从网络安全性到MD5文件加密算法和工具开发

1.最近来自半岛的网络木马病毒横行，人心惶惶。安全威胁应该从源头把关，不要下载安装来源不明的软件，软件开发者提供软件的同时，要在官网公布软件的MD5校验，以供用户分辨真假李逵，既能防止开发者辛苦研发出来的软件成为黑帽子们挂马的载体，也能防止唯利是图的广告商插播广告，侵害开发者利益。MD5加密是一种广范用于安全加秘和文件防篡改的加密算法。可以为文件，字串提供完整型保护。

2.MD5计算步骤   

MD5以512位分组来处理输入的信息，且每一分组又被划分为16个32位子分组，经过了一系列的处理后，算法的输出由四个32位分组组成，将这四个32位分组级联后将生成一个128位散列值。

第一步、填充

     如果输入信息的长度(bit)对512求余的结果不等于448，就需要填充使得对512求余的结果等于448。填充的方法是填充一个1和n个0。填充完后，信息的长度就为N*512+448(bit)；MD5计算步骤   

MD5以512位分组来处理输入的信息，且每一分组又被划分为16个32位子分组，经过了一系列的处理后，算法的输出由四个32位分组组成，将这四个32位分组级联后将生成一个128位散列值。

第一步、填充

     如果输入信息的长度(bit)对512求余的结果不等于448，就需要填充使得对512求余的结果等于448。填充的方法是填充一个1和n个0。填充完后，信息的长度就为N*512+448(bit)；

第二步、记录信息长度

     用64位来存储填充前信息长度。这64位加在第一步结果的后面，这样信息长度就变为N*512+448+64=(N+1)*512位。

第三步、装入标准的幻数（四个整数）

     标准的幻数（物理顺序）是（A=(01234567)16，B=(89ABCDEF)16，C=(FEDCBA98)16，D=(76543210)16）。如果在程序中定义应该是（A=0X67452301L，B=0XEFCDAB89L，C=0X98BADCFEL，D=0X10325476L）。有点晕哈，其实想一想就明白了。

第四步、四轮循环运算

3 。开发工具软件，用于给软件和文件夹提供MD5校验

package com.mysiming.util;import java.awt.BorderLayout;import java.awt.Button;import java.awt.Color;import java.awt.EventQueue;import java.awt.HeadlessException;import java.awt.Toolkit;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.io.BufferedReader;import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStreamReader;import java.math.BigInteger;import java.security.MessageDigest;import javax.swing.JFileChooser;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JLayeredPane;import javax.swing.JOptionPane;import javax.swing.JPanel;import javax.swing.JScrollPane;import javax.swing.JTextArea;import javax.swing.JTextField;import javax.swing.border.EmptyBorder;public class frame extends JFrame {/** *  */private static final long serialVersionUID = 1926273287648990244L;private JPanel contentPane;/** * Launch the application. */public static void main(String[] args) {EventQueue.invokeLater(new Runnable() {public void run() {try {frame frame = new frame();frame.setVisible(true);} catch (Exception e) {e.printStackTrace();}}});}/** * Create the frame. */int win_X = 100, win_Y = 100, win_W = 600, win_H = 400;int title_W = 154, title_H = 15, title_X = win_W / 2 - title_W / 2, title_Y = 20;int buttonX = 80, buttonY = 80 + 20, buttonW = 80, buttonH = 30, buttonSPACE = 20;int file_X = 100, file_Y = 20 + 20, file_W = 400, file_H = 21;int fileL_X = 20, fileL_Y = 26 + 20, fileL_W = 84, fileL_H = 15;int md5_X = 100, md5_Y = 50 + 20, md5_W = 400, md5_H = 21;int md5L_X = 20, md5L_Y = 56 + 20, md5L_W = 84, md5L_H = 15;int buttonY2 = 80 + 20 + 220;int file_Y2 = 20 + 20 + 130;int fileL_Y2 = 26 + 20 + 130;int md5_Y2 = 50 + 20 + 130;int md5L_Y2 = 56 + 20 + 130;int md5_H2 = 100;int title_Y2 = 20 + 130;String Logpath;public frame() {setBackground(Color.PINK);setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);setBounds(win_X, win_Y, win_W, win_H);contentPane = new JPanel();contentPane.setBackground(Color.GRAY);contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));contentPane.setLayout(new BorderLayout(0, 0));setContentPane(contentPane);JLayeredPane layeredPane = new JLayeredPane();layeredPane.setBackground(Color.CYAN);contentPane.add(layeredPane, BorderLayout.CENTER);JTextField textField = new JTextField();textField.setBounds(file_X, file_Y, file_W, file_H);layeredPane.add(textField);textField.setColumns(10);JTextField textField_1 = new JTextField();textField_1.setBounds(md5_X, md5_Y, md5_W, md5_H);layeredPane.add(textField_1);textField_1.setColumns(10);JLabel lblSetFile = new JLabel("设置文件");lblSetFile.setBounds(fileL_X, fileL_Y, fileL_W, fileL_H);layeredPane.add(lblSetFile);JLabel lblMd5 = new JLabel("设置Md5");lblMd5.setBounds(md5L_X, md5L_Y, md5L_W, md5L_H);layeredPane.add(lblMd5);/** * JFileChooser 是Java Swing提供的文件选择对话框 */JFileChooser jfc = new JFileChooser();// 构造一个指向用户默认目录的 JFileChooser。Button btnSet = new Button("选择文件");// Browse按钮用于获取文件btnSet.addActionListener(new ActionListener() {// Browse按钮 的 监听事件public void actionPerformed(ActionEvent arg0) {int result = jfc.showOpenDialog(null);// 弹出一个 "Open File"// 文件选择器对话框。String filepath = ""; // 初始化变量filepath(文件路径)if (result == JFileChooser.APPROVE_OPTION) {// JFileChooser.APPROVE_OPTION是个整型// 常量，代表0，当返回0值时，执行相关操作。filepath = jfc.getSelectedFile().getAbsolutePath();// 获得你选择的文件的绝对路径textField.setText(filepath);// 将选择的文件的绝对路径在文本框textField中显示。}String ff = textField.getText();int backslashIndex = ff.lastIndexOf('\\');// 路径名是最后一个'/'之前的字符Logpath = ff.substring(0, backslashIndex + 1);System.out.println(Logpath);}});btnSet.setBounds(buttonX, buttonY, buttonW, buttonH);layeredPane.add(btnSet);Button btnMd = new Button("生成MD5");// ********Count// Md5用于计算MD5值***********btnMd.addActionListener(new ActionListener() {// Count Md5按钮的监听事件public void actionPerformed(ActionEvent e) {File file = jfc.getSelectedFile();// 返回选中的文件String filemd5 = getMd5ByFile(file);// 得到文件的MD5值textField_1.setText(filemd5);// 将文件的MD5值在文本框textField中显示出来。}});btnMd.setBounds(buttonX + buttonW + buttonSPACE, buttonY, buttonW, buttonH);layeredPane.add(btnMd);Button checkMd = new Button("校验MD5");// ********Count// Md5用于计算MD5值***********checkMd.addActionListener(new ActionListener() {// Count Md5按钮的监听事件public void actionPerformed(ActionEvent e) {File file = jfc.getSelectedFile();// 返回选中的文件String filemd5 = getMd5ByFile(file);// 得到文件的MD5值String checkMd5 = textField_1.getText();Toolkit.getDefaultToolkit().beep();if (filemd5.equals(checkMd5)) {JOptionPane.showMessageDialog(null, "MD5校验正确", "MD5校验正确", JOptionPane.INFORMATION_MESSAGE);} else {JOptionPane.showMessageDialog(null, "MD5校验不对", "MD5校验不对", JOptionPane.INFORMATION_MESSAGE);}}});checkMd.setBounds(buttonX + buttonW * 2 + buttonSPACE * 2, buttonY, buttonW, buttonH);layeredPane.add(checkMd);Button saveMd = new Button("保存MD5");// ********Count// Md5用于计算MD5值***********saveMd.addActionListener(new ActionListener() {// Count Md5按钮的监听事件public void actionPerformed(ActionEvent e) {File file = jfc.getSelectedFile();// 返回选中的文件String filemd5 = getMd5ByFile(file);// 得到文件的MD5值String checkMd5 = textField_1.getText();String str = file.getPath() + "|" + filemd5;writeCheckSum(Logpath + "md5checksum.txt", str);}});saveMd.setBounds(buttonX + buttonW * 3 + buttonSPACE * 3, buttonY, buttonW, buttonH);layeredPane.add(saveMd);JLabel title = new JLabel("文件MD5");title.setBounds(title_X, title_Y, title_W, title_H);layeredPane.add(title);// ****************************************************************************************//\JTextField textField2 = new JTextField();textField2.setAutoscrolls(true);textField2.setBounds(file_X, file_Y2, file_W, file_H);layeredPane.add(textField2);textField2.setColumns(10);JTextArea textField_12 = new JTextArea();JScrollPane scroll = new JScrollPane(textField_12);scroll.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);scroll.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);// textField_12.setAutoscrolls(true);// textField_12.setLineWrap(true);scroll.setBounds(md5_X, md5_Y2, md5_W, md5_H2);// textField_12.setBounds(md5_X, md5_Y2, md5_W, md5_H2);// layeredPane.add(textField_12);layeredPane.add(scroll);// textField_12.setColumns(10);JLabel lblSetFile2 = new JLabel("设置文件夹");lblSetFile2.setBounds(fileL_X, fileL_Y2, fileL_W, fileL_H);layeredPane.add(lblSetFile2);JLabel lblMd52 = new JLabel("设置Md5路径");lblMd52.setBounds(md5L_X, md5L_Y2, md5L_W, md5L_H);layeredPane.add(lblMd52);/** * JFileChooser 是Java Swing提供的文件选择对话框 */JFileChooser jfc2 = new JFileChooser();// 构造一个指向用户默认目录的 JFileChooser。Button btnSet2 = new Button("选择文件夹");// Browse按钮用于获取文件btnSet2.addActionListener(new ActionListener() {// Browse按钮 的 监听事件public void actionPerformed(ActionEvent arg0) {jfc2.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);// 只能选择目录String path = null;File f = null;int flag = 0;try {flag = jfc2.showOpenDialog(null);} catch (HeadlessException head) {System.out.println("Open File Dialog ERROR!");}if (flag == JFileChooser.APPROVE_OPTION) {// 获得该文件f = jfc2.getSelectedFile();path = f.getPath();textField2.setText(path);// 将选择的文件的绝对路径在文本框textField中显示。}}});btnSet2.setBounds(buttonX, buttonY2, buttonW, buttonH);layeredPane.add(btnSet2);Button btnMd2 = new Button("生成MD5");// ********Count// Md5用于计算MD5值***********btnMd2.addActionListener(new ActionListener() {// Count Md5按钮的监听事件public void actionPerformed(ActionEvent e) {textField_12.setText("");File file = new File(textField2.getText());File[] tempList = file.listFiles();System.out.println("该目录下对象个数：" + tempList.length);StringBuffer sb = new StringBuffer();for (int i = 0; i < tempList.length; i++) {if (tempList[i].isFile()) {if (tempList[i].getName().indexOf("md5checksum") != 0) {System.out.println("文     件：" + tempList[i]);String filemd5 = getMd5ByFile(tempList[i]);// 得到文件的MD5值// textField_12.setText(sb.toString());//将文件的MD5值在文本框textField中显示出来。\textField_12.append(tempList[i].getName() + "|" + filemd5 + "\r\n");}}}}});btnMd2.setBounds(buttonX + buttonW + buttonSPACE, buttonY2, buttonW, buttonH);layeredPane.add(btnMd2);Button checkMd2 = new Button("校验MD5");// ********Count// Md5用于计算MD5值***********checkMd2.addActionListener(new ActionListener() {// Count Md5按钮的监听事件public void actionPerformed(ActionEvent e) {boolean error = false;String tempstr;File file = new File(textField2.getText() + "\\" + "md5checksum.txt");if (!file.exists()) {JOptionPane.showMessageDialog(null, "MD5校验不对", "找不到md5checksum.txt",JOptionPane.INFORMATION_MESSAGE);}try {FileInputStream fis;fis = new FileInputStream(file);BufferedReader br = new BufferedReader(new InputStreamReader(fis));while ((tempstr = br.readLine()) != null) {System.out.println(">>>>>>>>>>>>>>>" + tempstr);if (tempstr.indexOf('|') != -1) {String[] s = tempstr.split("\\|");System.out.println(">>>>>>>>>>>>>>>" + s[0]);System.out.println(">>>>>>>>>>>>>>>" + s[1]);System.out.println(">>>>>>>>>>>>>>>" + textField2.getText() + "\\" + s[0]);File f = new File(textField2.getText() + "\\" + s[0]);System.out.println(">>>>>>>>>>>>>>>" + f.getPath());String filemd5 = getMd5ByFile(f);// 得到文件的MD5值System.out.println(">>>>>>>>>>>>>>>filemd5=" + filemd5);if (!filemd5.equals(s[1])) {JOptionPane.showMessageDialog(null, textField2.getText() + "\\" + s[0] + "校验不对","MD5校验不对", JOptionPane.INFORMATION_MESSAGE);error = true;break;}}}if (!error) {JOptionPane.showMessageDialog(null, "MD5校验成功", "校验成功", JOptionPane.INFORMATION_MESSAGE);}} catch (IOException e1) {// TODO Auto-generated catch blocke1.printStackTrace();}}});checkMd2.setBounds(buttonX + buttonW * 2 + buttonSPACE * 2, buttonY2, buttonW, buttonH);layeredPane.add(checkMd2);Button saveMd2 = new Button("保存MD5");// ********Count// Md5用于计算MD5值***********saveMd2.addActionListener(new ActionListener() {// Count Md5按钮的监听事件public void actionPerformed(ActionEvent e) {String str = textField_12.getText();writeCheckSum(textField2.getText() + "\\" + "md5checksum.txt", str);}});saveMd2.setBounds(buttonX + buttonW * 3 + buttonSPACE * 3, buttonY2, buttonW, buttonH);layeredPane.add(saveMd2);JLabel title2 = new JLabel("文件夹MD5");title2.setBounds(title_X, title_Y2, title_W, title_H);layeredPane.add(title2);}public static void getFileList(String path) {File file = new File(path);File[] tempList = file.listFiles();System.out.println("该目录下对象个数：" + tempList.length);for (int i = 0; i < tempList.length; i++) {if (tempList[i].isFile()) {System.out.println("文     件：" + tempList[i]);}}}public static void writeCheckSum(String path, String str) {try {// String path="/root/test/testfilelog.log";File file = new File(path);if (!file.exists())file.createNewFile();// SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");FileOutputStream out = new FileOutputStream(file, false); // 如果追加方式用trueStringBuffer sb = new StringBuffer();// sb.append("-----------"+sdf.format(new Date())+"------------\n");sb.append(str + "\n");out.write(sb.toString().getBytes("utf-8"));// 注意需要转换对应的字符集out.close();} catch (IOException ex) {System.out.println(ex.getStackTrace());}}public static String getMd5ByFile(File file) {String value = null;FileInputStream in = null;try {in = new FileInputStream(file);} catch (FileNotFoundException e1) {e1.printStackTrace();}try {MessageDigest md5 = MessageDigest.getInstance("MD5");byte[] buffer = new byte[8192];int length;while ((length = in.read(buffer)) != -1) {md5.update(buffer, 0, length);}BigInteger bi = new BigInteger(1, md5.digest());value = bi.toString(16);} catch (Exception e) {e.printStackTrace();} finally {if (null != in) {try {in.close();} catch (IOException e) {e.printStackTrace();}}}return value;}}