NT Authentication

Tech Talk vb.Net
1

Here is a simple way to autenticate as user


Imports System.Management 

Private Function Authenticated() As Boolean 
        Dim queryCollection As ManagementObjectCollection 
        Dim co As New ConnectionOptions() 
        co.Username = UserName 'user name from user 
        co.Password = Password 'string password entered by user 

        Dim path As New System.Management.ManagementPath() 

        path.Server = ConnectionServer 'server to use for authentication 
        path.Path = "\\" & ConnectionServer & "\root\cimv2" 


        Dim ms As New System.Management.ManagementScope(path, co) 
        Dim oq As New System.Management.ObjectQuery("SELECT * FROM Win32_OperatingSystem") 'dummy query to test rights 
        Dim query As New ManagementObjectSearcher(ms, oq) 

        Try 
            queryCollection = query.Get() 
        Catch ex1 As System.UnauthorizedAccessException 
            Return False 'ouch nt authentication failed 
        Catch ex As Exception 
            MsgBox("Error: NT Verification Failed", MsgBoxStyle.Critical, "Error Connecting to Server For Authentication") 
            Application.Exit() 
        End Try 

        Return True 
    End Function
2

Here is another way from MDSN


Imports System 
Imports System.Threading 
Imports System.Security.Principal 
Imports Microsoft.VisualBasic 

Public Class Class1 
     
    Public Shared Sub Main() 
        'Get the current identity and put it into an identity object. 
        Dim MyIdentity As WindowsIdentity = WindowsIdentity.GetCurrent() 
         
        'Put the previous identity into a principal object. 
        Dim MyPrincipal As New WindowsPrincipal(MyIdentity) 
         
        'Principal values. 
        Dim PrincipalName As String = MyPrincipal.Identity.Name 
        Dim PrincipalType As String = MyPrincipal.Identity.AuthenticationType 
        Dim PrincipalAuth As String = MyPrincipal.Identity.IsAuthenticated.ToString() 
         
        'Identity values. 
        Dim IdentName As String = MyIdentity.Name 
        Dim IdentType As String = MyIdentity.AuthenticationType 
        Dim IdentIsAuth As String = MyIdentity.IsAuthenticated.ToString() 
        Dim ISAnon As String = MyIdentity.IsAnonymous.ToString() 
        Dim IsG As String = MyIdentity.IsGuest.ToString() 
        Dim IsSys As String = MyIdentity.IsSystem.ToString() 
        Dim Token As String = MyIdentity.Token.ToString() 
         
        'Print the values. 
        Console.WriteLine("Principal Values for current thread:") 
        Console.WriteLine(ControlChars.CrLf + ControlChars.CrLf + "Principal Name: {0}", PrincipalName) 
        Console.WriteLine("Principal Type: {0}", PrincipalType) 
        Console.WriteLine("Principal IsAuthenticated: {0}", PrincipalAuth) 
         
        Console.WriteLine(ControlChars.CrLf + ControlChars.CrLf + "Identity Values for current thread:") 
        Console.WriteLine("Identity Name: {0}", IdentName) 
        Console.WriteLine("Identity Type: {0}", IdentType) 
        Console.WriteLine("Identity IsAuthenticated: {0}", IdentIsAuth) 
        Console.WriteLine(ControlChars.CrLf + ControlChars.CrLf + "Identity IsAnonymous: {0}", ISAnon) 
        Console.WriteLine("Identity IsGuest: {0}", IsG) 
        Console.WriteLine("Identity IsSystem: {0}", IsSys) 
        Console.WriteLine("Identity Token: {0}", Token) 
    End Sub 
     
End Class

Here’s what they say the output will look like…


Principal Values for current thread: 

Principal Name: MYDOMAIN\myuseraccount 
Principal Type: NTLM 
Principal IsAuthenticated: True 

Identity Values for current thread: 

Identity Name: MYDOMAIN\myuseraccount 
Identity Type: NTLM 
Identity IsAuthenticated: True 

Identity IsAnonymous: False 
Identity IsGuest: False 
Identity IsSystem: False 
Identity Token: 276

Reference: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cpconrole-basedsecurity.asp