使用I/O流实现文件加密小工具

*2023-3-2 16:25:37* 评论(0) · 2023-3-2 16:25:37

代码展示

package com.xy;
import java.io.*;
import java.util.Objects;
import java.util.Scanner;
/**
* @author 谢阳
* @version 1.8.0_131
* @date 2023/1/15 23:07
* @description
*/
public class FileEncryptionApp {
private static final byte[] IS_CODED = new byte[4]; // 默认解密校验码
private static Integer mode; // 模式选择 1 加密 2解密
private static Scanner scanner = new Scanner(System.in);
private static String destName;
static {
IS_CODED[0] = 2;
IS_CODED[1] = 0;
IS_CODED[2] = 2;
IS_CODED[3] = 3;
}
public static void main(String[] args) throws IOException {
showMenu();
}
/**
* 菜单展示
*
* @throws IOException
*/
private static void showMenu() throws IOException {
boolean loop = true;
while (loop) {
System.out.println("----------------文件加密、解密小程序---------------");
System.out.println("\t\t\t\t\t1 文件加密");
System.out.println("\t\t\t\t\t2 文件解密");
System.out.println("\t\t\t\t\t3 退出");
System.out.println("-----------------------------------------------");
System.out.print("请输入您的选择:");
char key = scanner.next().charAt(0);
switch (key) {
case '1':
System.out.print("请输入需加密文件路径:");
String enCodePath = scanner.next();
System.out.print("请输入文件的加密密码:");
String enCodePassword = scanner.next();
System.out.println(enCode(enCodePath, enCodePassword) ? "加密成功,文件路径为:" + destName : "加密失败");
break;
case '2':
System.out.print("请输入需解密文件路径:");
String unCodePath = scanner.next();
System.out.print("请输入文件的解密密码:");
String unCodePassword = scanner.next();
System.out.println(unCode(unCodePath, unCodePassword) ? "解密成功,文件路径为:" + destName : "解密失败");
break;
case '3':
System.out.println("退出程序成功,欢迎您的再次使用~");
loop = false;
break;
default:
System.out.println("您的输入有误,请重新输入:)");
}
}
}
/**
* 文件加密
*
* @param path 文件路径
* @param password 加密文件密钥
* @return 是否加密成功（true/false）
*/
private static boolean enCode(String path, String password) throws IOException {
if (!checkPathAndPassword(path, password)) {
return false;
}
// 加密后的文件名
destName = path.substring(0, path.lastIndexOf(".")) + "-coded" + path.substring(path.lastIndexOf("."));
try (
BufferedInputStream bis = new BufferedInputStream(new FileInputStream(path));
BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(destName))
) {
bos.write(IS_CODED);// 写入默认加密密钥
byte[] passwordBytes = password.getBytes();
for (int i = 0; i < passwordBytes.length; i++) {
passwordBytes[i] ^= password.hashCode();
}
bos.write(passwordBytes); // 写入用户加密密钥
byte[] buf = new byte[1024];
int len;
int keyHash = password.hashCode(); // 加密hash值
long length = new File(path).length() % 10; // 文件长度
while ((len = bis.read(buf)) != -1) {
// 加密
for (int i = 0; i < len; i++) {
//buf[i] ^= keyHash;
buf[i] = (byte) ((buf[i] ^ keyHash) + length);
}
bos.write(buf, 0, len);
}
}
return true;
}
/**
* 文件解密
*
* @param path 文件路径
* @param password 解密文件密钥
* @return 是否解密成功（true/false)
*/
private static boolean unCode(String path, String password) throws IOException {
if (!checkPathAndPassword(path, password)) {
return false;
}
if (new File(path).length() < IS_CODED.length + password.getBytes().length) {
System.out.println("该文件不属于加密文件");
return false;
}
// 解密后的文件名
destName = path.substring(0, path.lastIndexOf(".")) + "-unCode" + path.substring(path.lastIndexOf("."));
try (
BufferedInputStream bis = new BufferedInputStream(new FileInputStream(path));
) {
// 验证默认密钥和用户密钥是否正确
if (!checkCodeAndPassword(bis, password)) {
return false;
}
byte[] buf = new byte[1024];
int len;
int keyHash = password.hashCode(); // 解密hash值
// 长度为上一次文件长度
long length = (new File(path).length() - password.getBytes().length - IS_CODED.length) % 10;
try (BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(destName))) {
while ((len = bis.read(buf)) != -1) {
// 解密
for (int i = 0; i < len; i++) {
//buf[i] ^= keyHash;
buf[i] = (byte) ((buf[i] - length) ^ keyHash);
}
bos.write(buf, 0, len);
}
}
}
return true;
}
/**
* 验证默认密钥和用户密钥是否正确
*
* @param bis
* @param password 用户密码
* @return ture/false
*/
private static boolean checkCodeAndPassword(BufferedInputStream bis, String password) throws IOException {
byte[] codedKey = new byte[IS_CODED.length]; // 默认加密密钥
bis.read(codedKey);
// 验证默认密钥
for (int i = 0; i < IS_CODED.length; i++) {
if (codedKey[i] != IS_CODED[i]) {
System.out.println("该文件不属于加密文件");
return false;
}
}
// 验证用户密钥
byte[] passwordBytes = password.getBytes();
byte[] pas = new byte[passwordBytes.length];
bis.read(pas);
for (int i = 0; i < passwordBytes.length; i++) {
if (pas[i] != (byte) (passwordBytes[i] ^ password.hashCode())) {
System.out.println("文件解密密码错误");
return false;
}
}
return true;
}
/**
* 文件、文件路径、密钥检测
*
* @param path 文件路径
* @param password 密钥
* @return 文件是否存在（true/false）
*/
private static boolean checkPathAndPassword(String path, String password) {
if (Objects.isNull(path)) {
System.out.println("文件路径不能为空");
return false;
}
if (Objects.isNull(password)) {
System.out.println("用户密钥不能为空");
return false;
}
File file = new File(path);
if (!file.exists()) {
System.out.println("该路径不在在,请检查文件路径是否存在");
return false;
}
if (!file.isFile()) {
System.out.println("该路径不是文件,请输入文件名");
return false;
}
if (!file.getName().contains(".")) {
System.out.println("不知此该文件格式");
return false;
}
return true;
}
}

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Java 使用I/O流实现文件加密小工具

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