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 ECFieldElement Sqrt() { uint[] y = x; if (Nat256.IsZero(y) || Nat256.IsOne(y)) { return(this); } uint[] array = Nat256.Create(); Curve25519Field.Square(y, array); Curve25519Field.Multiply(array, y, array); uint[] array2 = array; Curve25519Field.Square(array, array2); Curve25519Field.Multiply(array2, y, array2); uint[] array3 = Nat256.Create(); Curve25519Field.Square(array2, array3); Curve25519Field.Multiply(array3, y, array3); uint[] array4 = Nat256.Create(); Curve25519Field.SquareN(array3, 3, array4); Curve25519Field.Multiply(array4, array2, array4); uint[] array5 = array2; Curve25519Field.SquareN(array4, 4, array5); Curve25519Field.Multiply(array5, array3, array5); uint[] array6 = array4; Curve25519Field.SquareN(array5, 4, array6); Curve25519Field.Multiply(array6, array3, array6); uint[] array7 = array3; Curve25519Field.SquareN(array6, 15, array7); Curve25519Field.Multiply(array7, array6, array7); uint[] array8 = array6; Curve25519Field.SquareN(array7, 30, array8); Curve25519Field.Multiply(array8, array7, array8); uint[] array9 = array7; Curve25519Field.SquareN(array8, 60, array9); Curve25519Field.Multiply(array9, array8, array9); uint[] z = array8; Curve25519Field.SquareN(array9, 11, z); Curve25519Field.Multiply(z, array5, z); uint[] array10 = array5; Curve25519Field.SquareN(z, 120, array10); Curve25519Field.Multiply(array10, array9, array10); uint[] z2 = array10; Curve25519Field.Square(z2, z2); uint[] array11 = array9; Curve25519Field.Square(z2, array11); if (Nat256.Eq(y, array11)) { return(new Curve25519FieldElement(z2)); } Curve25519Field.Multiply(z2, PRECOMP_POW2, z2); Curve25519Field.Square(z2, array11); if (Nat256.Eq(y, array11)) { return(new Curve25519FieldElement(z2)); } return(null); }
public override ECFieldElement Sqrt() { uint[] x = this.x; if (Nat256.IsZero(x) || Nat256.IsOne(x)) { return(this); } uint[] z = Nat256.Create(); Curve25519Field.Square(x, z); Curve25519Field.Multiply(z, x, z); uint[] numArray3 = z; Curve25519Field.Square(z, numArray3); Curve25519Field.Multiply(numArray3, x, numArray3); uint[] numArray4 = Nat256.Create(); Curve25519Field.Square(numArray3, numArray4); Curve25519Field.Multiply(numArray4, x, numArray4); uint[] numArray5 = Nat256.Create(); Curve25519Field.SquareN(numArray4, 3, numArray5); Curve25519Field.Multiply(numArray5, numArray3, numArray5); uint[] numArray6 = numArray3; Curve25519Field.SquareN(numArray5, 4, numArray6); Curve25519Field.Multiply(numArray6, numArray4, numArray6); uint[] numArray7 = numArray5; Curve25519Field.SquareN(numArray6, 4, numArray7); Curve25519Field.Multiply(numArray7, numArray4, numArray7); uint[] numArray8 = numArray4; Curve25519Field.SquareN(numArray7, 15, numArray8); Curve25519Field.Multiply(numArray8, numArray7, numArray8); uint[] numArray9 = numArray7; Curve25519Field.SquareN(numArray8, 30, numArray9); Curve25519Field.Multiply(numArray9, numArray8, numArray9); uint[] numArray10 = numArray8; Curve25519Field.SquareN(numArray9, 60, numArray10); Curve25519Field.Multiply(numArray10, numArray9, numArray10); uint[] numArray11 = numArray9; Curve25519Field.SquareN(numArray10, 11, numArray11); Curve25519Field.Multiply(numArray11, numArray6, numArray11); uint[] numArray12 = numArray6; Curve25519Field.SquareN(numArray11, 120, numArray12); Curve25519Field.Multiply(numArray12, numArray10, numArray12); uint[] numArray13 = numArray12; Curve25519Field.Square(numArray13, numArray13); uint[] numArray14 = numArray10; Curve25519Field.Square(numArray13, numArray14); if (Nat256.Eq(x, numArray14)) { return(new Curve25519FieldElement(numArray13)); } Curve25519Field.Multiply(numArray13, PRECOMP_POW2, numArray13); Curve25519Field.Square(numArray13, numArray14); if (Nat256.Eq(x, numArray14)) { return(new Curve25519FieldElement(numArray13)); } return(null); }
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)); }
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)); }
protected virtual Curve25519FieldElement CalculateJacobianModifiedW(Curve25519FieldElement Z, uint[] ZSquared) { Curve25519FieldElement curve25519FieldElement = (Curve25519FieldElement)Curve.A; if (Z.IsOne) { return(curve25519FieldElement); } Curve25519FieldElement curve25519FieldElement2 = new Curve25519FieldElement(); if (ZSquared == null) { ZSquared = curve25519FieldElement2.x; Curve25519Field.Square(Z.x, ZSquared); } Curve25519Field.Square(ZSquared, curve25519FieldElement2.x); Curve25519Field.Multiply(curve25519FieldElement2.x, curve25519FieldElement.x, curve25519FieldElement2.x); return(curve25519FieldElement2); }
protected virtual Curve25519FieldElement CalculateJacobianModifiedW(Curve25519FieldElement Z, uint[] ZSquared) { Curve25519FieldElement a = (Curve25519FieldElement)this.Curve.A; if (Z.IsOne) { return(a); } Curve25519FieldElement element2 = new Curve25519FieldElement(); if (ZSquared == null) { ZSquared = element2.x; Curve25519Field.Square(Z.x, ZSquared); } Curve25519Field.Square(ZSquared, element2.x); Curve25519Field.Multiply(element2.x, a.x, element2.x); return(element2); }
protected virtual Curve25519FieldElement CalculateJacobianModifiedW(Curve25519FieldElement Z, uint[] ZSquared) { Curve25519FieldElement a4 = (Curve25519FieldElement)this.Curve.A; if (Z.IsOne) { return(a4); } Curve25519FieldElement W = new Curve25519FieldElement(); if (ZSquared == null) { ZSquared = W.x; Curve25519Field.Square(Z.x, ZSquared); } Curve25519Field.Square(ZSquared, W.x); Curve25519Field.Multiply(W.x, a4.x, W.x); return(W); }
/** * return a sqrt root - the routine verifies that the calculation returns the right value - if * none exists it returns null. */ public override ECFieldElement Sqrt() { /* * Q == 8m + 5, so we use Pocklington's method for this case. * * First, raise this element to the exponent 2^252 - 2^1 (i.e. m + 1) * * Breaking up the exponent's binary representation into "repunits", we get: * { 251 1s } { 1 0s } * * Therefore we need an addition chain containing 251 (the lengths of the repunits) * We use: 1, 2, 3, 4, 7, 11, 15, 30, 60, 120, 131, [251] */ uint[] x1 = this.x; if (Nat256.IsZero(x1) || Nat256.IsOne(x1)) { return(this); } uint[] x2 = Nat256.Create(); Curve25519Field.Square(x1, x2); Curve25519Field.Multiply(x2, x1, x2); uint[] x3 = x2; Curve25519Field.Square(x2, x3); Curve25519Field.Multiply(x3, x1, x3); uint[] x4 = Nat256.Create(); Curve25519Field.Square(x3, x4); Curve25519Field.Multiply(x4, x1, x4); uint[] x7 = Nat256.Create(); Curve25519Field.SquareN(x4, 3, x7); Curve25519Field.Multiply(x7, x3, x7); uint[] x11 = x3; Curve25519Field.SquareN(x7, 4, x11); Curve25519Field.Multiply(x11, x4, x11); uint[] x15 = x7; Curve25519Field.SquareN(x11, 4, x15); Curve25519Field.Multiply(x15, x4, x15); uint[] x30 = x4; Curve25519Field.SquareN(x15, 15, x30); Curve25519Field.Multiply(x30, x15, x30); uint[] x60 = x15; Curve25519Field.SquareN(x30, 30, x60); Curve25519Field.Multiply(x60, x30, x60); uint[] x120 = x30; Curve25519Field.SquareN(x60, 60, x120); Curve25519Field.Multiply(x120, x60, x120); uint[] x131 = x60; Curve25519Field.SquareN(x120, 11, x131); Curve25519Field.Multiply(x131, x11, x131); uint[] x251 = x11; Curve25519Field.SquareN(x131, 120, x251); Curve25519Field.Multiply(x251, x120, x251); uint[] t1 = x251; Curve25519Field.Square(t1, t1); uint[] t2 = x120; Curve25519Field.Square(t1, t2); if (Nat256.Eq(x1, t2)) { return(new Curve25519FieldElement(t1)); } /* * If the first guess is incorrect, we multiply by a precomputed power of 2 to get the second guess, * which is ((4x)^(m + 1))/2 mod Q */ Curve25519Field.Multiply(t1, PRECOMP_POW2, t1); Curve25519Field.Square(t1, t2); if (Nat256.Eq(x1, t2)) { return(new Curve25519FieldElement(t1)); } return(null); }
public override ECFieldElement Square() { uint[] z = Nat256.Create(); Curve25519Field.Square(x, z); return(new Curve25519FieldElement(z)); }
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)); }
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)); }
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)); }