public virtual bool Equals(SecP521R1FieldElement other)
{
if (this == other)
{
return(true);
}
if (null == other)
{
return(false);
}
return(Nat.Eq(17, x, other.x));
}
public virtual bool Equals(SecP521R1FieldElement other)
{
if (this == other)
{
return(true);
}
if (other == null)
{
return(false);
}
return(Nat.Eq(0x11, this.x, other.x));
}
public virtual bool Equals(SecP521R1FieldElement other)
{
if (this == other)
return true;
if (null == other)
return false;
return Nat.Eq(17, x, other.x);
}
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;
SecP521R1FieldElement rawXCoord = (SecP521R1FieldElement)base.RawXCoord;
SecP521R1FieldElement rawYCoord = (SecP521R1FieldElement)base.RawYCoord;
SecP521R1FieldElement element3 = (SecP521R1FieldElement)b.RawXCoord;
SecP521R1FieldElement element4 = (SecP521R1FieldElement)b.RawYCoord;
SecP521R1FieldElement element5 = (SecP521R1FieldElement)base.RawZCoords[0];
SecP521R1FieldElement element6 = (SecP521R1FieldElement)b.RawZCoords[0];
uint[] z = Nat.Create(0x11);
uint[] numArray2 = Nat.Create(0x11);
uint[] numArray3 = Nat.Create(0x11);
uint[] x = Nat.Create(0x11);
bool isOne = element5.IsOne;
if (isOne)
{
numArray5 = element3.x;
numArray6 = element4.x;
}
else
{
numArray6 = numArray3;
SecP521R1Field.Square(element5.x, numArray6);
numArray5 = numArray2;
SecP521R1Field.Multiply(numArray6, element3.x, numArray5);
SecP521R1Field.Multiply(numArray6, element5.x, numArray6);
SecP521R1Field.Multiply(numArray6, element4.x, numArray6);
}
bool flag2 = element6.IsOne;
if (flag2)
{
numArray7 = rawXCoord.x;
numArray8 = rawYCoord.x;
}
else
{
numArray8 = x;
SecP521R1Field.Square(element6.x, numArray8);
numArray7 = z;
SecP521R1Field.Multiply(numArray8, rawXCoord.x, numArray7);
SecP521R1Field.Multiply(numArray8, element6.x, numArray8);
SecP521R1Field.Multiply(numArray8, rawYCoord.x, numArray8);
}
uint[] numArray9 = Nat.Create(0x11);
SecP521R1Field.Subtract(numArray7, numArray5, numArray9);
uint[] numArray10 = numArray2;
SecP521R1Field.Subtract(numArray8, numArray6, numArray10);
if (Nat.IsZero(0x11, numArray9))
{
if (Nat.IsZero(0x11, numArray10))
{
return(this.Twice());
}
return(curve.Infinity);
}
uint[] numArray11 = numArray3;
SecP521R1Field.Square(numArray9, numArray11);
uint[] numArray12 = Nat.Create(0x11);
SecP521R1Field.Multiply(numArray11, numArray9, numArray12);
uint[] numArray13 = numArray3;
SecP521R1Field.Multiply(numArray11, numArray7, numArray13);
SecP521R1Field.Multiply(numArray8, numArray12, z);
SecP521R1FieldElement element7 = new SecP521R1FieldElement(x);
SecP521R1Field.Square(numArray10, element7.x);
SecP521R1Field.Add(element7.x, numArray12, element7.x);
SecP521R1Field.Subtract(element7.x, numArray13, element7.x);
SecP521R1Field.Subtract(element7.x, numArray13, element7.x);
SecP521R1FieldElement y = new SecP521R1FieldElement(numArray12);
SecP521R1Field.Subtract(numArray13, element7.x, y.x);
SecP521R1Field.Multiply(y.x, numArray10, numArray2);
SecP521R1Field.Subtract(numArray2, z, y.x);
SecP521R1FieldElement element9 = new SecP521R1FieldElement(numArray9);
if (!isOne)
{
SecP521R1Field.Multiply(element9.x, element5.x, element9.x);
}
if (!flag2)
{
SecP521R1Field.Multiply(element9.x, element6.x, element9.x);
}
ECFieldElement[] zs = new ECFieldElement[] { element9 };
return(new SecP521R1Point(curve, element7, y, zs, base.IsCompressed));
}
public override ECPoint Twice()
{
if (base.IsInfinity)
{
return(this);
}
ECCurve curve = this.Curve;
SecP521R1FieldElement rawYCoord = (SecP521R1FieldElement)base.RawYCoord;
if (rawYCoord.IsZero)
{
return(curve.Infinity);
}
SecP521R1FieldElement rawXCoord = (SecP521R1FieldElement)base.RawXCoord;
SecP521R1FieldElement element3 = (SecP521R1FieldElement)base.RawZCoords[0];
uint[] z = Nat.Create(0x11);
uint[] numArray2 = Nat.Create(0x11);
uint[] numArray3 = Nat.Create(0x11);
SecP521R1Field.Square(rawYCoord.x, numArray3);
uint[] numArray4 = Nat.Create(0x11);
SecP521R1Field.Square(numArray3, numArray4);
bool isOne = element3.IsOne;
uint[] x = element3.x;
if (!isOne)
{
x = numArray2;
SecP521R1Field.Square(element3.x, x);
}
SecP521R1Field.Subtract(rawXCoord.x, x, z);
uint[] numArray6 = numArray2;
SecP521R1Field.Add(rawXCoord.x, x, numArray6);
SecP521R1Field.Multiply(numArray6, z, numArray6);
Nat.AddBothTo(0x11, numArray6, numArray6, numArray6);
SecP521R1Field.Reduce23(numArray6);
uint[] numArray7 = numArray3;
SecP521R1Field.Multiply(numArray3, rawXCoord.x, numArray7);
Nat.ShiftUpBits(0x11, numArray7, 2, 0);
SecP521R1Field.Reduce23(numArray7);
Nat.ShiftUpBits(0x11, numArray4, 3, 0, z);
SecP521R1Field.Reduce23(z);
SecP521R1FieldElement element4 = new SecP521R1FieldElement(numArray4);
SecP521R1Field.Square(numArray6, element4.x);
SecP521R1Field.Subtract(element4.x, numArray7, element4.x);
SecP521R1Field.Subtract(element4.x, numArray7, element4.x);
SecP521R1FieldElement y = new SecP521R1FieldElement(numArray7);
SecP521R1Field.Subtract(numArray7, element4.x, y.x);
SecP521R1Field.Multiply(y.x, numArray6, y.x);
SecP521R1Field.Subtract(y.x, z, y.x);
SecP521R1FieldElement element6 = new SecP521R1FieldElement(numArray6);
SecP521R1Field.Twice(rawYCoord.x, element6.x);
if (!isOne)
{
SecP521R1Field.Multiply(element6.x, element3.x, element6.x);
}
return(new SecP521R1Point(curve, element4, y, new ECFieldElement[] { element6 }, base.IsCompressed));
}
public virtual bool Equals(SecP521R1FieldElement other)
{
return(this == other || (other != null && Nat.Eq(17, this.x, other.x)));
}
public override ECPoint Add(ECPoint b)
{
if (base.IsInfinity)
{
return(b);
}
if (b.IsInfinity)
{
return(this);
}
if (this == b)
{
return(Twice());
}
ECCurve curve = Curve;
SecP521R1FieldElement secP521R1FieldElement = (SecP521R1FieldElement)base.RawXCoord;
SecP521R1FieldElement secP521R1FieldElement2 = (SecP521R1FieldElement)base.RawYCoord;
SecP521R1FieldElement secP521R1FieldElement3 = (SecP521R1FieldElement)b.RawXCoord;
SecP521R1FieldElement secP521R1FieldElement4 = (SecP521R1FieldElement)b.RawYCoord;
SecP521R1FieldElement secP521R1FieldElement5 = (SecP521R1FieldElement)base.RawZCoords[0];
SecP521R1FieldElement secP521R1FieldElement6 = (SecP521R1FieldElement)b.RawZCoords[0];
uint[] array = Nat.Create(17);
uint[] array2 = Nat.Create(17);
uint[] array3 = Nat.Create(17);
uint[] array4 = Nat.Create(17);
bool isOne = secP521R1FieldElement5.IsOne;
uint[] array5;
uint[] array6;
if (isOne)
{
array5 = secP521R1FieldElement3.x;
array6 = secP521R1FieldElement4.x;
}
else
{
array6 = array3;
SecP521R1Field.Square(secP521R1FieldElement5.x, array6);
array5 = array2;
SecP521R1Field.Multiply(array6, secP521R1FieldElement3.x, array5);
SecP521R1Field.Multiply(array6, secP521R1FieldElement5.x, array6);
SecP521R1Field.Multiply(array6, secP521R1FieldElement4.x, array6);
}
bool isOne2 = secP521R1FieldElement6.IsOne;
uint[] array7;
uint[] array8;
if (isOne2)
{
array7 = secP521R1FieldElement.x;
array8 = secP521R1FieldElement2.x;
}
else
{
array8 = array4;
SecP521R1Field.Square(secP521R1FieldElement6.x, array8);
array7 = array;
SecP521R1Field.Multiply(array8, secP521R1FieldElement.x, array7);
SecP521R1Field.Multiply(array8, secP521R1FieldElement6.x, array8);
SecP521R1Field.Multiply(array8, secP521R1FieldElement2.x, array8);
}
uint[] array9 = Nat.Create(17);
SecP521R1Field.Subtract(array7, array5, array9);
uint[] array10 = array2;
SecP521R1Field.Subtract(array8, array6, array10);
if (Nat.IsZero(17, array9))
{
if (Nat.IsZero(17, array10))
{
return(Twice());
}
return(curve.Infinity);
}
uint[] array11 = array3;
SecP521R1Field.Square(array9, array11);
uint[] array12 = Nat.Create(17);
SecP521R1Field.Multiply(array11, array9, array12);
uint[] array13 = array3;
SecP521R1Field.Multiply(array11, array7, array13);
SecP521R1Field.Multiply(array8, array12, array);
SecP521R1FieldElement secP521R1FieldElement7 = new SecP521R1FieldElement(array4);
SecP521R1Field.Square(array10, secP521R1FieldElement7.x);
SecP521R1Field.Add(secP521R1FieldElement7.x, array12, secP521R1FieldElement7.x);
SecP521R1Field.Subtract(secP521R1FieldElement7.x, array13, secP521R1FieldElement7.x);
SecP521R1Field.Subtract(secP521R1FieldElement7.x, array13, secP521R1FieldElement7.x);
SecP521R1FieldElement secP521R1FieldElement8 = new SecP521R1FieldElement(array12);
SecP521R1Field.Subtract(array13, secP521R1FieldElement7.x, secP521R1FieldElement8.x);
SecP521R1Field.Multiply(secP521R1FieldElement8.x, array10, array2);
SecP521R1Field.Subtract(array2, array, secP521R1FieldElement8.x);
SecP521R1FieldElement secP521R1FieldElement9 = new SecP521R1FieldElement(array9);
if (!isOne)
{
SecP521R1Field.Multiply(secP521R1FieldElement9.x, secP521R1FieldElement5.x, secP521R1FieldElement9.x);
}
if (!isOne2)
{
SecP521R1Field.Multiply(secP521R1FieldElement9.x, secP521R1FieldElement6.x, secP521R1FieldElement9.x);
}
ECFieldElement[] zs = new ECFieldElement[1]
{
secP521R1FieldElement9
};
return(new SecP521R1Point(curve, secP521R1FieldElement7, secP521R1FieldElement8, zs, base.IsCompressed));
}
public override ECPoint Twice()
{
if (base.IsInfinity)
{
return(this);
}
ECCurve curve = Curve;
SecP521R1FieldElement secP521R1FieldElement = (SecP521R1FieldElement)base.RawYCoord;
if (secP521R1FieldElement.IsZero)
{
return(curve.Infinity);
}
SecP521R1FieldElement secP521R1FieldElement2 = (SecP521R1FieldElement)base.RawXCoord;
SecP521R1FieldElement secP521R1FieldElement3 = (SecP521R1FieldElement)base.RawZCoords[0];
uint[] array = Nat.Create(17);
uint[] array2 = Nat.Create(17);
uint[] array3 = Nat.Create(17);
SecP521R1Field.Square(secP521R1FieldElement.x, array3);
uint[] array4 = Nat.Create(17);
SecP521R1Field.Square(array3, array4);
bool isOne = secP521R1FieldElement3.IsOne;
uint[] array5 = secP521R1FieldElement3.x;
if (!isOne)
{
array5 = array2;
SecP521R1Field.Square(secP521R1FieldElement3.x, array5);
}
SecP521R1Field.Subtract(secP521R1FieldElement2.x, array5, array);
uint[] array6 = array2;
SecP521R1Field.Add(secP521R1FieldElement2.x, array5, array6);
SecP521R1Field.Multiply(array6, array, array6);
Nat.AddBothTo(17, array6, array6, array6);
SecP521R1Field.Reduce23(array6);
uint[] array7 = array3;
SecP521R1Field.Multiply(array3, secP521R1FieldElement2.x, array7);
Nat.ShiftUpBits(17, array7, 2, 0u);
SecP521R1Field.Reduce23(array7);
Nat.ShiftUpBits(17, array4, 3, 0u, array);
SecP521R1Field.Reduce23(array);
SecP521R1FieldElement secP521R1FieldElement4 = new SecP521R1FieldElement(array4);
SecP521R1Field.Square(array6, secP521R1FieldElement4.x);
SecP521R1Field.Subtract(secP521R1FieldElement4.x, array7, secP521R1FieldElement4.x);
SecP521R1Field.Subtract(secP521R1FieldElement4.x, array7, secP521R1FieldElement4.x);
SecP521R1FieldElement secP521R1FieldElement5 = new SecP521R1FieldElement(array7);
SecP521R1Field.Subtract(array7, secP521R1FieldElement4.x, secP521R1FieldElement5.x);
SecP521R1Field.Multiply(secP521R1FieldElement5.x, array6, secP521R1FieldElement5.x);
SecP521R1Field.Subtract(secP521R1FieldElement5.x, array, secP521R1FieldElement5.x);
SecP521R1FieldElement secP521R1FieldElement6 = new SecP521R1FieldElement(array6);
SecP521R1Field.Twice(secP521R1FieldElement.x, secP521R1FieldElement6.x);
if (!isOne)
{
SecP521R1Field.Multiply(secP521R1FieldElement6.x, secP521R1FieldElement3.x, secP521R1FieldElement6.x);
}
return(new SecP521R1Point(curve, secP521R1FieldElement4, secP521R1FieldElement5, new ECFieldElement[1]
{
secP521R1FieldElement6
}, 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;
SecP521R1FieldElement X1 = (SecP521R1FieldElement)this.RawXCoord, Y1 = (SecP521R1FieldElement)this.RawYCoord;
SecP521R1FieldElement X2 = (SecP521R1FieldElement)b.RawXCoord, Y2 = (SecP521R1FieldElement)b.RawYCoord;
SecP521R1FieldElement Z1 = (SecP521R1FieldElement)this.RawZCoords[0];
SecP521R1FieldElement Z2 = (SecP521R1FieldElement)b.RawZCoords[0];
uint[] t1 = Nat.Create(17);
uint[] t2 = Nat.Create(17);
uint[] t3 = Nat.Create(17);
uint[] t4 = Nat.Create(17);
bool Z1IsOne = Z1.IsOne;
uint[] U2, S2;
if (Z1IsOne)
{
U2 = X2.x;
S2 = Y2.x;
}
else
{
S2 = t3;
SecP521R1Field.Square(Z1.x, S2);
U2 = t2;
SecP521R1Field.Multiply(S2, X2.x, U2);
SecP521R1Field.Multiply(S2, Z1.x, S2);
SecP521R1Field.Multiply(S2, Y2.x, S2);
}
bool Z2IsOne = Z2.IsOne;
uint[] U1, S1;
if (Z2IsOne)
{
U1 = X1.x;
S1 = Y1.x;
}
else
{
S1 = t4;
SecP521R1Field.Square(Z2.x, S1);
U1 = t1;
SecP521R1Field.Multiply(S1, X1.x, U1);
SecP521R1Field.Multiply(S1, Z2.x, S1);
SecP521R1Field.Multiply(S1, Y1.x, S1);
}
uint[] H = Nat.Create(17);
SecP521R1Field.Subtract(U1, U2, H);
uint[] R = t2;
SecP521R1Field.Subtract(S1, S2, R);
// Check if b == this or b == -this
if (Nat.IsZero(17, H))
{
if (Nat.IsZero(17, 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;
SecP521R1Field.Square(H, HSquared);
uint[] G = Nat.Create(17);
SecP521R1Field.Multiply(HSquared, H, G);
uint[] V = t3;
SecP521R1Field.Multiply(HSquared, U1, V);
SecP521R1Field.Multiply(S1, G, t1);
SecP521R1FieldElement X3 = new SecP521R1FieldElement(t4);
SecP521R1Field.Square(R, X3.x);
SecP521R1Field.Add(X3.x, G, X3.x);
SecP521R1Field.Subtract(X3.x, V, X3.x);
SecP521R1Field.Subtract(X3.x, V, X3.x);
SecP521R1FieldElement Y3 = new SecP521R1FieldElement(G);
SecP521R1Field.Subtract(V, X3.x, Y3.x);
SecP521R1Field.Multiply(Y3.x, R, t2);
SecP521R1Field.Subtract(t2, t1, Y3.x);
SecP521R1FieldElement Z3 = new SecP521R1FieldElement(H);
if (!Z1IsOne)
{
SecP521R1Field.Multiply(Z3.x, Z1.x, Z3.x);
}
if (!Z2IsOne)
{
SecP521R1Field.Multiply(Z3.x, Z2.x, Z3.x);
}
ECFieldElement[] zs = new ECFieldElement[] { Z3 };
return(new SecP521R1Point(curve, X3, Y3, zs));
}
public override ECPoint Twice()
{
if (this.IsInfinity)
{
return(this);
}
ECCurve curve = this.Curve;
SecP521R1FieldElement Y1 = (SecP521R1FieldElement)this.RawYCoord;
if (Y1.IsZero)
{
return(curve.Infinity);
}
SecP521R1FieldElement X1 = (SecP521R1FieldElement)this.RawXCoord, Z1 = (SecP521R1FieldElement)this.RawZCoords[0];
uint[] t1 = Nat.Create(17);
uint[] t2 = Nat.Create(17);
uint[] Y1Squared = Nat.Create(17);
SecP521R1Field.Square(Y1.x, Y1Squared);
uint[] T = Nat.Create(17);
SecP521R1Field.Square(Y1Squared, T);
bool Z1IsOne = Z1.IsOne;
uint[] Z1Squared = Z1.x;
if (!Z1IsOne)
{
Z1Squared = t2;
SecP521R1Field.Square(Z1.x, Z1Squared);
}
SecP521R1Field.Subtract(X1.x, Z1Squared, t1);
uint[] M = t2;
SecP521R1Field.Add(X1.x, Z1Squared, M);
SecP521R1Field.Multiply(M, t1, M);
Nat.AddBothTo(17, M, M, M);
SecP521R1Field.Reduce23(M);
uint[] S = Y1Squared;
SecP521R1Field.Multiply(Y1Squared, X1.x, S);
Nat.ShiftUpBits(17, S, 2, 0);
SecP521R1Field.Reduce23(S);
Nat.ShiftUpBits(17, T, 3, 0, t1);
SecP521R1Field.Reduce23(t1);
SecP521R1FieldElement X3 = new SecP521R1FieldElement(T);
SecP521R1Field.Square(M, X3.x);
SecP521R1Field.Subtract(X3.x, S, X3.x);
SecP521R1Field.Subtract(X3.x, S, X3.x);
SecP521R1FieldElement Y3 = new SecP521R1FieldElement(S);
SecP521R1Field.Subtract(S, X3.x, Y3.x);
SecP521R1Field.Multiply(Y3.x, M, Y3.x);
SecP521R1Field.Subtract(Y3.x, t1, Y3.x);
SecP521R1FieldElement Z3 = new SecP521R1FieldElement(M);
SecP521R1Field.Twice(Y1.x, Z3.x);
if (!Z1IsOne)
{
SecP521R1Field.Multiply(Z3.x, Z1.x, Z3.x);
}
return(new SecP521R1Point(curve, X3, Y3, new ECFieldElement[] { Z3 }));
}
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;
SecP521R1FieldElement X1 = (SecP521R1FieldElement)this.RawXCoord, Y1 = (SecP521R1FieldElement)this.RawYCoord;
SecP521R1FieldElement X2 = (SecP521R1FieldElement)b.RawXCoord, Y2 = (SecP521R1FieldElement)b.RawYCoord;
SecP521R1FieldElement Z1 = (SecP521R1FieldElement)this.RawZCoords[0];
SecP521R1FieldElement Z2 = (SecP521R1FieldElement)b.RawZCoords[0];
uint[] t1 = Nat.Create(17);
uint[] t2 = Nat.Create(17);
uint[] t3 = Nat.Create(17);
uint[] t4 = Nat.Create(17);
bool Z1IsOne = Z1.IsOne;
uint[] U2, S2;
if (Z1IsOne)
{
U2 = X2.x;
S2 = Y2.x;
}
else
{
S2 = t3;
SecP521R1Field.Square(Z1.x, S2);
U2 = t2;
SecP521R1Field.Multiply(S2, X2.x, U2);
SecP521R1Field.Multiply(S2, Z1.x, S2);
SecP521R1Field.Multiply(S2, Y2.x, S2);
}
bool Z2IsOne = Z2.IsOne;
uint[] U1, S1;
if (Z2IsOne)
{
U1 = X1.x;
S1 = Y1.x;
}
else
{
S1 = t4;
SecP521R1Field.Square(Z2.x, S1);
U1 = t1;
SecP521R1Field.Multiply(S1, X1.x, U1);
SecP521R1Field.Multiply(S1, Z2.x, S1);
SecP521R1Field.Multiply(S1, Y1.x, S1);
}
uint[] H = Nat.Create(17);
SecP521R1Field.Subtract(U1, U2, H);
uint[] R = t2;
SecP521R1Field.Subtract(S1, S2, R);
// Check if b == this or b == -this
if (Nat.IsZero(17, H))
{
if (Nat.IsZero(17, 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;
SecP521R1Field.Square(H, HSquared);
uint[] G = Nat.Create(17);
SecP521R1Field.Multiply(HSquared, H, G);
uint[] V = t3;
SecP521R1Field.Multiply(HSquared, U1, V);
SecP521R1Field.Multiply(S1, G, t1);
SecP521R1FieldElement X3 = new SecP521R1FieldElement(t4);
SecP521R1Field.Square(R, X3.x);
SecP521R1Field.Add(X3.x, G, X3.x);
SecP521R1Field.Subtract(X3.x, V, X3.x);
SecP521R1Field.Subtract(X3.x, V, X3.x);
SecP521R1FieldElement Y3 = new SecP521R1FieldElement(G);
SecP521R1Field.Subtract(V, X3.x, Y3.x);
SecP521R1Field.Multiply(Y3.x, R, t2);
SecP521R1Field.Subtract(t2, t1, Y3.x);
SecP521R1FieldElement Z3 = new SecP521R1FieldElement(H);
if (!Z1IsOne)
{
SecP521R1Field.Multiply(Z3.x, Z1.x, Z3.x);
}
if (!Z2IsOne)
{
SecP521R1Field.Multiply(Z3.x, Z2.x, Z3.x);
}
ECFieldElement[] zs = new ECFieldElement[] { Z3 };
return new SecP521R1Point(curve, X3, Y3, zs, IsCompressed);
}
public override ECPoint Twice()
{
if (this.IsInfinity)
return this;
ECCurve curve = this.Curve;
SecP521R1FieldElement Y1 = (SecP521R1FieldElement)this.RawYCoord;
if (Y1.IsZero)
return curve.Infinity;
SecP521R1FieldElement X1 = (SecP521R1FieldElement)this.RawXCoord, Z1 = (SecP521R1FieldElement)this.RawZCoords[0];
uint[] t1 = Nat.Create(17);
uint[] t2 = Nat.Create(17);
uint[] Y1Squared = Nat.Create(17);
SecP521R1Field.Square(Y1.x, Y1Squared);
uint[] T = Nat.Create(17);
SecP521R1Field.Square(Y1Squared, T);
bool Z1IsOne = Z1.IsOne;
uint[] Z1Squared = Z1.x;
if (!Z1IsOne)
{
Z1Squared = t2;
SecP521R1Field.Square(Z1.x, Z1Squared);
}
SecP521R1Field.Subtract(X1.x, Z1Squared, t1);
uint[] M = t2;
SecP521R1Field.Add(X1.x, Z1Squared, M);
SecP521R1Field.Multiply(M, t1, M);
Nat.AddBothTo(17, M, M, M);
SecP521R1Field.Reduce23(M);
uint[] S = Y1Squared;
SecP521R1Field.Multiply(Y1Squared, X1.x, S);
Nat.ShiftUpBits(17, S, 2, 0);
SecP521R1Field.Reduce23(S);
Nat.ShiftUpBits(17, T, 3, 0, t1);
SecP521R1Field.Reduce23(t1);
SecP521R1FieldElement X3 = new SecP521R1FieldElement(T);
SecP521R1Field.Square(M, X3.x);
SecP521R1Field.Subtract(X3.x, S, X3.x);
SecP521R1Field.Subtract(X3.x, S, X3.x);
SecP521R1FieldElement Y3 = new SecP521R1FieldElement(S);
SecP521R1Field.Subtract(S, X3.x, Y3.x);
SecP521R1Field.Multiply(Y3.x, M, Y3.x);
SecP521R1Field.Subtract(Y3.x, t1, Y3.x);
SecP521R1FieldElement Z3 = new SecP521R1FieldElement(M);
SecP521R1Field.Twice(Y1.x, Z3.x);
if (!Z1IsOne)
{
SecP521R1Field.Multiply(Z3.x, Z1.x, Z3.x);
}
return new SecP521R1Point(curve, X3, Y3, new ECFieldElement[] { Z3 }, IsCompressed);
}