Impersonate problem

[Bala]

Hi

I am using below code for impersonating. Previosualy it was working fine.

Now its giving this error message. any idea how to resolve this.

LogonUser failed with error code : 87

thanks
bala

code:

Dim impContext As WindowsImperson ationContext = Nothing
Try
'
Response.Write( System.Security .Principal.Wind owsIdentity.Get Current().Name( ))
impContext = NetworkSecurity .ImpersonateUse r("WEB",
Session("WinLog in"), Session("WinPas sword"), LogonType.LOGON 32_LOGON_NETWOR K,
LogonProvider.L OGON32_PROVIDER _DEFAULT)

Catch ex As ApplicationExce ption
' impContext.Undo ()
Response.Write( ex.Message)
End Try

Public Shared Function ImpersonateUser (ByVal strDomain As String, ByVal
strLogin As String, ByVal strPwd As String, ByVal logonType As LogonType,
ByVal logonProvider As LogonProvider) As WindowsImperson ationContext
Dim tokenHandle As IntPtr = New IntPtr(0)
Dim dupeTokenHandle As IntPtr = New IntPtr(0)
Try
Const SecurityImperso nation As Integer = 2
tokenHandle = IntPtr.Zero
dupeTokenHandle = IntPtr.Zero
Dim returnValue As Boolean = SecuUtil32.Logo nUser(strLogin,
strDomain, strPwd, CType(logonType , Integer), CType(logonProv ider, Integer),
tokenHandle)
If False = returnValue Then
Dim ret As Integer = Marshal.GetLast Win32Error
Dim strErr As String = String.Format(" LogonUser failed
with error code : {0}", ret)
Throw New ApplicationExce ption(strErr, Nothing)
End If
Dim retVal As Boolean =
SecuUtil32.Dupl icateToken(toke nHandle, SecurityImperso nation, dupeTokenHandle )
If False = retVal Then
SecuUtil32.Clos eHandle(tokenHa ndle)
Throw New ApplicationExce ption("Failed to duplicate
token", Nothing)
End If
Dim newId As WindowsIdentity = New
WindowsIdentity (dupeTokenHandl e)
Dim impersonatedUse r As WindowsImperson ationContext =
newId.Impersona te
Return impersonatedUse r
Catch ex As Exception
Throw New ApplicationExce ption(ex.Messag e, ex)
End Try
Return Nothing
End Function

[Bala]

exact error message is :
Token cannot be zero
"Bala" wrote:

Hi

I am using below code for impersonating. Previosualy it was working fine.
Now its giving this error message. any idea how to resolve this.

LogonUser failed with error code : 87

thanks
bala

code:

Dim impContext As WindowsImperson ationContext = Nothing
Try
'
Response.Write( System.Security .Principal.Wind owsIdentity.Get Current().Name( ))
impContext = NetworkSecurity .ImpersonateUse r("WEB",
Session("WinLog in"), Session("WinPas sword"), LogonType.LOGON 32_LOGON_NETWOR K,
LogonProvider.L OGON32_PROVIDER _DEFAULT)

Catch ex As ApplicationExce ption
' impContext.Undo ()
Response.Write( ex.Message)
End Try

Public Shared Function ImpersonateUser (ByVal strDomain As String, ByVal
strLogin As String, ByVal strPwd As String, ByVal logonType As LogonType,
ByVal logonProvider As LogonProvider) As WindowsImperson ationContext
Dim tokenHandle As IntPtr = New IntPtr(0)
Dim dupeTokenHandle As IntPtr = New IntPtr(0)
Try
Const SecurityImperso nation As Integer = 2
tokenHandle = IntPtr.Zero
dupeTokenHandle = IntPtr.Zero
Dim returnValue As Boolean = SecuUtil32.Logo nUser(strLogin,
strDomain, strPwd, CType(logonType , Integer), CType(logonProv ider, Integer),
tokenHandle)
If False = returnValue Then
Dim ret As Integer = Marshal.GetLast Win32Error
Dim strErr As String = String.Format(" LogonUser failed
with error code : {0}", ret)
Throw New ApplicationExce ption(strErr, Nothing)
End If
Dim retVal As Boolean =
SecuUtil32.Dupl icateToken(toke nHandle, SecurityImperso nation, dupeTokenHandle )
If False = retVal Then
SecuUtil32.Clos eHandle(tokenHa ndle)
Throw New ApplicationExce ption("Failed to duplicate
token", Nothing)
End If
Dim newId As WindowsIdentity = New
WindowsIdentity (dupeTokenHandl e)
Dim impersonatedUse r As WindowsImperson ationContext =
newId.Impersona te
Return impersonatedUse r
Catch ex As Exception
Throw New ApplicationExce ption(ex.Messag e, ex)
End Try
Return Nothing
End Function