public string encrypt(string message, BigInteger e, BigInteger n)
{
int[] block = UtilityConverter.StringToNumBlock(message);
string hex = "";
for (int i = 0; i < block.Length; i++)
{
BigInteger enc = BigInteger.ModPow(block[i], e, n);
string hexTmp = enc.ToString("x");
//Console.WriteLine(enc + " to " + hexTmp + "("+hexTmp.Length+")");
if (hex == "")
{
hex = hexTmp;
}
else
{
hex += "g" + hexTmp;
}
}
//Console.WriteLine();
return(hex);
}
public static String decrypt(String chiperText, string ecbKey)
{
ASCIIEncoding encoder = new ASCIIEncoding();
DES des = new DES();
byte[] kbytes = UtilityConverter.GetBytes(ecbKey);
BitArray bitKey = new BitArray(kbytes);
BitArray bits = UtilityConverter.FromHex(chiperText);
BitArray[] group = new BitArray[(int)(bits.Length / 64)];
StringBuilder builder = new StringBuilder();
for (int i = 0; i < group.Length; i++)
{
group[i] = new BitArray(64);
for (int j = 0; j < 64; j++)
{
group[i][j] = bits[i * 64 + j];
}
BitArray dec = des.decrypt(group[i], bitKey);
builder.Append(UtilityConverter.ToString(dec));
}
return(builder.ToString().Replace("\0", ""));
}
public static String encrypt(String plainText, string ecbKey)
{
if (plainText == null)
{
return("");
}
ASCIIEncoding encoder = new ASCIIEncoding();
DES des = new DES();
byte[] kbytes = UtilityConverter.GetBytes(ecbKey);
BitArray bitKey = new BitArray(kbytes);
byte[] tempB = encoder.GetBytes(plainText);
byte[] bytes = new byte[(int)Math.Ceiling(tempB.Length / 8.0f) * 8];
for (int i = 0; i < tempB.Length; i++)
{
bytes[i] = tempB[i];
}
BitArray[] group = new BitArray[(int)Math.Ceiling(bytes.Length / 8.0)];
StringBuilder builder = new StringBuilder();
for (int i = 0; i < group.Length; i++)
{
byte[] b = new byte[8];
for (int j = 0; j < 8; j++)
{
b[j] = bytes[i * 8 + j];
}
group[i] = new BitArray(b);
BitArray enc = des.encrypt(group[i], bitKey);
//UtilityConverter.ShowBitsLine(enc);
builder.Append(UtilityConverter.ToHex(enc));
}
return(builder.ToString());
}
public string decrypt(string hex, BigInteger d, BigInteger n)
{
string[] hexBlock = hex.Split('g');
int length = hexBlock.Length;
int[] numblock = new int[length];
int i = 0;
foreach (string s in hexBlock)
{
BigInteger bint = BigInteger.Parse(s, NumberStyles.AllowHexSpecifier);
BigInteger dec = BigInteger.ModPow(bint, d, n);
numblock[i++] = (int)dec;
}
string plain = UtilityConverter.NumBlockToString(numblock);
return(plain);
}
private BitArray ChiperFunction(BitArray bit32, BitArray bit48)
{
// Expand
int[] expnansion = { 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 };
BitArray bitExp48 = new BitArray(48);
for (int i = 0; i < 48; i++)
{
bitExp48[i] = bit32[(expnansion[i] - 1)];
}
/*
* UtilityConverter.ShowBits(bit48);
* Console.Write(" | ");
* UtilityConverter.ShowBits(bit32);
* Console.Write(" >> ");
* UtilityConverter.ShowBitsLine(bitExp48);
*/
// XOR
bitExp48 = bitExp48.Xor(bit48);
//UtilityConverter.ShowBitsLine(bitExp48);
// convert to group
BitArray[] group = new BitArray[8];
for (int i = 0; i < 8; i++)
{
group[i] = new BitArray(6);
for (int j = 0; j < 6; j++)
{
group[i][j] = bitExp48[(i * 6) + j];
}
}
BitArray sboxSubs = new BitArray(32);
int subPos = 0;
for (int i = 0; i < 8; i++)
{
bool[] firstLast = { group[i].Get(0), group[i].Get(5) };
BitArray row = new BitArray(firstLast);
int rowInt = UtilityConverter.BinToInt(row);
BitArray col = new BitArray(new bool[]
{ group[i].Get(1), group[i].Get(2), group[i].Get(3), group[i].Get(4) });
int colInt = UtilityConverter.BinToInt(col);
//UtilityConverter.ShowBits(row);
//Console.WriteLine(rowInt+", "+colInt);
//UtilityConverter.ShowBitsLine(col);
BitArray bit4 = SBoxLookUp(i, rowInt, colInt);
//UtilityConverter.ShowBits(group[i]);
//Console.Write(" >> ");
//UtilityConverter.ShowBitsLine(bit4);
for (int shift = 0; shift < 4; shift++)
{
sboxSubs[subPos] = bit4[shift];
subPos++;
}
}
BitArray perm = new BitArray(32);
for (int i = 0; i < 32; i++)
{
perm[i] = sboxSubs[(chiperPermutation[i] - 1)];
}
//UtilityConverter.ShowBits(sboxSubs);
//Console.Write(" >> ");
//UtilityConverter.ShowBitsLine(perm);
return(perm);
}
