Autenticar con active directory (LDAP)

Todos sabemos que la autenticación con Active directory es muy buena y eficiente, siempre pensamos que la deberiamos de usar, pero realmente microsoft no pone tal facil la información para utilizar el active directory y por lo mismo muchos no lo usan, aquí les expongo codigo enviado por mi amigo Luis Gonzales de como a Autenticar y extraer datos del active directory como grupo de trabajo. espero les sirva cualquier comentario es bienvenido.



Imports System
Imports System.Text
Imports System.Collections
Imports System.DirectoryServices
Imports System.Configuration

Public Class AutenticarLDAP

Private _path As String
Private _filterAttribute As String
Private _descripcion As String

Public Sub New(ByVal path As String)
_path = path
End Sub

Public ReadOnly Property isDisplayName() As Integer
Get
Return _descripcion
End Get
End Property

Public Function Devuelve_Propiedad(ByVal Domain As String, ByVal username As String, ByVal pwd As String, ByVal Propiedad As String) As String
Dim domainAndUsername As String = (Domain & "\") + username
Dim entry As New DirectoryEntry(_path, domainAndUsername, pwd)

Try
Dim search As New DirectorySearcher(entry)
search.Filter = "(&(objectClass=user)(anr=" + username + "))"
Dim resEnt As SearchResult = search.FindOne()
Dim de As DirectoryEntry = resEnt.GetDirectoryEntry()

_descripcion = de.Properties(Propiedad).Value.ToString

entry.Close()
Catch ex As Exception
Return "Error al traer la informacion"
End Try

Return _descripcion
End Function

Public Function IsAuthenticated(ByVal Domain As String, ByVal username As String, ByVal pwd As String) As Boolean
Dim Success As Boolean = False
Dim Entry As New System.DirectoryServices.DirectoryEntry("LDAP://" & Domain, username, pwd)
Dim Searcher As New System.DirectoryServices.DirectorySearcher(Entry)
Searcher.SearchScope = DirectoryServices.SearchScope.OneLevel
Try
Dim Results As System.DirectoryServices.SearchResult = Searcher.FindOne
Success = Not (Results Is Nothing)
Catch
Success = False
End Try
Return Success
End Function

Public Function GetGroups() As String
Dim search As New DirectorySearcher(_path)
search.Filter = "(cn=" & _filterAttribute & ")"
search.PropertiesToLoad.Add("memberOf")
Dim groupNames As New StringBuilder()

Try
Dim result As SearchResult = search.FindOne()

Dim propertyCount As Integer = result.Properties("memberOf").Count

Dim dn As String
Dim equalsIndex As Integer, commaIndex As Integer

For propertyCounter As Integer = 0 To propertyCount - 1
dn = DirectCast(result.Properties("memberOf")(propertyCounter), String)

equalsIndex = dn.IndexOf("=", 1)
commaIndex = dn.IndexOf(",", 1)
If -1 = equalsIndex Then
Return Nothing
End If

groupNames.Append(dn.Substring((equalsIndex + 1), (commaIndex - equalsIndex) - 1))
groupNames.Append("|")

Next
Catch ex As Exception
Throw New Exception("Error obtaining group names. " & ex.Message)
End Try
Return groupNames.ToString()
End Function
End Class