详解C#如何加密解密RAR文件

实践过程

效果

代码

public partial class Form1 : Form
{
   public Form1()
   {
       InitializeComponent();
   }

private void Form1_Load(object sender, EventArgs e)
   {
       FileMenu(Application.ExecutablePath + ",0", Application.ExecutablePath);
       string[] str = Environment.GetCommandLineArgs();
       try
       {
           string strFile = "";
           for (int i = 2; i < str.Length; i++)
               strFile += str[i];
           FileInfo FInfo = new FileInfo(strFile);
           if (FInfo.Extension.ToLower() == ".mrrar")
               textBox1.Text = strFile;
       }
       catch { }
   }

//选择要加密或解密的文件
   private void button1_Click(object sender, EventArgs e)
   {
       openFileDialog1.Filter = "*.rar(rar压缩文件)|*.rar|*.mrrar(mrrar加密文件)|*.mrrar|*.*(所有文件)|*.*";
       if (openFileDialog1.ShowDialog() == DialogResult.OK)
           textBox1.Text = openFileDialog1.FileName;
   }

//加密rar文件
   private void button2_Click(object sender, EventArgs e)
   {
       string strPwd = textBox2.Text;
       byte[] btRKey = new byte[0];
       if (strPwd.Length == 6)
       {
           btRKey = new byte[] { (byte)strPwd[0], (byte)strPwd[1], (byte)strPwd[2], (byte)strPwd[3], (byte)strPwd[4], (byte)strPwd[5], (byte)strPwd[0], (byte)strPwd[1] };
       }
       if (strPwd.Length == 7)
       {
           btRKey = new byte[] { (byte)strPwd[0], (byte)strPwd[1], (byte)strPwd[2], (byte)strPwd[3], (byte)strPwd[4], (byte)strPwd[5], (byte)strPwd[6], (byte)strPwd[0] };
       }
       if (strPwd.Length >= 8)
       {
           btRKey = new byte[] { (byte)strPwd[0], (byte)strPwd[1], (byte)strPwd[2], (byte)strPwd[3], (byte)strPwd[4], (byte)strPwd[5], (byte)strPwd[6], (byte)strPwd[7] };
       }
       FileStream FStream = new FileStream(textBox1.Text, FileMode.Open, FileAccess.Read);
       FileStream NewFStream = new FileStream(textBox1.Text + ".mrrar", FileMode.OpenOrCreate, FileAccess.Write);
       NewFStream.SetLength((long)0);
       byte[] buffer = new byte[0x400];
       int MinNum = 0;
       long length = FStream.Length;
       int MaxNum = (int)(length / ((long)0x400));
       DES myDES = new DESCryptoServiceProvider();
       CryptoStream CStream = new CryptoStream(NewFStream, myDES.CreateEncryptor(btRKey, btRKey), CryptoStreamMode.Write);
       while (MinNum < length)
       {
           int count = FStream.Read(buffer, 0, 0x400);
           CStream.Write(buffer, 0, count);
           MinNum += count;
       }
       CStream.Close();
       NewFStream.Close();
       FStream.Close();
       File.Delete(textBox1.Text);
       MessageBox.Show("使用口令加密rar文件成功！", "信息提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
   }

//解密rar文件
   private void button3_Click(object sender, EventArgs e)
   {
       string strPwd = textBox2.Text;
       FileStream FStream = null;
       FileStream NewFStream = null;
       CryptoStream CStream = null;
       try
       {
           try
           {
               byte[] btRKey = new byte[0];
               if (strPwd.Length == 6)
               {
                   btRKey = new byte[] { (byte)strPwd[0], (byte)strPwd[1], (byte)strPwd[2], (byte)strPwd[3], (byte)strPwd[4], (byte)strPwd[5], (byte)strPwd[0], (byte)strPwd[1] };
               }
               if (strPwd.Length == 7)
               {
                   btRKey = new byte[] { (byte)strPwd[0], (byte)strPwd[1], (byte)strPwd[2], (byte)strPwd[3], (byte)strPwd[4], (byte)strPwd[5], (byte)strPwd[6], (byte)strPwd[0] };
               }
               if (strPwd.Length >= 8)
               {
                   btRKey = new byte[] { (byte)strPwd[0], (byte)strPwd[1], (byte)strPwd[2], (byte)strPwd[3], (byte)strPwd[4], (byte)strPwd[5], (byte)strPwd[6], (byte)strPwd[7] };
               }
               FStream = new FileStream(textBox1.Text, FileMode.Open, FileAccess.Read);
               string strNewFile = textBox1.Text.Substring(0, textBox1.Text.Length - 6);
               NewFStream = new FileStream(strNewFile, FileMode.OpenOrCreate, FileAccess.Write);
               NewFStream.SetLength((long)0);
               byte[] buffer = new byte[0x400];
               int MinNum = 0;
               long length = FStream.Length;
               int MaxNum = (int)(length / ((long)0x400));
               DES myDES = new DESCryptoServiceProvider();
               CStream = new CryptoStream(NewFStream, myDES.CreateDecryptor(btRKey, btRKey), CryptoStreamMode.Write);
               while (MinNum < length)
               {
                   int count = FStream.Read(buffer, 0, 0x400);
                   CStream.Write(buffer, 0, count);
                   MinNum += count;
               }
               CStream.Close();
               FStream.Close();
               NewFStream.Close();
               File.Delete(textBox1.Text);
               System.Diagnostics.Process.Start(strNewFile);
           }
           catch
           {
               MessageBox.Show("口令错误！", "信息提示", MessageBoxButtons.OK, MessageBoxIcon.Error);
               textBox2.Focus();
           }
       }
       finally
       {
           CStream.Close();
           FStream.Close();
           NewFStream.Close();
       }
   }

//创建快捷菜单
   public static void FileMenu(string strPath, string strName)
   {
       try
       {
           Registry.ClassesRoot.CreateSubKey(".mrrar");
           RegistryKey RKey1 = Registry.ClassesRoot.OpenSubKey(".mrrar", true);
           RKey1.SetValue("", "mrrarfile");
           RKey1.Close();
           Registry.ClassesRoot.CreateSubKey("mrrarfile");
           RegistryKey RKey2 = Registry.ClassesRoot.OpenSubKey("mrrarfile", true);
           RKey2.CreateSubKey("DefaultIcon");
           RKey2.CreateSubKey("shell");
           RKey2.Close();
           RegistryKey RKey3 = Registry.ClassesRoot.OpenSubKey("mrrarfile\\DefaultIcon", true);
           RKey3.SetValue("", strPath);
           RKey3.Close();
           RegistryKey RKey4 = Registry.ClassesRoot.OpenSubKey("mrrarfile\\shell", true);
           RKey4.CreateSubKey("使用口令打开");
           RKey4.Close();
           RegistryKey RKey5 = Registry.ClassesRoot.OpenSubKey("mrrarfile\\shell\\使用口令打开", true);
           RKey5.CreateSubKey("command");
           RKey5.Close();
           RegistryKey RKey6 = Registry.ClassesRoot.OpenSubKey("mrrarfile\\shell\\使用口令打开\\command", true);
           RKey6.SetValue("", strName + " \\F ％1");
           RKey6.Close();
       }
       catch
       {
       }
   }
}

partial class Form1
{
   /// <summary>
   /// 必需的设计器变量。
   /// </summary>
   private System.ComponentModel.IContainer components = null;

/// <summary>
   /// 清理所有正在使用的资源。
   /// </summary>
   /// <param name="disposing">如果应释放托管资源，为 true；否则为 false。</param>
   protected override void Dispose(bool disposing)
   {
       if (disposing && (components != null))
       {
           components.Dispose();
       }
       base.Dispose(disposing);
   }

#region Windows 窗体设计器生成的代码

/// <summary>
   /// 设计器支持所需的方法 - 不要
   /// 使用代码编辑器修改此方法的内容。
   /// </summary>
   private void InitializeComponent()
   {
       this.button3 = new System.Windows.Forms.Button();
       this.button2 = new System.Windows.Forms.Button();
       this.groupBox1 = new System.Windows.Forms.GroupBox();
       this.label1 = new System.Windows.Forms.Label();
       this.textBox1 = new System.Windows.Forms.TextBox();
       this.button1 = new System.Windows.Forms.Button();
       this.label3 = new System.Windows.Forms.Label();
       this.label2 = new System.Windows.Forms.Label();
       this.textBox2 = new System.Windows.Forms.TextBox();
       this.openFileDialog1 = new System.Windows.Forms.OpenFileDialog();
       this.groupBox1.SuspendLayout();
       this.SuspendLayout();
       //
       // button3
       //
       this.button3.Location = new System.Drawing.Point(250, 107);
       this.button3.Name = "button3";
       this.button3.Size = new System.Drawing.Size(59, 27);
       this.button3.TabIndex = 11;
       this.button3.Text = "打开";
       this.button3.UseVisualStyleBackColor = true;
       this.button3.Click += new System.EventHandler(this.button3_Click);
       //
       // button2
       //
       this.button2.Location = new System.Drawing.Point(185, 107);
       this.button2.Name = "button2";
       this.button2.Size = new System.Drawing.Size(59, 27);
       this.button2.TabIndex = 12;
       this.button2.Text = "加密";
       this.button2.UseVisualStyleBackColor = true;
       this.button2.Click += new System.EventHandler(this.button2_Click);
       //
       // groupBox1
       //
       this.groupBox1.Controls.Add(this.label1);
       this.groupBox1.Controls.Add(this.textBox1);
       this.groupBox1.Controls.Add(this.button1);
       this.groupBox1.Controls.Add(this.label3);
       this.groupBox1.Controls.Add(this.label2);
       this.groupBox1.Controls.Add(this.textBox2);
       this.groupBox1.Location = new System.Drawing.Point(5, 9);
       this.groupBox1.Name = "groupBox1";
       this.groupBox1.Size = new System.Drawing.Size(304, 92);
       this.groupBox1.TabIndex = 10;
       this.groupBox1.TabStop = false;
       this.groupBox1.Text = "rar文件加/解密设置";
       //
       // label1
       //
       this.label1.AutoSize = true;
       this.label1.Location = new System.Drawing.Point(6, 17);
       this.label1.Name = "label1";
       this.label1.Size = new System.Drawing.Size(95, 12);
       this.label1.TabIndex = 0;
       this.label1.Text = "请选择rar文件：";
       //
       // textBox1
       //
       this.textBox1.Location = new System.Drawing.Point(32, 35);
       this.textBox1.Name = "textBox1";
       this.textBox1.Size = new System.Drawing.Size(225, 21);
       this.textBox1.TabIndex = 1;
       //
       // button1
       //
       this.button1.Location = new System.Drawing.Point(263, 33);
       this.button1.Name = "button1";
       this.button1.Size = new System.Drawing.Size(33, 23);
       this.button1.TabIndex = 2;
       this.button1.Text = "…";
       this.button1.UseVisualStyleBackColor = true;
       this.button1.Click += new System.EventHandler(this.button1_Click);
       //
       // label3
       //
       this.label3.AutoSize = true;
       this.label3.ForeColor = System.Drawing.Color.Red;
       this.label3.Location = new System.Drawing.Point(201, 66);
       this.label3.Name = "label3";
       this.label3.Size = new System.Drawing.Size(95, 12);
       this.label3.TabIndex = 5;
       this.label3.Text = "(密码应大于6位)";
       //
       // label2
       //
       this.label2.AutoSize = true;
       this.label2.Location = new System.Drawing.Point(7, 66);
       this.label2.Name = "label2";
       this.label2.Size = new System.Drawing.Size(65, 12);
       this.label2.TabIndex = 3;
       this.label2.Text = "加密口令：";
       //
       // textBox2
       //
       this.textBox2.Location = new System.Drawing.Point(73, 63);
       this.textBox2.Name = "textBox2";
       this.textBox2.PasswordChar = '*';
       this.textBox2.Size = new System.Drawing.Size(127, 21);
       this.textBox2.TabIndex = 4;
       //
       // openFileDialog1
       //
       this.openFileDialog1.FileName = "openFileDialog1";
       //
       // Form1
       //
       this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F);
       this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
       this.ClientSize = new System.Drawing.Size(316, 140);
       this.Controls.Add(this.button3);
       this.Controls.Add(this.button2);
       this.Controls.Add(this.groupBox1);
       this.MaximizeBox = false;
       this.MinimizeBox = false;
       this.Name = "Form1";
       this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
       this.Text = "用口令加密rar压缩文件";
       this.Load += new System.EventHandler(this.Form1_Load);
       this.groupBox1.ResumeLayout(false);
       this.groupBox1.PerformLayout();
       this.ResumeLayout(false);

}

#endregion

private System.Windows.Forms.Button button3;
   private System.Windows.Forms.Button button2;
   private System.Windows.Forms.GroupBox groupBox1;
   private System.Windows.Forms.Label label1;
   private System.Windows.Forms.TextBox textBox1;
   private System.Windows.Forms.Button button1;
   private System.Windows.Forms.Label label3;
   private System.Windows.Forms.Label label2;
   private System.Windows.Forms.TextBox textBox2;
   private System.Windows.Forms.OpenFileDialog openFileDialog1;
}

来源：https://blog.csdn.net/qq_27489007/article/details/128436885