Configuring Client Authentication with LDAP
You can use Active Directory (AD) and/or LDAP to configure client authentication
across all of your Kafka clusters that use SASL/PLAIN. The SASL/PLAIN binding to
LDAP requires a password provided by the client. Note that you cannot bind SASL/SCRAM
to LDAP because client credentials (the password) cannot be sent by the client.
You must set up an LDAP server (for example, AD) before starting up the Kafka
cluster. The configuration that follows is based on the assumption that you have
an LDAP server at the URL LDAPSERVER.EXAMPLE.COM:3268
that is accessible using DNS
lookup from the host where the broker is run. The configuration expects a
Kerberos-enabled LDAP server (although Kerberos is not required–you can perform a
simple bind if your LDAP supports it) and the LDAP Authorizer configuration uses GSSAPI
for authentication. These security settings must match your LDAP server configuration.
If your LDAP server authenticates clients using Kerberos, a keytab file is
required for the LDAP authorizer and the keytab file and principal should be
updated in authorizer JAAS configuration option ldap.sasl.jaas.config
.
To configure LDAP, refer to Configure LDAP Group-Based Authorization for MDS.
To configure client authentication with AD/LDAP:
Start the LDAP server.
Add the user name and password to LDAP:
dn: uid=client,ou=people,dc=planetexpress,dc=com
userPassword: client-secret
Enable LDAP authentication for Kafka clients by adding the LDAP callback handler
to server.properties
in the broker.
Add the SASL configuration:
listener.name.sasl_plaintext.sasl.enabled.mechanisms=PLAIN
listener.name.sasl_plaintext.plain.sasl.jaas.config=org.apache.kafka.common.security.plain.PlainLoginModule required;
listener.name.sasl_plaintext.plain.sasl.server.callback.handler.class=
io.confluent.security.auth.provider.ldap.LdapAuthenticateCallbackHandler
If you want to use LDAP authentication for inter-broker communication, then
you must include the broker’s user name and password in your SASL configuration.
Add the LDAP configuration:
ldap.java.naming.provider.url=ldap://openldap:389
# Authenticate to LDAP
ldap.java.naming.security.principal=CN=admin,DC=planetexpress,DC=com
ldap.java.naming.security.credentials=GoodNewsEveryone
ldap.java.naming.security.authentication=simple
# Locate users
ldap.user.search.base=ou=people,dc=planetexpress,dc=com
ldap.user.name.attribute=uid
ldap.user.object.class=user
ldap.user.password.attribute=userPassword
Restart the Kafka broker.
/bin/kafka-server-start etc/kafka/server.properties
Specify the client configuration in producer.properties
and consumer.properties
:
sasl.mechanism=PLAIN
security.protocol=SASL_PLAINTEXT
sasl.jaas.config=org.apache.kafka.common.security.plain.PlainLoginModule
required username="client" password="client-secret";
It’s recommended that you encrypt the password in your client configuration
using Secrets Management. The following example shows an encrypted client configuration:
sasl.jaas.config=org.apache.kafka.common.security.plain.PlainLoginModule
required username="client" password=${securepass:/secretsDemo/server.properties:server.properties/sasl.jaas.config/=org.apache.kafka.common.security.plain.PlainLoginModule /password};
Note
Credentials are sent in PLAIN text, so be sure to use TLS with LDAP.