How make a demo verion?

[dutch]

Dear All,

I would like to make a demo version for the customer. In the past, I use Blinker to limit the time of running the program?

How can I make in xHarbour/FWH?

Thanks in advance and appreciate for all idea.

Best regards,
Dutch

[ukoenig]

Hello Dutch,

In case You need something for a Invoice-Application :
In one of my Applictions as a simple Solution, I defined a encrypted Date-Limit.
Ok, the User can change the Comuter-date, to make it working again.
But printing and saving with a wrong Date doesn't make sense for a Invoice-application.
The Date-Check, I used in different places inside the Application ( before saving a Invoice )

To make it nearly impossible, to patch the defined Date with a HEX-Editor,
I splitted the Date to Vars like :

"10.05.2010" // not encrypted, because maybe could be detected and changed with a Hexeditor.
Vars defined on different places :
a := "10."
b := "05."
c := "20"
d := "10"
the String from vars is decrypted and encrypted.

A Encrypt() and Decrypt() example You can find in < Testencr.prg >

Best regards
Uwe

[dutch]

Dear Uwe,

My Demo program now is disable printing to printer. The Demo license will set the printer to Preview mode only, it cannot print to printer. The problem is our competitor will be able to see and will know our program features (indeed), if it can run forever (change date case also). They will know the strong point and weak point of us.

If we can limit the time of running program, it will be perfectly. If we can add the number of running time in registry and deduct it every time the program run. Is it the good way?

Regards,
Dutch

[ukoenig]

Dear Dutch,

A time-limit is a good Idea, saving the encrypted Value to a Ini-file.
I have done something identically for my Login-password, but saved to the Login-dbf.
Be sure the Time is saved ( somewhere inside the Application ) not after Closing it.
In case, the User is switching of the Computer without closing the Application, nothing is saved.

Best Regards
Uwe

[StefanHaupt]

Dutch,

you can use the software Trial Creator from SoftwareKEY, it´s totally free and creates a fully functional demo, which stops working after 30 days.

From the website:

Without changing a line of your source code, you will be able to take your fully functioning program and create a copy that STOPS in 30 days! No needing to create a special version of your program that contains the shut-off code, nor do you need to provide your clients with software that is missing crucial features, "crippleware". Trial Creator is totally free and will remain functioning as long as you like.

You can download it here :
http://www.softwarekey.com/swk_products/trial_creator/

I use it and I think it´s very good.

[Bayron]

Dutch,
If you only have one costumer, make and give your costumer a small program that captures the hard drive serial number first, obtain that number from the costumer, and then have your software to compare it to a encrypted variable with the same number compiled inside your software (maye a small program that compiles the variable and then include already encrypted), together with the encrypted date as Uwe proposed... check the date as many times as possible from your software trough a function that you make CheckValidDate().

This way, only authorized costumers can make the software work....

[ukoenig]

Code: Select all  Expand view

...
...
SET DATE GERMAN
SET CENTURY ON

// I don't want < "10.05.2010" > can be detected with a Hex-Editor
// ---------------------------------------------------------------------------
cTest1a := "10."
...
...
cTest1b := "05."
...
cTest1c := "20"
...
cTest1d := "10"
...
...
cTest1 := cTest1a + cTest1b + cTest1c + cTest1d

MsgInfo( cTest1 := Encrypt( cTest1, "User1Key" ) )
MsgInfo( cTest1 := Decrypt( cTest1, "User1Key" ) )

MsgAlert( cTOD( ctest1 ) )

// Ask on different places inside Your Application
// -------------------------------------------------------
IF DATE() > cTOD( ctest1 )
    QUIT
ENDIF
 

Best Regards
Uwe

[alvaro533]

This is what I do:

Every time the program starts it checks if the current date is later that the date we want the demo to stop.

if date() >= expiration_date // (follow ukoening suggestion to avoid Hex-Editor modification)

If this is the case you can activate a secret flag showing that the trial period has expired, to do that you can choose between:

1. making a special entry in the registry
2. creating a file with a special name somewhere in the hard drive
3. adding a special record in one of the databases of the program.

Then in many parts of you program you can check if the trial period has expired looking for the secret flag you have set.
This way, if the user changes the system date after expiration, the program still does not work.

You may also set a secret counter in a file somewhere in the harddrive (I use system32 folder, and the name of the file may be something like "awds.dll" even if it is a text file for you) and decrease it every time you add an invoce or something like that.

Alvaro

[dutch]

Dear All,

Thank you very much for many idea. I've some question.
1) If they change the date to future (example 12/31/2020) before install.
2) Before they start the program, they change the date to the day before expire (example 01/01/2000).

How can we check it?

Best regards,
Dutch

[Bayron]

Dear All,

Thank you very much for many idea. I've some question.
1) If they change the date to future (example 12/31/2020) before install.
2) Before they start the program, they change the date to the day before expire (example 01/01/2000).

How can we check it?

Best regards,
Dutch

Dear Dutch,
only our imagination is the limit with FiveWin, you can check the date from files saved to the computer,

If(FileDate > DateInComputer) ==> Date error

If the information is that sensitive, you can create a online database and check from there accessibility to the software... I am getting a partner with a software I will develop, and he will collect the money from sales, so I am thinking on developing a KILL SWITCH, regardless of contracts, if he does not pay me, I can tell how many and which applications will run (cheaper than going to court), since all of them need internet access, at any given point I will know how many applications are running, and of course shut down any pirate applications, that way I can control who uses the software, and how many copies where sold. My partner will have a serial number generator, that will give me the serial numbers as well automatically and I will then activate the software after payment...

In this way, you can create a demo version as well, that will only run when the user gives you the email information and serial number, and any other information you will want before you give him/her the key to use/// Don't forget to check this key through out your software, for example before running any function...

[ukoenig]

Something about storing Informations to the Registry.
I think it is nearly impossible, to pay attention to every Situation

What happend :
I tested a Application valid Testing-Time 30 Days ( informations somewhere stored inside the Registry )
After 30 days, it didn't work anymore. Reinstall and new install didn't activate it again.
Because of many unused informations after a while inside the Registry, I used a Registry-Cleaner.
Now all unused Informations are deleted.
After some days, I installed a new Version and started the Test-Application again.
Because all Informations have been deleted in the Registry, I got again 30 Days Testingtime.
Using the Registry for Protection, is not a good Solution.

It shows, a 100 % Protection seems not to be possible. Even with a Hardlock (Dongle) -protection.
As soon somebody is looking for a Solution, he will find a Way, to get a Application working.

Best Regards
Uwe

[ricardog]

send a private mail
it's better in spanish, my english it's very bad


thanks

[ricardog]

excuse me my mail is

rguardadof@prodigy.net.mx

[Jeff Barnes]

This is what I do....

I have an application that collects data from other devices via a serial connection.
I have an encrypted .dll file (actually just a text file) where I store a countdown.
When the countdown hits zero I do not allow access to the serial connect function.

I also make a reg entry as a flag AND place a file in the windows folder also to be used as a flag so the user can't just reinstall.
If either the reg entry or file exist, the demo is over and my application becomes limited. (you could just quit the entire app if you want)

All other functions of my app are not blocked, so the user still has access to previously acquired data ... just can't get new data.

To remove the lock-out I use a software key based on the motherboard serial number OR I use USB drive as a HASP.
As long as their is a valid software key entered (only good for the system it was created for) or the USB hasp is inserted (I check for it every 45 seconds) the software will work fully.

[alvaro533]

Hi Jeff,

How do you get the motherboard serial number?

Thank you,

Alvaro