DES加解密代码

xiaoxiao2021-02-28  43

#include <cstdio> #include <cstring> // IP 初始置换表 const int IP_Table[64] = { 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 }; // E 扩展表 const int E_Table[48] = { 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 const int P_Table[32] = { 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 }; // IP逆置换表 const int IPR_Table[64] = { 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 }; // 密钥第一次置换表 const int PC1_Table[56] = { 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 }; // 密钥第二次置换表 const int PC2_Table[48] = { 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 }; // S盒 const int S_Box[8][4][16] = { // s1 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, // s2 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, // s3 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, // s4 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, // s5 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, // s6 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, // s7 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, // s8 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 }; /* * 类型转换函数 I * 将 char 型转化为二进制形式 * 8 * sizeof(char) = 8(位) 8 个字符 64 位 */ void CharToBit(const char input[], int output[], int bits) { for (int j = 0; j < 8; j++) { for (int i = 0; i < 8; i++) { output[7 * (j + 1) - i + j] = (input[j] >> i) & 1; } } } /* * 类型转换函数 II * 将二进制形式转化为 char 型 */ void BitToChar(const int intput[], char output[], int bits) { for (int j = 0; j < 8; j++) { for (int i = 0; i < 8; i++) { output[j] = output[j] * 2 + intput[i + 8 * j]; } } } /* * 异或函数 * 将数组 INA 和 INB 进行异或操作,并且保存在 INA 中 */ void Xor(int *INA, int *INB, int len) { for (int i = 0; i<len; i++) { *(INA + i) = *(INA + i) ^ *(INB + i); } } /* * IP 初始置换函数 * IP 根据 IP 初始置换表进行初始置换 */ void IP_Init_Rep(const int input[64], int output[64], const int table[64]) { for (int i = 0; i < 64; i++) { output[i] = input[table[i] - 1]; } } /* * E 扩展置换函数 * 根据 E 扩展表进行扩展 */ void E_Extend(const int input[32], int output[48], const int table[48]) { for (int i = 0; i < 48; i++) { output[i] = input[table[i] - 1]; } } /* * P 置换函数 * 根据 P 盒进行置换 */ void P_Rep(int input[32], int output[32], const int table[32]) { for (int i = 0; i < 32; i++) { output[i] = input[table[i] - 1]; } } /* * IP 逆置换函数 * IP 根据 IP 逆置换表进行置换 */ void IP_Inv_Rep(int input[64], int output[64], const int table[64]) { for (int i = 0; i < 64; i++) { output[i] = input[table[i] - 1]; } } /* * 密匙第一次置换函数 * 根据密匙第一次置换表进行置换 */ void PC_1(int input[64], int output[56], const int table[56]) { for (int i = 0; i < 56; i++) { output[i] = input[table[i] - 1]; } } /* * 密匙第二次置换函数 * 根据密匙第二次置换表进行置换 */ void PC_2(int input[56], int output[48], const int table[48]) { for (int i = 0; i < 48; i++) { output[i] = input[table[i] - 1]; } } /* * S 盒压缩函数 * 根据 8 个 S 盒进行压缩 */ void S_Comp(int input[48], int output[32], const int table[8][4][16]) { int INT[8]; for (int i = 0, j = 0; i < 48; i = i + 6) { INT[j] = table[j][(input[i] << 1) + (input[i + 5])][(input[i + 1] << 3) + (input[i + 2] << 2) + (input[i + 3] << 1) + (input[i + 4])]; j++; } for (int j = 0; j < 8; j++) { for (int i = 0; i < 4; i++) { output[3 * (j + 1) - i + j] = (INT[j] >> i) & 1; } } } /* * 轮迭代函数 * DES 核心迭代部分 */ static void F_func(int input[32], int output[32], int subKey[48]) { int len = 48; int temp0[48] = {0}; int temp1[32] = {0}; E_Extend(input, temp0, E_Table); Xor(temp0, subKey, len); S_Comp(temp0, temp1, S_Box); P_Rep(temp1, output, P_Table); }; /* * 密匙循环左移函数 * 密匙在不同轮数都要进行不同的左移操作 */ void RotateL(int input[28], int output[28], int leftCount) { int len = 28; for (int i = 0; i < len; i++) { output[i] = input[(i + leftCount) % len]; } } /* * 子密匙生成函数 * 生成 subKey,在第 1、2、9、16 轮循环左移 1 位,其他轮循环左移 2 位 */ void subKey_fun(int input[64], int Subkey[16][48]) { int loop0 = 1, loop1 = 2; int c[28], d[28]; int pc_1[56] = {0}; int pc_2[16][56] = {0}; int rotatel_c[16][28] = {0}; int rotatel_d[16][28] = {0}; PC_1(input, pc_1, PC1_Table); for (int i = 0; i < 28; i++) { c[i] = pc_1[i]; d[i] = pc_1[i + 28]; } int leftCount = 0; for (int i = 1; i < 17; i++) { if (i == 1 || i == 2 || i == 9 || i == 16) { leftCount += loop0; RotateL(c, rotatel_c[i - 1], leftCount); RotateL(d, rotatel_d[i - 1], leftCount); } else { leftCount += loop1; RotateL(c, rotatel_c[i - 1], leftCount); RotateL(d, rotatel_d[i - 1], leftCount); } } for (int i = 0; i < 16; i++) { for (int j = 0; j < 28; j++) { pc_2[i][j] = rotatel_c[i][j]; pc_2[i][j + 28] = rotatel_d[i][j]; } } for (int i = 0; i < 16; i++) { PC_2(pc_2[i], Subkey[i], PC2_Table); } } /* * DES 加密函数 * 传入明文 input 和密匙 inKey,获取 64 位二进制密文 output */ void DES_Efun(char input[8], char inKey[8], int output[64]) { int ip[64] = {0}; int output_1[64] = {0}; int subKeys[16][48]; int chartobit[64] = {0}; int key[64]; int l[17][32], r[17][32]; CharToBit(input, chartobit, 8); IP_Init_Rep(chartobit, ip, IP_Table); CharToBit(inKey, key, 8); subKey_fun(key, subKeys); for (int i = 0; i < 32; i++) { l[0][i] = ip[i]; r[0][i] = ip[32 + i]; } for (int j = 1; j < 16; j++) // 15 轮迭代 { for (int k = 0; k < 32; k++) { l[j][k] = r[j - 1][k]; } F_func(r[j - 1], r[j], subKeys[j - 1]); Xor(r[j], l[j - 1], 32); } int t = 0; for (t = 0; t < 32; t++) // 第 16 轮迭代 { r[16][t] = r[15][t]; } F_func(r[15], l[16], subKeys[15]); Xor(l[16], l[15], 32); for (t = 0; t < 32; t++) { output_1[t] = l[16][t]; output_1[32 + t] = r[16][t]; } IP_Inv_Rep(output_1, output, IPR_Table); } /* * DES 解密函数 * 传入 64 位二进制密文 input 和密匙 inKey 获取明文 output */ void DES_Dfun(int input[64], char inKey[8], char output[8]) { int ip[64] = {0}; int output_1[64] = {0}; int output_2[64] = {0}; int subKeys[16][48]; int key[64]; int l[17][32], r[17][32]; IP_Init_Rep(input, ip, IP_Table); CharToBit(inKey, key, 8); subKey_fun(key, subKeys); for (int i = 0; i < 32; i++) { l[0][i] = ip[i]; r[0][i] = ip[32 + i]; } for (int j = 1; j < 16; j++) // 15 轮迭代 { for (int k = 0; k < 32; k++) { l[j][k] = r[j - 1][k]; } F_func(r[j - 1], r[j], subKeys[16 - j]); Xor(r[j], l[j - 1], 32); } int t = 0; for (t = 0; t < 32; t++) // 第 16 轮迭代 { r[16][t] = r[15][t]; } F_func(r[15], l[16], subKeys[0]); Xor(l[16], l[15], 32); for (t = 0; t < 32; t++) { output_1[t] = l[16][t]; output_1[32 + t] = r[16][t]; } IP_Inv_Rep(output_1, output_2, IPR_Table); BitToChar(output_2, output, 8); } int output[64] = {0}; char A[9] = {0}; char B[9] = {0}; int main() { printf("Please enter the plaintext(8 bytes):\n"); scanf("%s", A); printf("Please enter the key(8 bytes):\n"); scanf("%s", B); DES_Efun(A, B, output); putchar(10); printf("Encryption\n"); for (int i = 0; i < 64; i++) { printf("%d", output[i]); if ((i + 1) % 8 == 0) { putchar(10); } else if ((i + 1) % 4 == 0) { putchar(' '); } } putchar(10); printf("Decryption\n"); DES_Dfun(output, B, A); for (int i = 0; i < 8; i++) { printf("%c", A[i]); } putchar(10); return 0; }
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