In the basic des algorithm
Made improvements to the input section on
#include <iostream>
#include <bitset>
#include <string>
using namespace std;
//Plaintext scramble table, 64-64
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 };
// key replacement table, 64-56
int k_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 };
// Compression permutation, 56-48
int k_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 };
// Number of bits to shift left each round
int shiftBits[] = { 1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1 };
// f function extended permutation table, 32-48
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 box replacement, 6-4
int sbox[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 permutation, 32-32
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 };
// end substitution table
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 };
bitset<48> roundkey[16];
bitset<64> Orikey;
bitset<28> keyshift(bitset<28> K, int shiftnum) {
bitset<28> shiftK;
for (int i = 0; i < 27; i++) {
if (i - shiftnum >= 0) {
shiftK[i] = K[i - shiftnum];
}
else
shiftK[i] = K[i - shiftnum + 28];
}
return shiftK;
};
bitset<32> f(bitset<32> Rm, bitset<48> K) {
bitset<48> Rm48;
bitset<32> sboxm;
for (int i = 0; i < 48; i++) {
Rm48[47 - i] = Rm[32 - E[i]];
}
Rm48 = Rm48 ^ K;
int s = 0;
for (int i = 0; i < 48; i += 6) {
int x = Rm48[47 - i - 5] + Rm48[47 - i]* 2;
int y = Rm48[47 - i - 4] + Rm48[47 - i - 3] * 2 + Rm48[47 - i - 2] * 4 + Rm48[47 - i - 1] * 8;
int sboxnum = sbox[(i + 1) / 6][x][y];
bitset<4> num(sboxnum);
sboxm[31 - x] = num[3];
sboxm[31 - x - 1] = num[2];
sboxm[31 - x - 2] = num[1];
sboxm[31 - x - 3] = num[0];
s += 4;
}
bitset<32> finalm = sboxm;
for (int i = 0; i < 32; i++) {
finalm[31 - i] = sboxm[32 - P[i]];
}
return finalm;
};
void KEY() {
bitset<28> leftkey;
bitset<28> rightkey;
bitset<56> key56;
bitset<48> key48;
for (int i = 0; i < 56; i++) {
key56[55 - i] = Orikey[64 - k_1[i]];
}
for (int round = 0; round < 16; round++) {
for (int i = 0; i < 28; i++) {
leftkey[i] = key56[i];
}
for (int i = 0; i < 28; i++) {
rightkey[i] = key56[i + 28];
}
leftkey = keyshift(leftkey, shiftBits[round]);
rightkey = keyshift(rightkey, shiftBits[round]);
for (int i = 0; i < 28; i++) {
key56[i] = leftkey[i];
}
for (int i = 0; i < 28; i++) {
key56[i + 28] = rightkey[i];
}
for (int i = 0; i < 48; i++) {
key48[47 - i] = key56[56 - k_2[i]];
}
roundkey[round] = key48;
}
};
bitset<64> chartobits(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;
};
bitset<64> des(string M, string K) {
bitset<64> m1 = chartobits(M.c_str());
Orikey = chartobits (K.c_str ());
KEY();
bitset<64> m;
bitset<32> r;
bitset<32> l;
bitset<32> nl;
bitset<64> cipher;
bitset<64> currentBits;
for (int i = 0; i<64; ++i)
m[63 - i] = m1[64 - IP[i]];
for (int i = 0; i < 32; i++) {
r[i] = m[i];
}
for (int i = 0; i < 32; i++) {
l[i] = m[i + 32];
}
for (int i = 0; i < 16; i++) {
nl = r;
r =l^ f(r, roundkey[i]);
l = nl;
}
for (int i = 0; i < 32; i++) {
cipher[i] = l[i];
}
for (int i = 0; i < 32; i++) {
cipher[i + 32] = r[i];
}
currentBits = cipher;
for (int i = 0; i<64; ++i)
cipher[63 - i] = currentBits[64 - IP_1[i]];
return cipher;
};
bitset<64> des1(bitset<64> c1, string K) {
Orikey = chartobits (K.c_str ());
KEY();
bitset<64> c;
bitset<32> r;
bitset<32> l;
bitset<32> nl;
bitset<64> plain;
bitset<64> currentBits;
for (int i = 0; i<64; ++i)
c[63 - i] = c1[64 - IP[i]];
for (int i = 0; i < 32; i++) {
r[i] = c[i];
}
for (int i = 0; i < 32; i++) {
l[i] = c[i + 32];
}
for (int i = 15; i >= 0; i--) {
nl = r;
r = l ^ f(r, roundkey[i]);
l = nl;
}
for (int i = 0; i < 32; i++) {
plain[i] = l[i];
}
for (int i = 0; i < 32; i++) {
plain[i + 32] = r[i];
}
currentBits = plain;
for (int i = 0; i<64; ++i)
plain[63 - i] = currentBits[64 - IP_1[i]];
return plain;
};
void bittochar(bitset<64> b) {
char c[8];
int x = 0;
for (int i = 0; i < 63; i += 8) {
c[x] = b[i] + b[i + 1] * 2 + b[i + 2] * 4 + b[i + 3] * 8 + b[i + 4] * 16 + b[i + 5] * 32 + b[i + 6] * 64 + b[i + 7] * 128;
x++;
}
for (int i = 0; i < 8; i++) {
cout << c[i];
}
};
int main() {
string m, key;
bitset<64> cipher;
bitset<64> plain;
while (cin>>m>>key) {
cipher = des(m, key);
cout<<"Ciphertext binary sequence:"<< cipher<< endl;
cout << "密文:";
bittochar(cipher);
cout<<endl <<"Plaintext binary sequence:"<<des1(cipher, key);
plain = des1(cipher, key);
cout<< endl <<"明文:";
bittochar(plain);
}
}
Made improvements to the input section on