58 lines
3.0 KiB
Java
58 lines
3.0 KiB
Java
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package org.bouncycastle.math.ec;
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import java.math.BigInteger;
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import org.bouncycastle.math.ec.ECCurve;
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import org.bouncycastle.math.ec.ECPoint;
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/* loaded from: classes6.dex */
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public class WTauNafMultiplier extends AbstractECMultiplier {
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static final String PRECOMP_NAME = "bc_wtnaf";
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@Override // org.bouncycastle.math.ec.AbstractECMultiplier
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protected ECPoint multiplyPositive(ECPoint eCPoint, BigInteger bigInteger) {
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if (!(eCPoint instanceof ECPoint.AbstractF2m)) {
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throw new IllegalArgumentException("Only ECPoint.AbstractF2m can be used in WTauNafMultiplier");
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}
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ECPoint.AbstractF2m abstractF2m = (ECPoint.AbstractF2m) eCPoint;
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ECCurve.AbstractF2m abstractF2m2 = (ECCurve.AbstractF2m) abstractF2m.getCurve();
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int fieldSize = abstractF2m2.getFieldSize();
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byte byteValue = abstractF2m2.getA().toBigInteger().byteValue();
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byte mu = Tnaf.getMu(byteValue);
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return multiplyWTnaf(abstractF2m, Tnaf.partModReduction(bigInteger, fieldSize, byteValue, abstractF2m2.getSi(), mu, (byte) 10), abstractF2m2.getPreCompInfo(abstractF2m, PRECOMP_NAME), byteValue, mu);
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}
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private ECPoint.AbstractF2m multiplyWTnaf(ECPoint.AbstractF2m abstractF2m, ZTauElement zTauElement, PreCompInfo preCompInfo, byte b, byte b2) {
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ZTauElement[] zTauElementArr = b == 0 ? Tnaf.alpha0 : Tnaf.alpha1;
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return multiplyFromWTnaf(abstractF2m, Tnaf.tauAdicWNaf(b2, zTauElement, (byte) 4, BigInteger.valueOf(16L), Tnaf.getTw(b2, 4), zTauElementArr), preCompInfo);
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}
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private static ECPoint.AbstractF2m multiplyFromWTnaf(ECPoint.AbstractF2m abstractF2m, byte[] bArr, PreCompInfo preCompInfo) {
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ECPoint.AbstractF2m[] preComp;
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ECCurve.AbstractF2m abstractF2m2 = (ECCurve.AbstractF2m) abstractF2m.getCurve();
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byte byteValue = abstractF2m2.getA().toBigInteger().byteValue();
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if (preCompInfo == null || !(preCompInfo instanceof WTauNafPreCompInfo)) {
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preComp = Tnaf.getPreComp(abstractF2m, byteValue);
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WTauNafPreCompInfo wTauNafPreCompInfo = new WTauNafPreCompInfo();
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wTauNafPreCompInfo.setPreComp(preComp);
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abstractF2m2.setPreCompInfo(abstractF2m, PRECOMP_NAME, wTauNafPreCompInfo);
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} else {
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preComp = ((WTauNafPreCompInfo) preCompInfo).getPreComp();
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}
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ECPoint.AbstractF2m[] abstractF2mArr = new ECPoint.AbstractF2m[preComp.length];
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for (int i = 0; i < preComp.length; i++) {
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abstractF2mArr[i] = (ECPoint.AbstractF2m) preComp[i].negate();
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}
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ECPoint.AbstractF2m abstractF2m3 = (ECPoint.AbstractF2m) abstractF2m.getCurve().getInfinity();
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int i2 = 0;
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for (int length = bArr.length - 1; length >= 0; length--) {
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i2++;
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byte b = bArr[length];
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if (b != 0) {
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abstractF2m3 = (ECPoint.AbstractF2m) abstractF2m3.tauPow(i2).add(b > 0 ? preComp[b >>> 1] : abstractF2mArr[(-b) >>> 1]);
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i2 = 0;
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}
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}
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return i2 > 0 ? abstractF2m3.tauPow(i2) : abstractF2m3;
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}
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}
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