Kerberos Setup

This document provides instructions for kerberizing Metron's Vagrant-based development environments; “Quick Dev” and “Full Dev”. These instructions do not cover the Ambari MPack or sensors. General Kerberization notes can be found in the metron-deployment README.md.

Setup

  1. Deploy a Vagrant development environment; either Full Dev or Quick Dev.

  2. Export the following environment variables. These need to be set for the remainder of the instructions. Replace node1 with the appropriate hosts, if you are running Metron anywhere other than Vagrant.

    # execute as root
sudo su -
export KAFKA_HOME="/usr/hdp/current/kafka-broker"
export ZOOKEEPER=node1:2181
export ELASTICSEARCH=node1:9200
export BROKERLIST=node1:6667
export HDP_HOME="/usr/hdp/current"
export KAFKA_HOME="${HDP_HOME}/kafka-broker"
export METRON_VERSION="0.4.0"
export METRON_HOME="/usr/metron/${METRON_VERSION}"

  3. Execute the following commands as root.

    	sudo su -

  4. Stop all Metron topologies. They will be restarted again once Kerberos has been enabled.

    	for topology in bro snort enrichment indexing; do
		storm kill $topology;
	done

  5. Create the metron user's home directory in HDFS.

    	sudo -u hdfs hdfs dfs -mkdir /user/metron
	sudo -u hdfs hdfs dfs -chown metron:hdfs /user/metron
	sudo -u hdfs hdfs dfs -chmod 770 /user/metron

Setup a KDC

  1. Install dependencies.

    	yum -y install krb5-server krb5-libs krb5-workstation

  2. Define the host, node1, as the KDC.

    	sed -i 's/kerberos.example.com/node1/g' /etc/krb5.conf
	cp -f /etc/krb5.conf /var/lib/ambari-server/resources/scripts

  3. Ensure the KDC can issue renewable tickets. This can be necessary on a real cluster, but should not be on full-dev. In /var/kerberos/krb5kdc/kdc.conf ensure the following is in the realm section

    max_renewable_life = 7d

  4. Do not copy/paste this full set of commands as the kdb5_util command will not run as expected. Run the commands individually to ensure they all execute. This step takes a moment. It creates the kerberos database.

    	kdb5_util create -s

	/etc/rc.d/init.d/krb5kdc start
	chkconfig krb5kdc on

	/etc/rc.d/init.d/kadmin start
	chkconfig kadmin on

  5. Setup the admin and metron principals. You'll kinit as the metron principal when running topologies. Make sure to remember the passwords.

    	kadmin.local -q "addprinc admin/admin"
	kadmin.local -q "addprinc metron"

Verify KDC

Ticket renewal is by default disallowed in many linux distributions. If the KDC cannot issue renewable tickets, an error will be thrown when starting Metron's Storm topologies:

Exception in thread "main" java.lang.RuntimeException: java.lang.RuntimeException: The TGT found is not renewable

Ensure the Metron keytab is renewable. Look for the ‘R’ flag from the following command

klist -f

If the ‘R’ flags are present, you may skip to next section.

If the ‘R’ flags are absent, you will need to follow the below steps: If the KDC is already setup, then editing max_life and max_renewable_life in /var/kerberos/krb5kdc/kdc.conf, and restarting kadmin and krb5kdc services will not change the policies for existing users.

You need to set the renew lifetime for existing users and krbtgt realm. Modify the appropriate principals to allow renewable tickets using the following commands. Adjust the parameters to match your desired KDC parameters:

kadmin.local -q "modprinc -maxlife 1days -maxrenewlife 7days +allow_renewable krbtgt/EXAMPLE.COM@EXAMPLE.COM"
kadmin.local -q "modprinc -maxlife 1days -maxrenewlife 7days +allow_renewable metron@EXAMPLE.COM"

Enable Kerberos

  1. In Ambari, setup Storm to use Kerberos and run worker jobs as the submitting user.

    a. Add the following properties to the custom storm-site:

    topology.auto-credentials=['org.apache.storm.security.auth.kerberos.AutoTGT']
nimbus.credential.renewers.classes=['org.apache.storm.security.auth.kerberos.AutoTGT']
supervisor.run.worker.as.user=true

    b. In the Storm config section in Ambari, choose “Add Property” under custom storm-site:

    custom storm-site

    c. In the dialog window, choose the “bulk property add mode” toggle button and add the below values:

    custom storm-site properties

  2. Kerberize the cluster via Ambari. More detailed documentation can be found here.

    a. For this exercise, choose existing MIT KDC (this is what we setup and installed in the previous steps.)

    enable keberos

    enable keberos get started

    b. Setup Kerberos configuration. Realm is EXAMPLE.COM. The admin principal will end up as admin/admin@EXAMPLE.COM when testing the KDC. Use the password you entered during the step for adding the admin principal.

    enable keberos configure

    c. Click through to “Start and Test Services.” Let the cluster spin up, but don‘t worry about starting up Metron via Ambari - we’re going to run the parsers manually against the rest of the Hadoop cluster Kerberized. The wizard will fail at starting Metron, but this is OK. Click “continue.” When you’re finished, the custom storm-site should look similar to the following:

    enable keberos configure

  3. Create a Metron keytab

    	kadmin.local -q "ktadd -k metron.headless.keytab metron@EXAMPLE.COM"
	cp metron.headless.keytab /etc/security/keytabs
	chown metron:hadoop /etc/security/keytabs/metron.headless.keytab
	chmod 440 /etc/security/keytabs/metron.headless.keytab

Kafka Authorization

  1. Acquire a Kerberos ticket using the metron principal.

    	kinit -kt /etc/security/keytabs/metron.headless.keytab metron@EXAMPLE.COM

  2. Create any additional Kafka topics that you will need. We need to create the topics before adding the required ACLs. The current full dev installation will deploy bro, snort, enrichments, and indexing only. For example, you may want to add a topic for ‘yaf’ telemetry.

    	${KAFKA_HOME}/bin/kafka-topics.sh \
  --zookeeper ${ZOOKEEPER} \
  --create \
  --topic yaf \
  --partitions 1 \
  --replication-factor 1

  3. Setup Kafka ACLs for the bro, snort, enrichments, and indexing topics. Run the same command against any additional topics that you might be using; for example yaf.

    	export KERB_USER=metron

	for topic in bro snort enrichments indexing; do
		${KAFKA_HOME}/bin/kafka-acls.sh \
      --authorizer kafka.security.auth.SimpleAclAuthorizer \
      --authorizer-properties zookeeper.connect=${ZOOKEEPER} \
      --add \
      --allow-principal User:${KERB_USER} \
      --topic ${topic}
	done

  4. Setup Kafka ACLs for the consumer groups. This command sets the ACLs for Bro, Snort, YAF, Enrichments, Indexing, and the Profiler. Execute the same command for any additional Parsers that you may be running.

    export KERB_USER=metron

	for group in bro_parser snort_parser yaf_parser enrichments indexing profiler; do
		${KAFKA_HOME}/bin/kafka-acls.sh \
      --authorizer kafka.security.auth.SimpleAclAuthorizer \
      --authorizer-properties zookeeper.connect=${ZOOKEEPER} \
      --add \
      --allow-principal User:${KERB_USER} \
      --group ${group}
	done

  5. Add the metron principal to the kafka-cluster ACL.

    	${KAFKA_HOME}/bin/kafka-acls.sh \
    --authorizer kafka.security.auth.SimpleAclAuthorizer \
    --authorizer-properties zookeeper.connect=${ZOOKEEPER} \
    --add \
    --allow-principal User:${KERB_USER} \
    --cluster kafka-cluster

HBase Authorization

  1. Acquire a Kerberos ticket using the hbase principal

    	kinit -kt /etc/security/keytabs/hbase.headless.keytab hbase-metron_cluster@EXAMPLE.COM

  2. Grant permissions for the HBase tables used in Metron.

    	echo "grant 'metron', 'RW', 'threatintel'" | hbase shell
	echo "grant 'metron', 'RW', 'enrichment'" | hbase shell

  3. If you are using the Profiler, do the same for its HBase table.

    	echo "create 'profiler', 'P'" | hbase shell
	echo "grant 'metron', 'RW', 'profiler', 'P'" | hbase shell

Storm Authorization

  1. Switch to the metron user and acquire a Kerberos ticket for the metron principal.

    	su metron
	kinit -kt /etc/security/keytabs/metron.headless.keytab metron@EXAMPLE.COM

  2. Create the directory /home/metron/.storm and switch to that directory.

    	mkdir /home/metron/.storm
	cd /home/metron/.storm

  3. Ensure the Metron keytab is renewable. See Verify KDC above

  4. Create a client JAAS file at /home/metron/.storm/client_jaas.conf. This should look identical to the Storm client JAAS file located at /etc/storm/conf/client_jaas.conf except for the addition of a Client stanza. The Client stanza is used for Zookeeper. All quotes and semicolons are necessary.

    cat << EOF > client_jaas.conf
StormClient {
    com.sun.security.auth.module.Krb5LoginModule required
    useTicketCache=true
    renewTicket=true
    serviceName="nimbus";
};
Client {
    com.sun.security.auth.module.Krb5LoginModule required
    useKeyTab=true
    keyTab="/etc/security/keytabs/metron.headless.keytab"
    storeKey=true
    useTicketCache=false
    serviceName="zookeeper"
    principal="metron@EXAMPLE.COM";
};
KafkaClient {
    com.sun.security.auth.module.Krb5LoginModule required
    useKeyTab=true
    keyTab="/etc/security/keytabs/metron.headless.keytab"
    storeKey=true
    useTicketCache=false
    serviceName="kafka"
    principal="metron@EXAMPLE.COM";
};
EOF

  5. Create a YAML file at /home/metron/.storm/storm.yaml. This should point to the client JAAS file. Set the array of nimbus hosts accordingly.

    cat << EOF > /home/metron/.storm/storm.yaml
nimbus.seeds : ['node1']
java.security.auth.login.config : '/home/metron/.storm/client_jaas.conf'
storm.thrift.transport : 'org.apache.storm.security.auth.kerberos.KerberosSaslTransportPlugin'
EOF

  6. Create an auxiliary storm configuration file at /home/metron/storm-config.json. Note the login config option in the file points to the client JAAS file.

    cat << EOF > /home/metron/storm-config.json
{
    "topology.worker.childopts" : "-Djava.security.auth.login.config=/home/metron/.storm/client_jaas.conf"
}
EOF

  7. Configure the Enrichment, Indexing and the Profiler topologies to use the client JAAS file. Add the following properties to each of the topology properties files.

    	kafka.security.protocol=PLAINTEXTSASL
	topology.worker.childopts=-Djava.security.auth.login.config=/home/metron/.storm/client_jaas.conf
    • ${METRON_HOME}/config/enrichment.properties
    • ${METRON_HOME}/config/elasticsearch.properties
    • ${METRON_HOME}/config/profiler.properties

    Use the following command to automate this step.

    for file in enrichment.properties elasticsearch.properties profiler.properties; do
  echo ${file}
  sed -i "s/^kafka.security.protocol=.*/kafka.security.protocol=PLAINTEXTSASL/" "${METRON_HOME}/config/${file}"
  sed -i "s/^topology.worker.childopts=.*/topology.worker.childopts=-Djava.security.auth.login.config=\/home\/metron\/.storm\/client_jaas.conf/" "${METRON_HOME}/config/${file}"
done

Start Metron

  1. Switch to the metron user and acquire a Kerberos ticket for the metron principal.

    	su metron
	kinit -kt /etc/security/keytabs/metron.headless.keytab metron@EXAMPLE.COM

  2. Restart the parser topologies. Be sure to pass in the new parameter, -ksp or --kafka_security_protocol. The following command will start only the Bro and Snort topologies. Execute the same command for any other Parsers that you may need, for example yaf.

    for parser in bro snort; do
   ${METRON_HOME}/bin/start_parser_topology.sh \
           -z ${ZOOKEEPER} \
           -s ${parser} \
           -ksp SASL_PLAINTEXT \
           -e /home/metron/storm-config.json;
done

  3. Restart the Enrichment and Indexing topologies.

    	${METRON_HOME}/bin/start_enrichment_topology.sh
	${METRON_HOME}/bin/start_elasticsearch_topology.sh

Metron should be ready to receive data.

Push Data

  1. Push some sample data to one of the parser topics. E.g for Bro we took raw data from incubator-metron/metron-platform/metron-integration-test/src/main/sample/data/bro/raw/BroExampleOutput

    	cat sample-bro.txt | ${KAFKA_HOME}/kafka-broker/bin/kafka-console-producer.sh \
	        --broker-list ${BROKERLIST}
      	--security-protocol SASL_PLAINTEXT \
        --topic bro

  2. Wait a few moments for data to flow through the system and then check for data in the Elasticsearch indices. Replace yaf with whichever parser type you’ve chosen.

    	curl -XGET "${ELASTICSEARCH}/bro*/_search"
	curl -XGET "${ELASTICSEARCH}/bro*/_count"

  3. You should have data flowing from the parsers all the way through to the indexes. This completes the Kerberization instructions

More Information

Kerberos

Unsure of your Kerberos principal associated with a keytab? There are a couple ways to get this. One is via the list of principals that Ambari provides via downloadable csv. If you didn’t download this list, you can also check the principal manually by running the following against the keytab.

klist -kt /etc/security/keytabs/<keytab-file-name>

E.g.

klist -kt /etc/security/keytabs/hbase.headless.keytab
Keytab name: FILE:/etc/security/keytabs/hbase.headless.keytab
KVNO Timestamp         Principal
---- ----------------- --------------------------------------------------------
   1 03/28/17 19:29:36 hbase-metron_cluster@EXAMPLE.COM
   1 03/28/17 19:29:36 hbase-metron_cluster@EXAMPLE.COM
   1 03/28/17 19:29:36 hbase-metron_cluster@EXAMPLE.COM
   1 03/28/17 19:29:36 hbase-metron_cluster@EXAMPLE.COM
   1 03/28/17 19:29:36 hbase-metron_cluster@EXAMPLE.COM

Kafka with Kerberos enabled

Write data to a topic with SASL

cat sample-yaf.txt | ${KAFKA_HOME}/bin/kafka-console-producer.sh \
        --broker-list ${BROKERLIST} \
        --security-protocol PLAINTEXTSASL \
        --topic yaf

View topic data from latest offset with SASL

${KAFKA_HOME}/bin/kafka-console-consumer.sh \
        --zookeeper ${ZOOKEEPER} \
        --security-protocol PLAINTEXTSASL \
        --topic yaf

Modify the sensor-stubs to send logs via SASL

sed -i 's/node1:6667 --topic/node1:6667 --security-protocol PLAINTEXTSASL --topic/' /opt/sensor-stubs/bin/start-*-stub
for sensorstub in bro snort; do
    service sensor-stubs stop ${sensorstub};
    service sensor-stubs start ${sensorstub};
done

References