10.3. LDAP Authentication

Presto can be configured to enable frontend LDAP authentication over HTTPS for clients, such as the Presto CLI, or the JDBC and ODBC drivers. At present only simple LDAP authentication mechanism involving user name and password is supported. The Presto client sends a user name and password to the coordinator and coordinator validates these credentials using an external LDAP service.

To enable LDAP authentication for Presto, configuration changes are made on the Presto coordinator. No changes are required to the worker configuration; only the communication from the clients to the coordinator is authenticated.

Presto Server Configuration

Environment Configuration

LDAP Server

You can configure the Presto coordinator to authenticate against one of the following types of LDAP server implementations:

  • Active Directory
  • OpenLDAP

Presto requires Secure LDAP (LDAPS), so make sure you have TLS enabled on your LDAP server.

TLS Configuration on Presto Coordinator

You need to import the LDAP server’s TLS certificate to the default Java truststore of the Presto coordinator to secure TLS connection. You can use the following example keytool command to import the certificate ldap_server.crt, to the truststore on the coordinator.

$ keytool -import -keystore <JAVA_HOME>/jre/lib/security/cacerts -trustcacerts -alias ldap_server -file ldap_server.crt

In addition to this, access to the Presto coordinator should be through HTTPS. You can do it by creating a Java Keystore File for TLS on the coordinator.

Presto Coordinator Node Configuration

You must make the following changes to the environment prior to configuring the Presto coordinator to use LDAP authentication and HTTPS.

You also need to make following changes to the Presto configuration files.

config.properties

LDAP authentication is configured in the coordinator node’s config.properties file. Properties that need to be added, along with their sample values, are listed below.

authentication.ldap.enabled=true
authentication.ldap.url=ldaps://ldap-server:636

http-server.https.enabled=true
http-server.https.port=8443

http-server.https.keystore.path=/etc/presto_keystore.jks
http-server.https.keystore.key=keystore_password

In addition to the above properties, you will need to add LDAP server implementation specific properties.

For Active Directory:

authentication.ldap.server-type=active_directory
authentication.ldap.ad-domain=corp.domain.com

For OpenLDAP:

authentication.ldap.server-type=openLDAP
authentication.ldap.base-dn=OU=Asia,DC=corp,DC=domain,DC=com
Property Description
authentication.ldap.enabled Enable LDAP authentication for the Presto coordinator. Must be set to true. Default value is false.
authentication.ldap.url The url to the LDAP server. The url scheme must be ldaps:// and Presto allows only Secure LDAP.
authentication.ldap.server-type The type of LDAP server implementation. Set to active_directory or openLDAP.
authentication.ldap.ad-domain The domain name of the Active Directory server. This property is required only if authentication.ldap.server-type is set to Active_Directory. Eg: corp.domain.com.
authentication.ldap.base-dn The base LDAP distinguished name for the user who who tries to connect to the server. This property is required if authentication.ldap.server-type is set to openLDAP or when specifying LDAP group membership properties.
http-server.https.enabled Enables HTTPS access for the Presto coordinator. Should be set to true. Default value is false.
http-server.https.port HTTPS server port.
http-server.https.keystore.path The location of the Java Keystore file that will be used to secure TLS.
http-server.https.keystore.key The password for the keystore. This must match the password you specified when creating the keystore.
Authorization based on LDAP Group Membership

You can further restrict the set of users allowed to connect to the Presto coordinator based on their group memberships. This optional feature is enabled if you set authentication.ldap.group-dn property. Only users belonging to the group with distinguished name authentication.ldap.group-dn are authenticated successfully.

In addition to the basic LDAP authentication properties, you need group-membership specific properties in config.properties. Properties that need to be added, along with their sample values, are listed below.

authentication.ldap.base-dn=OU=America,DC=corp,DC=domain,DC=com
authentication.ldap.group-dn=CN=AuthorizedGroup,OU=America,DC=corp,DC=domain,DC=com

For Active Directory:

authentication.ldap.user-object-class=person

For OpenLDAP:

authentication.ldap.user-object-class=inetOrgPerson

Note

Presto does not yet support providing multiple groups for authentication.ldap.group-dn. Nested group authorization, where you want to authorize a user who belongs to a group which is a member of authentication.ldap.group-dn is also not supported.

For OpenLDAP, for this feature to work, make sure you enable the memberOf overlay.

Property Description
authentication.ldap.base-dn The base LDAP distinguished name for the user who who tries to connect to the server.
authentication.ldap.group-dn The entire LDAP dn for the group which must be authorized to access Presto. The user trying to connect to the server with base dn authentication.ldap.base-dn must belong to this group for successful authentication.
authentication.ldap.user-object-class The LDAP objectClass the user implements in LDAP. Eg: person.

Presto CLI

Environment Configuration

TLS Configuration

Access to the Presto coordinator should be through HTTPS when using LDAP authentication. The Presto CLI can use either a Java Keystore file or Java Truststore for its TLS configuration.

If you are using keystore file, it can be copied to the client machine and used for its TLS configuration. If you are using truststore, you can either use default java truststores or create a custom truststore on the CLI. We do not recommend using self-signed certificates in production.

Presto CLI Execution

In addition to the options that are required when connecting to a Presto coordinator that does not require LDAP authentication, invoking the CLI with LDAP support enabled requires a number of additional command line options. You can either use --keystore-* or --truststore-* properties to secure TLS connection. The simplest way to invoke the CLI is with a wrapper script.

#!/bin/bash

./presto \
--server https://presto-coordinator.example.com:8443 \
--keystore-path /tmp/presto.jks \
--keystore-password password \
--truststore-path /tmp/presto_truststore.jks
--truststore-password password
--catalog <catalog> \
--schema <schema> \
--user <LDAP user>
--password <password for the user>
Option Description
--server The address and port of the Presto coordinator. The port must be set to the port the Presto coordinator is listening for HTTPS connections on. Presto CLI does not support using http scheme for the url when using LDAP authentication.
--keystore-path The location of the Java Keystore file that will be used to secure TLS.
--keystore-password The password for the keystore. This must match the password you specified when creating the keystore.
--truststore-path The location of the Java Truststore file that will be used to secure TLS.
--truststore-password The password for the truststore. This must match the password you specified when creating the truststore.
--user The LDAP username. For Active Directory this should be your sAMAccountName and for OpenLDAP this should be the uid of the user.
--password The password for the user.

Troubleshooting

Java Keystore File Verification

Verify the password for a keystore file and view its contents using Java Keystore File Verification.

SSL Debugging for Presto CLI

If you encounter any SSL related errors when running Presto CLI, you can run CLI using -Djavax.net.debug=ssl parameter for debugging. You should use the Presto CLI executable jar to enable this. Eg:

java -Djavax.net.debug=ssl \
-jar \
presto-cli-<version>-executable.jar \
--server https://coordinator:8443 \
<other_cli_arguments>

Common SSL errors

java.security.cert.CertificateException: No subject alternative names present

This error is seen when the Presto coordinator’s certificate is invalid and does not have the IP you provide in the --server argument of the CLI. You will have to regenerate the coordinator’s SSL certificate with the appropriate SAN added.

Adding a SAN to this certificate is required in cases where https:// uses IP address in the URL rather than the domain contained in the coordinator’s certificate, and the certificate does not contain the SAN parameter with the matching IP address as an alternative attribute.