what-the-bank/sources/org/bouncycastle/math/ec/ZSignedDigitR2LMultiplier.java

23 lines
861 B
Java

package org.bouncycastle.math.ec;
import java.math.BigInteger;
/* loaded from: classes6.dex */
public class ZSignedDigitR2LMultiplier extends AbstractECMultiplier {
@Override // org.bouncycastle.math.ec.AbstractECMultiplier
protected ECPoint multiplyPositive(ECPoint eCPoint, BigInteger bigInteger) {
ECPoint infinity = eCPoint.getCurve().getInfinity();
int bitLength = bigInteger.bitLength();
int lowestSetBit = bigInteger.getLowestSetBit();
ECPoint timesPow2 = eCPoint.timesPow2(lowestSetBit);
while (true) {
lowestSetBit++;
if (lowestSetBit >= bitLength) {
return infinity.add(timesPow2);
}
infinity = infinity.add(bigInteger.testBit(lowestSetBit) ? timesPow2 : timesPow2.negate());
timesPow2 = timesPow2.twice();
}
}
}