form1.vb

.NET DES加密算法的使用过程

Imports System.IO
Imports System.Text
Imports System.Security.Cryptography



Public Class Form1
    Inherits System.Windows.Forms.Form

#Region " Windows 窗体设计器生成的代码 "

    Public Sub New()
        MyBase.New()

        '该调用是 Windows 窗体设计器所必需的。
        InitializeComponent()

        '在 InitializeComponent() 调用之后添加任何初始化

    End Sub

    '窗体重写处置以清理组件列表。
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Windows 窗体设计器所必需的
    Private components As System.ComponentModel.IContainer

    '注意：以下过程是 Windows 窗体设计器所必需的
    '可以使用 Windows 窗体设计器修改此过程。
    '不要使用代码编辑器修改它。
    Friend WithEvents Label1 As System.Windows.Forms.Label
    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox
    Friend WithEvents Button1 As System.Windows.Forms.Button
    Friend WithEvents Label2 As System.Windows.Forms.Label
    Friend WithEvents TextBox2 As System.Windows.Forms.TextBox
    Friend WithEvents Button2 As System.Windows.Forms.Button
    Friend WithEvents Label3 As System.Windows.Forms.Label
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.Label1 = New System.Windows.Forms.Label()
        Me.TextBox1 = New System.Windows.Forms.TextBox()
        Me.Button1 = New System.Windows.Forms.Button()
        Me.Label2 = New System.Windows.Forms.Label()
        Me.TextBox2 = New System.Windows.Forms.TextBox()
        Me.Button2 = New System.Windows.Forms.Button()
        Me.Label3 = New System.Windows.Forms.Label()
        Me.SuspendLayout()
        '
        'Label1
        '
        Me.Label1.Location = New System.Drawing.Point(8, 16)
        Me.Label1.Name = "Label1"
        Me.Label1.Size = New System.Drawing.Size(200, 16)
        Me.Label1.TabIndex = 0
        Me.Label1.Text = "指定需要加密或解密的文件"
        '
        'TextBox1
        '
        Me.TextBox1.Location = New System.Drawing.Point(8, 32)
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.Size = New System.Drawing.Size(248, 21)
        Me.TextBox1.TabIndex = 1
        Me.TextBox1.Text = ""
        '
        'Button1
        '
        Me.Button1.Location = New System.Drawing.Point(184, 64)
        Me.Button1.Name = "Button1"
        Me.Button1.TabIndex = 2
        Me.Button1.Text = "浏览"
        '
        'Label2
        '
        Me.Label2.Location = New System.Drawing.Point(8, 96)
        Me.Label2.Name = "Label2"
        Me.Label2.Size = New System.Drawing.Size(200, 23)
        Me.Label2.TabIndex = 3
        Me.Label2.Text = "输入密码（8个字符）"
        '
        'TextBox2
        '
        Me.TextBox2.Location = New System.Drawing.Point(8, 120)
        Me.TextBox2.Name = "TextBox2"
        Me.TextBox2.Size = New System.Drawing.Size(248, 21)
        Me.TextBox2.TabIndex = 4
        Me.TextBox2.Text = ""
        '
        'Button2
        '
        Me.Button2.Location = New System.Drawing.Point(184, 184)
        Me.Button2.Name = "Button2"
        Me.Button2.TabIndex = 5
        Me.Button2.Text = "开始"
        '
        'Label3
        '
        Me.Label3.Location = New System.Drawing.Point(8, 152)
        Me.Label3.Name = "Label3"
        Me.Label3.Size = New System.Drawing.Size(200, 23)
        Me.Label3.TabIndex = 6
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(6, 14)
        Me.ClientSize = New System.Drawing.Size(272, 221)
        Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.Label3, Me.Button2, Me.TextBox2, Me.Label2, Me.Button1, Me.TextBox1, Me.Label1})
        Me.Name = "Form1"
        Me.Text = "加密/解密工具"
        Me.ResumeLayout(False)

    End Sub

#End Region
    ' 保存密钥的8字节的数组
    Public TheKey(7) As Byte

    ' 在向量中放入一些随机数据
    Private Vector() As Byte = {&H12, &H44, &H16, &HEE, &H88, &H15, &HDD, &H41}

    '/////加密 
    Sub Encrypt(ByVal inName As String, ByVal outName As String)
        Try
            ' 创建缓冲区
            Dim storage(4096) As Byte
            ' 已经写入的字节数量
            Dim totalBytesWritten As Long = 8
            ' 每次写入的字节数量
            Dim packageSize As Integer

            ' 声明文件流
            Dim fin As New FileStream(inName, FileMode.Open, FileAccess.Read)
            Dim fout As New FileStream(outName, FileMode.OpenOrCreate, _
              FileAccess.Write)
            fout.SetLength(0)
            ' 源文件的大小
            Dim totalFileLength As Long = fin.Length

            ' 创建加密对象
            Dim des As New DESCryptoServiceProvider()

            Dim crStream As New CryptoStream(fout, _
                   des.CreateEncryptor(TheKey, Vector), CryptoStreamMode.Write)

            ' 输出加密后的文件
            While totalBytesWritten < totalFileLength
                packageSize = fin.Read(storage, 0, 4096)
                crStream.Write(storage, 0, packageSize)
                totalBytesWritten = Convert.ToInt32(totalBytesWritten + packageSize / des.BlockSize * des.BlockSize)
            End While

            crStream.Close()


        Catch e As Exception
            MsgBox(e.Message)
        End Try

    End Sub


    '//////// 解密
    Sub Decrypt(ByVal inName As String, ByVal outName As String)

        Try

            Dim storage(4096) As Byte
            Dim totalBytesWritten As Long = 8
            Dim packageSize As Integer
            Dim fin As New FileStream(inName, FileMode.Open, FileAccess.Read)
            Dim fout As New FileStream(outName, FileMode.OpenOrCreate, _
              FileAccess.Write)
            fout.SetLength(0)
            Dim totalFileLength As Long = fin.Length


            Dim des As New DESCryptoServiceProvider()
            Dim crStream As New CryptoStream(fout, _
              des.CreateDecryptor(TheKey, Vector), CryptoStreamMode.Write)

            Dim ex As Exception

            While totalBytesWritten < totalFileLength
                packageSize = fin.Read(storage, 0, 4096)
                crStream.Write(storage, 0, packageSize)
                totalBytesWritten = Convert.ToInt32(totalBytesWritten + packageSize / des.BlockSize * des.BlockSize)
                Console.WriteLine("已处理 {0} 字节, 总 {1} 字节", packageSize, _
                   totalBytesWritten)
            End While

            crStream.Close()

        Catch e As Exception
            MsgBox(e.Message & "请确认你的密码是否正确!")
        End Try

    End Sub


    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim OpenFileDialog1 As OpenFileDialog
        OpenFileDialog1 = New OpenFileDialog()

        OpenFileDialog1.ShowDialog()
        TextBox1.Text = OpenFileDialog1.FileName
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Dim targetfile, sourcefile As String

        If TextBox1.Text = "" Or TextBox2.Text = "" Then MsgBox("必须输入文件名字和密码！.") : Exit Sub

        Dim ext As String
        Dim mainpath As String
        Dim n As Integer

        n = TextBox1.Text.IndexOf(".")
        If n <> -1 Then
            ext = TextBox1.Text.Substring(n + 1)
            mainpath = TextBox1.Text.Substring(0, TextBox1.Text.Length - ext.Length - 1)
        Else
            mainpath = TextBox1.Text
        End If

        If mainpath.Substring(mainpath.Length - 2) = "xx" Then     'this file will be decrypted 

            sourcefile = TextBox1.Text

            mainpath = mainpath.Substring(0, mainpath.Length - 2)
            If ext <> "" Then mainpath &= "." & ext
            targetfile = mainpath

            CreateKey(TextBox2.Text)
            Decrypt(sourcefile, targetfile)
            Label3.Text = "解密完成..."

            Exit Sub
        End If

        sourcefile = TextBox1.Text

        mainpath &= "xx"
        If ext <> "" Then mainpath &= "." & ext
        targetfile = mainpath

        CreateKey(TextBox2.Text)
        Encrypt(sourcefile, targetfile)

        Label3.Text = "加密完成..."

    End Sub
    Sub CreateKey(ByVal strKey As String)

        ' 保存密钥的字节数组
        Dim arrByte(7) As Byte

        Dim AscEncod As New ASCIIEncoding()
        Dim i As Integer = 0
        AscEncod.GetBytes(strKey, i, strKey.Length, arrByte, i)

        ' 获得密码的Hash值
        Dim hashSha As New SHA1CryptoServiceProvider()
        Dim arrHash() As Byte = hashSha.ComputeHash(arrByte)

        ' 将Hash值保存到密钥
        For i = 0 To 7
            TheKey(i) = arrHash(i)
        Next i

    End Sub


End Class