I have a WPF application whose output is a.exe. This application is dependent on an external b.dll (whose source code I have access to).
Requirements:
The output should only be a.exe which should contain the dll. I don't want to provide my users with a separate dll (if it can be avoided)
I should be able to obfuscate the code. (I don't want anyone to be able to modify it).
Approaches tried:
I embedded b.dll inside a.exe, it worked. But I was not able to obfuscate the exe as it gave an error that it was unable to find b.dll.
I obfuscated a.exe and b.dll but it did not work. It was unable to find b.dll.
Alternate approach :
Is there any way that I can perhaps add the spruce code of b.dll to my project and have the dll be compiled to the exe itself rather than a separate dll.
Is it possible to make this alternate approach work or are there any other ways ?
If nothing works, I know that I can compile a and b separately, obfuscate a and provide b as a separate file (what I'm trying to avoid).
Apologies for the formatting issues, if any, I'm using the android app. Let me know if you need any details.
I have had great success with Eazfuscator.Net in the past.
http://www.gapotchenko.com/eazfuscator.net
To run it from the command line enter the following command:
Eazfuscator.Net.exe -n a.exe b.dll
It will combine the two files into a single exe. The main program will be able to access the dll.
You can even set up Visual Studio so that the command line above runs as a post compile event.
Assembly embedding may seem quite confusing, so here is how it's usually done:
The dependencies are obfuscated if needed.
The target assembly is obfuscated. At this point, the obfuscator is also instructed to embed certain dependencies as a part of obfuscation process.
As a result, the embedded assemblies are stored as a resource of the target assembly.
In order to load dependencies at runtime, obfuscators usually install a handler for AppDomain.AssemblyResolve event that is raised by CLR when it fails to resolve an assembly automatically.
The handler extracts and loads an embedded assembly from the resource.
That's it. A good obfuscation tool allows achieving that quite easily. I don't see why it wouldn't work in the case with WPF application. If there are problems, I would recommend contacting product support.
Another option is assembly merging. Unlike embedded, the merged assemblies become an inseparable part of the target assembly code. For this reason, the assembly merging often helps to achieve a better obfuscation coverage and application startup time comparing to embedding. Although it may look a better option, merging may sometimes break the application functionality.
Related
I have a C# COM-Interop assembly which I am calling from a Visual Basic 6 application. This assembly makes HTTP requests to send and retrieve JSON.
The assembly works fine when being testing with a C# test client.
However, when using it from with the VB6 app, the following error is returned:
"Could not load file or assembly 'Newtonsoft.Json, Version=4.5.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed' or one of its dependencies. The system cannot find the file specified."
The Newtonsoft.Json.dll is located within the same folder as the COM-Interop DLL (TLB).
Does the Newtonsoft.Json.dll need to be explicitly loaded? Or maybe placed in the GAC?
Hans provided a great explanation for why this happens. Let me offer a workaround for making this work without having to register the Json DLL in the GAC or copying it to the VB6 EXE directory.
In your COM-visible C# library, we can tell the .NET runtime environment to search for the Json DLL in the directory of the C# library instead of the "usual" paths. We do that by attaching our own handler to the AssemblyResolve event:
AppDomain.CurrentDomain.AssemblyResolve += (sender, e) =>
{
// We only want this workaround for one particular DLL
if (e.Name != "Newtonsoft.Json")
return null;
var myLibraryFolder = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
var path = Path.Combine(myLibraryFolder, "Newtonsoft.Json.dll");
return Assembly.LoadFrom(path);
};
Notes about this workaround:
This code only works if it is executed in your C# library before doing anything that might cause the jitter to load the JSON library. For example, neither your library nor any other .NET library in your VB6 process must call any method referencing types from the JSON library before this code is executed.
You modify the the behaviour of the whole process, not just your library. If your VB6 process uses another library using JSON, your "redirect" affects the other library as well.
This is a standard DLL Hell problem, it is caused by using the /codepage option for Regasm.exe. Or, more commonly, the Project > Properties > Build tab > "Register for COM interop" checkbox. Both do the same thing, they write the path to the DLL into the registry. It is a very good option to use when you are busy developing and testing the project, it avoids having to re-register the DLL into the GAC every single time you make a change.
But what it does not do is help the CLR find any dependencies. The normal probing rules remain in effect, it looks for an appname.exe.config file in the directory where the EXE is stored. And first looks in the GAC, next in the EXE path for dependencies. Configuration remains under control of the usual victim of DLL Hell, whomever has to maintain the EXE. Frequently the end-user. So, explicitly, it does not look in the directory where your [ComVisible] DLL is stored.
It is the mild kind of DLL Hell, just a plain file-not-found mishap. Much milder than the nasty kind, finding a file with the right name but the wrong version. In general a strong problem with Newtonsoft.Json.dll, there are about 35 versions in the wild. Having so many versions and it being such a popular library also begets the other kind of nastiness, the program using another COM server that also uses the DLL. But almost inevitably a different version. Tends to happen long after you declared your project finished. One of them is going to lose, 50-50 odds that it is you. 100% odds for the end-user.
Yes, the GAC solves this problem. Each library gets the version they ask for. Ideally Newtonsoft would solve this problem for you with an installer that deploys the DLL into the GAC. But it is not the kind of commitment that open source library writers ever want to provide. They want (and need) to make it your problem. Microsoft does this, but they also have Windows Update to ensure that critical bug and security fixes get deployed. And have a large number of people working on making sure that any new revisions are always backwards compatible with the original release so the version number doesn't have to change.
Do note that you can take advantage of Microsoft's commitment. You can also use the DataContractJsonSerializer and JavascriptSerializer classes to get this job done. Part of the framework, they rarely get it wrong.
Meanwhile, do keep mind that is just a file-not-found problem. You don't have to use the GAC on your dev machine, and it is better if you don't, it is just as easy to copy the file into the right place to keep the CLR happy. Which is the same directory as your VB6 test program. And, extra quirk with VB6, into C:\Program Files (x86)\Visual Studio\VB6 if you want to use the VB6 debugger. Do use the GAC when you deploy.
I have a Visual Studio 2010 C# project which creates an .exe and this project is using some 3rd party class library.
My project is located in: /MyFramWork/tests/test1
3rd party library is located at: /MyFrameWork/bin/utils/
I am adding the reference to the library by using References->Add Reference->Browse. I can see that in the project file all is fine:
....\bin\utils\log4net.dll
False
I would like to reference the 3rd party library without using the option "Copy Local". However if I don't use the option, the library is not found and I get an exception.
My question is: Is there a way to specify that the 3rd party library should be found at ....\bin\utils. It seems that when the .exe gets build the information from the .csproj gets lost.
By default, .NET apps look for their dependencies in only two places: the EXE directory, and the GAC (Global Assembly Cache).
You have three choices:
You can make sure the dependency gets copied into the same directory as your EXE (this is what Copy Local does). This is the best choice most of the time, which is why it's the default when you reference an assembly that's not already in the GAC.
You can install your dependency into the GAC using gacutil. This might be a good choice if your dependency isn't going to change, is going to be in a different location on every development machine (i.e. if relative paths won't work well), and if you want to use it from many different projects. But it's a major pain if the dependency is still under active development and changing frequently. You'll also need to make sure to put the DLL into the GAC on every computer you deploy your app to.
You can customize the dependency-loading behavior so it looks in other places, as Hans noted in his comment. This is an advanced option and comes with a whole new set of headaches.
Normally, you would just use Copy Local; it's a very sensible default. You should need a fairly compelling reason to do anything different.
Use the <probing> element to specify where the CLR should search for your assemblies. The only restriction is that the assemblies must be located in subdirectories of your application's base directory.
For example, if your application base directory is C:\MyFramework, then you could have your assemblies in C:\MyFramework\bin.
Have a look at this article to learn how the CLR searches for assemblies.
If you need to load assemblies from custom locations, you could try the Assembly.LoadFile Method.
The following links may be useful:
C# - Correct Way to Load Assembly, Find Class and Call Run() Method
http://www.csharp-examples.net/reflection-examples/
It's me Potzon. I am still investigating this incredibly silly problem.
I have been hoping for some elegant solution. I am about to build fairly large framework with lots of assemblies which would be placed inside /Framework/bin/. However I wanted to have some directory structure inside the the directory, for example /bin/utils, /bin/test, /bin/devices/ and so on.
One possible solution that I have found is to define environmental variable DEVPATH (see here http://msdn.microsoft.com/en-us/library/cskzh7h6.aspx) but it turns out that .net4 is not using this variable when an assembly is run independently (outside the visual studio), or at least this is the case for me - I can't make it work.
It seems that the solution to put all the assemblies inside the /bin directory without using sub-directories is the best. I think I will give up and just do it this way.
Is there a way to keep any DLLs needed for my Visual C# program (such as SQLite) inside the actual EXE so it doesn't require the files to be present?
If not, can anyone show me how to make a wrapper for my program (independent of .NET, so maybe C++?) to copy/load required files to the working directory before starting the program itself.
What I intend to end up with is a single EXE file that can be deployed anywhere and set itself up like a transformer. All it requires is the following criteria:
SQLite is present
OpenHardwareMonitorLib is present
.NET 2.0 is installed (if not, offer install with redistributable package)
Microsoft provide a tool for merging DLLs. It's called ILMerge.
It doesn't always work, I believe certain things can cause problems. But it's definitely the easier option!
If the problem is redistribute only one file, you can create a "installer" exe, that unpack all your dependencies (from executable content).
If you don't want to leave all dlls in your production environment, you can merge all IL code in the main executable. you can use ILMerge (but it's not the only product that can do this)
You can merge the dependencies into the main executable. After your build completes you run an additional tool that combines the IL code into a single assembly.
ILMerge can do this but is a bit cumbersome to use.
Some (proprietary) tools can do this as well. I know of at least one obfuscator (DeepSea) that can do this. DeepSea also allows you to specify what you want to include and what types you want to expose from the resulting assembly.
Full disclosure: I know the guys that build DeepSea Obfuscator.
I guess you could embed the target assemblies as resources and then unpack them in some custom assembly resolution code?
Edit: there's an example of this here: Embedding assemblies inside another assembly
There are a lot of posts on here about this, I'm using this code from another SO post and placing a delegate assignation in my Main() method. None of the other posts have directly answered my question.
I've got my third party assembly embedded as a resource but when I fire up the app:
I'm getting a TypeInitializationException with an inner of FileNotFoundException. It's trying to find the assembly on the file system and failing.
it's never getting to the Main method, where the event handler for AssemblyResolve is assigned
I have two assembly refs that are embedded in my Resources.resx, one is a third party tool (command line parser) and the other is a Library file where the meat of the application resides.
Maybe this isn't possible with a console app? Seems unlikely but I don't see a way around it.
Re: ILMerge etc: I'd like to get this done entirely in code without involving any tools. Reason: I don't want to have source code in the repository that requires other team members to install a tool that they probably don't have already. If that's not possible then ILMerge looks like the next best option.
Consider using ILMerge to merge the assemlies into one rather than embedding as a resource. This is download site for ILMerge.
You would merge your third party assemblies into your console app.
You could also look at application virtualization tools like XenoCode. They can package multiple assemblies (including the .net framework itself) into a stand alone executable.
If it is mixed mode assembly, it has to reside on the disk. Some limitation or something.
I'm getting System.IO.FileNotFoundException: The specified module could not be found when running C# code that calls a C++/CLI assembly which in turn calls a pure C DLL. It happens as soon as an object is instantiated that calls the pure C DLL functions.
BackingStore is pure C.
CPPDemoViewModel is C++/CLI calling BackingStore it has a reference to BackingStore.
I tried the simplest possible case - add a new C# unit test project that just tries to create an object defined in CPPDemoViewModel . I added a reference from the C# project to CPPDemoViewModel .
A C++/CLI test project works fine with just the added ref to CPPDemoViewModel so it's something about going between the languages.
I'm using Visual Studio 2008 SP1 with .Net 3.5 SP1. I'm building on Vista x64 but have been careful to make sure my Platform target is set to x86.
This feels like something stupid and obvious I'm missing but it would be even more stupid of me to waste time trying to solve it in private so I'm out here embarrassing myself!
This is a test for a project porting a huge amount of legacy C code which I'm keeping in a DLL with a ViewModel implemented in C++/CLI.
edit
After checking directories, I can confirm that the BackingStore.dll has not been copied.
I have the standard unique project folders created with a typical multi-project solution.
WPFViewModelInCPP
BackingStore
CPPViewModel
CPPViewModelTestInCS
bin
Debug
Debug
The higher-level Debug appears to be a common folder used by the C and C++/CLI projects, to my surprise.
WPFViewModelInCPP\Debug contains BackingStore.dll, CPPDemoViewModel.dll, CPPViewModelTest.dll and their associated .ilk and .pdb files
WPFViewModelInCPP\CPPViewModelTestInCS\bin\Debug contains CPPDemoViewModel and CPPViewModelTestInCS .dll and .pdb files but not BackingStore. However, manually copying BackingStore into that directory did not fix the error.
CPPDemoViewModel has the property Copy Local set which I assume is responsible for copying its DLL when if is referenced. I can't add a reference from a C# project to a pure C DLL - it just says A Reference to Backing Store could not be added.
I'm not sure if I have just one problem or two.
I can use an old-fashioned copying build step to copy the BackingStore.dll into any given C# project's directories, although I'd hoped the new .net model didn't require that.
DependencyWalker is telling me that the missing file is GPSVC.dll which has been suggested indicates security setting issues. I suspect this is a red herring.
edit2
With a manual copy of BackingStore.dll to be adjacent to the executable, the GUI now works fine. The C# Test Project still has problems which I suspect is due to the runtime environment of a test project but I can live without that for now.
Are the C and C++ DLLs in the same directory as the C# assembly that's executing?
You may have to change your project output settings so that the C# assembly and the other DLLs all end up in the same folder.
I've often used the Dependency Walker in cases like this; it's a sanity check that shows that all the dependencies can actually be found.
Once your app is running, you may also want to try out Process Monitor on the code you are running, to see which DLLs are being referenced, and where they are located.
The answer for the GUI, other than changing output settings, was the addition of a Pre-Build Step
copy $(ProjectDir)..\Debug\BackingStore.* $(TargetDir)
The answer for the Test projects was to add the missing DLL to the Deployment tab of the testrunconfig. You can either do so by directly editing the default LocalTestRun.testrunconfig (appears in Solution under Solution Items) or right-click the Solution and Add a new test run config, which will then appear under the main Test menu.
Thanks for the answers on this SO question on test configurations for leading me to the answer.
The reason why this happens is because you either are loading DLLMAIN from managed code, before the CRT has an opportunity to be initialized. You may not have any managed code, be executed DIRECTLY or INDERECTLY from an effect of DllMain notifications. (See: Expert C++/CLI: .Net for Visual C++ Programmers, chapter 11++).
Or you have no native entrypoint defined wahtsoever, yet you have linked to MSVCRT. The CLR is automatically initialized for you with /clr, this detail causes a lot of confusion and must be taken into account. A mixed mode DLL actually delay loads the CLR through the use of hot-patching all of the managed entry point vtables in your classes.
A number of class initialization issues surround this topic, loader lock and delay loading CLR are a bit trickey sometimes. Try to declare global's static and do not use #pragma managed/unmanaged, isolate your code with /clr per-file.
If you can not isolate your code from the managed code, and are having trouble, (after taking some of these steps), you can also look towards hosting the CLR yourself and perhaps going through the effort of creating a domain manager, that would ensure your fully "in-the-loop" of runtime events and bootstrapping.
This is exactally why, it has nothting todo with your search path, or initialization. Unfortunately the Fusion log viewer does not help that much (which is the usual place to look for .NET CLR assembly binding issues not dependency walker).
Linking statically has nothing todo with this either. You can NOT statically link a C++/CLI application which is mixed mode.
Place your DLLMAIN function into a file by itself.
Ensure that this file does NOT have /CLR set in the build options (file build options)
Make sure your linking with /MD or /MDd, and all your dependencies which you LINK use the exact same CRT.
Evaluate your linker's settings for /DEFAULTLIB and /INCLUDE to identify any possiable reference issues, you can declare a prototype in your code and use /INCLUDE to override default library link resolution.
Good luck, also check that book it's very good.
Make sure the target system has the correct MS Visual C runtime, and that you are not accidentally building the C dll with a debug runtime.
This is an interesting dilemma. I've never heard of a problem loading native .DLLs from C++/CLI after a call into it from C# before. I can only assume the problem is as #Daniel L suggested, and that your .DLL simply isn't in a path the assembly loader can find.
If Daniel's suggestion doesn't work out, I suggest you try statically linking the native C code to the C++/CLI program, if you can. That would certainly solve the problem, as the .DLL would then be entirely absorbed into the C++/CLI .DLL.
Had the same problem switching to 64-bit Vista. Our application was calling Win32 DLLs which was confusing the target build for the application. To resolve it we did the following:
Go to project properties;
Select Build tab;
Change 'Platform target:' option to x86;
Rebuild the application.
When I re-ran the application it worked.