DES加密和解密C++实现
程序员文章站
2024-03-14 09:18:00
...
#include<bits/stdc++.h>
using namespace std;
mt19937 rnd(chrono::system_clock::now().time_since_epoch().count());
const int N = 1 << 6, M = 1 << 5, T = 16;
const int IP[N] = {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,
56, 48, 40, 32, 24, 16, 8, 0,
58, 50, 42, 34, 26, 18, 10, 2,
60, 52, 44, 36, 28, 20, 12, 4,
62, 54, 46, 38, 30, 22, 14, 6};
const int IP_1[N] = {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,
32, 0, 40, 8, 48, 16, 56, 24};
const int PC_1[56] = {56, 48, 40, 32, 24, 16, 8,
0, 57, 49, 41, 33, 25, 17,
9, 1, 58, 50, 42, 34, 26,
18, 10, 2, 59, 51, 43, 35,
62, 54, 46, 38, 30, 22, 14,
6, 61, 53, 45, 37, 29, 21,
13, 5, 60, 52, 44, 36, 28,
20, 12, 4, 27, 19, 11, 3};
const int PC_2[48] = {13, 16, 10, 23, 0, 4,
2, 27, 14, 5, 20, 9,
22, 18, 11, 3, 25, 7,
15, 6, 26, 19, 12, 1,
40, 51, 30, 36, 46, 54,
29, 39, 50, 44, 32, 47,
43, 48, 38, 55, 33, 52,
45, 41, 49, 35, 28, 31};
const int D[1 << 4] = {1, 2, 4, 6, 8, 10, 12, 14, 15, 17, 19, 21, 23, 25, 27, 28};
const int S[1 << 3][1 << 2][1 << 4] = {{
{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}
}
};
int K[T][48], Key[64];
int a[N], b[2][N];
inline void work(int i) {
for (int j = 0, k = 0, r, c; j < M; j += 4, k++) {
r = (b[i & 1 ^ 1][(j - 1 + M) % M] ^ K[i][k * 6 + 1]) |
((b[i & 1 ^ 1][(j + 4) % M] ^ K[i][(k + 1) * 6]) << 1);
c = 0;
for (int u = 0; u < 4; u++)
c |= (b[i & 1 ^ 1][j + u] ^ K[i][k * 6 + 2 + u]) << u;
for (int u = 0; u < 4; u++)
b[i & 1][j + u] ^= S[k][r][c] >> u & 1;
}
}
inline void encrypt() {
for (int i = 0; i < M; i++)b[0][i] = a[IP[i]];
for (int i = M; i < N; i++)b[1][i - M] = a[IP[i]];
for (int i = 0; i < T; i++)work(i);
for (int i = 0; i < N; i++)a[i] = IP_1[i] >= M ? b[0][IP_1[i] - M] : b[1][IP_1[i]];
}
inline void decode() {
for (int i = 0; i < M; i++)b[1][i] = a[IP[i]];
for (int i = M; i < N; i++)b[0][i - M] = a[IP[i]];
for (int i = T - 1; i >= 0; i--)work(i);
for (int i = 0; i < N; i++)a[i] = IP_1[i] >= M ? b[1][IP_1[i] - M] : b[0][IP_1[i]];
}
inline void out() {
for (int i = 0; i < N; i++)printf("%d", a[i]);
puts("");
}
int main() {
puts("**：");
for (int i = 0; i < N; i++)printf("%d", Key[i] = rnd() & 1);
puts("");
for (int i = 0; i < T; i++)
for (int j = 0; j < 48; j++)
K[i][j] = Key[PC_1[(PC_2[i] + D[i]) % 28 + (PC_2[i] > 27 ? 28 : 0)]];
for (int i = 0; i < N; i++)a[i] = rnd() & 1;
puts("明文："), out();
encrypt();
puts("密文："), out();
decode();
puts("明文："), out();
return 0;
}
运行结果：
**：
0100101000001010011000001011001101010000000000000110111110110000
明文：
0111011010001111010101101101001000111110110000010101100000111111
密文：
1010011001110111000100111101010100000111011101111101100001001111
明文：
0111011010001111010101101101001000111110110000010101100000111111