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)); }
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)); }
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)); }
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)); }
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 (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)); }
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)); }