public static int[,] GetKeyExpansion(string str)
{
str = str.ToLower();
byte[] buf = Encoding.UTF8.GetBytes(str);
StringBuilder s = new StringBuilder(128);
int nb = 4;
int nk = buf.Length / 4;
int nr = 0;
switch (nk)
{
case 4: nr = 10;
break;
case 6: nr = 12;
break;
case 8: nr = 14;
break;
}
int[,] key = new int[nb * (nr + 1), nb];
int[,] cipherKey = new int[nr + 1, 16];
int[] temp = new int[4];
for (int i = 0; i < buf.Length; i++)
{
for (int j = 7; j >= 0; j--)
{
s = s.Append(buf[i] >> j & 1);
}
}
for (int i = 0; i < nk; i++)
{
for (int j = 0; j < nb; j++)
{
key[i, j] = Convert.ToInt32(s.ToString(8 * j + i * 32, 8), 2);
}
}
for (int i = nk; i < nb * (nr + 1); i++)
{
temp[0] = key[i - 1, 0];
temp[1] = key[i - 1, 1];
temp[2] = key[i - 1, 2];
temp[3] = key[i - 1, 3];
for (int j = 0; j < nb; j++)
{
if (i % nk == 0)
{
temp[j] = SubBytes.GetSubByte(key[i - 1, (j + 1) % 4]) ^ Rcon[i / nk, j];
}
else if ((nk > 6) && (i % nk == 4))
{
temp[j] = SubBytes.GetSubByte(key[i - 1, j]);
}
key[i, j] = temp[j] ^ key[i - nk, j];
}
}
for (int i = 0; i < nr + 1; i++)
{
for (int j = 0; j < 16; j++)
{
cipherKey[i, j] = key[j / 4 + i * 4, j % 4];
}
}
return(cipherKey);
}
public static int[,] Getencryption(string str, int[,] key)
{
str = str.ToLower();
StringBuilder strB = new StringBuilder(str);
if (strB.Length % 16 != 0)
{
int len = strB.Length;
for (int i = 0; i < 32 - len % 32; i++)
{
strB = strB.Append(" ");
}
}
byte[] buf = Encoding.UTF8.GetBytes(strB.ToString());
int[] cipherkey = new int[16];
int[,] plain = new int[buf.Length / 16, 16];
int[,] ciphertext = new int[buf.Length / 16, 16];
int[] plaintext = new int[16];
StringBuilder s = new StringBuilder(100000);
for (int i = 0; i < buf.Length; i++)
{
for (int j = 7; j >= 0; j--)
{
s = s.Append(buf[i] >> j & 1);
}
}
for (int i = 0; i < plain.GetLength(0); i++)
{
for (int j = 0; j < 16; j++)
{
plain[i, j] = Convert.ToInt32(s.ToString(j * 8 + i * 128, 8), 2);
}
}
for (int i = 0; i < plain.GetLength(0); i++)
{
for (int h = 0; h < 16; h++)
{
cipherkey[h] = key[0, h];
plaintext[h] = plain[i, h];
}
plaintext = AddRoundKey(plaintext, cipherkey);
for (int j = 0; j < key.GetLength(0) - 2; j++)
{
for (int h = 0; h < 16; h++)
{
cipherkey[h] = key[j + 1, h];
}
for (int h = 0; h < plaintext.Length; h++)
{
plaintext[h] = SubBytes.GetSubByte(plaintext[h]);
}
plaintext = ShiftRows(plaintext);
plaintext = MixColumn.GetMixColumn(plaintext);
plaintext = AddRoundKey(plaintext, cipherkey);
}
for (int h = 0; h < 16; h++)
{
cipherkey[h] = key[key.GetLength(0) - 1, h];
}
for (int h = 0; h < plaintext.Length; h++)
{
plaintext[h] = SubBytes.GetSubByte(plaintext[h]);
}
plaintext = ShiftRows(plaintext);
plaintext = AddRoundKey(plaintext, cipherkey);
for (int j = 0; j < 16; j++)
{
ciphertext[i, j] = plaintext[j];
}
}
return(ciphertext);
}