How does it work ?

[Petrol king]

Hello,

First, sorry if my english isn't good it is because i' m french and i' m still at school.

If i post here it is to know how a Crack No Cd or an other crack works.

My intentions are not cracking or hacking, i don ' t want to know exactly
how it works, it should be very complicated, i just wanna know how it works globaly.

thx,


++

Petrol king,

[DABhand]

Basically its called Reverse Engineering, where you take the game code and rewrite it so that it functions differently.

[Petrol king]

I thought it was something like that and i tryed to get the asm code of a exe, it is enormous, never seen something like that, nothing understandable.
It is why i asked the question, i believed there was a other way to do that.

I thought of doing a copy of the cd on the computer and make the program read on the copy .I' d like to have your opinion on it, do you think this way is easier ?

thx

++
sn00bino

[TippeX]

Originally Posted by Petrol king

I thought of doing a copy of the cd on the computer and make the program read on the copy .I' d like to have your opinion on it, do you think this way is easier ?

of course its easier (especially if you dont know asm/cant crack), but you are simply bypassing the protection checks with the image/burned backup, the protection code is NOT magically removed

[Petrol king]

It is real that my knowledge in asm is limited.But can ' t i do a transformer from exe to a language who ' s not far from c++ ?

By exemple if i do that :

1 Create a prog with nothing in it.
2 Create a other prog like the first exept i add an if instruction
3 Create a prog which compare the 2 programs and return the differences.

So the third program returns me an instruction if.

And if i do that for all the basic instruction,and if i do a fourth program wich knows all this instructions.Won' t i be able to retrieve a almost-cpp source code ?

There is a other thing, if i want to delete the need of the cd, i must know when the program need it.So, Do you have an idea of the way to do that ?

thx,
++

PS: if you can 't understand something or if i do syntax or other fault don' t hesitate to tell me.

[TippeX]

c, delphi etc are all high level languages, they are compiled to assembly language by the compiler, so having experience in c can help but you really also need to know assembly so that you can change the instructions in the compiled exe.. a cdcheck can be done via various methods, the most simple being a call to GetDriveTypeA which returns 05 if the device passed in the parameters is a cdrom drive, so you then find the procedure that does the cdcheck and 'help' it so it returns 'hey there is a cd present, all is ok' back to the code, which then continues on... thats an example of a simplistic cdcheck, there are far far harder ones like on securom, starforce, safedisc etc... which most people can not 'bypass' as easily

in your examples, the 'differences' will probably be huge, and will be caused by the compiler, they will also be hex bytes which 'translate' to asm code, you won t see the 'code' you changed in a human readable form (like your c code)...