frmchgpwd.frm

程序加密算法

' ---------------------------------------------------------------------------
' Initialize local variables
' ---------------------------------------------------------------------------
  strInText = ""
  intLength = Len(m_strPassword)
  Set cMD5 = New clsMD5

' ---------------------------------------------------------------------------
' Concatenate the Password / Passphrase entered with the salt value from the
' database and hash the results.
' ---------------------------------------------------------------------------
  strInText = strInText & g_strSalt
  strHashed = cMD5.MD5_Hash_Data_String(strInText)
  Set cMD5 = Nothing
  
' ---------------------------------------------------------------------------
' compare just the hashed results with the ruslts stored in the database
' ---------------------------------------------------------------------------
  If StrComp(strInText, g_strHash, vbTextCompare) = 0 Then
      ' if a valid password was entered in the password
      ' textbox and it matched what was on file
      ' display an error message
      MsgBox "We have a password match.", _
             vbOKOnly + vbInformation, "Success"
      Good_Old_Password = True
  Else
      ' display an error message
      MsgBox "Password does not match what is on file.", _
             vbOKOnly + vbInformation, "Invalid Data"
      Good_Old_Password = False
  End If


Normal_Exit:
' ---------------------------------------------------------------------------
' clear variables holding the digital signatures for security reasons.
' Leave nothing in memory.
' ---------------------------------------------------------------------------
  strInText = String(intLength, 0)
  strInText = ""
  
End Function

Private Sub Form_Initialize()

' ---------------------------------------------------------------------------
' Centered on the screen
' ---------------------------------------------------------------------------
  Me.Move (Screen.Width - Me.Width) \ 2, (Screen.Height - Me.Height) \ 2

End Sub
Private Sub Form_Load()

' ---------------------------------------------------------------------------
' Make sure we do not show this form when first loading the application
' ---------------------------------------------------------------------------
  With frmPWord
       .txtPassword(0).Text = ""
       .txtPassword(1).Text = ""
       .lblMyLabel = "Freeware by Kenneth Ives  [e-mail]"
       .lblTitle = "XYZ Corporation" & vbCrLf & "Password Entry"
       .Hide
  End With
  
End Sub
Private Sub Form_QueryUnload(Cancel As Integer, UnloadMode As Integer)

' ---------------------------------------------------------------------------
' Empty variables
' ---------------------------------------------------------------------------
  Clear_Variables
  
' ---------------------------------------------------------------------------
' Based on the the unload code the system passes,
' we determine what to do
'
' Unloadmode codes
'     0 - Close from the control-menu box
'         or Upper left "X"
'     1 - Unload method from code elsewhere
'         in the application
'     2 - Windows Session is ending
'     3 - Task Manager is clostrIng the app
'     4 - MDI Parent is clostrIng
' ---------------------------------------------------------------------------
  Select Case UnloadMode
         Case 0: cmdChoice_Click 1  ' Return to the main menu
         Case 1: Exit Sub
         Case 2: StopApplication
         Case 3: StopApplication
         Case 4: StopApplication
  End Select
  
End Sub

Private Sub txtPassword_GotFocus(Index As Integer)
  
' ---------------------------------------------------------------------------
' Highlight all the text in the box
' ---------------------------------------------------------------------------
  With txtPassword(Index)
       .SelStart = 0
       .SelLength = Len(.Text)
  End With
  
End Sub

Private Sub txtPassword_KeyDown(Index As Integer, KeyCode As Integer, Shift As Integer)

' ---------------------------------------------------------------------------
' Define local variables
' ---------------------------------------------------------------------------
  Dim CtrlDown    As Integer
  Dim PressedKey  As Integer
  
' ---------------------------------------------------------------------------
' Initialize  variables
' ---------------------------------------------------------------------------
  CtrlDown = (Shift And vbCtrlMask) > 0   ' Define control key
  PressedKey = Asc(UCase(Chr(KeyCode)))   ' Convert to uppercase
    
' ---------------------------------------------------------------------------
' Check to see if it is okay to make changes
' ---------------------------------------------------------------------------
  If CtrlDown And PressedKey = vbKeyX Then
      Edit_Cut            ' Ctrl + X was pressed
  ElseIf CtrlDown And PressedKey = vbKeyA Then
      With txtPassword(Index)    ' Ctrl + A was pressed
           .SelStart = 0
           .SelLength = Len(.Text)
       End With
  ElseIf CtrlDown And PressedKey = vbKeyC Then
      Edit_Copy           ' Ctrl + C was pressed
  ElseIf CtrlDown And PressedKey = vbKeyV Then
      Edit_Paste          ' Ctrl + V was pressed
  ElseIf PressedKey = vbKeyDelete Then
      Edit_Delete         ' Delete key was pressed
  End If

End Sub

Private Sub txtPassword_KeyPress(Index As Integer, KeyAscii As Integer)

' ---------------------------------------------------------------------------
' If ENTER is pressed then nullify keystroke and execute the OK button
' ---------------------------------------------------------------------------
  If KeyAscii = 13 Then
      KeyAscii = 0
      cmdChoice(0).SetFocus
      SendKeys "{ENTER}"
      Exit Sub
  End If
  
' ---------------------------------------------------------------------------
' If TAB is pressed then nullify keystroke and TAB to the next tabstop
' ---------------------------------------------------------------------------
  If KeyAscii = 9 Then
      KeyAscii = 0
      SendKeys "{TAB}"
  End If
  
' ---------------------------------------------------------------------------
' Accept on valid characters
' ---------------------------------------------------------------------------
  Select Case KeyAscii
  
         ' backspace and other printable
         ' keyboard characters
         Case 8, 32 To 126:
              Exit Sub      ' Good input
              
         ' Bad input
         Case Else:
              KeyAscii = 0  ' Nullify keystroke
  End Select
  
End Sub

Private Sub txtPassword_LostFocus(Index As Integer)

' ---------------------------------------------------------------------------
' Remove leading and trailing blank spaces
' ---------------------------------------------------------------------------
  txtPassword(Index) = Trim(txtPassword(Index))
  
' ---------------------------------------------------------------------------
' Initial test of the input data
' ---------------------------------------------------------------------------
  Select Case Index
  
         ' User ID
         Case 0:
              If Len(txtPassword(0)) > 0 Then
                  txtPassword(0) = StrConv(txtPassword(0), vbUpperCase)
                  g_strUserID = txtPassword(0)
              Else
                  g_strUserID = ""
              End If
              
              ' change has occured in the userID text box
              g_strHash = ""
              g_strSalt = ""
              txtPassword(1) = ""
              m_strPassword = ""
              
         ' Password
         Case Else:
              ' if something is in the password box
              ' then save to another variable and
              ' fill the text box with asteriks
              If Len(txtPassword(1)) > 0 Then
                  m_strPassword = txtPassword(1)
                  txtPassword(1) = String(30, "*")
              Else
                  ' else empty the text box and the
                  ' variable
                  txtPassword(1) = ""
                  m_strPassword = ""
              End If
  End Select
  
End Sub