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I know this question is asked many times, I read every question but didn't find solution for my case.
Our team made an application in .Net 4.7.2 and in few days we have to deploy it. We are using web services, so even if user cracks license system, they won't be able to access services. Our only concern is to prevent its duplication (someone can resell under his brand and this happened to our previous versions) as these web services(simple CRUD operations) are very easy to implement, so someone can change URL to there servers and duplicate these services. For protection against this, we are using encrypted calls to server. Problem we are facing now is to protect this encryption algorithm and obfuscation is not enough for this.
Again our only concern is to protect code. Sorry for bad English.
I know about .Net Reactor but there are many unpacker that can unpack .Net reactor protected application. I don't know if these unpacker work on current version.
Should I use .Net Reactor?
Is there any solution out there to convert .Net 4.7 code to native code or any other way to prevent this(except for obfuscation or Ahead Of Time Compilation)?
Code you distribute can/will be analized (even copied/cloned) by all sorts of people, no way around that. Even only distributing compiled binaries is not a real hurdle for a determined adversary. Semi-compiled languages like Java's JVM or .NET often keep a lot of source information in the binary, to the point that sometimes decompiling to understandable source is more or less automatic. Source obfuscation can help a bit here, but that introduces another step (and possibly introduce bugs!), but an attacker will probably only be interested in localized swaths of code anyway.
If the services are "easy to duplicate", as you state, I wonder if they are really that valuable. Most extremely valuable 'net services use simple, even well known and publicly available protocols (as in "download a library to use our services here") to access them, but if I'd create my own clone of e.g. YouTube I'll get nowhere, the value is not in the interface but in the service offered.
Re keep encryption secret: Never forget Kerckhoffs' rules. In particular, homebrew encryption is usually ridiculously easy to break, getting at the exact algorithm is possible with some ingenuity even if it is only in hardware (like the MiFare card hack), and unless it has been carefully designed, it will be broken in short order. Do use the accepted cryptographic tools, like AES, Diffie-Hellman, RSA. Yes, it might be incur in some extra costs (in any case there are free/open source alternatives available for everything of interest), but it is much, much more secure than anything you could come up with.
One if the first things I learned when I started with C# was the most important one. You can decompile any .NET assembly with Reflector or other tools. Many developers are not aware of this fact and most of them are shocked when I show them their source code.
Protection against decompilation is still a difficult task. I am still looking for a fast, easy and secure way to do it. I don't want to obfuscate my code so my method names will be a,b,c or so. Reflector or other tools should be unable to recognize my application as .NET assembly at all. I know about some tools already but they are very expensive. Is there any other way to protect my applications?
EDIT:
The reason for my question is not to prevent piracy. I only want to stop competitors from reading my code. I know they will and they already did. They even told me so.
Maybe I am a bit paranoid but business rivals reading my code doesn't make me feel good.
One thing to keep in mind is that you want to do this in a way that makes business sense. To do that, you need to define your goals. So, exactly what are your goals?
Preventing piracy? That goal is not achievable. Even native code can be decompiled or cracked; the multitude of warez available online (even for products like Windows and Photoshop) is proof a determined hacker can always gain access.
If you can't prevent piracy, then how about merely reducing it? This, too, is misguided. It only takes one person cracking your code for it to be available to everyone. You have to be lucky every time. The pirates only have to be lucky once.
I put it to you the goal should be to maximize profits. You appear to believe that stopping piracy is necessary to this endeavor. It is not. Profit is simply revenue minus costs. Stopping piracy increases costs. It takes effort, which means adding cost somewhere in the process, and so reduces that side of the equation. Protecting your product also fails to increase your revenue. I know you look at all those pirates and see all the money you could make if only they would pay your license fees instead, but the reality is this will never happen. There is some hyperbole here, but it generally holds that pirates who are unable to crack your security will either find a similar product they can crack or do without. They will never buy it instead, and therefore they do not represent lost sales.
Additionally, securing your product actually reduces revenue. There are two reasons for this. One is the small percentage of customers who have trouble with your activation or security, and therefore decide not to buy again or ask for their money back. The other is the small percentage of people who actually try a pirated version of software to make sure it works before buying. Limiting the pirated distribution of your product (if you are somehow able to succeed at this) prevents these people from ever trying your product, and so they will never buy it. Moreover, piracy can also help your product spread to a wider audience, thus reaching more people who will be willing to pay for it.
A better strategy is to assume that your product will be pirated, and think about ways to take advantage of the situation. A couple more links on the topic:
How do i prevent my code from being stolen?
Securing a .NET Application
At work here we use Dotfuscator from PreEmptive Solutions.
Although it's impossible to protect .NET assemblies 100% Dotfuscator makes it hard enough I think.
I comes with a lot of obfuscation techniques;
Cross Assembly Renaming
Renaming Schemes
Renaming Prefix
Enhanced Overload Induction
Incremental Obfuscation
HTML Renaming Report
Control Flow
String Encryption
And it turned out that they're not very expensive for small companies. They have a special pricing for small companies.
(No I'm not working for PreEmptive ;-))
There are freeware alternatives of course;
Host your service in any cloud service provider.
How to preventing decompilation of any C# application
Pretty much describes the entire situation.
At some point the code will have to be translated to VM bytecode, and the user can get at it then.
Machine code isn't that much different either. A good interactive disassembler/debugger like IDA Pro makes just about any native application transparent. The debugger is smart enough to use AI to identify common APIs, compiler optimizations, etc. it allows the user to meticuloulsy rebuild higher level constructs from the assembly generated from machine code.
And IDA Pro supports .Net to some extent too.
Honestly, after working on an reverse engineering ( for compatibility ) project for a few years, the main thing I got out of my experience is that I probably shouldn't worry too much about people stealing my code. If anyone wants it, it will never be very hard to get it no matter what scheme I implement.
No obsfuscator can protect your application, not even any one described here. See this link, it's an deobsfuscator which can deobsfuscate almost every obsfuscator out there.
https://github.com/0xd4d/de4dot
The best way which can help you (but remember that they are also not full prof) is to use mixed codes, code your important codes in unmanaged language and make a DLL like in C or C++ and then protect them either with Armageddon or Themida.
Themida is not for every cracker, it's one of the best protector in the market, it can also protect your .NET software.
I know you don't want to obfuscate, but maybe you should check out dotfuscator, it will take your compiled assemblies and obfuscate them for you. I think it can even encrypt them.
I've heard about some projects that directly compile IL into native code.
You can get some additional info from this post:
Is it possible to compile .NET IL code to machine code?
We use SmartAssembly for .NET protection of an enterprise level distributed application, and it has worked great for us.
If you want to fully protect your app from decompilation, look at Aladdin's Hasp. You can wrap your assemblies in an encrypted shell that can only be accessed by your application. Of course one wonders how they're able to do this but it works. I don't know however if they protect your app from runtime attachment/reflection which is what Crack.NET is able to do.
-- Edit
Also be careful of compiling to native code as a solution...there are decompilers for native code as well.
Do you API?
Instead of trying to protect your one ddl file in one of your products on all of your customers devices, why not create an API service for your precious product features? Let the actual product that is saved on a device consume that API to deliver the product as you want it.
I Think this way you are 100% sure that your code is not decompiled and you set your own limits in your API so that developers / hackers don't consume your API in a way you don't want it.
Sure is some more work, but in the end, you are in control.
If someone has to steal your code, it likely means your business model is not working. What do I mean by that? For example, I buy your product and then I ask for support. You're too busy or believe my request is not valid and a waste of your time. I decode your product in order to support my relative business. Your product becomes more valuable to me and I prioritize my time in a way to resolve the business model for leveraging your product. I recode and re-brand your product and then go out and make the money that you decided to leave on the table. There are reasons for protecting code, but most likely you are looking at the problem from the wrong perspective. Of course you are. You're the "coder", and I'm the business man. ;-) Cheers!
ps. I'm also a developer. i.e. "coder"
I know this is old but, Themida is the most advanced anti-cracking software I've ever used.
It's not free, though.
Besides the third party products listed here, there is another one: NetLib Encryptionizer. However it works in a different way than the obfuscators. Obfuscators modify the assembly itself with a deobfuscation "engine" built into it. Encryptionizer encrypts the DLLs (Managed or Unmanaged) at the file level. So it does not modify the DLL except to encrypt it. The "engine" in this case is a kernel mode driver that sits between your application and the operating system. (Disclaimer: I am from NetLib Security)
I am in the last year of undergraduate degree and i am stumped by the lack of example in c++ and c# large project in my university. All the mini project and assignment are based on text based database, which is so inefficient, and console display and command, which is frustrating.
I want to develop a complete prototype of corporate software which deals in Inventory, Sales, Marketing, etc. Everything you would usually find in SAP. I am grateful if any of you could direct me to a books or article or sample program.
Some of the question are :
How to plan for this kind of programming? should i use the concept of 1 object(such as inventory) have its own process and program and have an integrator sit for all the program, or should i integrate it in 1 big program?
How to build and address a database? i have little bit knowledge in database and i know SQL but i never address database in a program before. Database are table, and how do you suppose to represent a table in a OOP way?
For development type, which is better PHP and C++ or C# and ASP.NET? I am planning to use Web Interface to set form and information, but using a background program to handle the compute. .NET is very much integrated and coding should be much faster, but i really wonder about performance if compared to PHP and C++ package
thank you for the info
This may not answer your question directly, but I thought this might help you get started in some way. So here it goes: I would say, "think through the process". This means, think through the software development process:
Gather requirements
Identify and define the problem.
Get as much information/facts as you can. (turn on green light, think about everything that you want to go into your software)
Come up with a baseline (turn on red lights, what you really want? the minimum functionality your software "must have" - cant live without)
Analyze
Know what you don’t know, what are the missing facts?
Evaluate your information or lack of it/reliability of information source.
Infer facts that you don’t know.
Form an assumption, opinion, or possible solutions.
Consider alternatives and implications of each solution.
Form an action plan.
Identify technology pros/cons.
Decide technology
Comeup with a functional specs.
Research
Dig into stuff that you would want to know (Best database, ORM, design practices, code samples - gather everything, read about inventory systems that are already there)
Design
Develop
Test
Fix
Prepare deployment plan
Release the product
Gather user feedback
Analyze user feedback
Plan for items in next release.
Repeat steps
And Enjoy!
Before I start this is a shallow answer to a deep question.
1) It looks like you have a reasonable grasp of the major components of your target application. As a .net developer I'd build assemblies that matched broad areas of functionality (not sure what the equivalent is in PHP) and then you can use those assemblies together as a single large app, or seperately as required. It's unlikely you'll get it right first time, so build it how it feels right, and then do some ruthless refactoring to make it better once you've got a handled on the problem.
2) This whole area is covered by Object Relational Mapping - ORM, NHibernate is the best of the bunch in the .Net world. BTW if you learn that you'll be way ahead of the game come graduation/work time. Raw sql is so last decade. I guess you know that Sql Server Express is a free download?
3) For development go with the languages/environment you feel most comfortable in. My preference is .net, and the integrated coding is much faster. Performance is definitely good enough, especially as this is learning project - SO runs on .Net and that supports a gazillion users pretty well.
Enjoy
I don't have any good recommendations for SAP-like projects in particular, but in general the best examples to use for things like this are well-established open-source projects. Anything else is going to be a "toy" example in one way or the other, and will be simplified and cleaned up. It's the "cleaned up" that makes it most unrealistic -- one of the really key things that makes real-world large software projects different from university examples is that the real world is messy, and real-world requirements are messy, and collaboration between lots of people with not quite the same priorities is messy, and real-world software projects have to adapt to and thrive in this messiness.
In answer to your specific questions, though:
1.) Do things in a modular way. This means you have something you can test and work with as soon as you get the first module done. That's especially important when you're learning, because (a) you probably won't have time to actually finish the whole thing, (b) you'll learn a lot from writing the first bit that you'll want to apply in future bits and then you'll probably want to rewrite the first bit, and (c) you'll learn even more from using the first bit.
2.) There are many views on this, and many online articles and books. I can't answer that in an answer here (except to note that in some cases trying to represent it in an OOP way is the wrong programming paradigm -- be careful about overconstraining the answer by the question you ask!); the right answer is to find things to read and spend some days reading them.
3.) You do not care about that sort of performance issue here. Successful programs have been written in both forms. You care about what will teach you the most, and what you are comfortable working with. Either one should be fine. You'll probably find more open-source pieces to look at with PHP and C++.
Your question pretty much covers the whole gamut of planning for a project; a whole thesis might be written (+:
Keep in mind what your team and your teaching-staff want out of the project.
1) Modular is my choice. It'll force you to address the application one module at a time and keep you focussed, but that is subject to
The familiarity of your team with the preferred/recommended language for this project.
Time in hand
Remember that modular means you will necessarily have to provide for module integration too.
2) C++ or C# ? Whichever offers the more learning experience. My own experience with both mentioned technologies is limited, but I remember there used to be a Database Template Library (DTL). C# on the other hand will probably be faster to develop. I could be wrong. There are any number of free DBMS engines available on the net. Unless the assignment explicitly recommends using a text, opt for one of these.
3) I concur w/Brooks up there ^^^
Good Luck!
You are a university undergraduate. And you are talking about complete inventory system.
I suggest building a blog application first with all the best practices (like blogengine), then move to e-commerece sites (nopcommerce, dotcommerce). And then do whatever you like.
This is a common problem with undergrads like you, of jumping way higher without building any simple projects first.
As a full time PHP developer, PHP sucks! ASP.net is okay (mmm... no it sucks too), but it locks you into proprietary licenses.
If you're starting from scratch, go for node.js. It's c++ and server-side javascript. Yes, it's new, but it has engineering promise. It'll be more commonplace in a few years.
And if you're worried about performance, don't. Javascript in V8 is extremely fast.
http://shootout.alioth.debian.org/u32/which-programming-languages-are-fastest.php
Here are some node.js links to get you started:
http://www.delicious.com/homer6/nodejs
Enjoy.
We have to perform a semester project with distributed computing using CORBA or ICE. It is a single-person project and we have a couple of months of time.
For the programming language I'd like to focus on c# for it may be any other like C++.
I don't want to write the one millionth prime generator, maybe there is something much more interesting which I didn't think of yet..
Not sure if the focus of the project is on the distributed processing portion or the actual task you decide upon.
CORBA is more prevalent than ICE in the real world, though hardly something you would want to hang a career around. It's still used in various embedded projects and it is still fairly popular in certain military applications.
ICE is easier to work with but doesn't have nearly the industry penetration (to my knowledge) of CORBA. But if your goal is to complete a project and learn distributed principles then I would go with it. It will be much less painful to learn and work with than CORBA. In fact ICE was developed by former CORBA engineers who wanted to correct some of the mistakes they saw in CORBA.
I've found that fault tolerance makes distributed computing projects a little more interesting. The task itself can be relatively simple, but ensuring that it can handle unavailable systems or faulty data adds a nice additional requirement.
If I were you, ....what I would do is go to your prof and ask to work outside the lines. Ask to be released from the CORBA or ICE requirement.
Ask if you can use something that is NOT Corba. Ask if you can use REST, or XML Web services, or even protobufs.
CORBA is not irrelevant, as far as the principles go, but it is nearly irrelevant in commercial appeal. Do something that will teach you some more current skills.
To me, it would be like studying vacuum tubes. Interesting academically and scientifically, but...
Rather than a prime number generator, why not get a little more interesting?
a distributed hash table, something like the new BitTorrent design.
a work distribution system for a compute farm. How would you build a distributed map/reduce across that farm? you could do encryption, compression, video ripping. Build a general purpose distributed work management system that would be appropriate for any of those jobs, with a modular architecture. How would you detect failures (host offline or non-responsive)? How would you deal with rescusitated hosts?
a SETI-#Home type of network. or protein folding. or climate trend analysis (using Public Domain databases - http://en.wikipedia.org/wiki/Public_Domain_Resource ) Something where you're doing something more practical than computing prime numbers.
OR - actually do the prime number problem, but apply it to cryptography, breaking keys.
a network of agents, where you actually distribute code to the nodes to execute. Something like JavaSpaces.
a poker bot.
just some ideas.
If your project is asking you use CORBA or ICE. I would say try both and see which one you make progress on first, then go with that one. They both seem to have C# interfaces (from google searches).
Otherwise you could look into using .Net Remoting. It wasn't too tough to get the rudiments working for me the one time I was asked to do it... ~2 years ago now.
I was thinking about obfuscating a commercial .Net application. But is it really worth the effort to select, buy and use such a tool? Are the obfuscated binaries really safe from reverse engineering?
You may not have to buy a tool - Visual Studio.NET comes with a community version of Dotfuscator. Other free obfuscation tools are listed here, and they may meet your needs.
It's possible that the obfuscated binaries aren't safe from reverse engineering, just like it's possible that your bike lock might be breakable/pickable. However, it's often the case that a small inconvenience is enough to deter would be code/bicycle thieves.
Also, if ever it comes time to assert your rights to a piece of code in court, having been seen to make an effort to protect it (by obfuscating it) may give you extra points. :-)
You do have to consider the downsides, though - it can be more difficult to use reflection with obfuscated code, and if you're using something like log4net to generate parts of log lines based on the name of the class involved, these messages can become much more difficult to interpret.
Remember that obfuscation is only a barrier to the casual examiner of your code. If someone is serious about figuring out what you wrote, you will have a very hard time stopping them.
If you have secrets in your code (like passwords), you're doing it wrong.
If you worried someone might produce your own software with your ideas, you'll have more luck in the marketplace by providing new versions that your customers want, with technical support, and by being a partner to them. Good business wins.
At our company we evaluated several different obfuscation technologies, but they all had problems. The biggest problem was that we rely a lot on reflection, e.g. to dynamically create grids based upon property names.
So all of the obfuscators rename things, you can disable it of course, but then you lose a lot of the benefit of obfuscation.
Also, in our code we have a lot of NUnit tests which rely on a lot more of the methods and properties being public, this prevented some of the obfuscators from being able to obfuscate those classes.
In the end we settled on a product called .NET Reactor
It works very well, and we don't have any of the problems associated with the other products.
"In contrast to obfuscators .NET Reactor completely stops any decompiling by mixing any pure .NET assembly (written in C#, VB.NET, Delphi.NET, J#, MSIL...) with native machine code. In detail, .NET Reactor builds a native wall between potential hackers and your .NET code. The result is a standard Windows based, not MSIL compatible, file. The original .NET code remains intact, well protected by native code and invisible for prying eyes. The original .NET code is not copied on harddisk at any time. There is no tool which is able to decompile .NET Reactor protected assemblies."
The fact that you actually can reverse engineer it does not make obfuscation useless. It does raise the bar significantly.
An unobfuscated .NET assembly will show you all the source, highlighted and all just by downloading the .NET Reflector. Add obfuscation to that and you'll reduce very significatively the amount of people who'll be able to modify the code.
It depends on you are you protecting yourself from. If you'll ship it unobfuscated, you might as well open source the application and benefit from marketing. Shipping it obfuscated will only allow people to relatively easily generate modified binaries through patches instead of being able to steal your code and create a direct competitor. Getting the actual source from obfuscated code is very hard, depending on the obfuscator, of course.
I think that it depends on the type of your product. If it is directed to be used by developers - obfuscation will hurt your customers. We've been using the ArcGIS products at work, and all the DLLs are obfuscated. It's making our job a lot harder, since we can't use Reflector to decipher weird behaviors. And we're buying customers who paid thousands of dollars for the product.
So please, don't obfuscate unless you really have to.
Things you should take into account:
Obfuscation does not protect your code or logic. It just makes it harder to read and understand.
Obfuscation does no one stop from reverse engineering. It just slows the process down.
Your intellectual property is protected by law in most countries. So if an competitor uses your code or specific implementation, you can sue him.
The one and only problem obfuscation can solve is that someone creates a 1:1 (or close to 1:1) copy of your specific implementation.
Also in an ideal world reverse engineering of an obfuscated application is economical unattractive.
But back to reality:
There exists no tool on this planet that stops someone from copying user interfaces, behaviors or results any application provide or produce. Obfuscation is in this situations 100% useless
The best obfuscator on the market cannot stop one from using some kind of disassembler or hex editor and for some geeks this is pretty good to look into the heart of an application. It's just harder than on an unobfuscated code.
So the reality is that you can make it harder and more time consuming to look into your application but you won't really get any reliable protection. Regardless if you use a free or an commercial product.
Advanced technologies like control flow obfuscation or code virtualization may help to make understanding of logic sometimes really hard but they can also cause a lot of funny and hard to debug or solve problems. So they are sometimes more like an additional problem than a solution.
From my point of view obfuscation is not worth the money some companies charge for their products. If you want to nag casual developers, open source obfuscators are good enough. If you want to make it as hard as possible to look into the heart of your applications, you need to use cryptographic containers with virtual execution environments and virtual filesystems but they also provide attack vectors and may also be a source for a bag full of problems.
Your intellectual property and your products are in most countries protected by law. So if there's one competitor analyzing and copying your code, you can sue him. If a bad guy or and hacker or cracker takes your application you are pranked - but an obfuscator does not make a difference.
So you should first think about your targets, your market and what you want to achieve with an obfuscator. As you can read here (and at other places) obfuscation does not really solve the problem of reverse engineering. It only makes it harder and more time consuming. But if this is what you want, you may have a look to open source obfuscators like e.g. sharpObfuscator or obfuscar which may be good enough to nag casual coders (a List can be found here: List of .NET Obfuscators on Wikipedia).
If it is possible in your scenario you might also be interested in SaaS-Concepts. This means that you provide access to your software but not the software itself. So the customer normally has no access to your assemblies. But depending on service level, security and user base it can be expensive, complex and difficult to realize a reliable, confident and performant SaaS-Service.
No, obfuscation has been proven that it does not prevent someone from being able to decipher the compiled code. It makes it more difficult to do so but not impossible.
I am very confortable reading x86 assembly code, what about people that is working with assembly for more than 20 years ?
You will always find someone that only need a minute to see what your c# or c code is doing...
Just a note to anyone else reading this years later - I just skimmed through the Dotfuscator Community Edition (that comes with VS2008) license a few hours ago, and I believe that you cannot use this version to distribute a commercial product, or to obfuscate code from a project that involves any developers other than yourself. So for commercial app developers, it's really just a trial version.
...snip...
these messages can become much more
difficult to interpret
Yes, but the free community edition that comes with Visual Studio has a map functionality.
With that you can back track the obfuscated method names to the original names.
I've had success putting the output from one free obfuscator into a different obfuscator. In Dotfuscator CE, only some of the obfuscation tricks are included, so using a second obfuscator that has different tricks makes it more obfuscated.
It's quite simple to reverse engineer a .net app using .net reflector - since the app will generate VB, VC and C# code straight from the MSIL, and it's possible to pull out all kinds of useful gems.
Code obfuscators hide code quite well from most reverse engineering hacks, and would be a good idea to use on proprietary and competitive code that adds value to your app.
There's a pretty good article on obfuscation and it's workings here
This post and the surrounding question have some discussion which might be of value. It isn't a yes-or-no issue.
Yes you definitely should. Not to protect it from a determined person, but to get some profit and have customers. By the way, if you reach a point here someone tries to crack your software, that means you sell a popular software.
The problem is what tool to choose for the job. Check out my experience with commercial obfuscators: https://stackoverflow.com/questions/337134/what-is-the-best-net-obfuscator-on-the-market/2356575#2356575
Yes, we do. We use BitHelmet obfuscator. It's new, but it works really well.
But is it really worth the effort to select, buy and use such a tool?
I found Eazfuscator cheap (free), and easy to use: took about a day.
I already had extensive automated tests (good coverage), so I reckon I could find any bugs that are/were introduced by obfuscation.