public Matrix AddRoundKey(Matrix state, Keys key, int Round)
{
// AddRoundKey
if (Round > key.RoundKeys.Count - 1)
{
throw new IndexOutOfRangeException(
"The round key is must between 0 and 10 in 128 bit AES.");
}
return(MatrixMultiplication.XOR(state, key.RoundKeys[Round]));
}
public static Matrix Multiply(Matrix a, Matrix b, bool IsMixColumns)
{
if (IsMixColumns)
{
return(MatrixMultiplication.MixColumnsMultiply(a, b));
}
else
{
return(null);
}
}
public Matrix MixColumns(Matrix state, bool IsReverse)
{
// MixColumns
if (IsReverse == false)
{
state = MatrixMultiplication.Multiply(TransformTables.MixColumnFactor, state, true);
}
else
{
state = MatrixMultiplication.Multiply(TransformTables.Inverse_MixColumFactor, state, true);
}
return(state);
}
public Keys KeyExpansion(Keys key, bool IsReverse)
{
for (int i = 4; i < key.RoundKeys.Count * 4; i++)
{
string[] Wi_1 = key.RoundKeys[(i - 1) / 4].getWord((i - 1) % 4);
Matrix mat_Wi_1 = new Matrix(4, 1);
mat_Wi_1.setWord(Wi_1, 0);
if (i % 4 == 0)
{
Wi_1 = this.RotWord(Wi_1);
mat_Wi_1.setWord(Wi_1, 0);
mat_Wi_1 = this.SubBytes(mat_Wi_1, false);
mat_Wi_1 = MatrixMultiplication.XOR(mat_Wi_1, TransformTables.Rcon[(i - 1) / 4]);
}
Matrix Wi_4 = new Matrix(4, 1);
Wi_4.setWord(key.RoundKeys[(i - 4) / 4].getWord((i - 4) % 4), 0);
Matrix temp = MatrixMultiplication.XOR(mat_Wi_1, Wi_4);
string[] Wi = temp.getWord(0);
key.RoundKeys[i / 4].setWord(Wi, i % 4);
}
return(key);
}
