How To Crack A Software And Make A Keygen

If y'all've ever heard software piracy terminology being discussed, I'm sure the term KeyGens came up. KeyGens is curt for central generator, which is a plan that exploits algorithmic faults in software by generating software license keys that appear to be 18-carat. Commonly used as a technique to protect the source code software and prevent piracy, a key generator exploits the key algorithm to finer nullify the demand for any software licenses. For example, nosotros must effort to find patterns in the keys, such every bit three 5s in every primal, all even numbers, etc. Any way that the program could validate a program without being online could be a manner that software is protected.

Normally, something like this would exist of no use, but everything has its purpose. Suppose that you lose source to one of your programs, wouldn't you want to have the ability to opposite it and recover the source code? Alternatively, if you made a tool that people enjoyed, and decided to sell information technology via licenses, you need to bank check information technology for vulnerabilities such equally these to mitigate the chances of your own software being stolen.

In today's Null Byte, let's go over how a KeyGen could work by cracking the algorithm used to verify software keys in a few examples. I will not be walking you through how to actually crack a program, because I tin't merely fissure a program for demonstration, merely the techniques applied to my examples should requite you the foundation needed to create your own. At that point, it's a exam of your morals if yous want to use your knowledge for skillful or bad.

You lot must follow The Hacks Behind Swell, Part 1 through until just before the final footstep, and then you can brainstorm the tutorial beneath.

Footstep 1 Pace Into the Part

Run the programme with the debugger and resume where you are asked to enter the key again with an interrupt on it.
Strike F7 to go inside the function.
Keep hit F7 until you find the credentials and key you lot entered in the disassembler once again, followed past a bound.
Shortly thereafter, you should find CMP 2D, DL, or something like. This is the office that is validating our key.

Stride two Commencement Reversing for the Key

You should see a bunch of CMP and shorts on the screen, likely alternating in design.
Click on, and examine CMP and what it is looking for, as opposed to what you entered.
This shows that information technology is looking for a dash, so let'due south endeavor adding a dash anywhere in the key nosotros are testing to see how far we tin can get in the validation. Remove all breakpoints and gear up a new one hither.
Gyre downwardly to the next naught byte and detect the i where the EAX is equal to the start part of your serial in decimal. You can utilize the converter built in to the Windows figurer.
Remove all previous breakpoints and ready the new breakpoint to the CMP section that, when clicked on, shows our key value in hex being compared to the value it should exist (because keys are generated based upon the name entered in the registration procedure).
The value hither is actually the first correct function of the key written in the field, so if we catechumen information technology from hex to decimal, we at present accept the side by side function of our cardinal. Set your new breakpoint, and rinse and repeat the past two steps until you lot receive a full cardinal lawmaking and register successfully.

To brand a central generator plan, yous have to repeat the steps at to the lowest degree one or 2 more times with different usernames and so you can get different and working keys. These keys will exist compared and examined for commonalities for algorithmic reversing. I hope you lot learned something.

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