want to login to windows through c#
 

hello all,
i need some help regarding windows login.i have created an application in C# which replaces the windows-login and which gets username and password from the user to enter the windows.
But my problem is that i have done the user authentication through win32 API function "LogonUser()" and it works fine.but i am not able to enter the windows.it always shows me a black screen.
Please help me what should i do for that is there any library or function or any related material so that i can go ahead.

thanks
DevGeek

Re: want to login to windows through c#
 

I you don't show us your relevant code I am affraid we can do much to help you out.

Re: want to login to windows through c#
 

Here is my code but i am not able to enter to my windows desktop.

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Text;



using System.Runtime.InteropServices; // DllImport

using System.Security.Principal; // WindowsImpersonationContext

using System.Security.Permissions; // PermissionSetAttribute



namespace loginwin

{



    class Program

    {



         enum SECURITY_IMPERSONATION_LEVEL

        {

            SecurityAnonymous,

            SecurityIdentification,

            SecurityImpersonation,

            SecurityDelegation

        }

        [DllImport("ADVAPI32.DLL")]

        public static extern bool LogonUser(String lpszUsername, String lpszDomain, String lpszPassword,

                                            int dwLogonType, int dwLogonProvider, out IntPtr phToken);

        [DllImport("ADVAPI32.DLL")]

        public extern static bool DuplicateToken(IntPtr ExistingTokenHandle, int

                                                SECURITY_IMPERSONATION_LEVEL, out IntPtr DuplicateTokenHandle);

        [DllImport("kernel32.DLL")]

        static extern bool CloseHandle(IntPtr hObject);

        

        

        public static WindowsImpersonationContext  ImpersonateUser(string sUsername, string sDomain, string sPassword)

        {

            // initialize tokens

            IntPtr pExistingTokenHandle = new IntPtr(0);

            IntPtr pDuplicateTokenHandle = new IntPtr(0);

            pExistingTokenHandle = IntPtr.Zero;

            pDuplicateTokenHandle = IntPtr.Zero;



            // if domain name was blank, assume local machine

            if (sDomain == "")

                sDomain = System.Environment.MachineName;



            try

            {

                string sResult = null;



                const int LOGON32_PROVIDER_DEFAULT = 0;

                // create token

                const int LOGON32_LOGON_INTERACTIVE = 2;

                //const int SecurityImpersonation = 2;

                // get handle to token

                bool bImpersonated = LogonUser(sUsername, sDomain, sPassword,LOGON32_LOGON_INTERACTIVE, LOGON32_PROVIDER_DEFAULT,out pExistingTokenHandle);



                // did impersonation fail?

                if (false == bImpersonated)

                {

                    int nErrorCode = Marshal.GetLastWin32Error();

                    sResult = "LogonUser() failed with error code: " +

                        nErrorCode + "\r\n";



                    // show the reason why LogonUser failed

                    Console.WriteLine(sResult + "Error");

                        

                }



                // Get identity before impersonation

                sResult += "Before impersonation: " +

                    WindowsIdentity.GetCurrent().Name + "\r\n";



                bool bRetVal = DuplicateToken(pExistingTokenHandle,

                    (int)SECURITY_IMPERSONATION_LEVEL.SecurityImpersonation,

                        out pDuplicateTokenHandle);



                // did DuplicateToken fail?

                if (false == bRetVal)

                {

                    int nErrorCode = Marshal.GetLastWin32Error();

                    // close existing handle

                    CloseHandle(pExistingTokenHandle);

                    sResult += "DuplicateToken() failed with error code: "

                        + nErrorCode + "\r\n";



                    // show the reason why DuplicateToken failed

                    Console.WriteLine(sResult+ "Error");

                        

                    return null;

                }

                else

                {

                    // create new identity using new primary token

                    WindowsIdentity newId = new WindowsIdentity

                                                (pDuplicateTokenHandle);

                    WindowsImpersonationContext impersonatedUser =

                                                newId.Impersonate();



                    // check the identity after impersonation

                    sResult += "After impersonation: " +

                        WindowsIdentity.GetCurrent().Name + "\r\n";



                    Console.WriteLine(sResult+"Success");

                    return impersonatedUser;

                }

            }

            catch (Exception ex)

            {

                throw ex;

            }

            finally

            {

                // close handle(s)

                if (pExistingTokenHandle != IntPtr.Zero)

                    CloseHandle(pExistingTokenHandle);

                if (pDuplicateTokenHandle != IntPtr.Zero)

                    CloseHandle(pDuplicateTokenHandle);



                

            }

        }

        static void Main(string[] args)

        {

            ImpersonateUser("Username", System.Environment.MachineName.ToString(), "Password");

            Console.Read();

        }

}

Re: want to login to windows through c#
 

Replacing MSGina is not as simple as I tihnk you're looking at there. I would guess a number of those elements fail as you're not logged in at that point. I dont believe its just a case of "impersonating" a specific user, you need windows to go through the real login process - Id imagine your window goes black as you're not calling any method for it to know it needs to launch the shell, and so on.

I wise man said:

Hes right.

Re: want to login to windows through c#
 

its too much necessary for me to replace windows login its my final year project.And i have to do it at any cost.So please do suggest some material or any other option(if possible) except Msgina.

Re: want to login to windows through c#
 

And one more thing that i have seen many winlogon theme that just replace the logontheme.exe with logonui.exe in c:\windows\system32\ and they don't change any msgina so please do suggest.what you people say about this.

Re: want to login to windows through c#
 

If its been told to you that you have to do this specific application for your final year, what reading material were you told to look at?

Re: want to login to windows through c#
 

it is my research project no material has been provided therefore i ask here.