using System; namespace Renci.SshNet.Security.Org.BouncyCastle.Math.EC { internal abstract class AbstractF2mPoint : ECPointBase { protected AbstractF2mPoint(ECCurve curve, ECFieldElement x, ECFieldElement y, bool withCompression) : base(curve, x, y, withCompression) { } protected AbstractF2mPoint(ECCurve curve, ECFieldElement x, ECFieldElement y, ECFieldElement[] zs, bool withCompression) : base(curve, x, y, zs, withCompression) { } protected override bool SatisfiesCurveEquation() { ECCurve curve = Curve; ECFieldElement rawXCoord = base.RawXCoord; ECFieldElement rawYCoord = base.RawYCoord; ECFieldElement eCFieldElement = curve.A; ECFieldElement eCFieldElement2 = curve.B; int coordinateSystem = curve.CoordinateSystem; ECFieldElement eCFieldElement5; ECFieldElement eCFieldElement4; if (coordinateSystem == 6) { ECFieldElement eCFieldElement3 = base.RawZCoords[0]; bool isOne = eCFieldElement3.IsOne; if (rawXCoord.IsZero) { eCFieldElement4 = rawYCoord.Square(); eCFieldElement5 = eCFieldElement2; if (!isOne) { ECFieldElement b = eCFieldElement3.Square(); eCFieldElement5 = eCFieldElement5.Multiply(b); } } else { ECFieldElement eCFieldElement6 = rawYCoord; ECFieldElement eCFieldElement7 = rawXCoord.Square(); if (isOne) { eCFieldElement4 = eCFieldElement6.Square().Add(eCFieldElement6).Add(eCFieldElement); eCFieldElement5 = eCFieldElement7.Square().Add(eCFieldElement2); } else { ECFieldElement eCFieldElement8 = eCFieldElement3.Square(); ECFieldElement y = eCFieldElement8.Square(); eCFieldElement4 = eCFieldElement6.Add(eCFieldElement3).MultiplyPlusProduct(eCFieldElement6, eCFieldElement, eCFieldElement8); eCFieldElement5 = eCFieldElement7.SquarePlusProduct(eCFieldElement2, y); } eCFieldElement4 = eCFieldElement4.Multiply(eCFieldElement7); } } else { eCFieldElement4 = rawYCoord.Add(rawXCoord).Multiply(rawYCoord); switch (coordinateSystem) { case 1: { ECFieldElement eCFieldElement9 = base.RawZCoords[0]; if (!eCFieldElement9.IsOne) { ECFieldElement b2 = eCFieldElement9.Square(); ECFieldElement b3 = eCFieldElement9.Multiply(b2); eCFieldElement4 = eCFieldElement4.Multiply(eCFieldElement9); eCFieldElement = eCFieldElement.Multiply(eCFieldElement9); eCFieldElement2 = eCFieldElement2.Multiply(b3); } break; } default: throw new InvalidOperationException("unsupported coordinate system"); case 0: break; } eCFieldElement5 = rawXCoord.Add(eCFieldElement).Multiply(rawXCoord.Square()).Add(eCFieldElement2); } return eCFieldElement4.Equals(eCFieldElement5); } protected override bool SatisfiesOrder() { ECCurve curve = Curve; BigInteger cofactor = curve.Cofactor; if (BigInteger.Two.Equals(cofactor)) return ((AbstractF2mFieldElement)Normalize().AffineXCoord.Add(curve.A)).Trace() == 0; if (BigInteger.ValueOf(4).Equals(cofactor)) { ECPoint eCPoint = Normalize(); ECFieldElement affineXCoord = eCPoint.AffineXCoord; ECFieldElement eCFieldElement = ((AbstractF2mCurve)curve).SolveQuadraticEquation(affineXCoord.Add(curve.A)); if (eCFieldElement == null) return false; ECFieldElement eCFieldElement2 = affineXCoord.Multiply(eCFieldElement).Add(eCPoint.AffineYCoord).Add(curve.A); if (((AbstractF2mFieldElement)eCFieldElement2).Trace() != 0) return ((AbstractF2mFieldElement)eCFieldElement2.Add(affineXCoord)).Trace() == 0; return true; } return base.SatisfiesOrder(); } public override ECPoint ScaleX(ECFieldElement scale) { if (!base.IsInfinity) { switch (CurveCoordinateSystem) { case 5: { ECFieldElement rawXCoord2 = base.RawXCoord; ECFieldElement rawYCoord2 = base.RawYCoord; ECFieldElement b2 = rawXCoord2.Multiply(scale); ECFieldElement y2 = rawYCoord2.Add(rawXCoord2).Divide(scale).Add(b2); return Curve.CreateRawPoint(rawXCoord2, y2, base.RawZCoords, base.IsCompressed); } case 6: { ECFieldElement rawXCoord = base.RawXCoord; ECFieldElement rawYCoord = base.RawYCoord; ECFieldElement eCFieldElement = base.RawZCoords[0]; ECFieldElement b = rawXCoord.Multiply(scale.Square()); ECFieldElement y = rawYCoord.Add(rawXCoord).Add(b); ECFieldElement eCFieldElement2 = eCFieldElement.Multiply(scale); return Curve.CreateRawPoint(rawXCoord, y, new ECFieldElement[1] { eCFieldElement2 }, base.IsCompressed); } default: return base.ScaleX(scale); } } return this; } public override ECPoint ScaleY(ECFieldElement scale) { if (base.IsInfinity) return this; int curveCoordinateSystem = CurveCoordinateSystem; if ((uint)(curveCoordinateSystem - 5) <= 1) { ECFieldElement rawXCoord = base.RawXCoord; ECFieldElement y = base.RawYCoord.Add(rawXCoord).Multiply(scale).Add(rawXCoord); return Curve.CreateRawPoint(rawXCoord, y, base.RawZCoords, base.IsCompressed); } return base.ScaleY(scale); } public override ECPoint Subtract(ECPoint b) { if (b.IsInfinity) return this; return Add(b.Negate()); } public virtual AbstractF2mPoint Tau() { if (!base.IsInfinity) { ECCurve curve = Curve; int coordinateSystem = curve.CoordinateSystem; ECFieldElement rawXCoord = base.RawXCoord; switch (coordinateSystem) { case 0: case 5: { ECFieldElement rawYCoord2 = base.RawYCoord; return (AbstractF2mPoint)curve.CreateRawPoint(rawXCoord.Square(), rawYCoord2.Square(), base.IsCompressed); } case 1: case 6: { ECFieldElement rawYCoord = base.RawYCoord; ECFieldElement eCFieldElement = base.RawZCoords[0]; return (AbstractF2mPoint)curve.CreateRawPoint(rawXCoord.Square(), rawYCoord.Square(), new ECFieldElement[1] { eCFieldElement.Square() }, base.IsCompressed); } default: throw new InvalidOperationException("unsupported coordinate system"); } } return this; } public virtual AbstractF2mPoint TauPow(int pow) { if (!base.IsInfinity) { ECCurve curve = Curve; int coordinateSystem = curve.CoordinateSystem; ECFieldElement rawXCoord = base.RawXCoord; switch (coordinateSystem) { case 0: case 5: { ECFieldElement rawYCoord2 = base.RawYCoord; return (AbstractF2mPoint)curve.CreateRawPoint(rawXCoord.SquarePow(pow), rawYCoord2.SquarePow(pow), base.IsCompressed); } case 1: case 6: { ECFieldElement rawYCoord = base.RawYCoord; ECFieldElement eCFieldElement = base.RawZCoords[0]; return (AbstractF2mPoint)curve.CreateRawPoint(rawXCoord.SquarePow(pow), rawYCoord.SquarePow(pow), new ECFieldElement[1] { eCFieldElement.SquarePow(pow) }, base.IsCompressed); } default: throw new InvalidOperationException("unsupported coordinate system"); } } return this; } } }