using an encrypted key to allow execution and\or store encrypted
information about the number of days left. (See the TEA package in the
ITT user contrib site)
-using a hardware dongle to allow execution and provide time limits.

The hardware dongle requires a DLM to implement, but makes it simple
to manage licenses. The cost of the dongles can be in the $20 range,
so this assumes your software is worth at least this much.

If you have actually developed a 'killer app', then you might want to
talk to ITT. They may have options you can use to license runtime
versions of the code.

Good Luck..

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Re: project license [message #59990 is a reply to message #59989]

Wed, 23 April 2008 14:56

David Fanning is currently offline

David Fanning
Messages: 11724
Registered: August 2001

Senior Member

nata writes:

> Similarly I can store the date of the last time the software was used.
> Also I could use another kind of "cryptgraphy" but I think this is
> more dificult.

The main thing is to make sure the software is *worth* stealing. :-)

Cheers,

David

--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming (www.dfanning.com)
Sepore ma de ni thui. ("Perhaps thou speakest truth.")

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Re: project license [message #59991 is a reply to message #59990]

Wed, 23 April 2008 14:54

natha is currently offline

natha
Messages: 482
Registered: October 2007

Senior Member

On Apr 23, 5:25 pm, Jean H <jghas...@DELTHIS.ucalgary.ANDTHIS.ca>
wrote:
>> If one user wants to crack the license only needs to change the clock
>> of his computer.
>
> to complete my previous post, you can have your program to write the
> date of the last time the software was used. If the current date is
> before the last date, or before the start date, then void the license.
>
> Jean

If I save the date or any other parameter in a sav file this could be
cracked.
Using a large amount of random numbers and a few numbers at known
position that hold the starting date of the
license is a good idea. I think I'll use that !

Similarly I can store the date of the last time the software was used.
Also I could use another kind of "cryptgraphy" but I think this is
more dificult.

Thanks

Bernat

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Re: project license [message #59992 is a reply to message #59991]

Wed, 23 April 2008 14:25

Jean H. is currently offline

Jean H.
Messages: 472
Registered: July 2006

Senior Member

> If one user wants to crack the license only needs to change the clock
> of his computer.

to complete my previous post, you can have your program to write the
date of the last time the software was used. If the current date is
before the last date, or before the start date, then void the license.

Jean

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Re: project license [message #59993 is a reply to message #59992]

Wed, 23 April 2008 14:34

R.G. Stockwell is currently offline

R.G. Stockwell
Messages: 363
Registered: July 1999

Senior Member

"nata" <bernat.puigdomenech@gmail.com> wrote in message
news:ca37bb97-c1c9-4145-a4cc-37510f641171@m73g2000hsh.google groups.com...
> I thought about this solution...
> Is not a good idea to associate the license with the systime.
>
> If one user wants to crack the license only needs to change the clock
> of his computer.

You could record the systime everytime the program runs and
store it some secret place, and if it ever 'jumps backwards' then
invalidate the license.

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Re: project license [message #59994 is a reply to message #59992]

Wed, 23 April 2008 14:29

natha is currently offline

natha
Messages: 482
Registered: October 2007

Senior Member

Thanks a lot people, :)

Bernat

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Re: project license [message #59995 is a reply to message #59992]

Wed, 23 April 2008 14:09

Bob[3] is currently offline

Bob[3]
Messages: 60
Registered: December 2006

Member

On Apr 23, 4:46 pm, nata <bernat.puigdomen...@gmail.com> wrote:
> I thought about this solution...
> Is not a good idea to associate the license with the systime.
>
> If one user wants to crack the license only needs to change the clock
> of his computer.

If you want the project "only available for X days" you're going to
have to deal with systime and such limitations.

If you want to limit it to a certain number of uses/sessions then you
could encrypt a counter (similar to Jean's date suggestion) in a
hidden file and check against that I suppose.

Bob.

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Re: project license [message #59996 is a reply to message #59995]

Wed, 23 April 2008 13:42

Jean H. is currently offline

Jean H.
Messages: 472
Registered: July 2006

Senior Member

nata wrote:
> Hi gurus,
>
> Anybody knows how to put a license in a IDL project ? I want to write
> a license for my project (only available for X days). Is it possible?
>
> Thanks

You could create a license file with a large amount of random numbers
and a few numbers at known position that hold the starting date of the
license. Then, have your main program read this file, extract the date,
and compare with today's date. The good point is that you could
automate the creation of this file in any language, including PHP, so no
need to modify your code each time you want to give your program to someone!

example:
license = fix(randomu(100,10000)*10) ;0 to 9
license[51] = 2
license[489] = 3 ;day = 23
license[9851] = 0
license[3246] = 4 ;month = 04
license[921] = 2
license[8001] = 0
license[5675] = 0
license[4854] = 8 ;year = 2008

Now in your program, read only the specified indexes and voila! ... make
sure that no ones finds the indexes you use!!!

Jean

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Re: project license [message #59997 is a reply to message #59996]

Wed, 23 April 2008 13:54

David Fanning is currently offline

David Fanning
Messages: 11724
Registered: August 2001

Senior Member

nata writes:

> I thought about this solution...
> Is not a good idea to associate the license with the systime.
>
> If one user wants to crack the license only needs to change the clock
> of his computer.
>
> Moreover, You can't distribute free licenses with that.

Oh, well, if you want to be official, you probably have
to spend the big bucks. ;-)

Cheers,

David
--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming (www.dfanning.com)
Sepore ma de ni thui. ("Perhaps thou speakest truth.")

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Re: project license [message #59998 is a reply to message #59996]

Wed, 23 April 2008 13:46

natha is currently offline

natha
Messages: 482
Registered: October 2007

Senior Member

I thought about this solution...
Is not a good idea to associate the license with the systime.

If one user wants to crack the license only needs to change the clock
of his computer.

Moreover, You can't distribute free licenses with that.

Thanks

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Re: project license [message #59999 is a reply to message #59996]

Wed, 23 April 2008 13:20

David Fanning is currently offline

David Fanning
Messages: 11724
Registered: August 2001

Senior Member

nata writes:

> Anybody knows how to put a license in a IDL project ? I want to write
> a license for my project (only available for X days). Is it possible?

IF Systime(/JULIAN) GT Julday(4, 25, 2008) THEN RETURN

Cheers,

David

P.S. It's a poor man's license, but it works OK. :-)
--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming (www.dfanning.com)
Sepore ma de ni thui. ("Perhaps thou speakest truth.")

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Re: project license [message #60069 is a reply to message #59971]

Thu, 24 April 2008 10:24

b_gom is currently offline

b_gom
Messages: 105
Registered: April 2003

Senior Member

We had a legally purchased copy of your book in the lab, but someone
walked off with it..

Brad

On Apr 24, 10:18 am, David Fanning <n...@dfanning.com> wrote:
> David Fanning writes:
>> Rather, try smiling while someone pulls out their dog-eared
>> photocopy of YOUR book and all you can think about is the
>> year you spent without income while your marriage nearly
>> disintegrated. It's harder than you think.
>
> What!? No comments?
>
> I'll have to check the revenues from the store. Money
> from shamed IDL users must be pouring in today. :-)
>
> Cheers,
>
> David
> --
> David Fanning, Ph.D.
> Fanning Software Consulting, Inc.
> Coyote's Guide to IDL Programming (www.dfanning.com)
> Sepore ma de ni thui. ("Perhaps thou speakest truth.")

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