vb.net - Open remote shared folder with credentials

Question

I need to open a folder on a remote server with different credentials in a window (explorer.exe).

I managed to do it with no credentials (my credentials), but when I do it with another username and another password than mine, it opens a prompt to enter a username and a password, and it says "access denied".

In the access log on the remote desktop, it says that I tried to connect with my own username, and not the other username I entered. So, the process obviously did not work.

But, I can't figure out why. My code is as follows:

Dim domain, username, passwordStr, remoteServerName As String
Dim password As New Security.SecureString
Dim command As New Process

domain = "domain.com"
username = "username"
passwordStr = "password"
remoteServerName = "serverName"

For Each c As Char In passwordStr.ToCharArray
    password.AppendChar(c)
Next


command.StartInfo.FileName = "explorer.exe"
command.StartInfo.Arguments = "" & serverName & "admin$Temp"

command.StartInfo.UserName = username
command.StartInfo.Password = password
command.StartInfo.Domain = domain
command.StartInfo.Verb = "open"
command.StartInfo.UseShellExecute = False

command.Start()

Answer 1

I ran into this same problem at work and was able to solve it with impersonation. just add a new class with the following:

    '*****************************************************************************************
'*****************************************************************************************
' Contents: AliasAccount Class
'
' This Class is a template class that provides all the functionality to impersonate a user
' over a designated instance.
'*****************************************************************************************
'*****************************************************************************************


Public Class AliasAccount
  Private _username, _password, _domainname As String

  Private _tokenHandle As New IntPtr(0)
  Private _dupeTokenHandle As New IntPtr(0)
  Private _impersonatedUser As System.Security.Principal.WindowsImpersonationContext


  Public Sub New(ByVal username As String, ByVal password As String)
    Dim nameparts() As String = username.Split("")
    If nameparts.Length > 1 Then
      _domainname = nameparts(0)
      _username = nameparts(1)
    Else
      _username = username
    End If
    _password = password
  End Sub

  Public Sub New(ByVal username As String, ByVal password As String, ByVal domainname As String)
    _username = username
    _password = password
    _domainname = domainname
  End Sub


  Public Sub BeginImpersonation()
    'Const LOGON32_PROVIDER_DEFAULT As Integer = 0
    'Const LOGON32_LOGON_INTERACTIVE As Integer = 2
    Const LOGON32_LOGON_NEW_CREDENTIALS As Integer = 9
    Const LOGON32_PROVIDER_WINNT50 As Integer = 3
    Const SecurityImpersonation As Integer = 2

    Dim win32ErrorNumber As Integer

    _tokenHandle = IntPtr.Zero
    _dupeTokenHandle = IntPtr.Zero

    If Not LogonUser(_username, _domainname, _password, LOGON32_LOGON_NEW_CREDENTIALS, LOGON32_PROVIDER_WINNT50, _tokenHandle) Then
      win32ErrorNumber = System.Runtime.InteropServices.Marshal.GetLastWin32Error()
      Throw New ImpersonationException(win32ErrorNumber, GetErrorMessage(win32ErrorNumber), _username, _domainname)
    End If

    If Not DuplicateToken(_tokenHandle, SecurityImpersonation, _dupeTokenHandle) Then
      win32ErrorNumber = System.Runtime.InteropServices.Marshal.GetLastWin32Error()

      CloseHandle(_tokenHandle)
      Throw New ImpersonationException(win32ErrorNumber, "Unable to duplicate token!", _username, _domainname)
    End If

    Dim newId As New System.Security.Principal.WindowsIdentity(_dupeTokenHandle)
    _impersonatedUser = newId.Impersonate()
  End Sub


  Public Sub EndImpersonation()
    If Not _impersonatedUser Is Nothing Then
      _impersonatedUser.Undo()
      _impersonatedUser = Nothing

      If Not System.IntPtr.op_Equality(_tokenHandle, IntPtr.Zero) Then
        CloseHandle(_tokenHandle)
      End If
      If Not System.IntPtr.op_Equality(_dupeTokenHandle, IntPtr.Zero) Then
        CloseHandle(_dupeTokenHandle)
      End If
    End If
  End Sub


  Public ReadOnly Property username() As String
    Get
      Return _username
    End Get
  End Property

  Public ReadOnly Property domainname() As String
    Get
      Return _domainname
    End Get
  End Property


  Public ReadOnly Property currentWindowsUsername() As String
    Get
      Return System.Security.Principal.WindowsIdentity.GetCurrent().Name
    End Get
  End Property


#Region "Exception Class"
  Public Class ImpersonationException
    Inherits System.Exception

    Public ReadOnly win32ErrorNumber As Integer

    Public Sub New(ByVal win32ErrorNumber As Integer, ByVal msg As String, ByVal username As String, ByVal domainname As String)
      MyBase.New(String.Format("Impersonation of {1}{0} failed! [{2}] {3}", username, domainname, win32ErrorNumber, msg))
      Me.win32ErrorNumber = win32ErrorNumber
    End Sub
  End Class
#End Region


#Region "External Declarations and Helpers"
  Private Declare Auto Function LogonUser Lib "advapi32.dll" (ByVal lpszUsername As [String], _
          ByVal lpszDomain As [String], ByVal lpszPassword As [String], _
          ByVal dwLogonType As Integer, ByVal dwLogonProvider As Integer, _
          ByRef phToken As IntPtr) As Boolean


  Private Declare Auto Function DuplicateToken Lib "advapi32.dll" (ByVal ExistingTokenHandle As IntPtr, _
              ByVal SECURITY_IMPERSONATION_LEVEL As Integer, _
              ByRef DuplicateTokenHandle As IntPtr) As Boolean


  Private Declare Auto Function CloseHandle Lib "kernel32.dll" (ByVal handle As IntPtr) As Boolean


  <System.Runtime.InteropServices.DllImport("kernel32.dll")> _
  Private Shared Function FormatMessage(ByVal dwFlags As Integer, ByRef lpSource As IntPtr, _
          ByVal dwMessageId As Integer, ByVal dwLanguageId As Integer, ByRef lpBuffer As [String], _
          ByVal nSize As Integer, ByRef Arguments As IntPtr) As Integer
  End Function


  Private Function GetErrorMessage(ByVal errorCode As Integer) As String
    Dim FORMAT_MESSAGE_ALLOCATE_BUFFER As Integer = &H100
    Dim FORMAT_MESSAGE_IGNORE_INSERTS As Integer = &H200
    Dim FORMAT_MESSAGE_FROM_SYSTEM As Integer = &H1000

    Dim messageSize As Integer = 255
    Dim lpMsgBuf As String = ""
    Dim dwFlags As Integer = FORMAT_MESSAGE_ALLOCATE_BUFFER Or FORMAT_MESSAGE_FROM_SYSTEM Or FORMAT_MESSAGE_IGNORE_INSERTS

    Dim ptrlpSource As IntPtr = IntPtr.Zero
    Dim prtArguments As IntPtr = IntPtr.Zero

    Dim retVal As Integer = FormatMessage(dwFlags, ptrlpSource, errorCode, 0, lpMsgBuf, messageSize, prtArguments)
    If 0 = retVal Then
      Throw New System.Exception("Failed to format message for error code " + errorCode.ToString() + ". ")
    End If

    Return lpMsgBuf
  End Function

#End Region

End Class

This will allow you to impersonate a designated user for a session. so you would than change your code to:

Dim domain, username, passwordStr, remoteServerName As String    
Dim password As New Security.SecureString    
Dim command As New Process  

domain = "domain.com"    
username = "username"    
passwordStr = "password"    
remoteServerName = "serverName"
Dim impersonator As New AliasAccount(username, password)

For Each c As Char In passwordStr.ToCharArray        
  password.AppendChar(c)    
Next


command.StartInfo.FileName = "explorer.exe"    
command.StartInfo.Arguments = "" & serverName & "admin$Temp"        

command.StartInfo.UserName = username    
command.StartInfo.Password = password    
command.StartInfo.Domain = domain    
command.StartInfo.Verb = "open"    
command.StartInfo.UseShellExecute = False 

  impersonator.BeginImpersonation()
command.Start() 
  impersonator.EndImpersonation()