how to reverse engineer software and create keygen

Apart from being illegal, it's a very complex task. Speaking just at a teoretical level the common way is to disassemble the program to crack and try to find where the key or the serialcode is checked. Easier said than done since any serious protection scheme will check values in multiple places and also will derive critical information from the serial key for later use so that when you think you guessed it, the program will crash. To create a crack you have to identify all the points where a check is done and modify the assembly code appropriately (often inverting a conditional jump or storing costants into memory locations). To create a keygen you have to understand the algorithm and write a program to re-do the exact same calculation (I remember an old version of MS Office whose serial had a very simple rule, the sum of the digit should have been a multiple of 7, so writing the keygen was rather trivial).

Both activities requires you to follow the execution of the application into a debugger and try to figure out what's happening. And you need to know the low level API of your Operating System. Some heavily protected application have the code encrypted so that the file can't be disassembled. It is decrypted when loaded into memory but then they refuse to start if they detect that an in-memory debugger has started, In essence it's something that requires a very deep knowledge, ingenuity and a lot of time! Oh, did I mention that is illegal in most countries? If you want to know more, Google for the +ORC Cracking Tutorials they are very old and probably useless nowdays but will give you a good idea of what it means.

Search Results of How to Reverse Engineer Software and Create Keygen. Check all videos related to How to Reverse Engineer Software and Create Keygen. More How To Reverse Engineer Software And Create Keygen videos. How to Make a KeyGen by bared145 in software. That's rather hard to do without reverse engineering the copy protection systems for the specific application.

How To Reverse Engineer Software And Create Keygen

Anyway, a very good reason to know all this is if you want to write your own protection scheme. The bad guys search for the key-check code using a disassembler. This is relative easy if you know how to do this. Afterwards you translate the key-checking code to C or another language (this step is optional).

Reversing the process of key-checking gives you a key-generator. If you know assembler it takes roughly a weekend to learn how to do this. I've done it just some years ago (never released anything though. It was just research for my game-development job.

To write a hard to crack key you have to understand how people approach cracking). Nils's post deals with key generators. For cracks, usually you find a branch point and invert (or remove the condition) the logic. For example, you'll test to see if the software is registered, and the test may return zero if so, and then jump accordingly. You can change the 'jump if equals zero (je)' to 'jump if not-equals zero (jne)' by modifying a single byte.

Or you can write no-operations over various portions of the code that do things that you don't want to do. Compiled programs can be disassembled and with enough time, determined people can develop binary patches. A crack is simply a binary patch to get the program to behave differently.

First, most copy-protection schemes aren't terribly well advanced, which is why you don't see a lot of people rolling their own these days. There are a few methods used to do this. You can step through the code in a debugger, which does generally require a decent knowledge of assembly. Using that you can get an idea of where in the program copy protection/keygen methods are called. With that, you can use a disassembler like to analyze the code more closely and try to understand what is going on, and how you can bypass it. I've cracked time-limited Betas before by inserting NOOP instructions over the date-check. It really just comes down to a good understanding of software and a basic understanding of assembly.

Did a two-part series on the first two episodes this season on kind of the basics of reverse engineering and cracking. It's really basic, but it's probably exactly what you're looking for. A would-be cracker disassembles the program and looks for the 'copy protection' bits, specifically for the algorithm that determines if a serial number is valid. From that code, you can often see what pattern of bits is required to unlock the functionality, and then write a generator to create numbers with those patterns.

Another alternative is to look for functions that return 'true' if the serial number is valid and 'false' if it's not, then develop a binary patch so that the function always returns 'true'. Everything else is largely a variant on those two ideas.

Copy protection is always breakable by definition - at some point you have to end up with executable code or the processor couldn't run it. The serial number you can just extract the algorithm and start throwing 'Guesses' at it and look for a positive response.

Computers are powerful, usually only takes a little while before it starts spitting out hits. As for hacking, I used to be able to step through programs at a high level and look for a point where it stopped working. Then you go back to the last 'Call' that succeeded and step into it, then repeat. Back then, the copy protection was usually writing to the disk and seeing if a subsequent read succeeded (If so, the copy protection failed because they used to burn part of the floppy with a laser so it couldn't be written to).

Then it was just a matter of finding the right call and hardcoding the correct return value from that call. I'm sure it's still similar, but they go through a lot of effort to hide the location of the call. Last one I tried I gave up because it kept loading code over the code I was single-stepping through, and I'm sure it's gotten lots more complicated since then.

.: Ellipsis:. If you want to be a 'hacker' then you want to be efficient. When you ask a stupid question without Google-ing here's what happens: [You Ask a Stupid Question] ->[We either Answer or Google it] ->[We Read Google's Results] ->[We Post Our Findings] ->[You Have the Answer] Let's make a minor modification for efficiencies sake: [You Google It] ->[You Ask a Stupid Question] ->[We either Answer or Google it] ->[We Read Google's Results] ->[We Post Our Findings] ->[You Have the Answer] If that doesn't work, then ask the question - But before you ask a question use (it's ). RIP F28 NO NIGGA LEFT BEHIND I am the best hacker on these forums. LoX: I dub thy 'the answer man', rise sir knight of rohitab facts to feminist bitchcunts are like garlic to vampires its like some wife thanking her husband for only giving her one black eye LOX I TOLD U MANY TIME DON:'T FUCK WITH ME or ARE YOU ONE OF SOPA CENSORING MY CONTENTS,FUCK YOU YOU YOU ARE FULL OF SHIT AND BASTARD SON OF A BEACH! FUCK YOU IN DA ASSSSSSSSSSSSSSSSSSSSSSSSS!

FUCK YOU IT ALL SHEET DELETE MY ACCOUNT and with my conten,if u hate me,hate what i have posted becuse it all worthless i don't even remember you any more i hate you ROHITABS!!!!!!!!!!!!!!! UR SOME RACIST,JACKLASSS!!!!!!!!!!!!!!!!!!!!!!!!!! It is not possible in every case, even if there is indeed an algorithm Your question is the same with finding a 'rule' for a sequence of numbers. This page has some info. In fact you're probably out of luck if you're trying to hack your phone company's keycodes for credit or something similar, since these probably have a database of random numbers they bought from people that generated them by some method that has nothing to do with computers (sensors that read data every now and then from chaotic phenomena), and there is no algorithm involved at all. Just one more word of advice: if the keygen has some sort of SMC (Self Modifing code) to prevent work to be stolen (or, at least, try) you're going to be spending one awfull lot of time trying to get ahold the algorithm. Note that the steps you should take is: a) Check if it's packed, unpack it. Black Box Phone Unlocker.

B) Check for some SMC inside the code, unroll it. C) Check for the 'common tips and tricks against anti-virus' (search that in the forum), and beware that'll make it a tad more complicated.

D) Check for the correct spot in the dissemblers output and try to go from there cleaning what you can find. Remember most people are all against being stolen (and people that worked on the keygen will most likely be pissed if you're just trying to steal the work they started with) so you might find some pitfalls. Used Iphone 5c Unlocked For Sale more. Also, as LoX said, if just one or some keys are working, check if the keygen is for the correct version of your application, or just plain dump it and go find something better. I have a software which gives you couple of codes after installation and then i have to call the owner and tell him the code which I'm give by the computer then he gives the password to me to enter the software! Codes are different in different PCs.

I wanted to know that anyone knows how can i know the algo of this in order to make a password generator for it? Or can i change the software's codes in a way that it could run everywhere using the code i have? Thanks in advance.