des.cpp.zip_Des加密解密_des_des.cpp_stemsusq

#include <iostream> #include <fstream> #include <bitset> #include <string> using namespace std; bitset<64> key; // 64位密钥 bitset<48> subKey[16]; // 存放16轮子密钥 // 初始置换表 int 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}; // 结尾置换表 int IP_1[] = {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}; /*------------------下面是生成密钥所用表-----------------*/ // 密钥置换表，将64位密钥变成56位 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}; // 压缩置换，将56位密钥压缩成48位子密钥 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}; // 每轮左移的位数 int shiftBits[] = {1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1}; /*------------------下面是密码函数 f 所用表-----------------*/ // 扩展置换表，将 32位 扩展至 48位 int 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}; // S盒，每个S盒是4x16的置换表，6位 -> 4位 int S_BOX[8][4][16] = { { {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} } }; // P置换，32位 -> 32位 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 }; /**********************************************************************/ /* */ /* 下面是DES算法实现 */ /* */ /**********************************************************************/ /** * 密码函数f，接收32位数据和48位子密钥，产生一个32位的输出 */ bitset<32> f(bitset<32> R, bitset<48> k) { bitset<48> expandR; // 第一步：扩展置换，32 -> 48 for(int i=0; i<48; ++i) expandR[47-i] = R[32-E[i]]; // 第二步：异或 expandR = expandR ^ k; // 第三步：查找S_BOX置换表 bitset<32> output; int x = 0; for(int i=0; i<48; i=i+6) { int row = expandR[47-i]*2 + expandR[47-i-5]; int col = expandR[47-i-1]*8 + expandR[47-i-2]*4 + expandR[47-i-3]*2 + expandR[47-i-4]; int num = S_BOX[i/6][row][col]; bitset<4> binary(num); output[31-x] = binary[3]; output[31-x-1] = binary[2]; output[31-x-2] = binary[1]; output[31-x-3] = binary[0]; x += 4; } // 第四步：P-置换，32 -> 32 bitset<32> tmp = output; for(int i=0; i<32; ++i) output[31-i] = tmp[32-P[i]]; return output; } /** * 对56位密钥的前后部分进行左移 */ bitset<28> leftShift(bitset<28> k, int shift) { bitset<28> tmp = k; for(int i=27; i>=0; --i) { if(i-shift<0) k[i] = tmp[i-shift+28]; else k[i] = tmp[i-shift]; } return k; } /** * 生成16个48位的子密钥 */ void generateKeys() { bitset<56> realKey; bitset<28> left; bitset<28> right; bitset<48> compressKey; // 去掉奇偶标记位，将64位密钥变成56位 for (int i=0; i<56; ++i) realKey[55-i] = key[64 - PC_1[i]]; // 生成子密钥，保存在 subKeys[16] 中 for(int round=0; round<16; ++round) { // 前28位与后28位 for(int i=28; i<56; ++i) left[i-28] = realKey[i]; for(int i=0; i<28; ++i) right[i] = realKey[i]; // 左移 left = leftShift(left, shiftBits[round]); right = leftShift(right, shiftBits[round]); // 压缩置换，由56位得到48位子密钥 for(int i=28; i<56; ++i) realKey[i] = left[i-28]; for(int i=0; i<28; ++i) realKey[i] = right[i]; for(int i=0; i<48; ++i) compressKey[47-i] = realKey[56 - PC_2[i]]; subKey[round] = compressKey; } } /** * 工具函数：将char字符数组转为二进制 */ bitset<64> charToBitset(const char s[8]) { bitset<64> bits; for(int i=0; i<8; ++i) for(int j=0; j<8; ++j) bits[i*8+j] = ((s[i]>>j) & 1); return bits; } /** * DES加密 */ bitset<64> encrypt(bitset<64>& plain) { bitset<64> cipher; bitset<64> currentBits; bitset<32> left; bitset<32> right; bitset<32> newLeft; // 第一步：初始置换IP for(int i=0; i<64; ++i) currentBits[63-i] = plain[64-IP[i]]; // 第二步：获取 Li 和 Ri for(int i=32; i<64; ++i) left[i-32] = currentBits[i]; for(int i=0; i<32; ++i) right[i] = currentBits[i]; // 第三步：共16轮迭代 for(int round=0; round<16; ++round) { newLeft = right; right = left ^ f(right,subKey[round]); left = newLeft; } // 第四步：合并L16和R16，注意合并为 R16L16 for(int i=0; i<32; ++i) cipher[i] = left[i]; for(int i=32; i<64; ++i) cipher[i] = right[i-32]; // 第五步：结尾置换IP-1 currentBits = cipher; for(int i=0; i<64; ++i) cipher[63-i] = currentBits[64-IP_1[i]]; // 返回密文 return cipher; } /** * DES解密 */ bitset<64> decrypt(bitset<64>& cipher) { bitset<64> plain; bitset<64> currentBits; bitset<32> left; bitset<32> right; bitset<32> newLeft; // 第一步：初始置换IP for(int i=0; i<64; ++i) currentBits[63-i] = cipher[64-IP[i]]; // 第二步：获取 Li 和 Ri for(int i=32; i<64; ++i) left[i-32] = currentBits[i]; for(int i=0; i<32; ++i) right[i] = currentBits[i]; // 第三步：共16轮迭代（子密钥逆序应用） for(int round=0; round<16; ++round) { newLeft = right; right = left ^ f(right,subKey[15-round]); left = newLeft; } // 第四步：合并L16和R16，注意合并为 R16L16 for(int i=0; i<32; ++i) plain[i] = left[i]; for(int i=32; i<64; ++i) plain[i] = right[i-32]; // 第五步：结尾置换IP-1 currentBits = plain; for(int i=0; i<64; ++i) plain[63-i] = currentBits[64-IP_1[i]]; // 返回明文 return plain; } /**********************************************************************/ /* 测试： */ /* 1.将一个 64 位的字符串加密， 把密文写入文件 a.txt */ /* 2.读取文件 a.txt 获得 64 位密文，解密之后再写入 b.txt */ /**********************************************************************/ int main() { string s = "16711132"; string k = "16711132"; bitset<64> plain = charToBitset(s.c_str()); key = charToBitset(k.c_str()); // 生成16