package org.bouncycastle.math.ec.custom.sec; import org.bouncycastle.math.ec.ECConstants; import org.bouncycastle.math.ec.ECCurve; import org.bouncycastle.math.ec.ECFieldElement; import org.bouncycastle.math.ec.ECPoint; import org.bouncycastle.math.ec.ECPoint.AbstractF2m; import org.bouncycastle.math.raw.Nat; import org.bouncycastle.math.raw.Nat576; public class SecT571R1Point extends AbstractF2m { /** * @deprecated Use ECCurve.createPoint to construct points */ public SecT571R1Point(ECCurve curve, ECFieldElement x, ECFieldElement y) { this(curve, x, y, false); } /** * @deprecated per-point compression property will be removed, refer {@link #getEncoded(boolean)} */ public SecT571R1Point(ECCurve curve, ECFieldElement x, ECFieldElement y, boolean withCompression) { super(curve, x, y); if ((x == null) != (y == null)) { throw new IllegalArgumentException("Exactly one of the field elements is null"); } this.withCompression = withCompression; } SecT571R1Point(ECCurve curve, ECFieldElement x, ECFieldElement y, ECFieldElement[] zs, boolean withCompression) { super(curve, x, y, zs); this.withCompression = withCompression; } protected ECPoint detach() { return new SecT571R1Point(null, getAffineXCoord(), getAffineYCoord()); } public ECFieldElement getYCoord() { ECFieldElement X = x, L = y; if (this.isInfinity() || X.isZero()) { return L; } // Y is actually Lambda (X + Y/X) here; convert to affine value on the fly ECFieldElement Y = L.add(X).multiply(X); ECFieldElement Z = zs[0]; if (!Z.isOne()) { Y = Y.divide(Z); } return Y; } protected boolean getCompressionYTilde() { ECFieldElement X = this.getRawXCoord(); if (X.isZero()) { return false; } ECFieldElement Y = this.getRawYCoord(); // Y is actually Lambda (X + Y/X) here return Y.testBitZero() != X.testBitZero(); } public ECPoint add(ECPoint b) { if (this.isInfinity()) { return b; } if (b.isInfinity()) { return this; } ECCurve curve = this.getCurve(); SecT571FieldElement X1 = (SecT571FieldElement)this.x; SecT571FieldElement X2 = (SecT571FieldElement)b.getRawXCoord(); if (X1.isZero()) { if (X2.isZero()) { return curve.getInfinity(); } return b.add(this); } SecT571FieldElement L1 = (SecT571FieldElement)this.y, Z1 = (SecT571FieldElement)this.zs[0]; SecT571FieldElement L2 = (SecT571FieldElement)b.getRawYCoord(), Z2 = (SecT571FieldElement)b.getZCoord(0); long[] t1 = Nat576.create64(); long[] t2 = Nat576.create64(); long[] t3 = Nat576.create64(); long[] t4 = Nat576.create64(); long[] Z1Precomp = Z1.isOne() ? null : SecT571Field.precompMultiplicand(Z1.x); long[] U2, S2; if (Z1Precomp == null) { U2 = X2.x; S2 = L2.x; } else { SecT571Field.multiplyPrecomp(X2.x, Z1Precomp, U2 = t2); SecT571Field.multiplyPrecomp(L2.x, Z1Precomp, S2 = t4); } long[] Z2Precomp = Z2.isOne() ? null : SecT571Field.precompMultiplicand(Z2.x); long[] U1, S1; if (Z2Precomp == null) { U1 = X1.x; S1 = L1.x; } else { SecT571Field.multiplyPrecomp(X1.x, Z2Precomp, U1 = t1); SecT571Field.multiplyPrecomp(L1.x, Z2Precomp, S1 = t3); } long[] A = t3; SecT571Field.add(S1, S2, A); long[] B = t4; SecT571Field.add(U1, U2, B); if (Nat576.isZero64(B)) { if (Nat576.isZero64(A)) { return twice(); } return curve.getInfinity(); } SecT571FieldElement X3, L3, Z3; if (X2.isZero()) { // TODO This can probably be optimized quite a bit ECPoint p = this.normalize(); X1 = (SecT571FieldElement)p.getXCoord(); ECFieldElement Y1 = p.getYCoord(); ECFieldElement Y2 = L2; ECFieldElement L = Y1.add(Y2).divide(X1); X3 = (SecT571FieldElement)L.square().add(L).add(X1).addOne(); if (X3.isZero()) { return new SecT571R1Point(curve, X3, SecT571R1Curve.SecT571R1_B_SQRT, this.withCompression); } ECFieldElement Y3 = L.multiply(X1.add(X3)).add(X3).add(Y1); L3 = (SecT571FieldElement)Y3.divide(X3).add(X3); Z3 = (SecT571FieldElement)curve.fromBigInteger(ECConstants.ONE); } else { SecT571Field.square(B, B); long[] APrecomp = SecT571Field.precompMultiplicand(A); long[] AU1 = t1; long[] AU2 = t2; SecT571Field.multiplyPrecomp(U1, APrecomp, AU1); SecT571Field.multiplyPrecomp(U2, APrecomp, AU2); X3 = new SecT571FieldElement(t1); SecT571Field.multiply(AU1, AU2, X3.x); if (X3.isZero()) { return new SecT571R1Point(curve, X3, SecT571R1Curve.SecT571R1_B_SQRT, this.withCompression); } Z3 = new SecT571FieldElement(t3); SecT571Field.multiplyPrecomp(B, APrecomp, Z3.x); if (Z2Precomp != null) { SecT571Field.multiplyPrecomp(Z3.x, Z2Precomp, Z3.x); } long[] tt = Nat576.createExt64(); SecT571Field.add(AU2, B, t4); SecT571Field.squareAddToExt(t4, tt); SecT571Field.add(L1.x, Z1.x, t4); SecT571Field.multiplyAddToExt(t4, Z3.x, tt); L3 = new SecT571FieldElement(t4); SecT571Field.reduce(tt, L3.x); if (Z1Precomp != null) { SecT571Field.multiplyPrecomp(Z3.x, Z1Precomp, Z3.x); } } return new SecT571R1Point(curve, X3, L3, new ECFieldElement[]{ Z3 }, this.withCompression); } public ECPoint twice() { if (this.isInfinity()) { return this; } ECCurve curve = this.getCurve(); SecT571FieldElement X1 = (SecT571FieldElement)this.x; if (X1.isZero()) { // A point with X == 0 is it's own additive inverse return curve.getInfinity(); } SecT571FieldElement L1 = (SecT571FieldElement)this.y, Z1 = (SecT571FieldElement)this.zs[0]; long[] t1 = Nat576.create64(); long[] t2 = Nat576.create64(); long[] Z1Precomp = Z1.isOne() ? null : SecT571Field.precompMultiplicand(Z1.x); long[] L1Z1, Z1Sq; if (Z1Precomp == null) { L1Z1 = L1.x; Z1Sq = Z1.x; } else { SecT571Field.multiplyPrecomp(L1.x, Z1Precomp, L1Z1 = t1); SecT571Field.square(Z1.x, Z1Sq = t2); } long[] T = Nat576.create64(); SecT571Field.square(L1.x, T); SecT571Field.addBothTo(L1Z1, Z1Sq, T); if (Nat576.isZero64(T)) { return new SecT571R1Point(curve, new SecT571FieldElement(T), SecT571R1Curve.SecT571R1_B_SQRT, withCompression); } long[] tt = Nat576.createExt64(); SecT571Field.multiplyAddToExt(T, L1Z1, tt); SecT571FieldElement X3 = new SecT571FieldElement(t1); SecT571Field.square(T, X3.x); SecT571FieldElement Z3 = new SecT571FieldElement(T); if (Z1Precomp != null) { SecT571Field.multiply(Z3.x, Z1Sq, Z3.x); } long[] X1Z1; if (Z1Precomp == null) { X1Z1 = X1.x; } else { SecT571Field.multiplyPrecomp(X1.x, Z1Precomp, X1Z1 = t2); } SecT571Field.squareAddToExt(X1Z1, tt); SecT571Field.reduce(tt, t2); SecT571Field.addBothTo(X3.x, Z3.x, t2); SecT571FieldElement L3 = new SecT571FieldElement(t2); return new SecT571R1Point(curve, X3, L3, new ECFieldElement[]{ Z3 }, this.withCompression); } public ECPoint twicePlus(ECPoint b) { if (this.isInfinity()) { return b; } if (b.isInfinity()) { return twice(); } ECCurve curve = this.getCurve(); SecT571FieldElement X1 = (SecT571FieldElement)this.x; if (X1.isZero()) { // A point with X == 0 is it's own additive inverse return b; } SecT571FieldElement X2 = (SecT571FieldElement)b.getRawXCoord(), Z2 = (SecT571FieldElement)b.getZCoord(0); if (X2.isZero() || !Z2.isOne()) { return twice().add(b); } SecT571FieldElement L1 = (SecT571FieldElement)this.y, Z1 = (SecT571FieldElement)this.zs[0]; SecT571FieldElement L2 = (SecT571FieldElement)b.getRawYCoord(); long[] t1 = Nat576.create64(); long[] t2 = Nat576.create64(); long[] t3 = Nat576.create64(); long[] t4 = Nat576.create64(); long[] X1Sq = t1; SecT571Field.square(X1.x, X1Sq); long[] L1Sq = t2; SecT571Field.square(L1.x, L1Sq); long[] Z1Sq = t3; SecT571Field.square(Z1.x, Z1Sq); long[] L1Z1 = t4; SecT571Field.multiply(L1.x, Z1.x, L1Z1); long[] T = L1Z1; SecT571Field.addBothTo(Z1Sq, L1Sq, T); long[] Z1SqPrecomp = SecT571Field.precompMultiplicand(Z1Sq); long[] A = t3; SecT571Field.multiplyPrecomp(L2.x, Z1SqPrecomp, A); SecT571Field.add(A, L1Sq, A); long[] tt = Nat576.createExt64(); SecT571Field.multiplyAddToExt(A, T, tt); SecT571Field.multiplyPrecompAddToExt(X1Sq, Z1SqPrecomp, tt); SecT571Field.reduce(tt, A); long[] X2Z1Sq = t1; SecT571Field.multiplyPrecomp(X2.x, Z1SqPrecomp, X2Z1Sq); long[] B = t2; SecT571Field.add(X2Z1Sq, T, B); SecT571Field.square(B, B); if (Nat576.isZero64(B)) { if (Nat576.isZero64(A)) { return b.twice(); } return curve.getInfinity(); } if (Nat576.isZero64(A)) { return new SecT571R1Point(curve, new SecT571FieldElement(A), SecT571R1Curve.SecT571R1_B_SQRT, withCompression); } SecT571FieldElement X3 = new SecT571FieldElement(); SecT571Field.square(A, X3.x); SecT571Field.multiply(X3.x, X2Z1Sq, X3.x); SecT571FieldElement Z3 = new SecT571FieldElement(t1); SecT571Field.multiply(A, B, Z3.x); SecT571Field.multiplyPrecomp(Z3.x, Z1SqPrecomp, Z3.x); SecT571FieldElement L3 = new SecT571FieldElement(t2); SecT571Field.add(A, B, L3.x); SecT571Field.square(L3.x, L3.x); Nat.zero64(18, tt); SecT571Field.multiplyAddToExt(L3.x, T, tt); SecT571Field.addOne(L2.x, t4); SecT571Field.multiplyAddToExt(t4, Z3.x, tt); SecT571Field.reduce(tt, L3.x); return new SecT571R1Point(curve, X3, L3, new ECFieldElement[]{ Z3 }, this.withCompression); } public ECPoint negate() { if (this.isInfinity()) { return this; } ECFieldElement X = this.x; if (X.isZero()) { return this; } // L is actually Lambda (X + Y/X) here ECFieldElement L = this.y, Z = this.zs[0]; return new SecT571R1Point(curve, X, L.add(Z), new ECFieldElement[]{ Z }, this.withCompression); } }