//Copyright (c), October 2007, Some Rights Reserved
//By Murat Firat
using System;
using System.Text;
using System.IO;
using System.Collections;
namespace Cipher
{
class DES
{
private byte[] IP, IP1, P, E, PC1, PC2, LeftShifts;
private byte[,] Ss;
protected string Key = null;
private BitArray[] Keys;
public DES()
{
InitializeTables();
}
protected BitArray Encrypt64Bit(BitArray block)
{
block = Table(IP, block);
BitArray Left = new BitArray(32),
Right = new BitArray(32),
Temp;
int tmp = block.Length / 2;
Copy(block, 0, Left, 0, tmp); //Left=block[0-31];
Copy(block, tmp, Right, 0, tmp); //Right=block[32-63];
for (int i = 1; i <= 16; i++)
{
Temp = Left;
Left = Right;
Right = Temp.Xor(F(Right, Keys[i - 1]));
}
Copy(Right, 0, block, 0, 32); //block[0-31]=Right;
Copy(Left, 0, block, 32, 32); //block[32-63]=Left;
block = Table(IP1, block);
return block;
}
protected BitArray Decrypt64Bit(BitArray block)
{
block = Table(IP, block);
BitArray Left = new BitArray(32),
Right = new BitArray(32),
Temp;
int tmp = block.Length / 2;
Copy(block, 0, Left, 0, tmp); //Left=block[0-31];
Copy(block, tmp, Right, 0, tmp); //Right=block[32-63];
for (int i = 1; i <= 16; i++)
{
Temp = Left;
Left = Right;
Right = Temp.Xor(F(Right, Keys[16 - i]));
}
Copy(Right, 0, block, 0, 32); //block[0-31]=Right;
Copy(Left, 0, block, 32, 32); //block[32-63]=Left;
block = Table(IP1, block);
return block;
}
private BitArray F(BitArray R, BitArray K)
{
R = Table(E, R);
BitArray B = R.Xor(K);
BitArray S = new BitArray(8 * 4);
int x, y;
BitArray Temp;
for (int i = 0; i < 8; i++)
{
x = (B[i * 6 + 0] ? 2 : 0) + (B[i * 6 + 5] ? 1 : 0);
y = (B[i * 6 + 1] ? 8 : 0) + (B[i * 6 + 2] ? 4 : 0) +
(B[i * 6 + 3] ? 2 : 0) + (B[i * 6 + 4] ? 1 : 0);
Temp = new BitArray(new byte[] { Ss[i, 16 * x + y] });
Copy(Temp, 0, S, i * 4, 4);
}
S = Table(P, S);
return S;
}
protected void PermuteKeys(string Key)
{
if (Key.Length != 8)
{
throw new Exception("Key Size Must Be 8 Characters Long..");
}
this.Key = Key;
BitArray key = new BitArray(Encoding.ASCII.GetBytes(Key));
key = Table(PC1, key);
BitArray C = new BitArray(28),
C_Old = new BitArray(28),
D = new BitArray(28),
D_Old = new BitArray(28);
Copy(key, 0, C, 0 * 28, 28);
Copy(key, 28, D, 0 * 28, 28);
Keys = new BitArray[16];//16 keys, each one of which has 48 bits
BitArray Temp = new BitArray(28 * 2), TempKey;
//generate 16 keys
for (int i = 1; i <= 16; i++)
{
C_Old = C;
D_Old = D;
//left shifts
for (int j = 0; j < 28; j++)
{
C[j] = C_Old[(j + LeftShifts[i - 1]) % 28];
D[j] = D_Old[(j + LeftShifts[i - 1]) % 28];
}
Copy(C, 0, Temp, 0, 28);
Copy(D, 0, Temp, 28, 28);
TempKey = Table(PC2, Temp);
//save the key
Keys[i - 1] = new BitArray(8 * 6);
Copy(TempKey, 0, Keys[i - 1], 0, 48);
}
}
private BitArray Table(byte[] Table, BitArray block)
{
int tmp = Table.Length;
BitArray Result = new BitArray(tmp);
for (int i = 0; i < tmp; i++)
{
Result[i] = block[Table[i] - 1];
}
return Result;
}
private void Copy(BitArray sourceArray, int sourceIndex,
BitArray destinationArray, int destinationIndex, int lenght)
{
for (int i = 0; i < lenght; i++)
{
if (sourceIndex + i < sourceArray.Length)
{
destinationArray[destinationIndex + i] = sourceArray[sourceIndex + i];
}
else
{
destinationArray[destinationIndex + i] = false;
}
}
}
protected void InitializeTables()
{
IP = new byte[8 * 8]{ 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 = new byte[8 * 6] {
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 = new byte[8 * 4]{
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
};
IP1 = new byte[8 * 8] {
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
};
PC1 = new byte[8 * 7]{
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
};
PC2 = new byte[8 * 6] {
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
};
LeftShifts = new byte[16] { 1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1 };
Ss = new byte[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
}
};
}
}
}
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