Question

I need to write a file to a windows share on a computer not part of a domain from ASP.net.

I’ve tried implementing impersonation like : http://support.microsoft.com/?id=306158 which wraps the LogonUserA api call. Something isn’t working though, and I don’t know why. (It doesn’t seem to give any error code or reason message…)

I think it’s because the remote computer is NOT on a domain. ? I don’t know.

I can’t use the “matching local user/pass on both machines” trick, can someone help?

Answer 1

From my answer on this question, give this a try:

 using (new NetworkConnection(@"\\server\read", readCredentials))
 using (new NetworkConnection(@"\\server2\write", writeCredentials)) {
    File.Copy(@"\\server\read\file", @"\\server2\write\file");
 }

---

I liked Mark Brackett‘s answer so much that I did my own quick implementation. Here it is if anyone else needs it in a hurry:

public class NetworkConnection : IDisposable
{
    string _networkName;

    public NetworkConnection(string networkName, 
        NetworkCredential credentials)
    {
        _networkName = networkName;

        var netResource = new NetResource()
        {
            Scope = ResourceScope.GlobalNetwork,
            ResourceType = ResourceType.Disk,
            DisplayType = ResourceDisplaytype.Share,
            RemoteName = networkName
        };

        var result = WNetAddConnection2(
            netResource, 
            credentials.Password,
            credentials.UserName,
            0);

        if (result != 0)
        {
            throw new Win32Exception(result, "Error connecting to remote share");
        }   
    }

    ~NetworkConnection()
    {
        Dispose(false);
    }

    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    protected virtual void Dispose(bool disposing)
    {
        WNetCancelConnection2(_networkName, 0, true);
    }

    [DllImport("mpr.dll")]
    private static extern int WNetAddConnection2(NetResource netResource, 
        string password, string username, int flags);

    [DllImport("mpr.dll")]
    private static extern int WNetCancelConnection2(string name, int flags,
        bool force);
}

[StructLayout(LayoutKind.Sequential)]
public class NetResource
{
    public ResourceScope Scope;
    public ResourceType ResourceType;
    public ResourceDisplaytype DisplayType;
    public int Usage;
    public string LocalName;
    public string RemoteName;
    public string Comment;
    public string Provider;
}

public enum ResourceScope : int
{
    Connected = 1,
    GlobalNetwork,
    Remembered,
    Recent,
    Context
};

public enum ResourceType : int
{
    Any = 0,
    Disk = 1,
    Print = 2,
    Reserved = 8,
}

public enum ResourceDisplaytype : int
{
    Generic = 0x0,
    Domain = 0x01,
    Server = 0x02,
    Share = 0x03,
    File = 0x04,
    Group = 0x05,
    Network = 0x06,
    Root = 0x07,
    Shareadmin = 0x08,
    Directory = 0x09,
    Tree = 0x0a,
    Ndscontainer = 0x0b
}