/// <summary>
/// Mask Generation Function
/// </summary>
/// <param name="Z">Initial pseudorandom Seed.</param>
/// <param name="l">Length of output required.</param>
/// <returns></returns>
private byte[] MGF(byte[] Z, int l)
{
if (l > (Math.Pow(2, 32)))
{
throw new ArgumentException("Mask too long.");
}
else
{
List <byte> result = new List <byte>();
for (int i = 0; i <= l / rsaParams.hLen; i++)
{
List <byte> data = new List <byte>();
data.AddRange(Z);
data.AddRange(RSAxUtils.I2OSP(i, 4, false));
result.AddRange(rsaParams.ComputeHash(data.ToArray()));
}
if (l <= result.Count)
{
return(result.GetRange(0, l).ToArray());
}
else
{
throw new ArgumentException("Invalid Mask Length.");
}
}
}
