| /* GENERATED SOURCE. DO NOT MODIFY. */ |
| package com.android.org.bouncycastle.math.ec.custom.sec; |
| |
| import com.android.org.bouncycastle.math.ec.ECCurve; |
| import com.android.org.bouncycastle.math.ec.ECFieldElement; |
| import com.android.org.bouncycastle.math.ec.ECPoint; |
| import com.android.org.bouncycastle.math.raw.Nat; |
| |
| /** |
| * @hide This class is not part of the Android public SDK API |
| */ |
| public class SecP521R1Point extends ECPoint.AbstractFp |
| { |
| SecP521R1Point(ECCurve curve, ECFieldElement x, ECFieldElement y) |
| { |
| super(curve, x, y); |
| } |
| |
| SecP521R1Point(ECCurve curve, ECFieldElement x, ECFieldElement y, ECFieldElement[] zs) |
| { |
| super(curve, x, y, zs); |
| } |
| |
| protected ECPoint detach() |
| { |
| return new SecP521R1Point(null, getAffineXCoord(), getAffineYCoord()); |
| } |
| |
| public ECPoint add(ECPoint b) |
| { |
| if (this.isInfinity()) |
| { |
| return b; |
| } |
| if (b.isInfinity()) |
| { |
| return this; |
| } |
| if (this == b) |
| { |
| return twice(); |
| } |
| |
| ECCurve curve = this.getCurve(); |
| |
| SecP521R1FieldElement X1 = (SecP521R1FieldElement)this.x, Y1 = (SecP521R1FieldElement)this.y; |
| SecP521R1FieldElement X2 = (SecP521R1FieldElement)b.getXCoord(), Y2 = (SecP521R1FieldElement)b.getYCoord(); |
| |
| SecP521R1FieldElement Z1 = (SecP521R1FieldElement)this.zs[0]; |
| SecP521R1FieldElement Z2 = (SecP521R1FieldElement)b.getZCoord(0); |
| |
| int[] t1 = Nat.create(17); |
| int[] t2 = Nat.create(17); |
| int[] t3 = Nat.create(17); |
| int[] t4 = Nat.create(17); |
| |
| boolean Z1IsOne = Z1.isOne(); |
| int[] 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); |
| } |
| |
| boolean Z2IsOne = Z2.isOne(); |
| int[] 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); |
| } |
| |
| int[] H = Nat.create(17); |
| SecP521R1Field.subtract(U1, U2, H); |
| |
| int[] 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.getInfinity(); |
| } |
| |
| int[] HSquared = t3; |
| SecP521R1Field.square(H, HSquared); |
| |
| int[] G = Nat.create(17); |
| SecP521R1Field.multiply(HSquared, H, G); |
| |
| int[] 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 ECPoint twice() |
| { |
| if (this.isInfinity()) |
| { |
| return this; |
| } |
| |
| ECCurve curve = this.getCurve(); |
| |
| SecP521R1FieldElement Y1 = (SecP521R1FieldElement)this.y; |
| if (Y1.isZero()) |
| { |
| return curve.getInfinity(); |
| } |
| |
| SecP521R1FieldElement X1 = (SecP521R1FieldElement)this.x, Z1 = (SecP521R1FieldElement)this.zs[0]; |
| |
| int[] t1 = Nat.create(17); |
| int[] t2 = Nat.create(17); |
| |
| int[] Y1Squared = Nat.create(17); |
| SecP521R1Field.square(Y1.x, Y1Squared); |
| |
| int[] T = Nat.create(17); |
| SecP521R1Field.square(Y1Squared, T); |
| |
| boolean Z1IsOne = Z1.isOne(); |
| |
| int[] Z1Squared = Z1.x; |
| if (!Z1IsOne) |
| { |
| Z1Squared = t2; |
| SecP521R1Field.square(Z1.x, Z1Squared); |
| } |
| |
| SecP521R1Field.subtract(X1.x, Z1Squared, t1); |
| |
| int[] M = t2; |
| SecP521R1Field.add(X1.x, Z1Squared, M); |
| SecP521R1Field.multiply(M, t1, M); |
| Nat.addBothTo(17, M, M, M); |
| SecP521R1Field.reduce23(M); |
| |
| int[] 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 ECPoint twicePlus(ECPoint b) |
| { |
| if (this == b) |
| { |
| return threeTimes(); |
| } |
| if (this.isInfinity()) |
| { |
| return b; |
| } |
| if (b.isInfinity()) |
| { |
| return twice(); |
| } |
| |
| ECFieldElement Y1 = this.y; |
| if (Y1.isZero()) |
| { |
| return b; |
| } |
| |
| return twice().add(b); |
| } |
| |
| public ECPoint threeTimes() |
| { |
| if (this.isInfinity() || this.y.isZero()) |
| { |
| return this; |
| } |
| |
| // NOTE: Be careful about recursions between twicePlus and threeTimes |
| return twice().add(this); |
| } |
| |
| protected ECFieldElement two(ECFieldElement x) |
| { |
| return x.add(x); |
| } |
| |
| protected ECFieldElement three(ECFieldElement x) |
| { |
| return two(x).add(x); |
| } |
| |
| protected ECFieldElement four(ECFieldElement x) |
| { |
| return two(two(x)); |
| } |
| |
| protected ECFieldElement eight(ECFieldElement x) |
| { |
| return four(two(x)); |
| } |
| |
| protected ECFieldElement doubleProductFromSquares(ECFieldElement a, ECFieldElement b, |
| ECFieldElement aSquared, ECFieldElement bSquared) |
| { |
| /* |
| * NOTE: If squaring in the field is faster than multiplication, then this is a quicker |
| * way to calculate 2.A.B, if A^2 and B^2 are already known. |
| */ |
| return a.add(b).square().subtract(aSquared).subtract(bSquared); |
| } |
| |
| public ECPoint negate() |
| { |
| if (this.isInfinity()) |
| { |
| return this; |
| } |
| |
| return new SecP521R1Point(curve, this.x, this.y.negate(), this.zs); |
| } |
| } |