The keytool password for the Java security cacerts file is ...

In case you ever need to manually a certificate to your ${JAVA_HOME}/jre/lib/security/cacerts file, it turns out the password for that file when using the Java keytool command is changeit.

To add a certificate to that file, you’ll want to use a command like this:

keytool \
    -import \
    -alias "" \
    -keystore ${JAVA_HOME}/jre/lib/security/cacerts \

I had to do this today for a Java/Scala script that accesses an HTTPS URL, and the site I’m accessing uses a “Let’s Encrypt” certificate.