form3.frm

用vb实现的古典密码

VERSION 5.00
Begin VB.Form Form3 
   BackColor       =   &H00808000&
   Caption         =   "维吉尼亚密码体制"
   ClientHeight    =   3675
   ClientLeft      =   3060
   ClientTop       =   3450
   ClientWidth     =   7170
   LinkTopic       =   "Form1"
   ScaleHeight     =   3675
   ScaleLeft       =   200
   ScaleMode       =   0  'User
   ScaleTop        =   200
   ScaleWidth      =   7215.284
   Begin VB.CommandButton Command3 
      BackColor       =   &H00FFC0C0&
      Caption         =   "清空"
      Height          =   375
      Left            =   5280
      Style           =   1  'Graphical
      TabIndex        =   8
      Top             =   3000
      Width           =   975
   End
   Begin VB.CommandButton Command2 
      BackColor       =   &H00FFC0C0&
      Caption         =   "解密"
      Height          =   375
      Left            =   3120
      Style           =   1  'Graphical
      TabIndex        =   7
      Top             =   3000
      Width           =   975
   End
   Begin VB.CommandButton Command1 
      BackColor       =   &H00FFC0C0&
      Caption         =   "加密"
      Height          =   375
      Left            =   720
      Style           =   1  'Graphical
      TabIndex        =   6
      Top             =   3000
      Width           =   975
   End
   Begin VB.TextBox Text3 
      BeginProperty Font 
         Name            =   "宋体"
         Size            =   15
         Charset         =   134
         Weight          =   400
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      Height          =   1935
      Left            =   4800
      MultiLine       =   -1  'True
      ScrollBars      =   2  'Vertical
      TabIndex        =   5
      Top             =   720
      Width           =   1815
   End
   Begin VB.TextBox Text2 
      BeginProperty Font 
         Name            =   "宋体"
         Size            =   15
         Charset         =   134
         Weight          =   400
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      Height          =   1935
      IMEMode         =   3  'DISABLE
      Left            =   2640
      MultiLine       =   -1  'True
      PasswordChar    =   "*"
      ScrollBars      =   2  'Vertical
      TabIndex        =   4
      Top             =   720
      Width           =   1815
   End
   Begin VB.TextBox Text1 
      BeginProperty Font 
         Name            =   "宋体"
         Size            =   15
         Charset         =   134
         Weight          =   400
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      Height          =   1935
      Left            =   360
      MultiLine       =   -1  'True
      ScrollBars      =   2  'Vertical
      TabIndex        =   3
      Top             =   720
      Width           =   1815
   End
   Begin VB.Label Label3 
      BackColor       =   &H00808000&
      Caption         =   "密 文"
      BeginProperty Font 
         Name            =   "宋体"
         Size            =   15.75
         Charset         =   134
         Weight          =   400
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      ForeColor       =   &H000080FF&
      Height          =   375
      Left            =   5280
      TabIndex        =   2
      Top             =   240
      Width           =   855
   End
   Begin VB.Label Label2 
      BackColor       =   &H00808000&
      Caption         =   "密 钥"
      BeginProperty Font 
         Name            =   "宋体"
         Size            =   15.75
         Charset         =   134
         Weight          =   400
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      ForeColor       =   &H000080FF&
      Height          =   375
      Left            =   3120
      TabIndex        =   1
      Top             =   240
      Width           =   855
   End
   Begin VB.Label Label1 
      BackColor       =   &H00808000&
      Caption         =   "明 文"
      BeginProperty Font 
         Name            =   "宋体"
         Size            =   15.75
         Charset         =   134
         Weight          =   400
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      ForeColor       =   &H000080FF&
      Height          =   375
      Left            =   960
      TabIndex        =   0
      Top             =   240
      Width           =   855
   End
End
Attribute VB_Name = "Form3"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Const aph = "abcdefghijklmnopqrstuvwxyz"        '定义字母表
Private Sub Command1_Click()    '加密
If Text1.Text = "" Then         '判断明文是否为空
MsgBox "请输入您要加密的明文", vbInformation
Text1.SetFocus
ElseIf Text2.Text = "" Then      '判断密钥是否为空
MsgBox "请输入密钥", vbInformation
Text2.SetFocus
Else
Dim l1%, l2%, i%, j%
Dim StrPos1%, Strpos2%, Ms%
Dim Mystr$, Mystr2$, mingwen$
l2 = Len(Text2.Text)       '获取密钥长度
j = 0
For i = 1 To l2             '判断密钥是否均为字母
Mystr2 = Mid(Text2.Text, i, 1)
Strpos2 = InStr(1, aph, Mystr2, 1)
If Strpos2 <> 0 Then
j = j + 1
End If
Next
If j <> l2 Then                     '判断密钥是否正确
MsgBox "请输入正确的密钥", vbExclamation
Text2.Text = ""
Text2.SetFocus
Else
mingwen = Text1.Text           '获取原明文
l1 = Len(Text1.Text)       '获取明文长度
j = 0
For i = 1 To l1 Step 1        '加密过程
Mystr = Mid(Text1.Text, i, 1)
If i Mod l2 = 0 Then
Mystr2 = Mid(Text2.Text, l2, 1)
Else
Mystr2 = Mid(Text2.Text, i Mod l2, 1)
End If
StrPos1 = InStr(1, aph, Mystr, 1)   '查找原文字母在字母表中的位置
Ms = InStr(1, aph, Mystr2, 1)      '查找密钥字母在字母表中的位置
If StrPos1 <> 0 Then
j = j + 1
Strpos2 = (StrPos1 + Ms - 1) Mod 26     '加密
If Strpos2 = 0 Then
Strpos2 = 26
End If
Mid$(mingwen, i, 1) = Mid$(aph, Strpos2, 1)
End If
Next i
If j <> l1 Then                 '判断明文是否正确即明文是否均为字母
MsgBox "请输入正确的加密数据", vbExclamation
Text1.SetFocus
Command3.Enabled = True
Else
mingwen = UCase(mingwen)           '把加密后的数据转换成大写
Text3.Text = mingwen               '显示加密后的数据
Command3.Enabled = True
End If
End If
End If
End Sub

Private Sub Command2_Click()                '解密
If Text3.Text = "" Then                   '判断密文是否为空
MsgBox "请输入您要解密的密文", vbInformation
Text3.SetFocus
ElseIf Text2.Text = "" Then                     '判断密钥是否为空
MsgBox "请输入密钥", vbInformation
Text2.SetFocus
Else
Dim l1%, l2%, i%, j%
Dim StrPos1%, Strpos2%, Ms%
Dim Mystr$, Mystr2$, miwen$
l2 = Len(Text2.Text)       '获取密钥长度
j = 0
For i = 1 To l2             '判断密钥是否均为字母
Mystr2 = Mid(Text2.Text, i, 1)
Strpos2 = InStr(1, aph, Mystr2, 1)
If Strpos2 <> 0 Then
j = j + 1
End If
Next
If j <> l2 Then               '判断密钥是否正确
MsgBox "请输入正确的密钥", vbExclamation
Text2.Text = ""
Text2.SetFocus
Else
miwen = Text3.Text           '获取密文
l1 = Len(Text3.Text)         '获取密文长度
j = 0
For i = 1 To l1 Step 1        '解密过程
Mystr = Mid(Text3.Text, i, 1)
If i Mod l2 = 0 Then
Mystr2 = Mid(Text2.Text, l2, 1)
Else
Mystr2 = Mid(Text2.Text, i Mod l2, 1)
End If
StrPos1 = InStr(1, aph, Mystr, 1)    '获取密文在字母表中的位置
Ms = InStr(1, aph, Mystr2, 1)         '获取密钥在字母表中的位置
If StrPos1 <> 0 Then
j = j + 1
Strpos2 = (StrPos1 - Ms + 1 + 26) Mod 26     '解密
If Strpos2 = 0 Then
Strpos2 = 26
End If
Mid$(miwen, i, 1) = Mid$(aph, Strpos2, 1)
End If
Next i
If j <> l1 Then                      '判断密文是否正确即密文是否均为字母
MsgBox "请输入正确的解密数据", vbExclamation
Text3.SetFocus
Command3.Enabled = True
Else
Text1.Text = miwen                               '显示解密后的数据
Command3.Enabled = True
End If
End If
End If
End Sub

Private Sub Command3_Click()      '清空
i = MsgBox("你确定要清除所有的内容吗？", vbOKCancel + vbInformation)
If i = 1 Then
Text1.Text = ""
Text2.Text = ""
Text3.Text = ""
Command3.Enabled = False
Else
End If
End Sub

Private Sub Form_Load()
Command3.Enabled = False
End Sub