encrypt2.frm

ras 加密 ras 加密

VERSION 5.00
Object = "{F9043C88-F6F2-101A-A3C9-08002B2F49FB}#1.2#0"; "COMDLG32.OCX"
Begin VB.Form Form1 
   Caption         =   "Quick Note"
   ClientHeight    =   4230
   ClientLeft      =   1095
   ClientTop       =   1800
   ClientWidth     =   6720
   LinkTopic       =   "Form1"
   ScaleHeight     =   4230
   ScaleWidth      =   6720
   Begin VB.TextBox txtNote 
      Height          =   3015
      Left            =   360
      MultiLine       =   -1  'True
      ScrollBars      =   3  'Both
      TabIndex        =   0
      Top             =   600
      Width           =   6015
   End
   Begin MSComDlg.CommonDialog CommonDialog1 
      Left            =   360
      Top             =   3720
      _ExtentX        =   847
      _ExtentY        =   847
      _Version        =   393216
      FontSize        =   1.17491e-38
   End
   Begin VB.Label lblFile 
      AutoSize        =   -1  'True
      Caption         =   "Type your note and then save it to disk."
      Height          =   180
      Left            =   360
      TabIndex        =   1
      Top             =   240
      Width           =   3600
   End
   Begin VB.Menu mnuFile 
      Caption         =   "&File"
      Begin VB.Menu mnuOpenItem 
         Caption         =   "&Open Encrypted File..."
      End
      Begin VB.Menu mnuItemSave 
         Caption         =   "&Save Encrypted File..."
      End
      Begin VB.Menu mnuItemDate 
         Caption         =   "Insert &Date"
      End
      Begin VB.Menu mnuItemExit 
         Caption         =   "E&xit"
      End
   End
End
Attribute VB_Name = "Form1"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Private Sub mnuItemDate_Click()
    Wrap$ = Chr$(13) & Chr$(10) 'add date to string
    txtNote.Text = Date$ & Wrap$ & txtNote.Text
End Sub

Private Sub mnuItemExit_Click()
    End                         'quit program
End Sub

Private Sub mnuItemSave_Click()
    CommonDialog1.Filter = "Text files (*.TXT)|*.TXT"
    CommonDialog1.ShowSave      'display Save dialog
    If CommonDialog1.FileName <> "" Then
        'get encryption code and use it to encrypt file
        code = InputBox("Enter Encryption Code", , 1)
        If code = "" Then Exit Sub  'if Cancel chosen, exit sub
        Form1.MousePointer = 11     'display hourglass
        charsInFile% = Len(txtNote.Text) 'find string length
        Open CommonDialog1.FileName For Output As #1 'open file
        For i% = 1 To charsInFile%  'for each character in file
            letter$ = Mid(txtNote.Text, i%, 1) 'read next char
            'convert to number w/ Asc, then use Xor to encrypt
            Print #1, Asc(letter$) Xor code; 'and save in file
        Next i%
        Close #1                'close file when finished
        CommonDialog1.FileName = ""  'clear filename
        Form1.MousePointer = 0  'reset mouse
    End If
End Sub

Private Sub mnuOpenItem_Click()
    Wrap$ = Chr$(13) + Chr$(10) 'create wrap character
    CommonDialog1.Filter = "Text files (*.TXT)|*.TXT"
    CommonDialog1.ShowOpen      'display Open dialog box
    If CommonDialog1.FileName <> "" Then
        'get encryption code to convert coded file to text
        code = InputBox("Enter encryption code", , 1)
        If code = "" Then Exit Sub 'if Cancel chosen, exit sub
        Form1.MousePointer = 11 'display hourglass
        Open CommonDialog1.FileName For Input As #1 'open file
        On Error GoTo Problem:  'set error handler
        decrypt$ = ""   'initialize string for decryption
        Do Until EOF(1)         'until end of file reached
            Input #1, Number&   'read encrypted numbers
            e$ = Chr$(Number& Xor code) 'convert with Xor
            decrypt$ = decrypt$ & e$    'and build string
        Loop
        lblFile.Caption = CommonDialog1.FileName 'set caption
        txtNote.Text = decrypt$ 'display converted string
        txtNote.Enabled = True  'and enable scroll bars
CleanUp:                        'when finished...
        Form1.MousePointer = 0  'reset mouse
        Close #1                'close file
        CommonDialog1.FileName = ""  'clear filename
    End If
    Exit Sub
Problem:  'if there is a problem, display appropriate message
    If Err.Number = 5 Then  'Chr$ problem means bad key
        MsgBox ("Incorrect Encryption Key")
    Else  'for other problems (like file too big) show error
        MsgBox "Error Opening File", , Err.Description
    End If
    Resume CleanUp:   'finally, finish with CleanUp routine
End Sub