Comment 1 for bug 1861883

Problem can be reproduced using a minimal Example as follows:

# This is what we have:

user@host:~/work$ ls -al
total 20
drwxrwx--- 2 user user 4096 Feb 14 17:33 .
drwxr-xr-x 5 user user 4096 Feb 14 17:29 ..
-rw-rw---- 1 user user 942 Feb 14 17:29 KerberosDemo.java
-rw-rw---- 1 user user 101 Feb 13 13:13 jaas_cached.conf
-rw-rw---- 1 user user 276 Feb 13 13:24 jaas_keytab.conf

# it's a minimal example

user@host:~/work$ cat KerberosDemo.java
import javax.security.auth.login.*;
import java.util.Iterator;
import java.util.Set;
import javax.security.auth.Subject;
import javax.security.auth.kerberos.KerberosTicket;

public class KerberosDemo {
        public static void main (String[] args) {
                LoginContext loginContext = null;
                try {
                        loginContext = new LoginContext("Demo");
                }
                catch (LoginException e) {
                        System.err.println("login context creation failed: "+e.getMessage());
                        System.exit(1);
                }
                try {
                        loginContext.login();
                }
                catch (LoginException e) {
                        System.out.println("authentication failed");
                        System.exit(1);
                }
                Subject subject = loginContext.getSubject();
                System.out.println("Authenticated principal: " + subject.getPrincipals());
                Set credentials = subject.getPrivateCredentials();
                Iterator iterator = credentials.iterator();
                KerberosTicket kt = (KerberosTicket) iterator.next();
                System.out.println("Client name: " + kt.getClient());
        }
}

# let's compile it

user@host:~/work$ javac KerberosDemo.java

# and use it either with a keytab (JAAS is getting the ticket) ...

user@host:~/work$ cat jaas_keytab.conf # use keytab!
Demo {
    com.sun.security.auth.module.Krb5LoginModule required
    useKeyTab=true
    keyTab="/etc/security/keytabs/myprincipal.service.keytab"
    storeKey=true
    useTicketCache=false
    serviceName="serviceprincipal"
    <email address hidden>";
};

# ... or with a ticket gotten earlier by MIT Kerberos client (kinit)

user@host:~/work$ cat jaas_cached.conf # use cached!
Demo {
    com.sun.security.auth.module.Krb5LoginModule required
    useKeyTab=false
    useTicketCache=true;
};

# this is how the ticket was placed in the cache

user@host:~/work$ kinit -kt /etc/security/keytabs/myprincipal.service.keytab <email address hidden>

# now, this is what happens with OpenJDK 1.8.0_232
# principal name and client name all refer to <email address hidden> (in AD, this is the servicePrincipalName):

user@host:~/work$ java -version
openjdk version "1.8.0_232"
OpenJDK Runtime Environment (build 1.8.0_232-8u232-b09-0ubuntu1~18.04.1-b09)
OpenJDK 64-Bit Server VM (build 25.232-b09, mixed mode)
user@host:~/work$ java -Djava.security.auth.login.config=jaas_keytab.conf KerberosDemo
Authenticated principal: [<email address hidden>]
Client name: <email address hidden>
user@host:~/work$ java -Djava.security.auth.login.config=jaas_cached.conf KerberosDemo
Authenticated principal: [<email address hidden>]
Client name: <email address hidden>

# while this is what we see with OpenJDK 1.8.0_242
# while for the cached ticket the results are the same, for the ticket gotten by JAAS the names differ!!!
# Note: $V9H200-TAD2F4IK2G09 is the sAMAccountName of the AD user with servicePrincipalName <email address hidden>

user@host:~/work$ java -version
openjdk version "1.8.0_242"
OpenJDK Runtime Environment (build 1.8.0_242-8u242-b08-0ubuntu3~18.04-b08)
OpenJDK 64-Bit Server VM (build 25.242-b08, mixed mode)
user@host:~/work$ java -Djava.security.auth.login.config=jaas_keytab.conf KerberosDemo
Authenticated principal: [<email address hidden>]
Client name: $<email address hidden>
user@host:~/work$ java -Djava.security.auth.login.config=jaas_cached.conf KerberosDemo
Authenticated principal: [<email address hidden>]
Client name: <email address hidden>