Is there a way to hook into the Windows File Copy API from C#? I'm aware this would require unmanaged code, but a code sample or starter would be helpful. I've already seen the C++ code, but it's all greek.
UPDATE: I apologize, I should have been more clear about my intentions. I wish to actually change the copy feature of Windows to be more rigid (e.g. allow queing, scheduling, handle restarts, pauses, etc.). When I said hook, I meant API hook so that when someone starts a copy I get the sources and destinations and can handle it to my heart's desire. I'm old school and used to hook the Mac OS API a lot to do these things so I assumed that in the C++ WINAPI world there was some type of equiv.
Update:
As others have stated, why not just use System.IO.File.Copy(...)? It calls this same underlying API. As Michael G points out, perhaps you intend to call the the FileCopyEx API that allows you to hook progress-indication callbacks(???) That's really the only reason to P/Invoke file-copy stuff in .NET. Details on how to implement FileCopyEx that can be found here: http://pinvoke.net/default.aspx/kernel32/CopyFileEx.html
Original answer: (which you really shouldn't use...)
Code snippet removed because you really shouldn't use it...
If you're hell-bent on making busted-code, you can find out how to use it at: Found at http://pinvoke.net/default.aspx/kernel32/CopyFile.html
I wish to actually change the copy feature of Windows to be more rigid
You shouldn't do that in managed code, because of the same reasons you should not write managed shell extensions.
You can do so by calling System.IO.File.Copy. Its internal implementation already uses the Windows API.
Edit: File.Copy also handles permissions correctly and has the benefit of throwing an exception with meaningful data if something fails, so you don't have to manually check and analyze the return status.
You can use Deviare API Hook that lets you intercept any API from .NET and read parameters using VARIANT types. There is a full example very easy to follow in C#.
The other benefit of using unmanaged Copy File API is the ability to have a progress callback.
Note: as stated in other answers, I would use the managed version of File.Copy as it's safer, and can usually do everything you require.
Related
I am working on an anticheat and I would like to hook APIs like Read/WriteProcessMemory, OpenProcess and maybe some more to check if it reads or writes some data to/from the game.
But I am not that experienced programmer to do it on my own so I tried to do it via easyhook. Firstly I got the example (http://www.codeproject.com/Articles/27637/EasyHook-The-reinvention-of-Windows-API-hooking) to work. Then I tried to replace CreateFile by ReadProcessMemory but there was a line This.Queue.Push(hProcess);, how am I supposed to replace hProcess in case I am hooking ReadProcessMemory?
I couldn't find any other example of hooking API in C# than the one hooking CreateFile posted above.
Also it doesn't need to be done by easyhook if there is a simpler way.
Thanks.
I didn't read all of that article but the way I understood it, the
This.Queue.Push(<argument to the original function>)
part is for the tracing portion of his example.
If all you want to do is prevent someone from calling ReadProcessMemory then you don't need to do this and you also won't be calling the original entry point - just return FALSE to the caller.
I am trying to execute an .exe file from my C# code. The .exe file requires some key to exist in the registry. Now I have two options:
1. Either I can add the key, execute the file, and then delete what I added from registry.
2. OR If possible, I can fake the key in registry so that .exe can execute and I don't have to modify the registry.
Can someone please tell me if #2 is possible? If not then is there any other better way to deal with this situation (perhapds undo changes I made from registry)? or do I have to stick with #1?
Please guide me on this.
Thanks
Intercepting registry reads is not for the faint of heart and will almost certainly require several orders of magnitude more work than option 1.
There is a function for that, but it only affects the process which calls it. So you would have to use DLL injection. C# (or any type of managed code) would not be my choice for accomplishing this.
If you must intercept the read, then start developing a driver in C/C++ that calls CmRegisterCallback to hook system-wide calls and filter out the ones you need. But I think you'll seriously regret even starting the project... just go with option 1 instead.
It's technically possible to intercept calls to the registry using something like Detours. However, the intercept code cannot be written in C# and must be in C++ (or C, I suppose). Not to mention, doing this in a robust manner is going to be a lot of work.
This is likely a long shot, but I thought I'd ask anyway. I'm using a document management system's API. They provide a "WriteFile" method to save a given document to disk. However, the library does not have a way to simply read a document into memory. My only option, it seems, is to write to disk, then read it back in again. I'm wondering if there is a better way to work around this obvious limitation.
The method takes a string for the resulting file path. Method signature:
void ImageInfo.WriteFile(string Filename);
Theoretically, it is possible to intercept the WriteFile win32 API calls of any process, be it .NET, C++, etc using something called as Import Address Table Hooking which actually is a valuable tool in software testing on windows.
Basically you could overwrite the WriteFile,kernel32.dll entry in the Import Address Table to point to your method and then intercept the bytes which are attempted to be written.
There are probably other ways in layers above, like in .NET where you could possibly change the ILASM code of the 3rd party app dll. Or have your own version of some of the .NET dlls which replace some of the standard .NET classes.
Practically, it might not really be worth it, for e.g. If the API does not explicitly flush the file to disk, your subsequent reads might end up coming from the OS file cache and won't be that big a perf problem. You could probably achieve this by creating the file and keeping it open before calling WriteFile (just a guess).
Of course, I suppose you have profiled and measured it already.
You'd need a Windows API hooking library that can call a managed code callback. Easyhook is one such library. Beware that you might out that you haven't gained anything after you're done, the file system cache already provides direct memory access to file data.
It sounds like the API does not provide the reading part because they can't provide a better (more performant) manner than what is already available in the .NET framework.
There are many articles about "how to turn off monitors in c#", but they all turn off all the monitors. Is there any possible way to turn off a particular monitor?
A little bit of research lead me here:
http://www.codeguru.com/forum/showthread.php?p=1011720#post1011720
Do you know how to call a function like that in c#?
-- Edit
Looks like this guy has done it all for you:
http://www.codeproject.com/KB/dotnet/Display_Settings.aspx
For calling Win32 Functions not exposed in the .NET Framework
PInvoke.net
is a good ressource.
The function mentioned in the link of silky can be found here.
Also have a look at the used data types.
Just copy the code mentioned in "C# Signature" to your project.
Given that the monitor belongs to the user, not you, why do you want to turn it off.
This is just the sort of think I think a OS should protect me from when a application tries it, so expect problems…
I'm a C# developer and I have to change my display resolution regularly.
There are plenty of examples on how to read the current display resolutions:
SystemInformation.PrimaryMonitorSize
I found the ChangeDisplaySettingsEx Function
Is the only way to do this in C# is with PInvoke???
It seems odd to me that it is very easy to get this information out, but difficult to set it...
You'll have to make a PInvoke call to ChangedisplaySetting.
Here's a link that has some sample code, http://www.xtremedotnettalk.com/printthread.php?t=73184.
I also recommend that you check out Jared Parsons PInvoke Toolkit. You can download it here:
http://www.codeplex.com/clrinterop/Release/ProjectReleases.aspx?ReleaseId=14120
It makes adding pinvoke signatures to your code a breeze. It doesn't always pick the right interop types, but it's usually pretty close, and even if you have to make some changes its still usually quicker than translating everything by hand.
Simple answer: Yes.
You should use PInvoke.