You can control access to Greenplum Database with an LDAP server and, optionally, secure the connection with encryption by adding parameters to pg_hba.conf file entries.
Greenplum Database supports LDAP authentication with the TLS/SSL protocol to encrypt communication with an LDAP server:
If no protocol is specified, Greenplum Database communicates with the LDAP server with a clear text connection.
To use LDAP authentication, the Greenplum Database master host must be configured as an LDAP client. See your LDAP documentation for information about configuring LDAP clients.
To enable STARTTLS with the TLS protocol, in the pg_hba.conf file, add an ldap
line and specify the ldaptls
parameter with the value 1. The default port is 389. In this example, the authentication method parameters include the ldaptls
parameter.
ldap ldapserver=myldap.com ldaptls=1 ldapprefix="uid=" ldapsuffix=",ou=People,dc=example,dc=com"
Specify a non-default port with the ldapport
parameter. In this example, the authentication method includes the ldaptls
parameter and the ldapport
parameter to specify the port 550.
ldap ldapserver=myldap.com ldaptls=1 ldapport=500 ldapprefix="uid=" ldapsuffix=",ou=People,dc=example,dc=com"
To enable a secure connection with TLS/SSL, add ldaps://
as the prefix to the LDAP server name specified in the ldapserver
parameter. The default port is 636.
This example ldapserver
parameter specifies a secure connection and the TLS/SSL protocol for the LDAP server myldap.com
.
ldapserver=ldaps://myldap.com
To specify a non-default port, add a colon (:) and the port number after the LDAP server name. This example ldapserver
parameter includes the ldaps://
prefix and the non-default port 550.
ldapserver=ldaps://myldap.com:550
If you have a system-wide OpenLDAP system and logins are configured to use LDAP with TLS or SSL in the pg_hba.conf file, logins may fail with the following message:
could not start LDAP TLS session: error code '-11'
To use an existing OpenLDAP system for authentication, Greenplum Database must be set up to use the LDAP server's CA certificate to validate user certificates. Follow these steps on both the master and standby hosts to configure Greenplum Database:
Copy the base64-encoded root CA chain file from the Active Directory or LDAP server to the Greenplum Database master and standby master hosts. This example uses the directory /etc/pki/tls/certs
.
Change to the directory where you copied the CA certificate file and, as the root user, generate the hash for OpenLDAP:
# cd /etc/pki/tls/certs
# openssl x509 -noout -hash -in <ca-certificate-file>
# ln -s <ca-certificate-file> <ca-certificate-file>.0
Configure an OpenLDAP configuration file for Greenplum Database with the CA certificate directory and certificate file specified.
As the root user, edit the OpenLDAP configuration file /etc/openldap/ldap.conf
:
SASL_NOCANON on
URI ldaps://ldapA.example.priv ldaps://ldapB.example.priv ldaps://ldapC.example.priv
BASE dc=example,dc=priv
TLS_CACERTDIR /etc/pki/tls/certs
TLS_CACERT /etc/pki/tls/certs/<ca-certificate-file>
NoteFor certificate validation to succeed, the hostname in the certificate must match a hostname in the URI property. Otherwise, you must also add
TLS_REQCERT allow
to the file.
As the gpadmin user, edit /usr/local/greenplum-db/greenplum_path.sh
and add the following line.
export LDAPCONF=/etc/openldap/ldap.conf
Greenplum Database logs an error if the following are specified in an pg_hba.conf file entry:
ldaps://
prefix and the ldaptls=1
parameter are specified.ldaps://
prefix and the ldapport
parameter are specified.Enabling encrypted communication for LDAP authentication only encrypts the communication between Greenplum Database and the LDAP server.
See Encrypting Client/Server Connections for information about encrypting client connections.
These are example entries from an pg_hba.conf file.
This example specifies LDAP authentication with no encryption between Greenplum Database and the LDAP server.
host all plainuser 0.0.0.0/0 ldap ldapserver=myldap.com ldapprefix="uid=" ldapsuffix=",ou=People,dc=example,dc=com"
This example specifies LDAP authentication with the STARTTLS and TLS protocol between Greenplum Database and the LDAP server.
host all tlsuser 0.0.0.0/0 ldap ldapserver=myldap.com ldaptls=1 ldapprefix="uid=" ldapsuffix=",ou=People,dc=example,dc=com"
This example specifies LDAP authentication with a secure connection and TLS/SSL protocol between Greenplum Database and the LDAP server.
host all ldapsuser 0.0.0.0/0 ldap ldapserver=ldaps://myldap.com ldapprefix="uid=" ldapsuffix=",ou=People,dc=example,dc=com"
Parent topic: Configuring Client Authentication