How to provide user name and password when connecting to a network share


When connecting to a network share for which the current user (in my case, a network enabled service user) has no rights, name and password have to be provided.

I know how to do this with Win32 functions (the WNet* family from mpr.dll), but would like to do it with .Net (2.0) functionality.

What options are available?

Maybe some more information helps:

  • The use case is a windows service, not an Asp.Net application.
  • The service is running under an account which has no rights on the share.
  • The user account needed for the share is not known on the client side.
  • Client and server are not members of the same domain.
11/17/2008 1:21:55 PM

Accepted Answer

You can either change the thread identity, or P/Invoke WNetAddConnection2. I prefer the latter, as I sometimes need to maintain multiple credentials for different locations. I wrap it into an IDisposable and call WNetCancelConnection2 to remove the creds afterwards (avoiding the multiple usernames error):

using (new NetworkConnection(@"\\server\read", readCredentials))
using (new NetworkConnection(@"\\server2\write", writeCredentials)) {
   File.Copy(@"\\server\read\file", @"\\server2\write\file");
11/17/2008 2:39:18 PM

Exper Answer

One option that might work is using WindowsIdentity.Impersonate (and change the thread principal) to become the desired user, like so. Back to p/invoke, though, I'm afraid...

Another cheeky (and equally far from ideal) option might be to spawn a process to do the work... ProcessStartInfo accepts a .UserName, .Password and .Domain.

Finally - perhaps run the service in a dedicated account that has access? (removed as you have clarified that this isn't an option).

11/17/2008 1:23:11 PM

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