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基于java数组的DES加密、解密的算法实现

技术2022-05-12  3


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      这是数据加密标准(DES)算法实现,网上有很多C/C++版本的,特写一个JAVA版本的,主要是想练练自己JAVA的编程能力,如果有不妥当的地方希望大家能指正,或者给出更好的建议,其实现代码如下:

/**  *  * @author Davy Chen  */ public class DES {     //初始换位IP表     byte 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     };     //逆初始换位IP^-1表     byte IIP[] = {         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     };     //密钥置换PC-1表     byte 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     };     //密钥置换PC-2表     byte 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     };     //E的选位表     byte[] E_box = {         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     };     //DES的中的S-Boxes     byte[][][] S_box = {         {             {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}         },         {             {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}         },         {             {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}         },         {             {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}         },         {             {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}         },         {             {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}         },         {             {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}         },         {             {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}         }     };     //S-Box之后的32位置换P表     byte[] P_box = {         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     };     byte[][] Lpart = new byte[4][8];     byte[][] Rpart = new byte[4][8];     //声明一个三维数组用来存储加密过程产生的16个密码     byte[][][] saveKey = new byte[16][8][6];     //保存加密后的二进制密文     //public byte[][] encryptTextBits;     //初始置换IP     private byte[][] initailDisplacementIP(byte[][] in) {         byte[][] out = new byte[8][8];         for (int i = 0; i < 64; i++) {             out[i / 8][i % 8] = in[(IP[i] - 1) / 8][(IP[i] - 1) % 8];         }         //System.arraycopy(out, 0, in, 0, 8);//源数组中位置在 srcPos 到 srcPos+length-1 之间的组件被分别复制到目标数组中的 destPos 到 destPos+length-1 位置         return out;     }//ip结束     public byte[][][] generateKey(byte[] key) {         //压缩变换PC-1后分割的结果C、D         byte[][] C = new byte[4][7];         byte[][] D = new byte[4][7];         //生成子密钥         byte[][] bitArray2 = new byte[8][8];         for (int i = 0; i < 8; i++) {             bitArray2[i] = Change.byteToBitArray(key[i]);         }         //压缩变换PC-1         bitArray2 = compressionTransformPC_1(bitArray2);         //密钥分割         // 将bitArray2经过PC1后的数组拆分成2组         for (int i = 0; i < 8; i++) {             for (int j = 0; j < 7; j++) {                 if (i < 4) {                     C[i][j] = bitArray2[i][j];                 } else {                     D[i - 4][j] = bitArray2[i][j];                 }             }         }         for (int i = 0; i < 16; i++) {             //向左移1位的情况             if (i == 0 || i == 1 || i == 8 || i == 15) {                 leftShift(C);                 leftShift(D);             } //向左移动2位的情况             else {                 leftShift(C);                 leftShift(C);                 leftShift(D);                 leftShift(D);             }             //在一个数组中存储K1-K16以便解密使用             saveKey[i] = compressionTransformPC_2(C, D);         }         return saveKey;     }     /**      * DES加密      * @param plainText      * @param key      */     public String encrypt(byte[] plainText, byte[][][] key) {         //将byteArray中的位取出并扩展成字节放在bitArray中         byte[][] bitArray = new byte[8][8];         for (int i = 0; i < 8; i++) {             bitArray[i] = Change.byteToBitArray(plainText[i]);         }         //完成初始置换IP         bitArray = initailDisplacementIP(bitArray);         //将bitArray分配给2个数组Lpart和Rpart         for (int i = 0; i < 8; i++) {             for (int j = 0; j < 8; j++) {                 if (i < 4) {                     Lpart[i][j] = bitArray[i][j];                 } else {                     Rpart[i - 4][j] = bitArray[i][j];                 }             }         }         byte[][] temp;         //进行16轮的加密变换         for (int i = 0; i < 16; i++) {             // 用临时数组temp保存明文右半部分             temp = (byte[][]) Rpart.clone();             XOR(Lpart, f(Rpart, key[i]));             Rpart = Lpart;             Lpart = temp;         }         // 左右两部分合并然后最终置换,由于最后一次循环之后左边和右边进行了一次交换,所以这里参数的顺序是Rpart在前Lpart在后         byte[][] encryptTextBits = contraryInitailDisplacementIIP(Rpart, Lpart);         //  转化为字节,然后转化为字符         byte[] out = new byte[8];         for (int i = 0; i < 8; i++) {             out[i] = Change.bitToByteArray(encryptTextBits[i]);         }         //输出16进制形式的字符串         return Change.bytesToHexString(out);     }     /**      * DES解密      * @param plainText      * @param key      */     public String decrypt(byte[] encryptText, byte[][][] key) {         //将byteArray中的位取出并扩展成字节放在bitArraye中         byte[][] bitArray = new byte[8][8];         for (int i = 0; i < 8; i++) {             bitArray[i] = Change.byteToBitArray(encryptText[i]);         }         //完成初始置换IP         bitArray = initailDisplacementIP(bitArray);         for (int i = 0; i < 4; i++) {             for (int j = 0; j < 8; j++) {                 Rpart[i][j] = bitArray[i][j];                 Lpart[i][j] = bitArray[i + 4][j];             }         }         byte[][] temp;         for (int i = 15; i >= 0; i--) {             temp = (byte[][]) Lpart.clone();             XOR(Rpart, f(Lpart, key[i]));             Lpart = Rpart;             Rpart = temp;         }         byte[][] result = contraryInitailDisplacementIIP(Lpart, Rpart);         //转化为字节,然后转化为字符         byte[] out = new byte[8];         for (int i = 0; i < 8; i++) {             out[i] = Change.bitToByteArray(result[i]);         }         //输出16进制形式的字符串         return Change.bytesToHexString(out);     }     public static void main(String[] args) {         DES des = new DES();         //二进制形式的原文         byte[][] plainTextBit = {             {(byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x01},             {(byte) 0x00, (byte) 0x00, (byte) 0x01, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x01, (byte) 0x01},             {(byte) 0x00, (byte) 0x01, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x01, (byte) 0x00, (byte) 0x01},             {(byte) 0x00, (byte) 0x01, (byte) 0x01, (byte) 0x00, (byte) 0x00, (byte) 0x01, (byte) 0x01, (byte) 0x01},             {(byte) 0x01, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x01, (byte) 0x00, (byte) 0x00, (byte) 0x01},             {(byte) 0x01, (byte) 0x00, (byte) 0x01, (byte) 0x00, (byte) 0x01, (byte) 0x00, (byte) 0x01, (byte) 0x01},             {(byte) 0x01, (byte) 0x01, (byte) 0x00, (byte) 0x00, (byte) 0x01, (byte) 0x01, (byte) 0x00, (byte) 0x01},             {(byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x00, (byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x01}         };         //二进制形式的密钥         byte[][] keyBit = {             {(byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x01, (byte) 0x00, (byte) 0x00, (byte) 0x01, (byte) 0x01},             {(byte) 0x00, (byte) 0x00, (byte) 0x01, (byte) 0x01, (byte) 0x00, (byte) 0x01, (byte) 0x00, (byte) 0x00},             {(byte) 0x00, (byte) 0x01, (byte) 0x00, (byte) 0x01, (byte) 0x00, (byte) 0x01, (byte) 0x01, (byte) 0x01},             {(byte) 0x00, (byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x00, (byte) 0x00, (byte) 0x01},             {(byte) 0x01, (byte) 0x00, (byte) 0x00, (byte) 0x01, (byte) 0x01, (byte) 0x00, (byte) 0x01, (byte) 0x01},             {(byte) 0x01, (byte) 0x00, (byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x00, (byte) 0x00},             {(byte) 0x01, (byte) 0x01, (byte) 0x00, (byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x01},             {(byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x01, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x01}         };         //转换为byte数组         byte[] plainTextByte = new byte[8];         byte[] keyByte = new byte[8];         for (int i = 0; i < 8; i++) {             plainTextByte[i] = Change.bitToByteArray(plainTextBit[i]);             keyByte[i] = Change.bitToByteArray(keyBit[i]);         }         byte[][][] key = des.generateKey(keyByte);         byte[] plainText2 = {(byte) 0x11, (byte) 0x12, (byte) 0x13, (byte) 0x14, (byte) 0x15, (byte) 0x16, (byte) 0x17, (byte) 0x18};         System.out.println("原文1为:" + Change.bytesToHexString(plainTextByte));         System.out.println("原文2为:" + Change.bytesToHexString(plainText2));         //输出密文         String encrypt = des.encrypt(plainTextByte, key);         String encrypt2 = des.encrypt(plainText2, key);         System.out.println("encrypt1=" + encrypt);         System.out.println("encrypt2=" + encrypt2);         byte[] encryptByte = Change.hexStringToBytes(encrypt);         byte[] encryptByte2 = Change.hexStringToBytes(encrypt2);         //输出原文         System.out.println("decrypt1=" + des.decrypt(encryptByte, key));         System.out.println("decrypt2=" + des.decrypt(encryptByte, key));         System.out.println("decrypt2=" + des.decrypt(encryptByte2, key));     }     /**      * PC-1压缩变换      */     private byte[][] compressionTransformPC_1(byte[][] in) {         byte[][] temp = new byte[8][7];         for (int i = 0; i < 56; i++) {             temp[i / 7][i % 7] = in[(PC_1[i] - 1) / 8][(PC_1[i] - 1) % 8];         }         return temp;     }     /**      * 左移函数      * @param C      */     private void leftShift(byte[][] b) {         byte temp = b[0][0];         for (int i = 0; i < 4; i++) {             for (int j = 0; j < 6; j++) {                 b[i][j] = b[i][j + 1];                 if (i == 3) {                     continue;                 }                 if (j == 5) {                     b[i][6] = b[i + 1][0];                 }             }         }         b[3][6] = temp;     }     /**      * PC-2压缩变换      * @param C      * @param D      * @return      */     private byte[][] compressionTransformPC_2(byte[][] C, byte[][] D) {         byte[][] out = new byte[8][6];         byte[][] temp = new byte[8][7];         //将C和D合并56位的         for (int i = 0; i < 28; i++) {             temp[i / 7][i % 7] = C[i / 7][i % 7];             temp[i / 7 + 4][i % 7] = D[i / 7][i % 7];         }         for (int i = 0; i < 48; i++) {             out[i / 6][i % 6] = temp[(PC_2[i] - 1) / 7][(PC_2[i] - 1) % 7];         }         return out;     }     private byte[][] f(byte[][] rPart, byte[][] key) {         byte[][] temp;         //32位扩展到48位         rPart = EBox(rPart);         XOR(rPart, key);         temp = Sbox(rPart);         return Pbox(temp);     }     /**      * 异或      * @param a      * @param b      */     private void XOR(byte[][] a, byte[][] b) {         for (int i = 0; i < a.length; i++) {             for (int j = 0; j < a[i].length; j++) {                 a[i][j] ^= b[i][j];             }         }     }     /**      * E-盒置换      * @param in      * @return      */     private byte[][] EBox(byte[][] in) {         byte[][] out = new byte[8][6];         for (int i = 0; i < 48; i++) {             out[i / 6][i % 6] = in[(E_box[i] - 1) / 8][(E_box[i] - 1) % 8];         }         return out;     }     /**      * S-盒替代      * @param rPart      * @return      */     private byte[][] Sbox(byte[][] in) {         byte[] temp = new byte[8];         byte[][] out = new byte[8][4];         //行号,列号         int m, n;         for (int i = 0; i < 8; i++) {             m = in[i][0] * 2 + in[i][5];             n = in[i][1] * 8 + in[i][2] * 4 + in[i][3] * 2 + in[i][4];             temp[i] = (byte) S_box[i][m][n];         }         for (int i = 0; i < 8; i++) {             for (int j = 3; j >= 0; j--) {                 out[i][j] = (byte) (temp[i] & 0x01);                 temp[i] >>= 1;             }         }         return out;     }     private byte[][] Pbox(byte[][] in) {         byte[][] temp = new byte[4][8];         for (int i = 0; i < 32; i++) {             temp[i / 8][i % 8] = in[(P_box[i] - 1) / 4][(P_box[i] - 1) % 4];         }         return temp;     }     private byte[][] contraryInitailDisplacementIIP(byte[][] Rpart, byte[][] Lpart) {         byte[][] out = new byte[8][8];         byte[][] temp = new byte[8][8];         for (int i = 0; i < 4; i++) {             for (int j = 0; j < 8; j++) {                 temp[i][j] = Rpart[i][j];                 temp[i + 4][j] = Lpart[i][j];             }         }         for (int i = 0; i < 64; i++) {             out[i / 8][i % 8] = temp[(IIP[i] - 1) / 8][(IIP[i] - 1) % 8];         }         return out;     } }


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