一、功能实现
1、可以加密任何文件
2、可以加密文件夹并保持文件夹目录层次不变
二、代码实现
import java.io.*;import java.math.BigInteger;import java.nio.MappedByteBuffer;import java.nio.channels.FileChannel;import java.nio.channels.FileChannel.MapMode;import java.util.Scanner;public class Des {static byte[] bytekey;private Des(String strKey) {this.bytekey = strKey.getBytes();}private static Des instance;private static byte[][] storecry;//单利模式，可以直接访问该类，不需要实例化该类的对象。保证一个类仅有一个实例，并提供一个访问它的全局访问点。//懒汉式，线程安全，synchronized实现多线程安全public static synchronized Des getInstance(String strKey) {if (instance == null) {instance = new Des(strKey);}return instance;}public static String newFileName;// 初始置换IP 64位private static final int[] INIT_REP_IP = {58, 50, 42, 34, 26, 18, 10, 2, 60, 52,44, 36, 28, 20, 12, 4, 62, 54, 46, 38, 30, 22, 14, 6, 64, 56, 48,40, 32, 24, 16, 8, 57, 49, 41, 33, 25, 17, 9, 1, 59, 51, 43, 35,27, 19, 11, 3, 61, 53, 45, 37, 29, 21, 13, 5, 63, 55, 47, 39, 31,23, 15, 7};// 初始逆置换IP 64位private static final int[] INIT_INVER_REP_IP = {40, 8, 48, 16, 56, 24, 64, 32, 39, 7,47, 15, 55, 23, 63, 31, 38, 6, 46, 14, 54, 22, 62, 30, 37, 5, 45,13, 53, 21, 61, 29, 36, 4, 44, 12, 52, 20, 60, 28, 35, 3, 43, 11,51, 19, 59, 27, 34, 2, 42, 10, 50, 18, 58, 26, 33, 1, 41, 9, 49,17, 57, 25};// 置换选择1，56位private static final int[] PC_1 = {57, 49, 41, 33, 25, 17, 9, 1, 58, 50,42, 34, 26, 18, 10, 2, 59, 51, 43, 35, 27, 19, 11, 3, 60, 52, 44,36, 63, 55, 47, 39, 31, 23, 15, 7, 62, 54, 46, 38, 30, 22, 14, 6,61, 53, 45, 37, 29, 21, 13, 5, 28, 20, 12, 4};// 置换选择2即压缩置换 48位private static final int[] PC_2 = {14, 17, 11, 24, 1, 5, 3, 28, 15, 6, 21,10, 23, 19, 12, 4, 26, 8, 16, 7, 27, 20, 13, 2, 41, 52, 31, 37, 47,55, 30, 40, 51, 45, 33, 48, 44, 49, 39, 56, 34, 53, 46, 42, 50, 36,29, 32};// 扩展置换E 48位private static final int[] Ext_Per_E = {32, 1, 2, 3, 4, 5, 4, 5, 6, 7, 8, 9, 8, 9,10, 11, 12, 13, 12, 13, 14, 15, 16, 17, 16, 17, 18, 19, 20, 21, 20,21, 22, 23, 24, 25, 24, 25, 26, 27, 28, 29, 28, 29, 30, 31, 32, 1};// P盒 32位private static final int[] P = {16, 7, 20, 21, 29, 12, 28, 17, 1, 15, 23,26, 5, 18, 31, 10, 2, 8, 24, 14, 32, 27, 3, 9, 19, 13, 30, 6, 22,11, 4, 25};// S_Boxprivate static final int[][][] S_Box = {//S-盒{// S_Box[1]{14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7},{0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8},{4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0},{15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13}},{// S_Box[2]{15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10},{3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5},{0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15},{13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9}},{// S_Box[3]{10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8},{13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1},{13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7},{1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12}},{// S_Box[4]{7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15},{13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9},{10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4},{3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14}},{// S_Box[5]{2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9},{14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6},{4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14},{11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3}},{// S_Box[6]{12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11},{10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8},{9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6},{4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13}},{// S_Box[7]{4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1},{13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6},{1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2},{6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12}},{// S_Box[8]{13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7},{1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2},{7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8},{2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11}}};public static final int[] LeftMove = {1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1};//循环左移的轮数private static final int LEFT_MOVE_COUNT = 16;//加密的轮数private static final int ENCRY_COUNT = 16;//解密的论数private static final int DECIP_COUNT = 15;//cbc模式中的初始向量I CBCMODE_I[64]private static final byte[] CBCMODE_I = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};static int[] keydata = new int[64];// 二进制加密数据static int[] encryptdata = new int[64]; // 加密操作完成后的字节数组static byte[] EncryptCode = new byte[8];// 密钥初试化成二维数组static int[][] keyArray;// 循环移位操作函数static int[] c0 = new int[28];static int[] d0 = new int[28];static int[] c1 = new int[28];static int[] d1 = new int[28];static int[] L0 = new int[32];static int[] R0 = new int[32];static int[] L1 = new int[32];static int[] R1 = new int[32];static int[] RE = new int[48];static int[][] S = new int[8][6];static int[] sBoxData = new int[8];static int[] sValue = new int[32];static int[] RP = new int[32];/*** des 中加解密的核心算法** @param des_data 加密的数据，也就是明文* @param flag1就是加密，0就是解密* @return*/public static byte[] DesEncrypt(byte[] des_data, int flag) {byte[] format_key = DataFormat(bytekey);byte[] format_data = DataFormat(des_data);int datalen = format_data.length;byte[] result_data = new byte[datalen];result_data = EcbModel(flag, format_key, format_data, datalen, result_data);// 当前为解密过程，去掉加密时产生的填充位byte[] decryptbytearray = null;if (flag == 0) {int delete_len = result_data[datalen - 8 - 1];delete_len = ((delete_len >= 1) && (delete_len <= 8)) ? delete_len : 0;decryptbytearray = new byte[datalen - delete_len - 8];System.arraycopy(result_data, 0, decryptbytearray, 0, datalen - delete_len - 8);}return (flag == 1) ? result_data : decryptbytearray;}/*** 如若需要则对秘钥进行扩展** @param data* @return*/public static byte[] DataFormat(byte[] data) {//0~7字节拓展为8字节，8~15字节拓展为16字节int len = data.length;int padlen = 8 - (len % 8);int newlen = len + padlen;byte[] newdata = new byte[newlen];System.arraycopy(data, 0, newdata, 0, len);//将data完整复制给newdatafor (int i = len; i < newlen; i++)//拓展newdata[i] = (byte) padlen;return newdata;}/*** 使用ECB模式对明文进行加/解密** @param flag* @param format_key* @param format_data* @param datalen* @param result_data*/public static byte[] EcbModel(int flag, byte[] format_key, byte[] format_data, int datalen, byte[] result_data) {// 使用了电码本模式ECB,8个字节8个字节一加密int unitcount = datalen / 8;byte[] tmpkey = new byte[8];byte[] tmpdata = new byte[8];// 取格式化话后秘钥的前八个字节System.arraycopy(format_key, 0, tmpkey, 0, 8);for (int i = 0; i < unitcount; i++) {//每次取格式化后数据的8个字节System.arraycopy(format_data, i * 8, tmpdata, 0, 8);byte[] tmpresult = UnitDes(tmpkey, tmpdata, flag);System.arraycopy(tmpresult, 0, result_data, i * 8, 8);}return result_data;}/*** 每8个字节加解密** @param des_key 秘钥* @param des_data 数据* @param flag1加密，0解密* @return byte数组*/public static byte[] UnitDes(byte[] des_key, byte[] des_data, int flag) {keydata = ReadDataToBirnaryIntArray(des_key);// 初试化密钥为二维密钥数组encryptdata = ReadDataToBirnaryIntArray(des_data);// 将加密数据字节数组转换成二进制字节数组if (keyArray == null) {keyArray = new int[16][48];keyArray = KeyInitialize(keydata, keyArray); // 生成16个48位的子秘钥}EncryptCode = Encrypt(encryptdata, flag, keyArray);return EncryptCode;}/*** 将数据转换成二进制的整形数组** @param intdata* @return*/public static int[] ReadDataToBirnaryIntArray(byte[] intdata) {int i;int j;int[] IntDa = new int[8];int[] IntVa = new int[64];// 将数据转换为二进制数，存储到数组for (i = 0; i < 8; i++) {IntDa[i] = intdata[i];if (IntDa[i] < 0) {IntDa[i] += 256;IntDa[i] %= 256;}}//除2的方式for (i = 0; i < 8; i++) {for (j = 0; j < 8; j++) {IntVa[((i * 8) + 7) - j] = IntDa[i] % 2;IntDa[i] = IntDa[i] / 2;}}return IntVa;}static int[] K0 = new int[56];// 初始密钥记作Y0，它由64位01序列组成，但其中8位用于奇偶校验，所以实际用于加密的只有56位，记为K0/*** 通过此方法生成16个子秘钥** @param key初始64位二进制的秘钥* @param keyarray 存放每一轮的子秘钥*/public static int[][] KeyInitialize(int[] key, int[][] keyarray) {int i;int j;for (i = 0; i < 56; i++) {K0[i] = key[PC_1[i] - 1]; // 密钥进行PC-1变换。置换表PC_1的第i位为n，就把数据表key的第n位（key[n-1]）放到这K0表的第i位}for (i = 0; i < LEFT_MOVE_COUNT; i++) {LeftBitMove(K0, LeftMove[i]); //Ci,Di循环左移得到Ci+1,Di+1，Ci+1Di+1合并做PC_2置换for (j = 0; j < 48; j++) {keyarray[i][j] = K0[PC_2[j] - 1]; // 生成子密钥keyarray[i][j]}}return keyarray;}/*** 循环左移** @param k通过置换函数PC-1置换后生成的56二进制位* @param offset 左移的位数*/public static void LeftBitMove(int[] k, int offset) {int i;for (i = 0; i < 28; i++) {c0[i] = k[i];d0[i] = k[i + 28];}if (offset == 1) {for (i = 0; i < 27; i++) {// 循环左移一位c1[i] = c0[i + 1];d1[i] = d0[i + 1];}c1[27] = c0[0];d1[27] = d0[0];} else if (offset == 2) {for (i = 0; i < 26; i++) {// 循环左移两位c1[i] = c0[i + 2];d1[i] = d0[i + 2];}c1[26] = c0[0];d1[26] = d0[0];c1[27] = c0[1];d1[27] = d0[1];}for (i = 0; i < 28; i++) {k[i] = c1[i];k[i + 28] = d1[i];}}/*** 执行加密解密操作** @param encryptdata 64位的明文* @param flag 1即为加密操作* @param keyarray 16轮子秘钥* @return*/static byte[] encrypt = new byte[8];static int[] MIP_1 = new int[64];static int[] M = new int[64];public static byte[] Encrypt(int[] encryptdata, int flag, int[][] keyarray) {int i;// 通过初始置换函数对明文进行初始置换for (i = 0; i < 64; i++) {M[i] = encryptdata[INIT_REP_IP[i] - 1]; // 明文IP变换}if (flag == 1) {// 加密for (i = 0; i < ENCRY_COUNT; i++) {M = LoopF(M, i, flag, keyarray);}} else if (flag == 0) {// 解密for (i = DECIP_COUNT; i >= 0; i--) {M = LoopF(M, i, flag, keyarray);}}for (i = 0; i < 64; i++) {MIP_1[i] = M[INIT_INVER_REP_IP[i] - 1]; // 进行IP_1逆运算}encrypt = BirnaryIntArrayToInt(MIP_1);// 返回加密数据return encrypt;}/*** 循环迭代16轮** @param M 明文* @param times 次数* @param flag1为加密，0为解密* @param keyarray 每一轮的子秘钥*/public static int[] LoopF(int[] M, int times, int flag, int[][] keyarray) {int i;int j;for (i = 0; i < 32; i++) {L0[i] = M[i]; // 明文左侧的初始化R0[i] = M[i + 32]; // 明文右侧的初始化}// R0经过扩展置换表E，由32位变为48位的RE，再由子秘钥Ki加密for (i = 0; i < 48; i++) {RE[i] = R0[Ext_Per_E[i] - 1];RE[i] = RE[i] + keyarray[times][i]; // 子秘钥Ki加密，与KeyArray[times][i]按位作不进位加法运算(异或运算)if (RE[i] == 2) {RE[i] = 0;}}//RE经过S盒压缩，变为32位的sValuefor (i = 0; i < 8; i++) {for (j = 0; j < 6; j++) {S[i][j] = RE[(i * 6) + j]; // 48位分成8组，每组6位}// 下面经过S盒，得到一个十进制数sBoxData[i] = S_Box[i][(S[i][0] << 1) + S[i][5]][(S[i][1] << 3) + (S[i][2] << 2) + (S[i][3] << 1) + S[i][4]];// S盒中取得的十进制数变为4位二进制for (j = 0; j < 4; j++) {sValue[((i * 4) + 3) - j] = sBoxData[i] % 2;sBoxData[i] = sBoxData[i] / 2;}}//sValue经过P变换变成32位的RPfor (i = 0; i < 32; i++) {RP[i] = sValue[P[i] - 1]; // 经过P变换L1[i] = R0[i]; // 右边移到左边R1[i] = L0[i] + RP[i];//与L0与RP按位作不进位加法运算(异或运算)，得R1if (R1[i] == 2) {R1[i] = 0;}// 重新合成M，返回数组M// 最后一次变换时，左右不进行互换。此处采用两次变换实现不变if (((flag == 0) && (times == 0)) || ((flag == 1) && (times == 15))) {M[i] = R1[i];M[i + 32] = L1[i];} else {M[i] = L1[i];M[i + 32] = R1[i];}}return M;}/*** 将二进制转为十进制的byte类型** @param data* @return*/public static byte[] BirnaryIntArrayToInt(int[] data) {int i;int j;byte[] value = new byte[8];for (i = 0; i < 8; i++) {for (j = 0; j < 8; j++) {value[i] += (data[(i << 3) + j] << (7 - j));}}for (i = 0; i < 8; i++) {value[i] %= 256;if (value[i] > 128) {value[i] -= 255;}}return value;}/*** 根据byte数组，生成文件*/public static void generateFile(byte[] bfile, String filePath, String fileName) {BufferedOutputStream bos = null;FileOutputStream fos = null;File file = null;try {File dir = new File(filePath);if (!dir.exists() && dir.isDirectory()) {//判断文件目录是否存在dir.mkdirs();}file = new File(filePath + "\\" + fileName);fos = new FileOutputStream(file);bos = new BufferedOutputStream(fos);bos.write(bfile);} catch (Exception e) {e.printStackTrace();} finally {if (bos != null) {try {bos.close();} catch (IOException e1) {e1.printStackTrace();}}if (fos != null) {try {fos.close();} catch (IOException e1) {e1.printStackTrace();}}}}/*** 根据路径获取文件的byte数组** @param path* @return*/public static byte[] getFileByte(String path) {FileChannel fc = null;byte[] result = null;try {fc = new RandomAccessFile(path, "r").getChannel();MappedByteBuffer byteBuffer = fc.map(MapMode.READ_ONLY, 0,fc.size()).load();result = new byte[(int) fc.size()];if (byteBuffer.remaining() > 0) {byteBuffer.get(result, 0, byteBuffer.remaining());}} catch (IOException e) {e.printStackTrace();} finally {try {fc.close();} catch (IOException e) {e.printStackTrace();}}return result;}public static void readfile(String filepath) throws IOException {Scanner in = new Scanner(System.in);try {File file = new File(filepath);if (!file.isDirectory()) {byte[] fileByte = getFileByte(file.getAbsolutePath());int[] fileByteToBirnary = ReadDataToBirnaryIntArray(fileByte);//字节流转换成二进制数组// 加密byte[] result = DesEncrypt(fileByte, 1);generateFile(result, "F:\\Desktop\\物联网安全\\密文", file.getName() + "的密文");// 解密byte[] tempresult = DesEncrypt(result, 0);generateFile(tempresult, "F:\\Desktop\\物联网安全\\解密", file.getName());} else if (file.isDirectory()) {String path1;//密文路径String path2;//解密路径path1 = filepath.replace("F:\\Desktop\\物联网安全\\明文", "F:\\Desktop\\物联网安全\\密文");path2 = filepath.replace("F:\\Desktop\\物联网安全\\明文", "F:\\Desktop\\物联网安全\\解密");File dir = new File(path1);if (!dir.exists()) {//判断文件目录是否存在dir.mkdirs();}File dir2 = new File(path2);if (!dir2.exists()) {//判断文件目录是否存在dir2.mkdirs();}String[] filelist = file.list();for (int i = 0; i < filelist.length; i++) {File readfile = new File(filepath + "\\" + filelist[i]);if (!readfile.isDirectory()) {byte[] fileByte = getFileByte(readfile.getAbsolutePath());// 加密byte[] result = DesEncrypt(fileByte, 1);generateFile(result, path1, "密文_" + readfile.getName());// 解密byte[] tempresult = DesEncrypt(result, 0);generateFile(tempresult, path2, readfile.getName());} else if (readfile.isDirectory()) {readfile(filepath + "\\" + filelist[i]);}}}} catch (FileNotFoundException e) {System.out.println("readfile() Exception:" + e.getMessage());}}public static void main(String[] args) throws IOException {Scanner in = new Scanner(System.in);System.out.println("请输入秘钥:");String key = in.nextLine();Des desUtil = Des.getInstance(key);//秘钥变成二进制try {readfile("F:\\Desktop\\物联网安全\\明文");} catch (FileNotFoundException e) {System.out.println("readfile() Exception:" + e.getMessage());}System.out.println("加解密成功，请到相应目录下查看");}}
三、使用说明
1、创建三个文件夹：明文、密文、解密。明文文件夹存放原文件，密文文件夹存放密文，解密文件夹存放解密后的明文。
2、输入的秘钥多少位都行，最好8位以内（一定不会出问题）
3、虽然各种文件都能加解密，但是文件不要太大，文件大小的上限是多少我忘记了，但150KB是没问题的
