/// <summary>
/// Creates elliptic curve domain parameters based on the
/// specified values. </summary>
/// <param name="curve"> the elliptic curve which this parameter
/// defines. </param>
/// <param name="g"> the generator which is also known as the base point. </param>
/// <param name="n"> the order of the generator {@code g}. </param>
/// <param name="h"> the cofactor. </param>
/// <exception cref="NullPointerException"> if {@code curve},
/// {@code g}, or {@code n} is null. </exception>
/// <exception cref="IllegalArgumentException"> if {@code n}
/// or {@code h} is not positive. </exception>
public ECParameterSpec(EllipticCurve curve, ECPoint g, System.Numerics.BigInteger n, int h)
{
if (curve == null)
{
throw new NullPointerException("curve is null");
}
if (g == null)
{
throw new NullPointerException("g is null");
}
if (n == null)
{
throw new NullPointerException("n is null");
}
if (n.signum() != 1)
{
throw new IllegalArgumentException("n is not positive");
}
if (h <= 0)
{
throw new IllegalArgumentException("h is not positive");
}
this.Curve_Renamed = curve;
this.g = g;
this.n = n;
this.h = h;
}
/// <summary>
/// Creates an elliptic curve prime finite field
/// with the specified prime {@code p}. </summary>
/// <param name="p"> the prime. </param>
/// <exception cref="NullPointerException"> if {@code p} is null. </exception>
/// <exception cref="IllegalArgumentException"> if {@code p}
/// is not positive. </exception>
public ECFieldFp(System.Numerics.BigInteger p)
{
if (p.signum() != 1)
{
throw new IllegalArgumentException("p is not positive");
}
this.p = p;
}
// Check coefficient c is a valid element in ECField field.
private static void CheckValidity(ECField field, System.Numerics.BigInteger c, String cName)
{
// can only perform check if field is ECFieldFp or ECFieldF2m.
if (field is ECFieldFp)
{
System.Numerics.BigInteger p = ((ECFieldFp)field).P;
if (p.CompareTo(c) != 1)
{
throw new IllegalArgumentException(cName + " is too large");
}
else if (c.signum() < 0)
{
throw new IllegalArgumentException(cName + " is negative");
}
}
else if (field is ECFieldF2m)
{
int m = ((ECFieldF2m)field).M;
if (c.bitLength() > m)
{
throw new IllegalArgumentException(cName + " is too large");
}
}
}