(Visual Basic 6.0) NTLM Client and Server Code

Demonstrates the NTLM authentication algorithm for both client and server.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

' This example assumes the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

Dim ntlmClient As New ChilkatNtlm
Dim ntlmServer As New ChilkatNtlm

' The NTLM protocol begins by the client sending the server
' a Type1 message. 
Dim type1Msg As String
ntlmClient.Workstation = "MyWorkstation"
type1Msg = ntlmClient.GenType1()

Debug.Print "Type1 message from client to server:"
Debug.Print type1Msg

' If the server wishes to examine the information embedded within the
' Type1 message, it may call ParseType1. 
' This step is not necessary, it is only for informational purposes..
Dim type1Info As String
type1Info = ntlmServer.ParseType1(type1Msg)

Debug.Print "---"
Debug.Print type1Info

' The server now generates a Type2 message to be sent to the client.
' The Type2 message requires a TargetName.  A TargetName is
' the authentication realm in which the authenticating account
' has membership (a domain name for domain accounts, or server name
' for local machine accounts).
ntlmServer.TargetName = "myAuthRealm"

Dim type2Msg As String
type2Msg = ntlmServer.GenType2(type1Msg)
If (ntlmServer.LastMethodSuccess <> 1) Then
    Debug.Print ntlmServer.LastErrorText
    Exit Sub
End If

Debug.Print "Type2 message from server to client:"
Debug.Print type2Msg

' The client may examine the information embedded in the Type2 message 
' by calling ParseType2, which returns XML.  This is only for informational purposes
' and is not required.
Dim type2Info As String
type2Info = ntlmClient.ParseType2(type2Msg)

Debug.Print "---"
Debug.Print type2Info

' The client will now generate the final Type3 message to be sent to the server.
' This requires the Username and Password:
ntlmClient.UserName = "test123"
ntlmClient.Password = "myPassword"

Dim type3Msg As String
type3Msg = ntlmClient.GenType3(type2Msg)
If (ntlmClient.LastMethodSuccess <> 1) Then
    Debug.Print ntlmClient.LastErrorText
    Exit Sub
End If

Debug.Print "Type3 message from client to server:"
Debug.Print type3Msg

' The server may verify the response by first "loading" the Type3 message.
' This sets the various properties such as Username, Domain, Workstation,
' and ClientChallenge to the values embedded within theType3 message.
' The server may then use the Username to lookup the password.  
' Looking up the password is dependent on your infrastructure.  Perhaps your
' usernames/passwords are stored in a secure database.  If that's the case, you would
' write code to issue a query to get the password string for the given username.
' Once the password is obtained, set the Password property and then 
' generate the Type3 response again.  If the server's Type3 response matches
' the client's Type3 response, then the client's password is correct.

Dim success As Long
success = ntlmServer.LoadType3(type3Msg)
If (success <> 1) Then
    Debug.Print ntlmServer.LastErrorText
    Exit Sub
End If

' The Username property now contains the username that was embedded within
' the Type3 message.  It can be used to lookup the password.
Dim clientUsername As String
clientUsername = ntlmServer.UserName

' For this example, we'll simply set the password to a literal string:
ntlmServer.Password = "myPassword"

' The server may generate the Type3 message again, using the client's correct
' password:
Dim expectedType3Msg As String
expectedType3Msg = ntlmServer.GenType3(type2Msg)

Debug.Print "Expected Type3 Message:"
Debug.Print expectedType3Msg

' If the Type3 message received from the client is exactly the same as the
' expected Type3 message, then the client must've used the same password,
' and authentication is successful