How to authenticate and access the registry remotely using C#

Connecting to the remote registry of another workstation or server can be done as long as authentication has been done first.

Here is an example for connecting to remote registry.

  1. Create a new C# Console project in Visual Studio.
  2. Add a new class called NetworkShare. I know I got this from another site sometime last year and added to it, but I didn’t document the source web site.
    using System;
    using System.Runtime.InteropServices;
    
    using BOOL = System.Int32;
    
    namespace NetworkConnection
    {
        public class NetworkShare
        {
            #region Member Variables
            [DllImport("mpr.dll")]
            private static extern int WNetAddConnection2A(ref NetResource refNetResource, string inPassword, string inUsername, int inFlags);
            [DllImport("mpr.dll")]
            private static extern int WNetCancelConnection2A(string inServer, int inFlags, int inForce);
    
            private String _Server;
            private String _Share;
            private String _DriveLetter = null;
            private String _Username = null;
            private String _Password = null;
            private int _Flags = 0;
            private NetResource _NetResource = new NetResource();
            BOOL _AllowDisconnectWhenInUse = 0; // 0 = False; Any other value is True;
            #endregion
    
            #region Constructors
            /// <summary>
            /// The default constructor
            /// </summary>
            public NetworkShare()
            {
            }
    
            /// <summary>
            /// This constructor takes a server and a share.
            /// </summary>
            public NetworkShare(String inServer, String inShare)
            {
                _Server = inServer;
                _Share = inShare;
            }
    
            /// <summary>
            /// This constructor takes a server and a share and a local drive letter.
            /// </summary>
            public NetworkShare(String inServer, String inShare, String inDriveLetter)
            {
                _Server = inServer;
                _Share = inShare;
                DriveLetter = inDriveLetter;
            }
    
            /// <summary>
            /// This constructor takes a server, share, username, and password.
            /// </summary>
            public NetworkShare(String inServer, String inShare, String inUsername, String inPassword)
            {
                _Server = inServer;
                _Share = inShare;
                _Username = inUsername;
                _Password = inPassword;
            }
    
            /// <summary>
            /// This constructor takes a server, share, drive letter, username, and password.
            /// </summary>
            public NetworkShare(String inServer, String inShare, String inDriveLetter, String inUsername, String inPassword)
            {
                _Server = inServer;
                _Share = inShare;
                _DriveLetter = inDriveLetter;
                _Username = inUsername;
                _Password = inPassword;
            }
            #endregion
    
            #region Properties
            public String Server
            {
                get { return _Server; }
                set { _Server = value; }
            }
    
            public String Share
            {
                get { return _Share; }
                set { _Share = value; }
            }
    
            public String FullPath
            {
                get { return string.Format(@"\\{0}\{1}", _Server, _Share); }
            }
    
            public String DriveLetter
            {
                get { return _DriveLetter; }
                set { SetDriveLetter(value); }
            }
    
            public String Username
            {
                get { return String.IsNullOrEmpty(_Username) ? null : _Username; }
                set { _Username = value; }
            }
    
            public String Password
            {
                get { return String.IsNullOrEmpty(_Password) ? null : _Username; }
                set { _Password = value; }
            }
    
            public int Flags
            {
                get { return _Flags; }
                set { _Flags = value; }
            }
    
            public NetResource Resource
            {
                get { return _NetResource; }
                set { _NetResource = value; }
            }
    
            public bool AllowDisconnectWhenInUse
            {
                get { return Convert.ToBoolean(_AllowDisconnectWhenInUse); }
                set { _AllowDisconnectWhenInUse = Convert.ToInt32(value); }
            }
    
            #endregion
    
            #region Functions
            /// <summary>
            /// Establishes a connection to the share.
            ///
            /// Throws:
            ///
            ///
            /// </summary>
            public int Connect()
            {
                _NetResource.Scope = (int)Scope.RESOURCE_GLOBALNET;
                _NetResource.Type = (int)Type.RESOURCETYPE_DISK;
                _NetResource.DisplayType = (int)DisplayType.RESOURCEDISPLAYTYPE_SHARE;
                _NetResource.Usage = (int)Usage.RESOURCEUSAGE_CONNECTABLE;
                _NetResource.RemoteName = FullPath;
                _NetResource.LocalName = DriveLetter;
    
                return WNetAddConnection2A(ref _NetResource, _Password, _Username, _Flags);
            }
    
            /// <summary>
            /// Disconnects from the share.
            /// </summary>
            public int Disconnect()
            {
                int retVal = 0;
                if (null != _DriveLetter)
                {
                    retVal = WNetCancelConnection2A(_DriveLetter, _Flags, _AllowDisconnectWhenInUse);
                    retVal = WNetCancelConnection2A(FullPath, _Flags, _AllowDisconnectWhenInUse);
                }
                else
                {
                    retVal = WNetCancelConnection2A(FullPath, _Flags, _AllowDisconnectWhenInUse);
                }
                return retVal;
            }
    
            private void SetDriveLetter(String inString)
            {
                if (inString.Length == 1)
                {
                    if (char.IsLetter(inString.ToCharArray()[0]))
                    {
                        _DriveLetter = inString + ":";
                    }
                    else
                    {
                        // The character is not a drive letter
                        _DriveLetter = null;
                    }
                }
                else if (inString.Length == 2)
                {
                    char[] drive = inString.ToCharArray();
                    if (char.IsLetter(drive[0]) && drive[1] == ':')
                    {
                        _DriveLetter = inString;
                    }
                    else
                    {
                        // The character is not a drive letter
                        _DriveLetter = null;
                    }
                }
                else
                {
                    // If we get here the value passed in is not valid
                    // so make it null.
                    _DriveLetter = null;
                }
            }
            #endregion
    
            #region NetResource Struct
            [StructLayout(LayoutKind.Sequential)]
            public struct NetResource
            {
                public uint Scope;
                public uint Type;
                public uint DisplayType;
                public uint Usage;
                public string LocalName;
                public string RemoteName;
                public string Comment;
                public string Provider;
            }
            #endregion
    
            #region Enums
            public enum Scope
            {
                RESOURCE_CONNECTED = 1,
                RESOURCE_GLOBALNET,
                RESOURCE_REMEMBERED,
                RESOURCE_RECENT,
                RESOURCE_CONTEXT
            }
    
            public enum Type : uint
            {
                RESOURCETYPE_ANY,
                RESOURCETYPE_DISK,
                RESOURCETYPE_PRINT,
                RESOURCETYPE_RESERVED = 8,
                RESOURCETYPE_UNKNOWN = 4294967295
            }
    
            public enum DisplayType
            {
                RESOURCEDISPLAYTYPE_GENERIC,
                RESOURCEDISPLAYTYPE_DOMAIN,
                RESOURCEDISPLAYTYPE_SERVER,
                RESOURCEDISPLAYTYPE_SHARE,
                RESOURCEDISPLAYTYPE_FILE,
                RESOURCEDISPLAYTYPE_GROUP,
                RESOURCEDISPLAYTYPE_NETWORK,
                RESOURCEDISPLAYTYPE_ROOT,
                RESOURCEDISPLAYTYPE_SHAREADMIN,
                RESOURCEDISPLAYTYPE_DIRECTORY,
                RESOURCEDISPLAYTYPE_TREE,
                RESOURCEDISPLAYTYPE_NDSCONTAINER
            }
    
            public enum Usage : uint
            {
                RESOURCEUSAGE_CONNECTABLE = 1,
                RESOURCEUSAGE_CONTAINER = 2,
                RESOURCEUSAGE_NOLOCALDEVICE = 4,
                RESOURCEUSAGE_SIBLING = 8,
                RESOURCEUSAGE_ATTACHED = 16,
                RESOURCEUSAGE_ALL = 31,
                RESOURCEUSAGE_RESERVED = 2147483648
            }
    
            public enum ConnectionFlags : uint
            {
                CONNECT_UPDATE_PROFILE = 1,
                CONNECT_UPDATE_RECENT = 2,
                CONNECT_TEMPORARY = 4,
                CONNECT_INTERACTIVE = 8,
                CONNECT_PROMPT = 16,
                CONNECT_NEED_DRIVE = 32,
                CONNECT_REFCOUNT = 64,
                CONNECT_REDIRECT = 128,
                CONNECT_LOCALDRIVE = 256,
                CONNECT_CURRENT_MEDIA = 512,
                CONNECT_DEFERRED = 1024,
                CONNECT_COMMANDLINE = 2048,
                CONNECT_CMD_SAVECRED = 4096,
                CONNECT_CRED_RESET = 8192,
                CONNECT_RESERVED = 4278190080
            }
            #endregion
        }
    }
    

    Note: This class actually is to map a drive, but authenticating to a share and authenticating to connect to remote registry are done the same way.

  3. Now here is a Program.cs that shows how to use the NetworkShare class to connect to a device and access the remote registry.
    using System;
    using Microsoft.Win32;
    using NetworkConnection;
    using System.Management;
    
    namespace RemoteRegistryExample
    {
        class Program
        {
            static void Main(string[] args)
            {
                String ServerName = "Server1";
    
                // Create an object that can authenticate to a network share when you
                // already have credentials
                NetworkShare share = new NetworkShare(ServerName, "ipc$");
    
                // Create an object that can authenticate to a network share when you
                // do NOT already have credentials
                //NetworkShare share = new NetworkShare(ServerName, "C$", "User", "SomePasswd");
    
                // Connect to the remote drive
                share.Connect();
    
                // Note: another connection option is to add a reference to System.Management,
                // Then add a using statement for System.Management and use ConnectionOptions
                // and ManagementScope objects. For more information see this link:
                // http://msdn.microsoft.com/en-us/library/system.management.managementscope%28v=VS.100%29.aspx
    
                // If these same credentials allow remote registry, you are now authenticated
                // Get the Windows ProductName from HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion
                String ProductName = string.Empty;
                RegistryKey key = RegistryKey.OpenRemoteBaseKey(RegistryHive.LocalMachine, ServerName);
                if (key != null)
                {
                    key = key.OpenSubKey(@"SOFTWARE\Microsoft\Windows NT\CurrentVersion");
                    if (key != null)
                        ProductName = key.GetValue("ProductName").ToString();
                }
    
                // Display the value
                Console.WriteLine("The device " + ServerName + " is running " + ProductName + ".");
    
                // Disconnect the share
                share.Disconnect();
            }
        }
    }
    

    You now are reading from remote registry.

Leave a Reply

Your email address will not be published. Required fields are marked *

  1. whats second parameter in
    NetworkShare share = new NetworkShare(ServerName, “ipc$”); and three more parameters can be mentioned in this constructor, I dint get the third one “indriverletter”.

    swati ail

    • Authentication for remote registry is actually allowed by mapping a UNC Share to the IPC$ share. So this code works for mapping a UNC share to a drive letter to.

  2. This works perfectly! You should post this on stackoverflow.com. I’ve come across some posts there on how to do this and they don’t work.

    Thank you good sir.