package org.bouncycastle.crypto.generators;

import java.math.BigInteger;
import java.security.SecureRandom;
import org.bouncycastle.crypto.params.DHParameters;
import org.bouncycastle.math.ec.WNafUtil;
import org.bouncycastle.util.BigIntegers;

/* loaded from: classes6.dex */
class DHKeyGeneratorHelper {
    static final DHKeyGeneratorHelper INSTANCE = new DHKeyGeneratorHelper();
    private static final BigInteger ONE = BigInteger.valueOf(1);
    private static final BigInteger TWO = BigInteger.valueOf(2);

    /* JADX INFO: Access modifiers changed from: package-private */
    public BigInteger calculatePublic(DHParameters dHParameters, BigInteger bigInteger) {
        return dHParameters.getG().modPow(bigInteger, dHParameters.getP());
    }

    /* JADX INFO: Access modifiers changed from: package-private */
    public BigInteger calculatePrivate(DHParameters dHParameters, SecureRandom secureRandom) {
        BigInteger createRandomInRange;
        BigInteger bit;
        int l = dHParameters.getL();
        if (l == 0) {
            BigInteger bigInteger = TWO;
            int m = dHParameters.getM();
            BigInteger shiftLeft = m != 0 ? ONE.shiftLeft(m - 1) : bigInteger;
            BigInteger q = dHParameters.getQ();
            if (q == null) {
                q = dHParameters.getP();
            }
            BigInteger subtract = q.subtract(bigInteger);
            int bitLength = subtract.bitLength();
            do {
                createRandomInRange = BigIntegers.createRandomInRange(shiftLeft, subtract, secureRandom);
            } while (WNafUtil.getNafWeight(createRandomInRange) < (bitLength >>> 2));
            return createRandomInRange;
        }
        do {
            bit = new BigInteger(l, secureRandom).setBit(l - 1);
        } while (WNafUtil.getNafWeight(bit) < (l >>> 2));
        return bit;
    }

    private DHKeyGeneratorHelper() {
    }
}