Ejemplo n.º 1
0
        protected virtual Curve25519Point TwiceJacobianModified(bool calculateW)
        {
            Curve25519FieldElement X1 = (Curve25519FieldElement)this.RawXCoord, Y1 = (Curve25519FieldElement)this.RawYCoord,
                                   Z1 = (Curve25519FieldElement)this.RawZCoords[0], W1 = GetJacobianModifiedW();

            uint c;

            uint[] M    = Nat256.Create();
            Curve25519Field.Square(X1.x, M);
            c  = Nat256.AddBothTo(M, M, M);
            c += Nat256.AddTo(W1.x, M);
            Curve25519Field.Reduce27(c, M);

            uint[] _2Y1 = Nat256.Create();
            Curve25519Field.Twice(Y1.x, _2Y1);

            uint[] _2Y1Squared = Nat256.Create();
            Curve25519Field.Multiply(_2Y1, Y1.x, _2Y1Squared);

            uint[] S    = Nat256.Create();
            Curve25519Field.Multiply(_2Y1Squared, X1.x, S);
            Curve25519Field.Twice(S, S);

            uint[] _8T = Nat256.Create();
            Curve25519Field.Square(_2Y1Squared, _8T);
            Curve25519Field.Twice(_8T, _8T);

            Curve25519FieldElement X3 = new Curve25519FieldElement(_2Y1Squared);

            Curve25519Field.Square(M, X3.x);
            Curve25519Field.Subtract(X3.x, S, X3.x);
            Curve25519Field.Subtract(X3.x, S, X3.x);

            Curve25519FieldElement Y3 = new Curve25519FieldElement(S);

            Curve25519Field.Subtract(S, X3.x, Y3.x);
            Curve25519Field.Multiply(Y3.x, M, Y3.x);
            Curve25519Field.Subtract(Y3.x, _8T, Y3.x);

            Curve25519FieldElement Z3 = new Curve25519FieldElement(_2Y1);

            if (!Nat256.IsOne(Z1.x))
            {
                Curve25519Field.Multiply(Z3.x, Z1.x, Z3.x);
            }

            Curve25519FieldElement W3 = null;

            if (calculateW)
            {
                W3 = new Curve25519FieldElement(_8T);
                Curve25519Field.Multiply(W3.x, W1.x, W3.x);
                Curve25519Field.Twice(W3.x, W3.x);
            }

            return(new Curve25519Point(this.Curve, X3, Y3, new ECFieldElement[] { Z3, W3 }, IsCompressed));
        }
    public override ECPoint Twice()
    {
        if (base.IsInfinity)
        {
            return(this);
        }
        ECCurve curve = Curve;
        SecP256K1FieldElement secP256K1FieldElement = (SecP256K1FieldElement)base.RawYCoord;

        if (secP256K1FieldElement.IsZero)
        {
            return(curve.Infinity);
        }
        SecP256K1FieldElement secP256K1FieldElement2 = (SecP256K1FieldElement)base.RawXCoord;
        SecP256K1FieldElement secP256K1FieldElement3 = (SecP256K1FieldElement)base.RawZCoords[0];

        uint[] array = Nat256.Create();
        SecP256K1Field.Square(secP256K1FieldElement.x, array);
        uint[] array2 = Nat256.Create();
        SecP256K1Field.Square(array, array2);
        uint[] array3 = Nat256.Create();
        SecP256K1Field.Square(secP256K1FieldElement2.x, array3);
        uint x = Nat256.AddBothTo(array3, array3, array3);

        SecP256K1Field.Reduce32(x, array3);
        uint[] array4 = array;
        SecP256K1Field.Multiply(array, secP256K1FieldElement2.x, array4);
        x = Nat.ShiftUpBits(8, array4, 2, 0u);
        SecP256K1Field.Reduce32(x, array4);
        uint[] array5 = Nat256.Create();
        x = Nat.ShiftUpBits(8, array2, 3, 0u, array5);
        SecP256K1Field.Reduce32(x, array5);
        SecP256K1FieldElement secP256K1FieldElement4 = new SecP256K1FieldElement(array2);

        SecP256K1Field.Square(array3, secP256K1FieldElement4.x);
        SecP256K1Field.Subtract(secP256K1FieldElement4.x, array4, secP256K1FieldElement4.x);
        SecP256K1Field.Subtract(secP256K1FieldElement4.x, array4, secP256K1FieldElement4.x);
        SecP256K1FieldElement secP256K1FieldElement5 = new SecP256K1FieldElement(array4);

        SecP256K1Field.Subtract(array4, secP256K1FieldElement4.x, secP256K1FieldElement5.x);
        SecP256K1Field.Multiply(secP256K1FieldElement5.x, array3, secP256K1FieldElement5.x);
        SecP256K1Field.Subtract(secP256K1FieldElement5.x, array5, secP256K1FieldElement5.x);
        SecP256K1FieldElement secP256K1FieldElement6 = new SecP256K1FieldElement(array3);

        SecP256K1Field.Twice(secP256K1FieldElement.x, secP256K1FieldElement6.x);
        if (!secP256K1FieldElement3.IsOne)
        {
            SecP256K1Field.Multiply(secP256K1FieldElement6.x, secP256K1FieldElement3.x, secP256K1FieldElement6.x);
        }
        return(new SecP256K1Point(curve, secP256K1FieldElement4, secP256K1FieldElement5, new ECFieldElement[1]
        {
            secP256K1FieldElement6
        }, base.IsCompressed));
    }
Ejemplo n.º 3
0
        protected virtual Curve25519Point TwiceJacobianModified(bool calculateW)
        {
            Curve25519FieldElement curve25519FieldElement  = (Curve25519FieldElement)base.RawXCoord;
            Curve25519FieldElement curve25519FieldElement2 = (Curve25519FieldElement)base.RawYCoord;
            Curve25519FieldElement curve25519FieldElement3 = (Curve25519FieldElement)base.RawZCoords[0];
            Curve25519FieldElement jacobianModifiedW       = GetJacobianModifiedW();

            uint[] array = Nat256.Create();
            Curve25519Field.Square(curve25519FieldElement.x, array);
            uint num = Nat256.AddBothTo(array, array, array);

            num += Nat256.AddTo(jacobianModifiedW.x, array);
            Curve25519Field.Reduce27(num, array);
            uint[] array2 = Nat256.Create();
            Curve25519Field.Twice(curve25519FieldElement2.x, array2);
            uint[] array3 = Nat256.Create();
            Curve25519Field.Multiply(array2, curve25519FieldElement2.x, array3);
            uint[] array4 = Nat256.Create();
            Curve25519Field.Multiply(array3, curve25519FieldElement.x, array4);
            Curve25519Field.Twice(array4, array4);
            uint[] array5 = Nat256.Create();
            Curve25519Field.Square(array3, array5);
            Curve25519Field.Twice(array5, array5);
            Curve25519FieldElement curve25519FieldElement4 = new Curve25519FieldElement(array3);

            Curve25519Field.Square(array, curve25519FieldElement4.x);
            Curve25519Field.Subtract(curve25519FieldElement4.x, array4, curve25519FieldElement4.x);
            Curve25519Field.Subtract(curve25519FieldElement4.x, array4, curve25519FieldElement4.x);
            Curve25519FieldElement curve25519FieldElement5 = new Curve25519FieldElement(array4);

            Curve25519Field.Subtract(array4, curve25519FieldElement4.x, curve25519FieldElement5.x);
            Curve25519Field.Multiply(curve25519FieldElement5.x, array, curve25519FieldElement5.x);
            Curve25519Field.Subtract(curve25519FieldElement5.x, array5, curve25519FieldElement5.x);
            Curve25519FieldElement curve25519FieldElement6 = new Curve25519FieldElement(array2);

            if (!Nat256.IsOne(curve25519FieldElement3.x))
            {
                Curve25519Field.Multiply(curve25519FieldElement6.x, curve25519FieldElement3.x, curve25519FieldElement6.x);
            }
            Curve25519FieldElement curve25519FieldElement7 = null;

            if (calculateW)
            {
                curve25519FieldElement7 = new Curve25519FieldElement(array5);
                Curve25519Field.Multiply(curve25519FieldElement7.x, jacobianModifiedW.x, curve25519FieldElement7.x);
                Curve25519Field.Twice(curve25519FieldElement7.x, curve25519FieldElement7.x);
            }
            return(new Curve25519Point(Curve, curve25519FieldElement4, curve25519FieldElement5, new ECFieldElement[2]
            {
                curve25519FieldElement6,
                curve25519FieldElement7
            }, base.IsCompressed));
        }
Ejemplo n.º 4
0
        protected virtual Curve25519Point TwiceJacobianModified(bool calculateW)
        {
            Curve25519FieldElement rawXCoord         = (Curve25519FieldElement)base.RawXCoord;
            Curve25519FieldElement rawYCoord         = (Curve25519FieldElement)base.RawYCoord;
            Curve25519FieldElement element3          = (Curve25519FieldElement)base.RawZCoords[0];
            Curve25519FieldElement jacobianModifiedW = this.GetJacobianModifiedW();

            uint[] z = Nat256.Create();
            Curve25519Field.Square(rawXCoord.x, z);
            uint x = Nat256.AddBothTo(z, z, z) + Nat256.AddTo(jacobianModifiedW.x, z);

            Curve25519Field.Reduce27(x, z);
            uint[] numArray2 = Nat256.Create();
            Curve25519Field.Twice(rawYCoord.x, numArray2);
            uint[] numArray3 = Nat256.Create();
            Curve25519Field.Multiply(numArray2, rawYCoord.x, numArray3);
            uint[] numArray4 = Nat256.Create();
            Curve25519Field.Multiply(numArray3, rawXCoord.x, numArray4);
            Curve25519Field.Twice(numArray4, numArray4);
            uint[] numArray5 = Nat256.Create();
            Curve25519Field.Square(numArray3, numArray5);
            Curve25519Field.Twice(numArray5, numArray5);
            Curve25519FieldElement element5 = new Curve25519FieldElement(numArray3);

            Curve25519Field.Square(z, element5.x);
            Curve25519Field.Subtract(element5.x, numArray4, element5.x);
            Curve25519Field.Subtract(element5.x, numArray4, element5.x);
            Curve25519FieldElement y = new Curve25519FieldElement(numArray4);

            Curve25519Field.Subtract(numArray4, element5.x, y.x);
            Curve25519Field.Multiply(y.x, z, y.x);
            Curve25519Field.Subtract(y.x, numArray5, y.x);
            Curve25519FieldElement element7 = new Curve25519FieldElement(numArray2);

            if (!Nat256.IsOne(element3.x))
            {
                Curve25519Field.Multiply(element7.x, element3.x, element7.x);
            }
            Curve25519FieldElement element8 = null;

            if (calculateW)
            {
                element8 = new Curve25519FieldElement(numArray5);
                Curve25519Field.Multiply(element8.x, jacobianModifiedW.x, element8.x);
                Curve25519Field.Twice(element8.x, element8.x);
            }
            return(new Curve25519Point(this.Curve, element5, y, new ECFieldElement[] { element7, element8 }, base.IsCompressed));
        }
Ejemplo n.º 5
0
        public override ECPoint Add(ECPoint b)
        {
            if (this.IsInfinity)
            {
                return(b);
            }
            if (b.IsInfinity)
            {
                return(this);
            }
            if (this == b)
            {
                return(Twice());
            }

            ECCurve curve = this.Curve;

            SecP256K1FieldElement X1 = (SecP256K1FieldElement)this.RawXCoord, Y1 = (SecP256K1FieldElement)this.RawYCoord;
            SecP256K1FieldElement X2 = (SecP256K1FieldElement)b.RawXCoord, Y2 = (SecP256K1FieldElement)b.RawYCoord;

            SecP256K1FieldElement Z1 = (SecP256K1FieldElement)this.RawZCoords[0];
            SecP256K1FieldElement Z2 = (SecP256K1FieldElement)b.RawZCoords[0];

            uint c;

            uint[] tt1 = Nat256.CreateExt();
            uint[] t2  = Nat256.Create();
            uint[] t3  = Nat256.Create();
            uint[] t4  = Nat256.Create();

            bool Z1IsOne = Z1.IsOne;

            uint[] U2, S2;
            if (Z1IsOne)
            {
                U2 = X2.x;
                S2 = Y2.x;
            }
            else
            {
                S2 = t3;
                SecP256K1Field.Square(Z1.x, S2);

                U2 = t2;
                SecP256K1Field.Multiply(S2, X2.x, U2);

                SecP256K1Field.Multiply(S2, Z1.x, S2);
                SecP256K1Field.Multiply(S2, Y2.x, S2);
            }

            bool Z2IsOne = Z2.IsOne;

            uint[] U1, S1;
            if (Z2IsOne)
            {
                U1 = X1.x;
                S1 = Y1.x;
            }
            else
            {
                S1 = t4;
                SecP256K1Field.Square(Z2.x, S1);

                U1 = tt1;
                SecP256K1Field.Multiply(S1, X1.x, U1);

                SecP256K1Field.Multiply(S1, Z2.x, S1);
                SecP256K1Field.Multiply(S1, Y1.x, S1);
            }

            uint[] H = Nat256.Create();
            SecP256K1Field.Subtract(U1, U2, H);

            uint[] R = t2;
            SecP256K1Field.Subtract(S1, S2, R);

            // Check if b == this or b == -this
            if (Nat256.IsZero(H))
            {
                if (Nat256.IsZero(R))
                {
                    // this == b, i.e. this must be doubled
                    return(this.Twice());
                }

                // this == -b, i.e. the result is the point at infinity
                return(curve.Infinity);
            }

            uint[] HSquared = t3;
            SecP256K1Field.Square(H, HSquared);

            uint[] G = Nat256.Create();
            SecP256K1Field.Multiply(HSquared, H, G);

            uint[] V = t3;
            SecP256K1Field.Multiply(HSquared, U1, V);

            SecP256K1Field.Negate(G, G);
            Nat256.Mul(S1, G, tt1);

            c = Nat256.AddBothTo(V, V, G);
            SecP256K1Field.Reduce32(c, G);

            SecP256K1FieldElement X3 = new SecP256K1FieldElement(t4);

            SecP256K1Field.Square(R, X3.x);
            SecP256K1Field.Subtract(X3.x, G, X3.x);

            SecP256K1FieldElement Y3 = new SecP256K1FieldElement(G);

            SecP256K1Field.Subtract(V, X3.x, Y3.x);
            SecP256K1Field.MultiplyAddToExt(Y3.x, R, tt1);
            SecP256K1Field.Reduce(tt1, Y3.x);

            SecP256K1FieldElement Z3 = new SecP256K1FieldElement(H);

            if (!Z1IsOne)
            {
                SecP256K1Field.Multiply(Z3.x, Z1.x, Z3.x);
            }
            if (!Z2IsOne)
            {
                SecP256K1Field.Multiply(Z3.x, Z2.x, Z3.x);
            }

            ECFieldElement[] zs = new ECFieldElement[] { Z3 };

            return(new SecP256K1Point(curve, X3, Y3, zs, IsCompressed));
        }
Ejemplo n.º 6
0
        public override ECPoint Twice()
        {
            if (this.IsInfinity)
            {
                return(this);
            }

            ECCurve curve = this.Curve;

            SecP256K1FieldElement Y1 = (SecP256K1FieldElement)this.RawYCoord;

            if (Y1.IsZero)
            {
                return(curve.Infinity);
            }

            SecP256K1FieldElement X1 = (SecP256K1FieldElement)this.RawXCoord, Z1 = (SecP256K1FieldElement)this.RawZCoords[0];

            uint c;

            uint[] Y1Squared = Nat256.Create();
            SecP256K1Field.Square(Y1.x, Y1Squared);

            uint[] T = Nat256.Create();
            SecP256K1Field.Square(Y1Squared, T);

            uint[] M = Nat256.Create();
            SecP256K1Field.Square(X1.x, M);
            c = Nat256.AddBothTo(M, M, M);
            SecP256K1Field.Reduce32(c, M);

            uint[] S = Y1Squared;
            SecP256K1Field.Multiply(Y1Squared, X1.x, S);
            c = Nat.ShiftUpBits(8, S, 2, 0);
            SecP256K1Field.Reduce32(c, S);

            uint[] t1 = Nat256.Create();
            c = Nat.ShiftUpBits(8, T, 3, 0, t1);
            SecP256K1Field.Reduce32(c, t1);

            SecP256K1FieldElement X3 = new SecP256K1FieldElement(T);

            SecP256K1Field.Square(M, X3.x);
            SecP256K1Field.Subtract(X3.x, S, X3.x);
            SecP256K1Field.Subtract(X3.x, S, X3.x);

            SecP256K1FieldElement Y3 = new SecP256K1FieldElement(S);

            SecP256K1Field.Subtract(S, X3.x, Y3.x);
            SecP256K1Field.Multiply(Y3.x, M, Y3.x);
            SecP256K1Field.Subtract(Y3.x, t1, Y3.x);

            SecP256K1FieldElement Z3 = new SecP256K1FieldElement(M);

            SecP256K1Field.Twice(Y1.x, Z3.x);
            if (!Z1.IsOne)
            {
                SecP256K1Field.Multiply(Z3.x, Z1.x, Z3.x);
            }

            return(new SecP256K1Point(curve, X3, Y3, new ECFieldElement[] { Z3 }, IsCompressed));
        }
Ejemplo n.º 7
0
        public override ECPoint Add(ECPoint b)
        {
            if (base.IsInfinity)
            {
                return(b);
            }
            if (b.IsInfinity)
            {
                return(this);
            }
            if (this == b)
            {
                return(Twice());
            }
            ECCurve curve = Curve;
            Curve25519FieldElement curve25519FieldElement  = (Curve25519FieldElement)base.RawXCoord;
            Curve25519FieldElement curve25519FieldElement2 = (Curve25519FieldElement)base.RawYCoord;
            Curve25519FieldElement curve25519FieldElement3 = (Curve25519FieldElement)base.RawZCoords[0];
            Curve25519FieldElement curve25519FieldElement4 = (Curve25519FieldElement)b.RawXCoord;
            Curve25519FieldElement curve25519FieldElement5 = (Curve25519FieldElement)b.RawYCoord;
            Curve25519FieldElement curve25519FieldElement6 = (Curve25519FieldElement)b.RawZCoords[0];

            uint[] array  = Nat256.CreateExt();
            uint[] array2 = Nat256.Create();
            uint[] array3 = Nat256.Create();
            uint[] array4 = Nat256.Create();
            bool   isOne  = curve25519FieldElement3.IsOne;

            uint[] array5;
            uint[] array6;
            if (isOne)
            {
                array5 = curve25519FieldElement4.x;
                array6 = curve25519FieldElement5.x;
            }
            else
            {
                array6 = array3;
                Curve25519Field.Square(curve25519FieldElement3.x, array6);
                array5 = array2;
                Curve25519Field.Multiply(array6, curve25519FieldElement4.x, array5);
                Curve25519Field.Multiply(array6, curve25519FieldElement3.x, array6);
                Curve25519Field.Multiply(array6, curve25519FieldElement5.x, array6);
            }
            bool isOne2 = curve25519FieldElement6.IsOne;

            uint[] array7;
            uint[] array8;
            if (isOne2)
            {
                array7 = curve25519FieldElement.x;
                array8 = curve25519FieldElement2.x;
            }
            else
            {
                array8 = array4;
                Curve25519Field.Square(curve25519FieldElement6.x, array8);
                array7 = array;
                Curve25519Field.Multiply(array8, curve25519FieldElement.x, array7);
                Curve25519Field.Multiply(array8, curve25519FieldElement6.x, array8);
                Curve25519Field.Multiply(array8, curve25519FieldElement2.x, array8);
            }
            uint[] array9 = Nat256.Create();
            Curve25519Field.Subtract(array7, array5, array9);
            uint[] array10 = array2;
            Curve25519Field.Subtract(array8, array6, array10);
            if (Nat256.IsZero(array9))
            {
                if (Nat256.IsZero(array10))
                {
                    return(Twice());
                }
                return(curve.Infinity);
            }
            uint[] array11 = Nat256.Create();
            Curve25519Field.Square(array9, array11);
            uint[] array12 = Nat256.Create();
            Curve25519Field.Multiply(array11, array9, array12);
            uint[] array13 = array3;
            Curve25519Field.Multiply(array11, array7, array13);
            Curve25519Field.Negate(array12, array12);
            Nat256.Mul(array8, array12, array);
            uint x = Nat256.AddBothTo(array13, array13, array12);

            Curve25519Field.Reduce27(x, array12);
            Curve25519FieldElement curve25519FieldElement7 = new Curve25519FieldElement(array4);

            Curve25519Field.Square(array10, curve25519FieldElement7.x);
            Curve25519Field.Subtract(curve25519FieldElement7.x, array12, curve25519FieldElement7.x);
            Curve25519FieldElement curve25519FieldElement8 = new Curve25519FieldElement(array12);

            Curve25519Field.Subtract(array13, curve25519FieldElement7.x, curve25519FieldElement8.x);
            Curve25519Field.MultiplyAddToExt(curve25519FieldElement8.x, array10, array);
            Curve25519Field.Reduce(array, curve25519FieldElement8.x);
            Curve25519FieldElement curve25519FieldElement9 = new Curve25519FieldElement(array9);

            if (!isOne)
            {
                Curve25519Field.Multiply(curve25519FieldElement9.x, curve25519FieldElement3.x, curve25519FieldElement9.x);
            }
            if (!isOne2)
            {
                Curve25519Field.Multiply(curve25519FieldElement9.x, curve25519FieldElement6.x, curve25519FieldElement9.x);
            }
            uint[] zSquared = (!isOne || !isOne2) ? null : array11;
            Curve25519FieldElement curve25519FieldElement10 = CalculateJacobianModifiedW(curve25519FieldElement9, zSquared);

            ECFieldElement[] zs = new ECFieldElement[2]
            {
                curve25519FieldElement9,
                curve25519FieldElement10
            };
            return(new Curve25519Point(curve, curve25519FieldElement7, curve25519FieldElement8, zs, base.IsCompressed));
        }
Ejemplo n.º 8
0
    public override ECPoint Add(ECPoint b)
    {
        if (base.IsInfinity)
        {
            return(b);
        }
        if (b.IsInfinity)
        {
            return(this);
        }
        if (this == b)
        {
            return(Twice());
        }
        ECCurve curve = Curve;
        SecP256R1FieldElement secP256R1FieldElement  = (SecP256R1FieldElement)base.RawXCoord;
        SecP256R1FieldElement secP256R1FieldElement2 = (SecP256R1FieldElement)base.RawYCoord;
        SecP256R1FieldElement secP256R1FieldElement3 = (SecP256R1FieldElement)b.RawXCoord;
        SecP256R1FieldElement secP256R1FieldElement4 = (SecP256R1FieldElement)b.RawYCoord;
        SecP256R1FieldElement secP256R1FieldElement5 = (SecP256R1FieldElement)base.RawZCoords[0];
        SecP256R1FieldElement secP256R1FieldElement6 = (SecP256R1FieldElement)b.RawZCoords[0];

        uint[] array  = Nat256.CreateExt();
        uint[] array2 = Nat256.Create();
        uint[] array3 = Nat256.Create();
        uint[] array4 = Nat256.Create();
        bool   isOne  = secP256R1FieldElement5.IsOne;

        uint[] array5;
        uint[] array6;
        if (isOne)
        {
            array5 = secP256R1FieldElement3.x;
            array6 = secP256R1FieldElement4.x;
        }
        else
        {
            array6 = array3;
            SecP256R1Field.Square(secP256R1FieldElement5.x, array6);
            array5 = array2;
            SecP256R1Field.Multiply(array6, secP256R1FieldElement3.x, array5);
            SecP256R1Field.Multiply(array6, secP256R1FieldElement5.x, array6);
            SecP256R1Field.Multiply(array6, secP256R1FieldElement4.x, array6);
        }
        bool isOne2 = secP256R1FieldElement6.IsOne;

        uint[] array7;
        uint[] array8;
        if (isOne2)
        {
            array7 = secP256R1FieldElement.x;
            array8 = secP256R1FieldElement2.x;
        }
        else
        {
            array8 = array4;
            SecP256R1Field.Square(secP256R1FieldElement6.x, array8);
            array7 = array;
            SecP256R1Field.Multiply(array8, secP256R1FieldElement.x, array7);
            SecP256R1Field.Multiply(array8, secP256R1FieldElement6.x, array8);
            SecP256R1Field.Multiply(array8, secP256R1FieldElement2.x, array8);
        }
        uint[] array9 = Nat256.Create();
        SecP256R1Field.Subtract(array7, array5, array9);
        uint[] array10 = array2;
        SecP256R1Field.Subtract(array8, array6, array10);
        if (Nat256.IsZero(array9))
        {
            if (Nat256.IsZero(array10))
            {
                return(Twice());
            }
            return(curve.Infinity);
        }
        uint[] array11 = array3;
        SecP256R1Field.Square(array9, array11);
        uint[] array12 = Nat256.Create();
        SecP256R1Field.Multiply(array11, array9, array12);
        uint[] array13 = array3;
        SecP256R1Field.Multiply(array11, array7, array13);
        SecP256R1Field.Negate(array12, array12);
        Nat256.Mul(array8, array12, array);
        uint x = Nat256.AddBothTo(array13, array13, array12);

        SecP256R1Field.Reduce32(x, array12);
        SecP256R1FieldElement secP256R1FieldElement7 = new SecP256R1FieldElement(array4);

        SecP256R1Field.Square(array10, secP256R1FieldElement7.x);
        SecP256R1Field.Subtract(secP256R1FieldElement7.x, array12, secP256R1FieldElement7.x);
        SecP256R1FieldElement secP256R1FieldElement8 = new SecP256R1FieldElement(array12);

        SecP256R1Field.Subtract(array13, secP256R1FieldElement7.x, secP256R1FieldElement8.x);
        SecP256R1Field.MultiplyAddToExt(secP256R1FieldElement8.x, array10, array);
        SecP256R1Field.Reduce(array, secP256R1FieldElement8.x);
        SecP256R1FieldElement secP256R1FieldElement9 = new SecP256R1FieldElement(array9);

        if (!isOne)
        {
            SecP256R1Field.Multiply(secP256R1FieldElement9.x, secP256R1FieldElement5.x, secP256R1FieldElement9.x);
        }
        if (!isOne2)
        {
            SecP256R1Field.Multiply(secP256R1FieldElement9.x, secP256R1FieldElement6.x, secP256R1FieldElement9.x);
        }
        ECFieldElement[] zs = new ECFieldElement[1]
        {
            secP256R1FieldElement9
        };
        return(new SecP256R1Point(curve, secP256R1FieldElement7, secP256R1FieldElement8, zs, base.IsCompressed));
    }
Ejemplo n.º 9
0
        public override ECPoint Add(ECPoint b)
        {
            if (this.IsInfinity)
            {
                return(b);
            }
            if (b.IsInfinity)
            {
                return(this);
            }
            if (this == b)
            {
                return(Twice());
            }

            ECCurve curve = this.Curve;

            Curve25519FieldElement X1 = (Curve25519FieldElement)this.RawXCoord, Y1 = (Curve25519FieldElement)this.RawYCoord,
                                   Z1 = (Curve25519FieldElement)this.RawZCoords[0];
            Curve25519FieldElement X2 = (Curve25519FieldElement)b.RawXCoord, Y2 = (Curve25519FieldElement)b.RawYCoord,
                                   Z2 = (Curve25519FieldElement)b.RawZCoords[0];

            uint c;

            uint[] tt1 = Nat256.CreateExt();
            uint[] t2  = Nat256.Create();
            uint[] t3  = Nat256.Create();
            uint[] t4  = Nat256.Create();

            bool Z1IsOne = Z1.IsOne;

            uint[] U2, S2;
            if (Z1IsOne)
            {
                U2 = X2.x;
                S2 = Y2.x;
            }
            else
            {
                S2 = t3;
                Curve25519Field.Square(Z1.x, S2);

                U2 = t2;
                Curve25519Field.Multiply(S2, X2.x, U2);

                Curve25519Field.Multiply(S2, Z1.x, S2);
                Curve25519Field.Multiply(S2, Y2.x, S2);
            }

            bool Z2IsOne = Z2.IsOne;

            uint[] U1, S1;
            if (Z2IsOne)
            {
                U1 = X1.x;
                S1 = Y1.x;
            }
            else
            {
                S1 = t4;
                Curve25519Field.Square(Z2.x, S1);

                U1 = tt1;
                Curve25519Field.Multiply(S1, X1.x, U1);

                Curve25519Field.Multiply(S1, Z2.x, S1);
                Curve25519Field.Multiply(S1, Y1.x, S1);
            }

            uint[] H = Nat256.Create();
            Curve25519Field.Subtract(U1, U2, H);

            uint[] R = t2;
            Curve25519Field.Subtract(S1, S2, R);

            // Check if b == this or b == -this
            if (Nat256.IsZero(H))
            {
                if (Nat256.IsZero(R))
                {
                    // this == b, i.e. this must be doubled
                    return(this.Twice());
                }

                // this == -b, i.e. the result is the point at infinity
                return(curve.Infinity);
            }

            uint[] HSquared = Nat256.Create();
            Curve25519Field.Square(H, HSquared);

            uint[] G = Nat256.Create();
            Curve25519Field.Multiply(HSquared, H, G);

            uint[] V = t3;
            Curve25519Field.Multiply(HSquared, U1, V);

            Curve25519Field.Negate(G, G);
            Nat256.Mul(S1, G, tt1);

            c = Nat256.AddBothTo(V, V, G);
            Curve25519Field.Reduce27(c, G);

            Curve25519FieldElement X3 = new Curve25519FieldElement(t4);

            Curve25519Field.Square(R, X3.x);
            Curve25519Field.Subtract(X3.x, G, X3.x);

            Curve25519FieldElement Y3 = new Curve25519FieldElement(G);

            Curve25519Field.Subtract(V, X3.x, Y3.x);
            Curve25519Field.MultiplyAddToExt(Y3.x, R, tt1);
            Curve25519Field.Reduce(tt1, Y3.x);

            Curve25519FieldElement Z3 = new Curve25519FieldElement(H);

            if (!Z1IsOne)
            {
                Curve25519Field.Multiply(Z3.x, Z1.x, Z3.x);
            }
            if (!Z2IsOne)
            {
                Curve25519Field.Multiply(Z3.x, Z2.x, Z3.x);
            }

            uint[] Z3Squared = (Z1IsOne && Z2IsOne) ? HSquared : null;

            // TODO If the result will only be used in a subsequent addition, we don't need W3
            Curve25519FieldElement W3 = CalculateJacobianModifiedW((Curve25519FieldElement)Z3, Z3Squared);

            ECFieldElement[] zs = new ECFieldElement[] { Z3, W3 };

            return(new Curve25519Point(curve, X3, Y3, zs, IsCompressed));
        }
Ejemplo n.º 10
0
        public override ECPoint Add(ECPoint b)
        {
            uint[] numArray5;
            uint[] numArray6;
            uint[] numArray7;
            uint[] numArray8;
            if (base.IsInfinity)
            {
                return(b);
            }
            if (b.IsInfinity)
            {
                return(this);
            }
            if (this == b)
            {
                return(this.Twice());
            }
            ECCurve curve = this.Curve;
            Curve25519FieldElement rawXCoord = (Curve25519FieldElement)base.RawXCoord;
            Curve25519FieldElement rawYCoord = (Curve25519FieldElement)base.RawYCoord;
            Curve25519FieldElement element3  = (Curve25519FieldElement)base.RawZCoords[0];
            Curve25519FieldElement element4  = (Curve25519FieldElement)b.RawXCoord;
            Curve25519FieldElement element5  = (Curve25519FieldElement)b.RawYCoord;
            Curve25519FieldElement element6  = (Curve25519FieldElement)b.RawZCoords[0];

            uint[] zz        = Nat256.CreateExt();
            uint[] numArray2 = Nat256.Create();
            uint[] numArray3 = Nat256.Create();
            uint[] x         = Nat256.Create();
            bool   isOne     = element3.IsOne;

            if (isOne)
            {
                numArray5 = element4.x;
                numArray6 = element5.x;
            }
            else
            {
                numArray6 = numArray3;
                Curve25519Field.Square(element3.x, numArray6);
                numArray5 = numArray2;
                Curve25519Field.Multiply(numArray6, element4.x, numArray5);
                Curve25519Field.Multiply(numArray6, element3.x, numArray6);
                Curve25519Field.Multiply(numArray6, element5.x, numArray6);
            }
            bool flag2 = element6.IsOne;

            if (flag2)
            {
                numArray7 = rawXCoord.x;
                numArray8 = rawYCoord.x;
            }
            else
            {
                numArray8 = x;
                Curve25519Field.Square(element6.x, numArray8);
                numArray7 = zz;
                Curve25519Field.Multiply(numArray8, rawXCoord.x, numArray7);
                Curve25519Field.Multiply(numArray8, element6.x, numArray8);
                Curve25519Field.Multiply(numArray8, rawYCoord.x, numArray8);
            }
            uint[] z = Nat256.Create();
            Curve25519Field.Subtract(numArray7, numArray5, z);
            uint[] numArray10 = numArray2;
            Curve25519Field.Subtract(numArray8, numArray6, numArray10);
            if (Nat256.IsZero(z))
            {
                if (Nat256.IsZero(numArray10))
                {
                    return(this.Twice());
                }
                return(curve.Infinity);
            }
            uint[] numArray11 = Nat256.Create();
            Curve25519Field.Square(z, numArray11);
            uint[] numArray12 = Nat256.Create();
            Curve25519Field.Multiply(numArray11, z, numArray12);
            uint[] numArray13 = numArray3;
            Curve25519Field.Multiply(numArray11, numArray7, numArray13);
            Curve25519Field.Negate(numArray12, numArray12);
            Nat256.Mul(numArray8, numArray12, zz);
            Curve25519Field.Reduce27(Nat256.AddBothTo(numArray13, numArray13, numArray12), numArray12);
            Curve25519FieldElement element7 = new Curve25519FieldElement(x);

            Curve25519Field.Square(numArray10, element7.x);
            Curve25519Field.Subtract(element7.x, numArray12, element7.x);
            Curve25519FieldElement y = new Curve25519FieldElement(numArray12);

            Curve25519Field.Subtract(numArray13, element7.x, y.x);
            Curve25519Field.MultiplyAddToExt(y.x, numArray10, zz);
            Curve25519Field.Reduce(zz, y.x);
            Curve25519FieldElement element9 = new Curve25519FieldElement(z);

            if (!isOne)
            {
                Curve25519Field.Multiply(element9.x, element3.x, element9.x);
            }
            if (!flag2)
            {
                Curve25519Field.Multiply(element9.x, element6.x, element9.x);
            }
            uint[] zSquared = (!isOne || !flag2) ? null : numArray11;
            Curve25519FieldElement element10 = this.CalculateJacobianModifiedW(element9, zSquared);

            ECFieldElement[] zs = new ECFieldElement[] { element9, element10 };
            return(new Curve25519Point(curve, element7, y, zs, base.IsCompressed));
        }