Password – Number of attempts (97/2k)

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I am trying to figure out the code which would allow a user three attempts at a password and if still incorrect, an action is invoked.
The textbox requiring the password is on a form. It has no buttons as yet.
Help please.

Rob

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Hi Rob,

I don’t have time to work out an example for you now . Have a look at ACC2000: How to Create a Password Protected Form or Report. It shouldn’t be too hard to add a variable intNumberOfAttempts to the sample code given there, increment it each time a password is evaluated and do whatever you deem necessary when a predetermined count is reached.

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Thanks Hans. I’ve downloaded the code and I’m working my way through it.

Regards

Rob

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Rob,

Here is the code I use. You will notice a CMD5 Type, that is an MD5 Hashing Class module. I store my passwords using the MD5 hashing algorythm in the db and not plaintext. MD5 is a one way algorythm.

The key component is the Static declaration for intTries. Static keeps the value across separate “runs” of the code.

A couple of other notes:

gcintLOGINATTEMPTS is a global constant that defines the number of login attempts since I needed a way to quickly change the number of attempts. IIRC, if you set this value to a negative number, then you can an unlimited number of attempts.

Private Sub cmdOK_Click()
'--------------------------------------------------------------------------
'.Purpose      : To handle the OK button Click event and
'.                verify login information
'.Author       : Bryan Carbonnell
'.Date         : 18-Oct-2002
'.Revised      : 18-Oct-2002 - Original
'--------------------------------------------------------------------------
Const cstrProcName As String = "cmdOK_Click"
Static intTries As Integer
Dim strSQL As String
Dim rst As DAO.Recordset
Dim md5 As CMD5
Dim strMsg As String

'Build SQL String
strSQL = "SELECT * FROM tblUser " & _
          "WHERE UserName ='" & txtUserName & "'"
'Open RecordSet
Set rst = CurrentDb().OpenRecordset(strSQL)

If rst.BOF = True And rst.EOF = True Then
  'No records, so we have an invalid UserName
  intTries = intTries + 1
  mbolValidLogin = False
Else
  'Valid UserName, now we need to check the password
  Set md5 = New CMD5
  If md5.md5(txtPassword & "")  rst!fldPassword Then
    'Invalid Password
    intTries = intTries + 1
    mbolValidLogin = False
  Else
    mbolValidLogin = True
    gstrUserName = txtUserName
  End If
End If

If intTries >= gcintLOGINATTEMPTS  And gcintLOGINATTEMPTS > 0Then
  'Too many tries, so boot the user
  strMsg = "You have exceeded the maximum number of Login attempts." _
            & vbCrLf & "" _
            & vbCrLf & "Please contact the Systems Administrator if you continue" _
            & vbCrLf & "having problems logging in." _
            & vbCrLf & "" _
            & vbCrLf & "The application will now shut down."
  'Display message box
  MsgBox strMsg, vbCritical + vbOKOnly, "Login Failure"
  '
  Application.Quit
Else
  Select Case Me.ValidLogin
    Case False
      'Invalid Login
      strMsg = "Invalid User Name or Password entered." & vbCrLf & vbCrLf & _
                "Click OK to try again. Clcik Cancel to Exit Application."
      
      If MsgBox(strMsg, vbOKCancel + vbExclamation, "Invalid Login") = vbCancel Then
        Application.Quit
      End If
    Case True
      'Valid Login
      Me.Visible = False
  End Select
End If
End Sub

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Thanks Bryan. I’m trying to get my head around two sets of code. I’m still a relative beginner wrt Access. The exercise will do me good. I’ll get back if I experience difficulties.

Best Wishes

Rob

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Please do get back if you have questions.

It’s not one of my more commented “public” procedures.

I just ripped it right out of one of my apps.

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MD5 Hashing Class module.
Is this one of the inner functions of Access?
Pat

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I wish!

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Pat,

No it’s not. It’s a class module I got off the web from http://www.frez.co.uk/freecode.htm%5B/url%5D

I took the VB version and imported it into Access and everything was fine.

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Thanks Bryan

That will prove useful.

Pat

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