public static sbyte[] decryptBloc(sbyte[] input)
{
sbyte[] tmp = new sbyte[input.Length];
sbyte[][] state = RectangularArrays.ReturnRectangularSbyteArray(4, Nb);
for (int i = 0; i < input.Length; i++)
{
state[i / 4][i % 4] = input[i % 4 * 4 + i / 4];
}
state = AddRoundKey(state, w, Nr);
FileHelper.GetDescription("start round initialisation from " + (Nr - 1) + " to " + 1);
for (int round = Nr - 1; round >= 1; round--)
{
FileHelper.GetDescription("round: {0}", round.ToString());
state = InvSubBytes(state);
FileHelper.GetDescription("{0,18}", "InvSubBytes state");
FileHelper.GetMatrixState(state);
state = InvShiftRows(state);
FileHelper.GetDescription("{0, 19}", "InvShiftRows state");
FileHelper.GetMatrixState(state);
state = AddRoundKey(state, w, round);
FileHelper.GetDescription("{0, 21}", "AddRoundKey state");
FileHelper.GetMatrixState(state);
state = InvMixColumns(state);
FileHelper.GetDescription("{0, 20}", "InvMixColumns state");
FileHelper.GetMatrixState(state);
}
FileHelper.GetDescription("round: {0}", "0");
state = InvSubBytes(state);
FileHelper.GetMatrixState(state);
state = InvShiftRows(state);
FileHelper.GetDescription("{0, 19}", "InvShiftRows state");
FileHelper.GetMatrixState(state);
state = AddRoundKey(state, w, 0);
FileHelper.GetDescription("{0, 21}", "AddRoundKey state");
FileHelper.GetMatrixState(state);
for (int i = 0; i < tmp.Length; i++)
{
tmp[i % 4 * 4 + i / 4] = state[i / 4][i % 4];
}
return(tmp);
}
public static sbyte[][] SubBytes(sbyte[][] state)
{
sbyte[][] tmp = RectangularArrays.ReturnRectangularSbyteArray(state.Length, state[0].Length);
for (int row = 0; row < 4; row++)
{
for (int col = 0; col < Nb; col++)
{
tmp[row][col] = unchecked ((sbyte)(sbox[(state[row][col] & 0x000000ff)] & 0xff));
}
}
return(tmp);
}
public static sbyte[][] AddRoundKey(sbyte[][] state, sbyte[][] w, int round)
{
sbyte[][] tmp = RectangularArrays.ReturnRectangularSbyteArray(state.Length, state[0].Length);
for (int c = 0; c < Nb; c++)
{
for (int l = 0; l < 4; l++)
{
tmp[l][c] = (sbyte)(state[l][c] ^ w[round * Nb + c][l]);
}
}
return(tmp);
}
private static sbyte[][] generateSubkeys(sbyte[] key)
{
sbyte[][] tmp = RectangularArrays.ReturnRectangularSbyteArray(Nb * (Nr + 1), 4);
int i = 0;
while (i < Nk)
{
tmp[i][0] = key[i * 4];
tmp[i][1] = key[i * 4 + 1];
tmp[i][2] = key[i * 4 + 2];
tmp[i][3] = key[i * 4 + 3];
i++;
}
i = Nk;
while (i < Nb * (Nr + 1))
{
sbyte[] temp = new sbyte[4];
for (int k = 0; k < 4; k++)
{
temp[k] = tmp[i - 1][k];
}
if (i % Nk == 0)
{
temp = SubWord(rotateWord(temp));
temp[0] = (sbyte)(temp[0] ^ (Rcon[i / Nk] & 0xff));
}
else if (Nk > 6 && i % Nk == 4)
{
temp = SubWord(temp);
}
tmp[i] = xor_func(tmp[i - Nk], temp);
i++;
}
return(tmp);
}
