protected internal ECPoint(
ECCurve curve,
ECFieldElement x,
ECFieldElement y,
bool withCompression)
{
if (curve == null)
throw new ArgumentNullException("curve");
this.curve = curve;
this.x = x;
this.y = y;
this.withCompression = withCompression;
}
public static int GetByteLength(
ECFieldElement fe)
{
return (fe.FieldSize + 7) / 8;
}
protected bool Equals(
ECFieldElement other)
{
return ToBigInteger().Equals(other.ToBigInteger());
}
public abstract ECFieldElement Divide(ECFieldElement b);
public abstract ECFieldElement Multiply(ECFieldElement b);
public abstract ECFieldElement Subtract(ECFieldElement b);
public abstract ECFieldElement Add(ECFieldElement b);
public override ECFieldElement Divide(
ECFieldElement b)
{
return new FpFieldElement(q, x.Multiply(b.ToBigInteger().ModInverse(q)).Mod(q));
}
public override ECFieldElement Subtract(
ECFieldElement b)
{
return new FpFieldElement(q, x.Subtract(b.ToBigInteger()).Mod(q));
}
public override ECFieldElement Add(
ECFieldElement b)
{
return new FpFieldElement(q, x.Add(b.ToBigInteger()).Mod(q));
}
/**
* Create a point that encodes with or without point compresion.
*
* @param curve the curve to use
* @param x affine x co-ordinate
* @param y affine y co-ordinate
* @param withCompression if true encode with point compression
*/
public FpPoint(
ECCurve curve,
ECFieldElement x,
ECFieldElement y,
bool withCompression)
: base(curve, x, y, withCompression)
{
if ((x != null && y == null) || (x == null && y != null))
throw new ArgumentException("Exactly one of the field elements is null");
}
/**
* Create a point which encodes with point compression.
*
* @param curve the curve to use
* @param x affine x co-ordinate
* @param y affine y co-ordinate
*/
public FpPoint(
ECCurve curve,
ECFieldElement x,
ECFieldElement y)
: this(curve, x, y, false)
{
}
protected internal ECPointBase(
ECCurve curve,
ECFieldElement x,
ECFieldElement y,
bool withCompression)
: base(curve, x, y, withCompression)
{
}