public override ECPoint Twice() { if (base.IsInfinity) { return(this); } ECCurve curve = this.Curve; SecP256R1FieldElement rawYCoord = (SecP256R1FieldElement)base.RawYCoord; if (rawYCoord.IsZero) { return(curve.Infinity); } SecP256R1FieldElement rawXCoord = (SecP256R1FieldElement)base.RawXCoord; SecP256R1FieldElement element3 = (SecP256R1FieldElement)base.RawZCoords[0]; uint[] z = Nat256.Create(); uint[] numArray2 = Nat256.Create(); uint[] numArray3 = Nat256.Create(); SecP256R1Field.Square(rawYCoord.x, numArray3); uint[] numArray4 = Nat256.Create(); SecP256R1Field.Square(numArray3, numArray4); bool isOne = element3.IsOne; uint[] x = element3.x; if (!isOne) { x = numArray2; SecP256R1Field.Square(element3.x, x); } SecP256R1Field.Subtract(rawXCoord.x, x, z); uint[] numArray6 = numArray2; SecP256R1Field.Add(rawXCoord.x, x, numArray6); SecP256R1Field.Multiply(numArray6, z, numArray6); SecP256R1Field.Reduce32(Nat256.AddBothTo(numArray6, numArray6, numArray6), numArray6); uint[] numArray7 = numArray3; SecP256R1Field.Multiply(numArray3, rawXCoord.x, numArray7); SecP256R1Field.Reduce32(Nat.ShiftUpBits(8, numArray7, 2, 0), numArray7); SecP256R1Field.Reduce32(Nat.ShiftUpBits(8, numArray4, 3, 0, z), z); SecP256R1FieldElement element4 = new SecP256R1FieldElement(numArray4); SecP256R1Field.Square(numArray6, element4.x); SecP256R1Field.Subtract(element4.x, numArray7, element4.x); SecP256R1Field.Subtract(element4.x, numArray7, element4.x); SecP256R1FieldElement y = new SecP256R1FieldElement(numArray7); SecP256R1Field.Subtract(numArray7, element4.x, y.x); SecP256R1Field.Multiply(y.x, numArray6, y.x); SecP256R1Field.Subtract(y.x, z, y.x); SecP256R1FieldElement element6 = new SecP256R1FieldElement(numArray6); SecP256R1Field.Twice(rawYCoord.x, element6.x); if (!isOne) { SecP256R1Field.Multiply(element6.x, element3.x, element6.x); } return(new SecP256R1Point(curve, element4, y, new ECFieldElement[] { element6 }, base.IsCompressed)); }
public override ECFieldElement Add(ECFieldElement b) { uint[] z = Nat256.Create(); SecP256R1Field.Add(x, ((SecP256R1FieldElement)b).x, z); return(new SecP256R1FieldElement(z)); }
public override ECPoint Twice() { if (this.IsInfinity) { return(this); } ECCurve curve = this.Curve; SecP256R1FieldElement Y1 = (SecP256R1FieldElement)this.RawYCoord; if (Y1.IsZero) { return(curve.Infinity); } SecP256R1FieldElement X1 = (SecP256R1FieldElement)this.RawXCoord, Z1 = (SecP256R1FieldElement)this.RawZCoords[0]; uint c; uint[] t1 = Nat256.Create(); uint[] t2 = Nat256.Create(); uint[] Y1Squared = Nat256.Create(); SecP256R1Field.Square(Y1.x, Y1Squared); uint[] T = Nat256.Create(); SecP256R1Field.Square(Y1Squared, T); bool Z1IsOne = Z1.IsOne; uint[] Z1Squared = Z1.x; if (!Z1IsOne) { Z1Squared = t2; SecP256R1Field.Square(Z1.x, Z1Squared); } SecP256R1Field.Subtract(X1.x, Z1Squared, t1); uint[] M = t2; SecP256R1Field.Add(X1.x, Z1Squared, M); SecP256R1Field.Multiply(M, t1, M); c = Nat256.AddBothTo(M, M, M); SecP256R1Field.Reduce32(c, M); uint[] S = Y1Squared; SecP256R1Field.Multiply(Y1Squared, X1.x, S); c = Nat.ShiftUpBits(8, S, 2, 0); SecP256R1Field.Reduce32(c, S); c = Nat.ShiftUpBits(8, T, 3, 0, t1); SecP256R1Field.Reduce32(c, t1); SecP256R1FieldElement X3 = new SecP256R1FieldElement(T); SecP256R1Field.Square(M, X3.x); SecP256R1Field.Subtract(X3.x, S, X3.x); SecP256R1Field.Subtract(X3.x, S, X3.x); SecP256R1FieldElement Y3 = new SecP256R1FieldElement(S); SecP256R1Field.Subtract(S, X3.x, Y3.x); SecP256R1Field.Multiply(Y3.x, M, Y3.x); SecP256R1Field.Subtract(Y3.x, t1, Y3.x); SecP256R1FieldElement Z3 = new SecP256R1FieldElement(M); SecP256R1Field.Twice(Y1.x, Z3.x); if (!Z1IsOne) { SecP256R1Field.Multiply(Z3.x, Z1.x, Z3.x); } return(new SecP256R1Point(curve, X3, Y3, new ECFieldElement[] { Z3 }, IsCompressed)); }
public override ECPoint Twice() { if (base.IsInfinity) { return(this); } ECCurve curve = Curve; SecP256R1FieldElement secP256R1FieldElement = (SecP256R1FieldElement)base.RawYCoord; if (secP256R1FieldElement.IsZero) { return(curve.Infinity); } SecP256R1FieldElement secP256R1FieldElement2 = (SecP256R1FieldElement)base.RawXCoord; SecP256R1FieldElement secP256R1FieldElement3 = (SecP256R1FieldElement)base.RawZCoords[0]; uint[] array = Nat256.Create(); uint[] array2 = Nat256.Create(); uint[] array3 = Nat256.Create(); SecP256R1Field.Square(secP256R1FieldElement.x, array3); uint[] array4 = Nat256.Create(); SecP256R1Field.Square(array3, array4); bool isOne = secP256R1FieldElement3.IsOne; uint[] array5 = secP256R1FieldElement3.x; if (!isOne) { array5 = array2; SecP256R1Field.Square(secP256R1FieldElement3.x, array5); } SecP256R1Field.Subtract(secP256R1FieldElement2.x, array5, array); uint[] array6 = array2; SecP256R1Field.Add(secP256R1FieldElement2.x, array5, array6); SecP256R1Field.Multiply(array6, array, array6); uint x = Nat256.AddBothTo(array6, array6, array6); SecP256R1Field.Reduce32(x, array6); uint[] array7 = array3; SecP256R1Field.Multiply(array3, secP256R1FieldElement2.x, array7); x = Nat.ShiftUpBits(8, array7, 2, 0u); SecP256R1Field.Reduce32(x, array7); x = Nat.ShiftUpBits(8, array4, 3, 0u, array); SecP256R1Field.Reduce32(x, array); SecP256R1FieldElement secP256R1FieldElement4 = new SecP256R1FieldElement(array4); SecP256R1Field.Square(array6, secP256R1FieldElement4.x); SecP256R1Field.Subtract(secP256R1FieldElement4.x, array7, secP256R1FieldElement4.x); SecP256R1Field.Subtract(secP256R1FieldElement4.x, array7, secP256R1FieldElement4.x); SecP256R1FieldElement secP256R1FieldElement5 = new SecP256R1FieldElement(array7); SecP256R1Field.Subtract(array7, secP256R1FieldElement4.x, secP256R1FieldElement5.x); SecP256R1Field.Multiply(secP256R1FieldElement5.x, array6, secP256R1FieldElement5.x); SecP256R1Field.Subtract(secP256R1FieldElement5.x, array, secP256R1FieldElement5.x); SecP256R1FieldElement secP256R1FieldElement6 = new SecP256R1FieldElement(array6); SecP256R1Field.Twice(secP256R1FieldElement.x, secP256R1FieldElement6.x); if (!isOne) { SecP256R1Field.Multiply(secP256R1FieldElement6.x, secP256R1FieldElement3.x, secP256R1FieldElement6.x); } return(new SecP256R1Point(curve, secP256R1FieldElement4, secP256R1FieldElement5, new ECFieldElement[1] { secP256R1FieldElement6 }, 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; SecP256R1FieldElement X1 = (SecP256R1FieldElement)this.RawXCoord, Y1 = (SecP256R1FieldElement)this.RawYCoord; SecP256R1FieldElement X2 = (SecP256R1FieldElement)b.RawXCoord, Y2 = (SecP256R1FieldElement)b.RawYCoord; SecP256R1FieldElement Z1 = (SecP256R1FieldElement)this.RawZCoords[0]; SecP256R1FieldElement Z2 = (SecP256R1FieldElement)b.RawZCoords[0]; uint[] tt1 = Nat256.CreateExt(); uint[] tt2 = Nat256.CreateExt(); 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; SecP256R1Field.Square(Z1.x, S2); U2 = tt2; SecP256R1Field.Multiply(S2, X2.x, U2); SecP256R1Field.Multiply(S2, Z1.x, S2); SecP256R1Field.Multiply(S2, Y2.x, S2); } bool Z2IsOne = Z2.IsOne; uint[] U1, S1; if (Z2IsOne) { U1 = X1.x; S1 = Y1.x; } else { S1 = t4; SecP256R1Field.Square(Z2.x, S1); U1 = tt1; SecP256R1Field.Multiply(S1, X1.x, U1); SecP256R1Field.Multiply(S1, Z2.x, S1); SecP256R1Field.Multiply(S1, Y1.x, S1); } uint[] H = Nat256.Create(); SecP256R1Field.Subtract(U1, U2, H); uint[] R = tt2; SecP256R1Field.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; SecP256R1Field.Square(H, HSquared); uint[] G = Nat256.Create(); SecP256R1Field.Multiply(HSquared, H, G); uint[] V = t3; SecP256R1Field.Multiply(HSquared, U1, V); Nat256.Mul(S1, G, tt1); SecP256R1FieldElement X3 = new SecP256R1FieldElement(t4); SecP256R1Field.Square(R, X3.x); SecP256R1Field.Add(X3.x, G, X3.x); SecP256R1Field.Subtract(X3.x, V, X3.x); SecP256R1Field.Subtract(X3.x, V, X3.x); SecP256R1FieldElement Y3 = new SecP256R1FieldElement(G); SecP256R1Field.Subtract(V, X3.x, Y3.x); Nat256.Mul(Y3.x, R, tt2); SecP256R1Field.SubtractExt(tt2, tt1, tt2); SecP256R1Field.Reduce(tt2, Y3.x); SecP256R1FieldElement Z3 = new SecP256R1FieldElement(H); if (!Z1IsOne) { SecP256R1Field.Multiply(Z3.x, Z1.x, Z3.x); } if (!Z2IsOne) { SecP256R1Field.Multiply(Z3.x, Z2.x, Z3.x); } ECFieldElement[] zs = new ECFieldElement[] { Z3 }; return(new SecP256R1Point(curve, X3, Y3, zs, IsCompressed)); }