How to extract CN from JKS in Java/Scala?

Question

I want to extract CN from Kafka keystore.jks. This issue How to extract CN from X509Certificate in Java? can help you to extract CN from X509certificate, but it doesn't say how to extract from JKS and I spent a lot of time to get the right solution for my own question. I assume that my solution can help somebody to get the right answer faster. You should read keystore then convert to the X509 and take advantage of cryptacular lib (CertUtil.subjectCN). My code in Scala demonstrates this below.

Answer 1

That's my Scala code for extracting CN from JKS cert:

import org.cryptacular.util.CertUtil
import java.io.FileInputStream
import java.security.KeyStore
import java.security.cert.X509Certificate
....

  val keystore = KeyStore.getInstance("JKS")
  val keystoreLocation = new FileInputStream("your_path_to_the_certificate")
  keystore.load(keystoreLocation, "your_password".toCharArray)
  val aliases = keystore.aliases()

  while (aliases.hasMoreElements) {
    val alias = aliases.nextElement
    logger.info("alias name: " + alias)
    val certificate = keystore.getCertificate(alias).asInstanceOf[X509Certificate]
    val CN = CertUtil.subjectCN(certificate)
    logger.info("Common Name: " + CN)
  }