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

Question

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 kn

Answer 1

The Luke Quinane solution looks good, but did work only partially in my ASP.NET MVC application. Having two shares on the same server with different credentials I could use the impersonation only for the first one.

The problem with WNetAddConnection2 is also that it behaves differently on different windows versions. That is why I looked for alternatives and found the LogonUser function. Here is my code which also works in ASP.NET:

public sealed class WrappedImpersonationContext
{
    public enum LogonType : int
    {
        Interactive = 2,
        Network = 3,
        Batch = 4,
        Service = 5,
        Unlock = 7,
        NetworkClearText = 8,
        NewCredentials = 9
    }

    public enum LogonProvider : int
    {
        Default = 0,  // LOGON32_PROVIDER_DEFAULT
        WinNT35 = 1,
        WinNT40 = 2,  // Use the NTLM logon provider.
        WinNT50 = 3   // Use the negotiate logon provider.
    }

    [DllImport("advapi32.dll", EntryPoint = "LogonUserW", SetLastError = true, CharSet = CharSet.Unicode)]
    public static extern bool LogonUser(String lpszUsername, String lpszDomain,
        String lpszPassword, LogonType dwLogonType, LogonProvider dwLogonProvider, ref IntPtr phToken);

    [DllImport("kernel32.dll")]
    public extern static bool CloseHandle(IntPtr handle);

    private string _domain, _password, _username;
    private IntPtr _token;
    private WindowsImpersonationContext _context;

    private bool IsInContext
    {
        get { return _context != null; }
    }

    public WrappedImpersonationContext(string domain, string username, string password)
    {
        _domain = String.IsNullOrEmpty(domain) ? "." : domain;
        _username = username;
        _password = password;
    }

    // Changes the Windows identity of this thread. Make sure to always call Leave() at the end.
    [PermissionSetAttribute(SecurityAction.Demand, Name = "FullTrust")]
    public void Enter()
    {
        if (IsInContext)
            return;

        _token = IntPtr.Zero;
        bool logonSuccessfull = LogonUser(_username, _domain, _password, LogonType.NewCredentials, LogonProvider.WinNT50, ref _token);
        if (!logonSuccessfull)
        {
            throw new Win32Exception(Marshal.GetLastWin32Error());
        }
        WindowsIdentity identity = new WindowsIdentity(_token);
        _context = identity.Impersonate();

        Debug.WriteLine(WindowsIdentity.GetCurrent().Name);
    }

    [PermissionSetAttribute(SecurityAction.Demand, Name = "FullTrust")]
    public void Leave()
    {
        if (!IsInContext)
            return;

        _context.Undo();

        if (_token != IntPtr.Zero)
        {
            CloseHandle(_token);
        }
        _context = null;
    }
}

Usage:

var impersonationContext = new WrappedImpersonationContext(Domain, Username, Password);
impersonationContext.Enter();

//do your stuff here

impersonationContext.Leave();