Module winauth
    Dim logfile As System.IO.StreamWriter
    Dim pwdfile As System.IO.StreamReader
    Dim INI As New Class_ini_ops
    Function Main(ByVal cmdArgs() As String) As Integer
        Dim oContext As System.DirectoryServices.AccountManagement.PrincipalContext
        Dim oGroupUsers As System.DirectoryServices.AccountManagement.GroupPrincipal
        Dim usrName As String
        Dim usrPass As String
        Dim returnValue As Boolean

        Dim ini_file = System.Environment.CurrentDirectory.ToString & "\" & "config.ini"
        Dim ini_section = "Configuration"

        'chk ini file
        If INI.GetSectionParams(ini_file, ini_section) Is Nothing Then
            Echo("Incorrect INI format.")
            Return 1
        End If

        Dim GroupName As String
        GroupName = INI.GetParamValue(ini_file, ini_section, "GroupName")
        If GroupName Is Nothing Then
            Echo("User target group not set in ini-file.")
            Return 1
        End If

        'имя(и путь) файла вынести в конфиг
        logfile = My.Computer.FileSystem.OpenTextFileWriter("winauth.log", True, _
                                                    System.Text.Encoding.GetEncoding(1251))
        logfile.AutoFlush = True

        'check args
        If cmdArgs.Count <> 1 Then
            Echo("Wrong parametrs.")
            Return 1
        Else
            Try
                pwdfile = My.Computer.FileSystem.OpenTextFileReader(cmdArgs(0).ToString, _
                                                    System.Text.Encoding.GetEncoding(1251))
            Catch ex As Exception
                Echo(ex.Message.ToString)
                Echo("pwdfile not found.")
            End Try

            Try
                usrName = pwdfile.ReadLine.ToString
            Catch ex As Exception
                Echo(ex.Message.ToString)
                Echo("No data in pwdfile.")
                Return 1
            End Try

            Try
                usrPass = pwdfile.ReadLine.ToString
            Catch ex As Exception
                Echo(ex.Message.ToString)
                Echo("No password in pwdfile.")
                Return 1
            End Try
        End If
        pwdfile.Close()

        'Get Auth context from INI, default is Local
        Dim iniContext
        iniContext = INI.GetParamValue(ini_file, ini_section, "Context")
        If iniContext Is Nothing Then
            iniContext = "Local"
        End If

        ' Set PrincipalContext
        Dim DN As String = ""
        Dim PDC As String = ""
        Select Case iniContext
            Case "Local"
                oContext = New System.DirectoryServices.AccountManagement.PrincipalContext( _
                            System.DirectoryServices.AccountManagement.ContextType.Machine, _
                            System.Environment.MachineName.ToString)
            Case "Domain"
                PDC = INI.GetParamValue(ini_file, ini_section, "PDC")
                If PDC Is Nothing Then
                    Echo("PDC not set in ini-file.")
                    Return 1
                End If
                DN = INI.GetParamValue(ini_file, ini_section, "DN")
                If DN Is Nothing Then
                    Echo("DN not set in ini-file.")
                    Return 1
                End If
                oContext = New System.DirectoryServices.AccountManagement.PrincipalContext( _
                                System.DirectoryServices.AccountManagement.ContextType.Domain, _
                                PDC, DN)
            Case Else
                Echo("Context not set in ini-file or incorrect.")
                Return 1
        End Select

        'Check that the user is a member of the group
        oGroupUsers = System.DirectoryServices.AccountManagement.GroupPrincipal.FindByIdentity(oContext, _
                                DirectoryServices.AccountManagement.IdentityType.Name, _
                                GroupName)
        Dim oUsers As System.DirectoryServices.AccountManagement.PrincipalSearchResult(Of  _
                                        System.DirectoryServices.AccountManagement.Principal)
        oUsers = Nothing
        If oGroupUsers Is Nothing Then
            Echo("No such group [" & GroupName & "] found.")
            Return 1
        Else
            oUsers = oGroupUsers.GetMembers
        End If

        If oUsers.Contains(System.DirectoryServices.AccountManagement.Principal.FindByIdentity(oContext, usrName)) Then
            Debug.Print("caught!")
        Else
            Debug.Print("shot at milk...")
            Select Case iniContext
                Case "Local"
                    Echo("Group check failure: the user is not a member of [" & GroupName & "].")
                Case "Domain"
                    Echo("Group check failure: the user is not a member of [" & GroupName & "@{" & DN & "}].")
            End Select
            Return 1
        End If

        Try
            returnValue = oContext.ValidateCredentials(usrName, usrPass)
        Catch ex As Exception
            Echo(ex.Message.ToString)
            Return 1
            'Error Codes list for Microsoft technologies:
            'http://www.symantec.com/business/support/index?page=content&id=TECH12638
            '"HRESULT: 0x80070533" == "Logon failure: account currently disabled."
        End Try

        Select Case returnValue
            Case False
                Echo("Logon failure: username or password incorrect.")
                Return 1
            Case True
                Echo("Logon is successful.")
                Return 0
            Case Else
                Echo("Unknown Error?")
                Return 1
        End Select
    End Function
    Sub Echo(ByVal text)
        Console.WriteLine(text)
        Debug.Print(text)
        logfile.WriteLine(Now() & ":> " & text)
    End Sub
End Module

Public Class Class_ini_ops
    'изначально была копипаста отсюда: http://www.cyberforum.ru/vb-net/thread382768.html
#Region "API Calls"
    Private Declare Unicode Function WritePrivateProfileString Lib "kernel32" _
    Alias "WritePrivateProfileStringW" (ByVal lpApplicationName As String, _
    ByVal lpKeyName As String, ByVal lpString As String, _
    ByVal lpFileName As String) As Integer

    Private Declare Unicode Function GetPrivateProfileString Lib "kernel32" _
    Alias "GetPrivateProfileStringW" (ByVal lpApplicationName As String, _
    ByVal lpKeyName As String, ByVal lpDefault As String, _
    ByVal lpReturnedString As String, ByVal nSize As Int32, _
    ByVal lpFileName As String) As Integer
#End Region
    ReadOnly CallBufferSize As Short = 4096
    Public Function GetSectionsList(ByVal INIfile As String) As Array
        Dim n As Integer
        Dim sData As String
        Dim sb As New System.Text.StringBuilder
        sData = sb.Insert(0, vbNullChar, CallBufferSize).ToString
        n = GetPrivateProfileString(vbNullString, vbNullString, vbNullString, sData, CallBufferSize, INIfile)
        If n > 0 Then
            GetSectionsList = sData.Substring(0, n - 1).Split(vbNullChar)
        Else
            GetSectionsList = Nothing
        End If
    End Function
    Public Function GetSectionParams(ByVal INIfile As String, ByVal SectionName As String) As Array
        Dim n As Integer
        Dim sData As String
        Dim sb As New System.Text.StringBuilder
        sData = sb.Insert(0, vbNullChar, CallBufferSize).ToString
        n = GetPrivateProfileString(SectionName, vbNullString, vbNullString, sData, CallBufferSize, INIfile)
        If n > 0 Then
            GetSectionParams = sData.Substring(0, n - 1).Split(vbNullChar)
        Else
            GetSectionParams = Nothing
        End If
    End Function
    Public Overloads Function GetParamValue(ByVal INIfile As String, ByVal SectionName As String, ByVal ParamName As String) As String
        Dim n As Integer
        Dim sData As String
        Dim sb As New System.Text.StringBuilder
        sData = sb.Insert(0, vbNullChar, CallBufferSize).ToString
        n = GetPrivateProfileString(SectionName, ParamName, vbNullString, sData, CallBufferSize, INIfile)
        If n > 0 Then
            GetParamValue = sData.Substring(0, n)
        Else
            GetParamValue = Nothing
        End If
    End Function
    Public Overloads Function GetParamValue(ByVal INIfile As String, ByVal SectionName As String, ByVal ParamName As String, _
                                            ByVal DefaultValue As String) As String
        Dim n As Integer
        Dim sData As String
        Dim sb As New System.Text.StringBuilder
        sData = sb.Insert(0, vbNullChar, CallBufferSize).ToString
        n = GetPrivateProfileString(SectionName, ParamName, DefaultValue, sData, CallBufferSize, INIfile)
        If n > 0 Then
            GetParamValue = sData.Substring(0, n)
        Else
            GetParamValue = Nothing
        End If
    End Function
    Public Function SetParamValue(ByVal INIfile As String, ByVal SectionName As String, ByVal ParamName As String, _
                                  ByVal ParamValue As String) As Boolean
        Call WritePrivateProfileString(SectionName, ParamName, ParamValue, INIfile)
        If ParamValue = GetParamValue(INIfile, SectionName, ParamName) Then
            SetParamValue = True
        Else
            SetParamValue = False
        End If
    End Function
End Class

[Configuration]
;set auth context
;Local - check local credentials(default)
;Domain -  check credentials in Domain
Context = Local

; Used only in Context = Domain
PDC = MyServer
DN = "DC=mydomain,DC=local"

;target user group
GroupName = "Операторы сервера"

Module WinAuth
    Dim logfile As System.IO.StreamWriter
    Dim pwdfile As System.IO.StreamReader
    Function Main(ByVal cmdArgs() As String) As Integer
        Dim instance As System.DirectoryServices.AccountManagement.PrincipalContext
        Dim usrName As String
        Dim usrPass As String
        Dim returnValue As Boolean
        logfile = My.Computer.FileSystem.OpenTextFileWriter("winauth.log", True, _
                                                    System.Text.Encoding.GetEncoding(1251))
        logfile.AutoFlush = True
        If cmdArgs.Count <> 1 Then
            Echo("Wrong parametrs.")
            Return 1
        Else
            Try
                pwdfile = My.Computer.FileSystem.OpenTextFileReader(cmdArgs(0).ToString, _
                                                    System.Text.Encoding.GetEncoding(1251))
            Catch ex As Exception
                Echo(ex.Message.ToString)
                Echo("pwdfile not found.")
            End Try

            Try
                usrName = pwdfile.ReadLine.ToString
            Catch ex As Exception
                Echo(ex.Message.ToString)
                Echo("No data in pwdfile.")
                Return 1
            End Try

            Try
                usrPass = pwdfile.ReadLine.ToString
            Catch ex As Exception
                Echo(ex.Message.ToString)
                Echo("No password in pwdfile.")
                Return 1
            End Try

        End If
        pwdfile.Close()
        instance = New System.DirectoryServices.AccountManagement.PrincipalContext( _
            System.DirectoryServices.AccountManagement.ContextType.Machine, _
            System.Environment.MachineName.ToString)
        Try
            returnValue = instance.ValidateCredentials(usrName, usrPass)
        Catch ex As Exception
            Echo(ex.Message.ToString)
            Return 1
            'Error Codes list for Microsoft technologies:
            'http://www.symantec.com/business/support/index?page=content&id=TECH12638
            '"HRESULT: 0x80070533" == "Logon failure: account currently disabled."
        End Try

        Select Case returnValue
            Case False
                Echo("Logon failure: username or password incorrect.")
                Return 1
            Case True
                Echo("Logon is successful.")
                Return 0
            Case Else
                Echo("Unknown Error?")
                Return 1
        End Select
    End Function
    Sub Echo(ByVal text)
        Console.WriteLine(text)
        Debug.Print(text)
        logfile.WriteLine(Now() & ":> " & text)
    End Sub
End Module

        instance = New System.DirectoryServices.AccountManagement.PrincipalContext( _
            System.DirectoryServices.AccountManagement.ContextType.Machine, _
            System.Environment.MachineName.ToString)