How to use

plus

method

in

java.time.Year

/**
 * {@inheritDoc}
 * @throws DateTimeException {@inheritDoc}
 * @throws ArithmeticException {@inheritDoc}
 */
@Override
public Year minus(long amountToSubtract, TemporalUnit unit) {
  return (amountToSubtract == Long.MIN_VALUE ? plus(Long.MAX_VALUE, unit).plus(1, unit) : plus(-amountToSubtract, unit));
}

public static Certificate newCert(String parentCertFile, String keyFile, String host) {
  try {
    Date before = Date.from(Instant.now());
    Date after = Date.from(Year.now().plus(3, ChronoUnit.YEARS).atDay(1).atStartOfDay(ZoneId.systemDefault()).toInstant());
    X509CertificateHolder parent = readPemFromFile(parentCertFile);
    PEMKeyPair pemKeyPair = readPemFromFile(keyFile);
    KeyPair keyPair = new JcaPEMKeyConverter()
        .setProvider(PROVIDER)
        .getKeyPair(pemKeyPair);
    X509v3CertificateBuilder x509 = new JcaX509v3CertificateBuilder(
        parent.getSubject(),
        new BigInteger(64, new SecureRandom()),
        before,
        after,
        new X500Name("CN=" + host),
        keyPair.getPublic());
    ContentSigner signer = new JcaContentSignerBuilder("SHA256WithRSAEncryption")
        .build(keyPair.getPrivate());
    JcaX509CertificateConverter x509CertificateConverter = new JcaX509CertificateConverter()
        .setProvider(PROVIDER);
    return new Certificate(
        keyPair,
        x509CertificateConverter.getCertificate(x509.build(signer)),
        x509CertificateConverter.getCertificate(parent));
  } catch (Exception e) {
    throw new IllegalStateException(e);
  }
}