int val = s[i][row][col];
op += char(val / 8 + '0');
val = val % 8;
op += char(val / 4 + '0');
val = val % 4;
op += char(val / 2 + '0');
val = val % 2;
op += char(val + '0');
}
// Straight D-box
op = permute(op, per, 32);
// XOR left and op
x = xor_(op, left);
left = x;
// Swapper
if (i != 15) {
swap(left, right);
}
cout << "Round " << i + 1 << " " << bin2hex(left) << " "
<< bin2hex(right) << " " << rk[i] << endl;
}
// Combination
string combine = left + right;
// Final Permutation Table
int final_perm[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 };
// Final Permutation
string cipher = bin2hex(permute(combine, final_perm, 64));
return cipher;
}
int main()
{
// pt is plain text
string pt, key;
cout<<"Enter plain text(in hexadecimal): ";
cin>>pt;
cout<<"Enter key(in hexadecimal): ";
cin>>key;
// pt = "123456ABCD132536";
// key = "AABB09182736CCDD";
// Key Generation
// Hex to binary
key = hex2bin(key);
// Parity bit drop table
int keyp[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 };
// getting 56 bit key from 64 bit using the parity bits
key = permute(key, keyp, 56); // key without parity
// Number of bit shifts
int shift_table[16] = { 1, 1, 2, 2,
2, 2, 2, 2,
1, 2, 2, 2,
2, 2, 2, 1 };
// Key- Compression Table
int key_comp[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 };
// Splitting
string left = key.substr(0, 28);
string right = key.substr(28, 28);
vector rkb; // rkb for RoundKeys in binary
vector rk; // rk for RoundKeys in hexadecimal
for (int i = 0; i < 16; i++) {
// Shifting
left = shift_left(left, shift_table[i]);
right = shift_left(right, shift_table[i]);
// Combining
string combine = left + right;
// Key Compression
string RoundKey = permute(combine, key_comp, 48);
rkb.push_back(RoundKey);
rk.push_back(bin2hex(RoundKey));
}
cout << "\nEncryption:\n\n";
string cipher = encrypt(pt, rkb, rk);
cout << "\nCipher Text: " << cipher << endl;
cout << "\nDecryption\n\n";
reverse(rkb.begin(), rkb.end());
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