If you configure HiveServer2 to use Kerberos authentication, HiveServer2 acquires a Kerberos ticket during startup. HiveServer2 requires a principal and keytab file specified in the configuration. Client applications (for example, JDBC or Beeline) must have a valid Kerberos ticket before initiating a connection to HiveServer2.

String url = "jdbc:hive2://node1:10000/default;principal=hive/HiveServer2Host@YOUR-REALM.COM"
Connection con = DriverManager.getConnection(url);

$ /usr/lib/hive/bin/beeline
beeline> !connect jdbc:hive2://localhost:10000/default;principal=hive/HiveServer2Host@YOUR-REALM.COM
0: jdbc:hive2://localhost:10000/default>

As an alternative to Kerberos authentication, you can configure HiveServer2 to use user and password validation backed by LDAP. The client sends a username and password during connection initiation. HiveServer2 validates these credentials using an external LDAP service.

You can enable LDAP Authentication with HiveServer2 using Active Directory or OpenLDAP.

  Important: When using LDAP username/password authentication with HiveServer2, you must enable encrypted communication between HiveServer2 and its client drivers to avoid sending cleartext passwords. For instructions, see Configuring Encrypted Communication Between HiveServer2 and Client Drivers. To avoid sending LDAP credentials over a network in cleartext, see Configuring LDAPS Authentication with HiveServer2.

String url = "jdbc:hive2://node1:10000/default;user=LDAP_Userid;password=LDAP_Password"
Connection con = DriverManager.getConnection(url);

HiveServer2 supports LDAP username/password authentication for clients. Clients send LDAP credentials to HiveServer2 which in turn verifies them against the configured LDAP provider, such as OpenLDAP or Microsoft Active Directory. Most implementations now support LDAPS (LDAP over TLS/SSL), an authentication protocol that uses TLS/SSL to encrypt communication between the LDAP service and its client (in this case, HiveServer2) to avoid sending LDAP credentials in cleartext.

To configure the LDAPS service with HiveServer2:

1. Import the LDAP server CA certificate or the server certificate into a truststore on the HiveServer2 host. If you import the CA certificate, HiveServer2 will trust any server with a certificate issued by the LDAP server's CA. If you only import the server certificate, HiveServer2 trusts only that server. See Understanding Keystores and Truststores for more details.
2. Make sure the truststore file is readable by the hive user.
3. Set the hive.server2.authentication.ldap.url configuration property in hive-site.xml to the LDAPS URL. For example, ldaps://sample.myhost.com.
     Note: The URL scheme should be ldaps and not ldap.

4. In Cloudera Manager, go to the Hive service and select Configuration. Under Category, select Security. In the right panel, search for HiveServer2 TLS/SSL Certificate Trust Store File, and add the path to the truststore file that you created in step 1.

5. Restart HiveServer2.

Pluggable authentication allows you to provide a custom authentication provider for HiveServer2.

To enable pluggable authentication:

1. In the Cloudera Manager Admin Console, click Hive in the list of components, and then select the Configuration tab.
2. Type hive-site.xml in the Search text box to locate the configuration fields.
3. Add entries similar to the following to Hive Service Advanced Configuration Snippet (Safety Valve) for hive-site.xml:

   <property>
     <name>hive.server2.authentication</name>
     <value>CUSTOM</value>
     <description>Client authentication types.
     NONE: no authentication check
     LDAP: LDAP/AD based authentication
     KERBEROS: Kerberos/GSSAPI authentication
     CUSTOM: Custom authentication provider
     (Use with property hive.server2.custom.authentication.class)
     </description>
   </property>
   
   <property>
     <name>hive.server2.custom.authentication.class</name>
     <value>pluggable-auth-class-name</value>
     <description>
     Custom authentication class. Used when property
     'hive.server2.authentication' is set to 'CUSTOM'. Provided class
     must be a proper implementation of the interface
     org.apache.hive.service.auth.PasswdAuthenticationProvider. HiveServer2
     will call its Authenticate(user, passed) method to authenticate requests.
     The implementation may optionally extend the Hadoop's
     org.apache.hadoop.conf.Configured class to grab Hive's Configuration object.
     </description>
   </property>

4. Make the class available in the CLASSPATH of HiveServer2.

HiveServer2 determines the identity of the connecting user from the authentication subsystem (Kerberos or LDAP). Any new session started for this connection runs on behalf of this connecting user. If the server is configured to proxy the user at the Hadoop level, then all MapReduce jobs and HDFS accesses will be performed with the identity of the connecting user. If Apache Sentry is configured, then this connecting userid can also be used to verify access rights to underlying tables and views.

Users with Hadoop superuser privileges can request an alternate user for the given session. HiveServer2 checks that the connecting user can proxy the requested userid, and if so, runs the new session as the alternate user. For example, the Hadoop superuser hue can request that a connection's session be run as user bob.

# Login as super user Hue 
kinit hue -k -t hue.keytab hue@MY-REALM.COM

# Connect using following JDBC connection string 
# jdbc:hive2://myHost.myOrg.com:10000/default;principal=hive/_HOST@MY-REALM.COM;hive.server2.proxy.user=bob

The connecting user must have Hadoop-level proxy privileges over the alternate user.

  Important: This is not the recommended method to implement HiveServer2 authorization. Cloudera recommends you use Sentry to implement this instead.

HiveServer2 impersonation lets users execute queries and access HDFS files as the connected user rather than as the super user. Access policies are applied at the file level using the HDFS permissions specified in ACLs (access control lists). Enabling HiveServer2 impersonation bypasses Sentry from the end-to-end authorization process. Specifically, although Sentry enforces access control policies on tables and views within the Hive warehouse, it does not control access to the HDFS files that underlie the tables. This means that users without Sentry permissions to tables in the warehouse may nonetheless be able to bypass Sentry authorization checks and execute jobs and queries against tables in the warehouse as long as they have permissions on the HDFS files supporting the table.

To configure Sentry correctly, restrict ownership of the Hive warehouse to hive:hive and disable Hive impersonation as described here.

To enable impersonation in HiveServer2:

1. Add the following property to the /etc/hive/conf/hive-site.xml file and set the value to true. (The default value is false.)

   <property>
     <name>hive.server2.enable.impersonation</name>
     <description>Enable user impersonation for HiveServer2</description>
     <value>true</value>
   </property>

2. In HDFS or MapReduce configurations, add the following property to the core-site.xml file:

   <property>
     <name>hadoop.proxyuser.hive.hosts</name>
     <value>*</value>
   </property>
   <property>
     <name>hadoop.proxyuser.hive.groups</name>
     <value>*</value>
   </property>

See also File System Permissions.

  Note: This is not the recommended method to protect the Hive Metastore. Cloudera recommends you use Sentry to implement this instead.

To prevent users from accessing the Hive metastore and the Hive metastore database using any method other than through HiveServer2, the following actions are recommended:

• Add a firewall rule on the metastore service host to allow access to the metastore port only from the HiveServer2 host. You can do this using iptables.
• Grant access to the metastore database only from the metastore service host. This is specified for MySQL as:

  GRANT ALL PRIVILEGES ON metastore.* TO 'hive'@'metastorehost';

  where metastorehost is the host where the metastore service is running.
• Make sure users who are not admins cannot log on to the host on which HiveServer2 runs.