Access Denied (5) Error when trying to connect to named pipe from C++ client to C# application

Question

_{Friday, February 26, 2010 4:47 AM}

Hi,

I am running a c# application under my account which has Administrator priviliges. I am trying to have a c++ low integrity application connect to the named pipe. I keep getting Access Denied when I call CreateFile in the c++ code. When I change the C++ client to not be low integrity app anymore it works just fine. How do I Create my named pipe in C# to allow the low integrity apps to connect to it.

Here is my c# code:

SafeFileHandle

handle = Win32Wrapper.CreateNamedPipe("\\.\pipe\newpipename",

Win32Wrapper.DUPLEX,

if (handle.IsInvalid)

Thread.Sleep(100);

continue;

int result = Win32Wrapper.ConnectNamedPipe(handle, IntPtr.Zero);

The CreateNamePipe call is just a wrapper for the c++ one.

Then in C++ I try to do this:

"\\.\pipe\newpipename", GENERIC_READ | GENERIC_WRITE, FILE_SHARE_WRITE | FILE_SHARE_READ,

char buffer[2];

'M';

'\0';

DWORD bytesWritten = 0;

WriteFile(handle, buffer, 1, &bytesWritten, NULL);

But I am always getting access denied on the create file cause of it being a low integrity app.

Any help would be appreciated.

Thanks

buffer[1] =

buffer[0] =

HANDLE handle = CreateFile(

All replies (3)

_{Friday, February 26, 2010 8:50 AM ✅Answered | 1 vote}

Hello

Modifying a resource's integrity level is well-covered in the following post by Kenny Kerr: http://weblogs.asp.net/kennykerr/archive/2006/09/29/Windows-Vista-for-Developers-_1320_-Part-4-_1320_-User-Account-Control.aspx

See Resource integrity levels and the relevant sample code.

Regards,
Jialiang Ge
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_{Friday, February 26, 2010 5:45 AM}

http://en.wikipedia.org/wiki/Mandatory_Integrity_Control The following is signature, not part of post
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Visual C++ MVP

_{Friday, February 26, 2010 6:31 AM}

Interesting read, it says you can make the named pipe object be accessible at a low integrity level so low integrity apps can communicate with it. Thats great, and I figured you could do that. But it doesn't tell me how to in C# make it work. I have tried lots of different security stuff to try and get this working cause it should according to that wikipedia article.

Thanks