Merge pull request #1 from bcgit/master

Update from original

1 files changed, 296 insertions, 0 deletions

diff --git a/crypto/src/math/ec/custom/sec/SecT283K1Point.cs b/crypto/src/math/ec/custom/sec/SecT283K1Point.cs
new file mode 100644
index 000000000..f85706c63
--- /dev/null
+++ b/crypto/src/math/ec/custom/sec/SecT283K1Point.cs
@@ -0,0 +1,296 @@
+using System;
+
+namespace Org.BouncyCastle.Math.EC.Custom.Sec
+{
+    internal class SecT283K1Point
+        : AbstractF2mPoint
+    {
+        /**
+         * @deprecated Use ECCurve.createPoint to construct points
+         */
+        public SecT283K1Point(ECCurve curve, ECFieldElement x, ECFieldElement y)
+            : this(curve, x, y, false)
+        {
+        }
+
+        /**
+         * @deprecated per-point compression property will be removed, refer {@link #getEncoded(bool)}
+         */
+        public SecT283K1Point(ECCurve curve, ECFieldElement x, ECFieldElement y, bool withCompression)
+            : base(curve, x, y, withCompression)
+        {
+            if ((x == null) != (y == null))
+                throw new ArgumentException("Exactly one of the field elements is null");
+        }
+
+        internal SecT283K1Point(ECCurve curve, ECFieldElement x, ECFieldElement y, ECFieldElement[] zs, bool withCompression)
+            : base(curve, x, y, zs, withCompression)
+        {
+        }
+
+        protected override ECPoint Detach()
+        {
+            return new SecT283K1Point(null, this.AffineXCoord, this.AffineYCoord); // earlier JDK
+        }
+
+        public override ECFieldElement YCoord
+        {
+            get
+            {
+                ECFieldElement X = RawXCoord, L = RawYCoord;
+
+                if (this.IsInfinity || X.IsZero)
+                    return L;
+
+                // Y is actually Lambda (X + Y/X) here; convert to affine value on the fly
+                ECFieldElement Y = L.Add(X).Multiply(X);
+
+                ECFieldElement Z = RawZCoords[0];
+                if (!Z.IsOne)
+                {
+                    Y = Y.Divide(Z);
+                }
+
+                return Y;
+            }
+        }
+
+        protected internal override bool CompressionYTilde
+        {
+            get
+            {
+                ECFieldElement X = this.RawXCoord;
+                if (X.IsZero)
+                    return false;
+
+                ECFieldElement Y = this.RawYCoord;
+
+                // Y is actually Lambda (X + Y/X) here
+                return Y.TestBitZero() != X.TestBitZero();
+            }
+        }
+
+        public override ECPoint Add(ECPoint b)
+        {
+            if (this.IsInfinity)
+                return b;
+            if (b.IsInfinity)
+                return this;
+
+            ECCurve curve = this.Curve;
+
+            ECFieldElement X1 = this.RawXCoord;
+            ECFieldElement X2 = b.RawXCoord;
+
+            if (X1.IsZero)
+            {
+                if (X2.IsZero)
+                    return curve.Infinity;
+
+                return b.Add(this);
+            }
+
+            ECFieldElement L1 = this.RawYCoord, Z1 = this.RawZCoords[0];
+            ECFieldElement L2 = b.RawYCoord, Z2 = b.RawZCoords[0];
+
+            bool Z1IsOne = Z1.IsOne;
+            ECFieldElement U2 = X2, S2 = L2;
+            if (!Z1IsOne)
+            {
+                U2 = U2.Multiply(Z1);
+                S2 = S2.Multiply(Z1);
+            }
+
+            bool Z2IsOne = Z2.IsOne;
+            ECFieldElement U1 = X1, S1 = L1;
+            if (!Z2IsOne)
+            {
+                U1 = U1.Multiply(Z2);
+                S1 = S1.Multiply(Z2);
+            }
+
+            ECFieldElement A = S1.Add(S2);
+            ECFieldElement B = U1.Add(U2);
+
+            if (B.IsZero)
+            {
+                if (A.IsZero)
+                    return Twice();
+
+                return curve.Infinity;
+            }
+
+            ECFieldElement X3, L3, Z3;
+            if (X2.IsZero)
+            {
+                // TODO This can probably be optimized quite a bit
+                ECPoint p = this.Normalize();
+                X1 = p.XCoord;
+                ECFieldElement Y1 = p.YCoord;
+
+                ECFieldElement Y2 = L2;
+                ECFieldElement L = Y1.Add(Y2).Divide(X1);
+
+                //X3 = L.Square().Add(L).Add(X1).Add(curve.A);
+                X3 = L.Square().Add(L).Add(X1);
+                if (X3.IsZero)
+                {
+                    //return new SecT283K1Point(curve, X3, curve.B.sqrt(), IsCompressed);
+                    return new SecT283K1Point(curve, X3, curve.B, IsCompressed);
+                }
+
+                ECFieldElement Y3 = L.Multiply(X1.Add(X3)).Add(X3).Add(Y1);
+                L3 = Y3.Divide(X3).Add(X3);
+                Z3 = curve.FromBigInteger(BigInteger.One);
+            }
+            else
+            {
+                B = B.Square();
+
+                ECFieldElement AU1 = A.Multiply(U1);
+                ECFieldElement AU2 = A.Multiply(U2);
+
+                X3 = AU1.Multiply(AU2);
+                if (X3.IsZero)
+                {
+                    //return new SecT283K1Point(curve, X3, curve.B.sqrt(), IsCompressed);
+                    return new SecT283K1Point(curve, X3, curve.B, IsCompressed);
+                }
+
+                ECFieldElement ABZ2 = A.Multiply(B);
+                if (!Z2IsOne)
+                {
+                    ABZ2 = ABZ2.Multiply(Z2);
+                }
+
+                L3 = AU2.Add(B).SquarePlusProduct(ABZ2, L1.Add(Z1));
+
+                Z3 = ABZ2;
+                if (!Z1IsOne)
+                {
+                    Z3 = Z3.Multiply(Z1);
+                }
+            }
+
+            return new SecT283K1Point(curve, X3, L3, new ECFieldElement[] { Z3 }, IsCompressed);
+        }
+
+        public override ECPoint Twice()
+        {
+            if (this.IsInfinity)
+                return this;
+
+            ECCurve curve = this.Curve;
+
+            ECFieldElement X1 = this.RawXCoord;
+            if (X1.IsZero)
+            {
+                // A point with X == 0 is it's own Additive inverse
+                return curve.Infinity;
+            }
+
+            ECFieldElement L1 = this.RawYCoord, Z1 = this.RawZCoords[0];
+
+            bool Z1IsOne = Z1.IsOne;
+            ECFieldElement Z1Sq = Z1IsOne ? Z1 : Z1.Square();
+            ECFieldElement T;
+            if (Z1IsOne)
+            {
+                T = L1.Square().Add(L1);
+            }
+            else
+            {
+                T = L1.Add(Z1).Multiply(L1);
+            }
+
+            if (T.IsZero)
+            {
+                //return new SecT283K1Point(curve, T, curve.B.sqrt(), withCompression);
+                return new SecT283K1Point(curve, T, curve.B, IsCompressed);
+            }
+
+            ECFieldElement X3 = T.Square();
+            ECFieldElement Z3 = Z1IsOne ? T : T.Multiply(Z1Sq);
+
+            ECFieldElement t1 = L1.Add(X1).Square();
+            ECFieldElement t2 = Z1IsOne ? Z1 : Z1Sq.Square();
+            ECFieldElement L3 = t1.Add(T).Add(Z1Sq).Multiply(t1).Add(t2).Add(X3).Add(Z3);
+
+            return new SecT283K1Point(curve, X3, L3, new ECFieldElement[] { Z3 }, IsCompressed);
+        }
+
+        public override ECPoint TwicePlus(ECPoint b)
+        {
+            if (this.IsInfinity)
+                return b;
+            if (b.IsInfinity)
+                return Twice();
+
+            ECCurve curve = this.Curve;
+
+            ECFieldElement X1 = this.RawXCoord;
+            if (X1.IsZero)
+            {
+                // A point with X == 0 is it's own Additive inverse
+                return b;
+            }
+
+            // NOTE: TwicePlus() only optimized for lambda-affine argument
+            ECFieldElement X2 = b.RawXCoord, Z2 = b.RawZCoords[0];
+            if (X2.IsZero || !Z2.IsOne)
+            {
+                return Twice().Add(b);
+            }
+
+            ECFieldElement L1 = this.RawYCoord, Z1 = this.RawZCoords[0];
+            ECFieldElement L2 = b.RawYCoord;
+
+            ECFieldElement X1Sq = X1.Square();
+            ECFieldElement L1Sq = L1.Square();
+            ECFieldElement Z1Sq = Z1.Square();
+            ECFieldElement L1Z1 = L1.Multiply(Z1);
+
+            //ECFieldElement T = curve.A.Multiply(Z1Sq).Add(L1Sq).Add(L1Z1);
+            ECFieldElement T = L1Sq.Add(L1Z1);
+            ECFieldElement L2plus1 = L2.AddOne();
+            //ECFieldElement A = curve.A.Add(L2plus1).Multiply(Z1Sq).Add(L1Sq).MultiplyPlusProduct(T, X1Sq, Z1Sq);
+            ECFieldElement A = L2plus1.Multiply(Z1Sq).Add(L1Sq).MultiplyPlusProduct(T, X1Sq, Z1Sq);
+            ECFieldElement X2Z1Sq = X2.Multiply(Z1Sq);
+            ECFieldElement B = X2Z1Sq.Add(T).Square();
+
+            if (B.IsZero)
+            {
+                if (A.IsZero)
+                    return b.Twice();
+
+                return curve.Infinity;
+            }
+
+            if (A.IsZero)
+            {
+                //return new SecT283K1Point(curve, A, curve.B.sqrt(), withCompression);
+                return new SecT283K1Point(curve, A, curve.B, IsCompressed);
+            }
+
+            ECFieldElement X3 = A.Square().Multiply(X2Z1Sq);
+            ECFieldElement Z3 = A.Multiply(B).Multiply(Z1Sq);
+            ECFieldElement L3 = A.Add(B).Square().MultiplyPlusProduct(T, L2plus1, Z3);
+
+            return new SecT283K1Point(curve, X3, L3, new ECFieldElement[] { Z3 }, IsCompressed);
+        }
+
+        public override ECPoint Negate()
+        {
+            if (this.IsInfinity)
+                return this;
+
+            ECFieldElement X = this.RawXCoord;
+            if (X.IsZero)
+                return this;
+
+            // L is actually Lambda (X + Y/X) here
+            ECFieldElement L = this.RawYCoord, Z = this.RawZCoords[0];
+            return new SecT283K1Point(Curve, X, L.Add(Z), new ECFieldElement[] { Z }, IsCompressed);
+        }
+    }
+}