49 lines
1.9 KiB
Java
49 lines
1.9 KiB
Java
package org.bouncycastle.crypto.generators;
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import java.math.BigInteger;
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import java.security.SecureRandom;
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import org.bouncycastle.crypto.params.DHParameters;
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import org.bouncycastle.math.ec.WNafUtil;
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import org.bouncycastle.util.BigIntegers;
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/* loaded from: classes6.dex */
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class DHKeyGeneratorHelper {
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static final DHKeyGeneratorHelper INSTANCE = new DHKeyGeneratorHelper();
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private static final BigInteger ONE = BigInteger.valueOf(1);
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private static final BigInteger TWO = BigInteger.valueOf(2);
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/* JADX INFO: Access modifiers changed from: package-private */
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public BigInteger calculatePublic(DHParameters dHParameters, BigInteger bigInteger) {
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return dHParameters.getG().modPow(bigInteger, dHParameters.getP());
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}
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/* JADX INFO: Access modifiers changed from: package-private */
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public BigInteger calculatePrivate(DHParameters dHParameters, SecureRandom secureRandom) {
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BigInteger createRandomInRange;
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BigInteger bit;
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int l = dHParameters.getL();
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if (l == 0) {
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BigInteger bigInteger = TWO;
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int m = dHParameters.getM();
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BigInteger shiftLeft = m != 0 ? ONE.shiftLeft(m - 1) : bigInteger;
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BigInteger q = dHParameters.getQ();
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if (q == null) {
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q = dHParameters.getP();
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}
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BigInteger subtract = q.subtract(bigInteger);
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int bitLength = subtract.bitLength();
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do {
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createRandomInRange = BigIntegers.createRandomInRange(shiftLeft, subtract, secureRandom);
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} while (WNafUtil.getNafWeight(createRandomInRange) < (bitLength >>> 2));
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return createRandomInRange;
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}
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do {
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bit = new BigInteger(l, secureRandom).setBit(l - 1);
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} while (WNafUtil.getNafWeight(bit) < (l >>> 2));
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return bit;
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}
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private DHKeyGeneratorHelper() {
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}
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}
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