NTLM Client and Server Code

Demonstrates the NTLM authentication algorithm for both client and server.

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Dim ntlmClient As New Chilkat.Ntlm()

Dim success As Boolean
success = ntlmClient.UnlockComponent("Anything for 30-day trial")
If (success <> true) Then
    TextBox1.Text = TextBox1.Text & ntlmClient.LastErrorText & vbCrLf
    Exit Sub
End If

'  UnlockComponent only needs to be called once on the 1st object instance.

Dim ntlmServer As New Chilkat.Ntlm()

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

TextBox1.Text = TextBox1.Text & "Type1 message from client to server:" & vbCrLf
TextBox1.Text = TextBox1.Text & type1Msg & vbCrLf

'  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)

TextBox1.Text = TextBox1.Text & "---" & vbCrLf
TextBox1.Text = TextBox1.Text & type1Info & vbCrLf

'  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 (type2Msg = vbNullString ) Then
    TextBox1.Text = TextBox1.Text & ntlmServer.LastErrorText & vbCrLf
    Exit Sub
End If


TextBox1.Text = TextBox1.Text & "Type2 message from server to client:" & vbCrLf
TextBox1.Text = TextBox1.Text & type2Msg & vbCrLf

'  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)

TextBox1.Text = TextBox1.Text & "---" & vbCrLf
TextBox1.Text = TextBox1.Text & type2Info & vbCrLf

'  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 (type3Msg = vbNullString ) Then
    TextBox1.Text = TextBox1.Text & ntlmClient.LastErrorText & vbCrLf
    Exit Sub
End If


TextBox1.Text = TextBox1.Text & "Type3 message from client to server:" & vbCrLf
TextBox1.Text = TextBox1.Text & type3Msg & vbCrLf

'  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.

success = ntlmServer.LoadType3(type3Msg)
If (success <> true) Then
    TextBox1.Text = TextBox1.Text & ntlmServer.LastErrorText & vbCrLf
    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)

TextBox1.Text = TextBox1.Text & "Expected Type3 Message:" & vbCrLf
TextBox1.Text = TextBox1.Text & expectedType3Msg & vbCrLf

'  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.