CODEWITHSUNDEEP
c#.netfileauthenticationio
BlueRaja - Danny Pflughoeft
BlueRaja - Danny Pflughoeft

Reputation: 85966

Copying files over network (requiring authentication)

Is there some way to authenticate as a local (not network) user in order to copy files over the network in .Net?

net use is not an option, and I can't seem to get LogonUser to work.

Any ideas?

[Edit] Here is some code:

public class UserImpersonator : IDisposable
{
    private WindowsImpersonationContext _impersonationContext;
    private IntPtr _userHandle = IntPtr.Zero;

    [DllImport("advapi32.dll", SetLastError = true)]
    private static extern bool LogonUser(
        string lpszUsername,
        string lpszDomain,
        string lpszPassword,
        int dwLogonType,
        int dwLogonProvider,
        out IntPtr phToken
        );

    [DllImport("kernel32.dll", SetLastError = true)]
    private static extern bool CloseHandle(IntPtr hHandle);

    public UserImpersonator(string username, string password)
    {
        LogonUser(username, "", password, (int)LogonType.LOGON32_LOGON_NETWORK,
                  (int)LogonProvider.LOGON32_PROVIDER_DEFAULT, out _userHandle);
        _impersonationContext = WindowsIdentity.Impersonate(_userHandle);
    }

    public void Dispose()
    {
        CloseHandle(_userHandle);
        _impersonationContext.Undo();
    }

    private enum LogonType : int
    {
        LOGON32_LOGON_INTERACTIVE = 2,
        LOGON32_LOGON_NETWORK = 3,
        LOGON32_LOGON_BATCH = 4,
        LOGON32_LOGON_SERVICE = 5,
        LOGON32_LOGON_UNLOCK = 7,
        LOGON32_LOGON_NETWORK_CLEARTEXT = 8,
        LOGON32_LOGON_NEW_CREDENTIALS = 9,
    }

    private enum LogonProvider
    {
        LOGON32_PROVIDER_DEFAULT = 0,
    }
}

When I wrap the File.Copy operation in using(new UserImpersonator(username, password)), I get:

System.IO.IOException: Logon failure: unknown user name or bad password.

If, however, I first try to connect to the share in explorer (entering the authentication info when it asks for it), the File.Copy works. It appears that the above code doesn't do anything at all.

Upvotes: 7

Views: 23972

Answers (3)

Jesse C. Slicer
Jesse C. Slicer

Reputation: 20157

Might I direct you to my answer I put over here? It should work for your needs.

Upvotes: 1

Steven Sudit
Steven Sudit

Reputation: 19620

You really need to logon to either a local account that is a member of a group on the domain controller, or just log directly onto a DC account. Without more information, though, I'm not sure what you're having trouble with. Could you post code?

edit

Ok, I see two problems.

The main problem is that you're passing an empty string for the domain parameter of LogonUser. Try passing in the name of the local machine or the network DC.

The side problem is that you need to log in using Batch or Interactive, not Network. Network login gives you an impersonation token, not a primary logon, which may prevent you from reaching network resources unless delegation is enabled.

Also, once you get this working, you're going to want to remove the IntPtr entirely and replace it with a SafeHandle.

Upvotes: 0

Joe
Joe

Reputation: 42597

You can use WNetUseConnection with p/invokes.

See this thread:

Accessing a Shared File (UNC) From a Remote, Non-Trusted Domain With Credentials

Upvotes: 4

Related Questions