what-the-bank/sources/org/bouncycastle/crypto/ec/ECFixedTransform.java

52 lines
2.0 KiB
Java

package org.bouncycastle.crypto.ec;
import java.math.BigInteger;
import org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.crypto.params.ECDomainParameters;
import org.bouncycastle.crypto.params.ECPublicKeyParameters;
import org.bouncycastle.math.ec.ECMultiplier;
import org.bouncycastle.math.ec.ECPoint;
import org.bouncycastle.math.ec.FixedPointCombMultiplier;
/* loaded from: classes6.dex */
public class ECFixedTransform implements ECPairFactorTransform {
private BigInteger k;
private ECPublicKeyParameters key;
@Override // org.bouncycastle.crypto.ec.ECPairTransform
public ECPair transform(ECPair eCPair) {
ECPublicKeyParameters eCPublicKeyParameters = this.key;
if (eCPublicKeyParameters == null) {
throw new IllegalStateException("ECFixedTransform not initialised");
}
ECDomainParameters parameters = eCPublicKeyParameters.getParameters();
BigInteger n = parameters.getN();
ECMultiplier createBasePointMultiplier = createBasePointMultiplier();
BigInteger mod = this.k.mod(n);
ECPoint[] eCPointArr = {createBasePointMultiplier.multiply(parameters.getG(), mod).add(eCPair.getX()), this.key.getQ().multiply(mod).add(eCPair.getY())};
parameters.getCurve().normalizeAll(eCPointArr);
return new ECPair(eCPointArr[0], eCPointArr[1]);
}
@Override // org.bouncycastle.crypto.ec.ECPairTransform
public void init(CipherParameters cipherParameters) {
if (!(cipherParameters instanceof ECPublicKeyParameters)) {
throw new IllegalArgumentException("ECPublicKeyParameters are required for fixed transform.");
}
this.key = (ECPublicKeyParameters) cipherParameters;
}
@Override // org.bouncycastle.crypto.ec.ECPairFactorTransform
public BigInteger getTransformValue() {
return this.k;
}
protected ECMultiplier createBasePointMultiplier() {
return new FixedPointCombMultiplier();
}
public ECFixedTransform(BigInteger bigInteger) {
this.k = bigInteger;
}
}