Cassandra Kerberos Authenticator
A GSSAPI authentication provider for Apache Cassandra
This authenticator plugin is intended to work with the Cassandra Java Driver Kerberos Authenticator plugin for the Cassandra Java driver.
Supported versions:
-
2.2
-
3.0
-
3.11
-
4.0
Warning
|
if you install / configure this authenticator, with open source Cassandra, for now, you will not be able to connect through CQL shell anymore as this functionality is not implemented in CQL shell yet. This authenticator is meant to be used only in connection with Java applications for which you need to setup your driver to use Kerberos Java driver, also from Instaclustr. |
Build
To build the project, just run mvn clean install
.
The project is organised into modules, each module per major Cassandra version. You will find in target
of each module for respective Cassandra version:
-
JAR
-
DEB package
-
RPM package
Environment set-up
-
Ensure that the following pre-requisite systems are configured:
-
A unique DNS record is created for each node (use
hostname -f
on each node to verify that the DNS FQDN is configured) -
A reverse DNS record is created for each node, matching the
broadcast_rpc_address
-
A Kerberos 5 KDC server is available
-
Kerberos client libraries are installed on each Cassandra node
-
An NTP client is installed & configured on each Cassandra node. Ideally the Cassandra nodes sync with the same time source as the KDC in order to minimise potential time-sync issues.
-
If using Oracle Java, ensure that the Java Cryptographic Extensions Unlimited Strength Jurisdiction Policy Files are installed (not necessary when using OpenJDK or other JRE implementations)
-
-
Ensure that the value of rpc_address (and optionally broadcast_rpc_address, if using) in the
cassandra.yaml
config file is not set tolocalhost
. Reverse-DNS records must be created to match thebroadcast_rpc_address
. This enables clients to resolve the Kerberos service principal’s hostname from the IP address. -
Configure the
/etc/krb5.conf
Kerberos config file on each node (see here for further details). Below is an examplekrb5.conf
for anEXAMPLE.COM
Kerberos realm:[logging] default = FILE:/var/log/krb5libs.log [libdefaults] default_realm = EXAMPLE.COM dns_lookup_realm = false dns_lookup_kdc = false [realms] EXAMPLE.COM = { kdc = kdc.example.com admin_server = kdc.example.com } [domain_realm] .example.com = EXAMPLE.COM example.com = EXAMPLE.COM
-
For each cassandra node, create a new Kerberos service principal (see here for further details) Note that the service name portion of the principal (
cassandra
, in this example) must be the same for each node in the cluster, and must also match the SASL protocol name specified when configuring the Cassandra Java driver Kerberos authenticator. The hostname portion of the principal (e.g.node1.mycluster.example.com
) must match the DNS entry for each Cassandra node.kadmin -q "addprinc -randkey cassandra/[email protected]" kadmin -q "addprinc -randkey cassandra/[email protected]" kadmin -q "addprinc -randkey cassandra/[email protected]"
-
Create a keytab for each newly created service principal (see here for further details)
kadmin -q "ktadd -k /node1.keytab cassandra/[email protected]" kadmin -q "ktadd -k /node2.keytab cassandra/[email protected]" kadmin -q "ktadd -k /node3.keytab cassandra/[email protected]"
-
Copy the corresponding keytab file to the Cassandra configuration directory on each node, and set the appropriate access controls
scp kdc.example.com:/node1.keytab /etc/cassandra/node1.keytab chown cassandra:cassandra /etc/cassandra/node1.keytab chmod 400 /etc/cassandra/node1.keytab
Install & configure the Kerberos authenticator
-
Copy the
cassandra-krb5.properties
file to the Cassandra configuration directory on each node (e.g./etc/cassandra/conf
or/etc/cassandra
, based on OS). Setservice_principal
andkeytab
to correspond to the service principals and keytabs created in the previous steps.service_principal=cassandra/[email protected] keytab=node1.keytab qop=auth
-
Copy the authenicator jar to the Cassandra
lib
directory (e.g./usr/share/cassandra/lib/
) -
Set the authenticator option in the
cassandra.yaml
config file.authenticator: com.instaclustr.cassandra.auth.KerberosAuthenticator
You may control where to fetch the configuration file from by system property set upon Cassandra startup, for example -Dcassandra.krb5.config=/path/to/conf.properties
In case you are using packages, JAR and conf file is installed into the right place automatically.
In case you are Please see status for Instaclustr support status of this project