How can I convert my C# code to DLL file in a way that the user of DLL can’t view my source code?
When I make DLL in the way I always do by making a class library project, importing my classes and compiling it, the source code can still be viewed.
I believe you are looking for an obfuscator. This is a tool that will take a compiled DLL and rewrite the code with the intent of it not being meaningfully decompiled by another user. Visual Studio comes with a free Dotfuscator
Note, this will not actually prevent people from looking at your code. They will instead be looking at a very weird translation of your code. There is no way to prevent people from looking at decompiled versions of your code in C# or any other .Net language for that matter.
This is not something that is unique to C#. It is fact a flaw of every language in existence. It's perfectly possible to decompile C code. The difference though is it's much easier to maintain a lot of the original code structure when decompiling managed languages (.Net and Java for instance) because the metadata maintains the original structure.
obfuscation is what you want to search for.
There is a free one (that is limited) in visual studio called Dotfuscator.
Uses fancy methods to rename your code and alter flowpaths to obscure it.
Consider using an obfuscator.
If you are developing desktop applications converting your code to Dll will not hide the it( there are many tools to decompile the dll or exe files).
but if you are using Asp.Net, then you can compile your site to Dll, and the code will not be visible in the aspx pages, it will be compiled to Dll, you can do that by right click on your project on solution explorer, then choose Publish website
But in all cases .Net Exe files and DLL will be easy to decompile and extract the source code again, unless you use tool to obfuscator your code.
If you mean, the end-user can view your source code by decompiling it, you can protect yourself using an obfuscator.
There is standard obfuscator build in into Visual Studio. In the menu choose Tools / Dotfuscator community edition.
I think my reply to a similar question about JavaScript obfuscation applies here as well: in short, why bother? Your question has already been answered here ("use an obfuscator"), but I thought it wouldn't hurt to find out what your motivations are. Generally, code that you give to people is "in the hands of the enemy" -- if somebody wants to use it/figure out how it works badly enough, they will.
Related
I have an .exe which is a portable program. It is assembled with Microsoft Visual C# / Basic .NET
I managed to find out that in order OllyDBG to be able to open it, it should be running and also JIT compiler producing some code. I am a beginner and not at all understand the full process. When it's running, it doesn't create any other files near it ( though when laucnhing the installable version it creates a temporary .dat file aside it). But the portable version is the same size so I am working with it.
While it is running, anyway the debugger can't open it ( nor the installed version )... So my question is - what am I missing in order to make it readable. I just need to make a small change in the .exe but I cannot get into it. Please help me with few more details to make it happen.
If it really is a managed application built with a .NET compiler, then the assembly program is actually composed of IL code, which can more or less be reverted back into source code for you to modify. In order to do this, you can use a tool such as ILSpy or .NET Reflector.
There is a possibility that the assembly may have some kind of obfuscation to discourage decompilation, and in that case, you will need either look to the developer of the software for permission, or to a specialized deobfuscation program like de4dot.
Keep in mind, the terms of service of the application may forbid you from modifying the assembly, but this isn't a legal advice forum.
I've read many solutions to the issue of using C# code in a C++ project, including this one: How to use c# code in C++ project
I've also read this, and one answerer says Compile your C++ code with the /clr flag. With that, you can call into any .NET code with relative ease.
Does this mean that I can use C++ & C# code together, within the same project if I append the /clr flag?
I'm a little confused by this, and it'll just waste time if I went the long route of converting the C# project that I'm trying to use parts of to C++, if doing so isn't actually needed.
Basically, I answered my own question on a different topic a couple of days ago without realising that the actual code of the sample project is C#:
Obtaining Current Network Rate
Can anybody give me a firm clarification to whether I understand this correctly (that I can use C# code in a C++ project with no issues, apart from the /clr switch being required)?
I'm not sure if SO is the right place to ask a question like this, so please tell me if it isn't instead of downvoting with no explanation.
Thanks.
Edit
Forgot to mention that this is a C++/CLI gameserver application DLL on Windows. If it matters, it is used on only Windows Server 2008 R2 and Windows 7.
If you use C++/CLI, then you can add references to other .net assemblies, but you do not mix C++ and C# code in the same project. What you would do is to create a new project (or add an existing one) in your solution using C#, and then add a reference to it in the C++/CLI project.
The drawback is that you need to marshal between C++ and .Net types (std::string vs System::String^), and you also need to learn the additional syntax used by C++/CLI (^, gcnew, etc.).
Further reading: Pure C++: Hello, C++/CLI
It means, that with the /clr switch, you can access assemblies (DLL or EXE) written for the .Net framework. Because such assemblies can be created with any .net language (including C#), you can use "code" written in C# from within C++, but it doesn't mean that you would be able to write C# in C++ project. Unfortunately - you can't.
You need to make a C++/CLI project in visual studio.
C++/CLI is a bit different to C++, because there is the managed stack, so memory is managed and you can avoid memory leaks (garbage collection).
Simply create a C++/CLI project and click on propietys and add a reference to your C# project, it should work :D
http://www.codeproject.com/KB/cs/ManagedCOM.aspx
I have an application I made that I lost the source code for, but the application has worked on my Win 2K computer. Now when moving to a Windows 7 computer it won't start. Probably some dependencies that needs to be solved, but I don't know which. The only error I got is a System.InvalidOperation without further description
Is there any tools(free) that I can use to get more specific information on what goes on
I am not sure how/if you can debug the application, but here is another idea.
There are tool out there called "reflectors", which allow you to look inside the .NET dll or executable.
They basically do the reverse of the compiler convert the dll/exe to source code (Now it won't be exactly the code you wrote, for example some local variables might have changed their names and some things might have been optimized, but the end result is the same, since this reflected code came from the same dll/exe.)
Now you can take the output of this and use it to rebuild and then debug your application.
Here are some ofthese tool:
dotPeek - free
.NET Reflector - not free
I know dotPeek doesn't allow you to debug inside of it, so you have to rebuild your application. The other one seems to be able to do that with its most expensive licence. Good luck!
You can also use Microsoft Debugging Tools for Windows (WinDbg). Here is an article that can help you.
http://www.dependencywalker.com/ will tell you dependencies and missing ones.
Also, you can attach visual studio, or get visual studio to launch a exe in debug mode without the source code.
my first try would be dependency walker just to make sure your not
missing some piece of native code
then I would look to just attempting to attach the program to visual
studio.
My next step would be to use something like reflector to get some
version of source code.
The pro version of regate's reflector let's you debug an existing dll without the sourcecode, costs $ 138 tho.
Ilspy will let you see the source for free, maybe you can figure it out from that.
Rgds Gert-JAn
I'm going to ask a newbie question here. I need to use a control I found online in my code, but it was written in the wrong language. It is in C# and I am using VB.net for work. I have all of the code for the control which works beautifully in C#, but I had issues with it not working very well in VB.
The source code and a demo project are available here, but I am not sure exactly which files I should use to build the dll for VB.
It seems a lot to ask, but would someone mind taking a look and pointing me in the right direction?
Cheers
Add the project to your solution, or just build it using your version of Visual Studio. Then add a reference, either to the project in the first case, or the .dll in the second.
If the Control doesn't work well, it's not because it's written in C# as opposed to VB.Net.
You should be able to use/reference the DLL as-is from your visual basic solution. It doesn't matter whether it was written in C#, VB.NET or any other .net language.
One you compile a dll from the c# source it will work exactly the same as if it were written in vb. You simply need to create a reference to the dll in visual studio.
I am trying to using PDF Library ITextSharp, in my project. ITextSharp has so many features, i am not using even 5% of it. I am just wondering, why i should ship the complete dll file, when i use only 5% of it.
Is there any way to statically link the library to my project and remove all unused methods,features from the library ?
Disclaimer: I work for the company whose product I'm going to mention. I do know that other tools can do this as well but I only have direct experience with this one.
It is not necessary to modify any of the ITextSharp source or to perform your own custom build. It is possible to achieve all that you need with just the assemblies in your bin directory.
You can use Dotfuscator (the Removal option) to perform static analysis of the entirety of your application and output an assembly that only contains code that is actually used in your app. In addition you can use the Linking feature to link the DLL into your exe so that you are only shipping one file to the customer. This can result in a significantly smaller application footprint. You can take advantage of all of this functionality even if you choose not to use the obfuscation features that make you application harder to crack and reverse engineer.
Dotfuscator can be added into your build process in a number of ways, we integrate directly into Visual Studio (versions 2002 through 2010) so that you can just build your solution, there is also an MSBuild task for using on a Team Build server (if you choose not to have the build server build your solution), as well as a command line version for any other build system.
Dotfuscator will work on any .NET assembly type from including Silverlight assemblies.
These features are only available in the Pro version of Dotfuscator, if you contact PreEmptive Solutions we can set you up with a free, time limited evaluation so you can see how the product works for you.
If you just want to perform linking of assemblies there is also the ILMerge utility from Microsoft Research that will link multiple .NET assemblies into a single assembly.
There is no benefit of static linking with .NET dlls.
Its not easy to judge that you are using only 5% of the library, library may be using so much of internal code inside it to do lots of small small things that may not be seen by naked eye.
However iTextSharp is open source, you can create striped down version of iTextSharp to ship with your project.
By the way iTextSharp is smaller quite compared to earlier dlls required on non .net days.
Without modifying the source code and building your own .dll, no there is no way to not ship the entire thing. Additionally, if you wanted to head the route of creating your own modified .dll, please be aware of any possible licensing issues involved (I don't know if there are any, but it's certainly something you should be aware of). And finally, I would add, I don't know how big the iTextSharp .dll is, but really ask yourself if however much space it takes up actually matters.
If you want to reduce the size you have two options an obfuscator or an assembly compressor.
I haven't used any obfuscator for .Net just for Java so I can't recommend you any but they do what you pretend: remove unused methods and classes.
Or you can create a single compressed executable with all the needed assemblies that is auto decompressed when started like the popular Aspack and UPX do for windows executables http://en.wikipedia.org/wiki/Executable_compression . I have tried .NetZ and was happy with the results.
In this type of situation, your best bet is the site where you downloaded the code.
In many cases they use conditional compilation to include/exclude certain pieces. If the code isn't written with conditional compilation in mind, it will be "difficult" to do it yourself.
I personally would not recompile the source, unless there is a bug that needs to be fixed and you cannot wait for a new release. The time spent on the changes is time lost on your main project (the one you're getting paid for).