LDAPAuthnConfiguration

Current File(s): conf/authn/password-authn-config.xml, conf/ldap.properties, conf/authn/ldap-authn-config.xml (V4.0), conf/authn/authn.properties (V4.1+)
Format: Native Spring

1 Overview
2 General Configuration
3 Reference
4 Advanced Features

Overview

The LDAPCredentialValidator for the password authentication login flow uses native LDAP libraries for password-based authentication instead of using a JAAS module. The primary advantages are slightly better performance and more control over the process, such as the ability to extract detailed account status information from the directory during a login. One disadvantage is that JAAS configurations may be reloaded each time they're used, while the native configuration is static.

General Configuration

Configuring LDAP as a back-end relies on beans defined via an import in authn/password-authn-config.xml:

Import in authn/password-authn-config.xml

<import resource="ldap-authn-config.xml" />

The properties in ldap.properties do most of the work out of the box. Adding additional beans may be needed in very advanced cases where a higher degree of control is required.

These beans also act as global defaults that can be overridden on specific instances of beans inheriting from shibboleth.LDAPValidator defined in authn/password-authn-config.xml in the shibboleth.authn.Password.Validators bean.

In the simple case of LDAP used alone:

Defining use of LDAP in password-authn-config.xml

<util:list id="shibboleth.authn.Password.Validators">
    <!-- Default bean uses the settings defined in ldap-authn-config.xml and ldap.properties -->
    <ref bean="shibboleth.LDAPValidator" />
</util:list>

If desired, it's possible to directly configure the various settings within the validator bean instead of or in addition to relying on the defaults.

As an example, you could chain together multiple LDAP servers (rather than hoping the client library will do it for you) like this:

Chaining LDAP validators

<!--
These use the settings defined in ldap-authn-config.xml and
ldap.properties except the ones overridden here.
You can override any parameter (like p:ldapUrl) that can be defined for a
shibboleth.LDAPAuthenticationFactory, see system/flows/authn/password-authn-beans.xml
-->

<util:list id="shibboleth.authn.Password.Validators">
	<bean p:id="ldap1" parent="shibboleth.LDAPValidator">
    	<property name="authenticator">
			<bean parent="shibboleth.LDAPAuthenticationFactory" p:ldapUrl="ldaps://ldap1.example.org" />
		</property>
	</bean>
	<bean p:id="ldap2" parent="shibboleth.LDAPValidator">
    	<property name="authenticator">
			<bean parent="shibboleth.LDAPAuthenticationFactory" p:ldapUrl="ldaps://ldap2.example.org" />
		</property>
	</bean>
</util:list>

Note Regarding Upgrades

The ldap-authn-config.xml file has changed dramatically since V3 and is now very short, relying primarily on a special bean with a hidden parent definition taking a large set of properties that will generally auto-configure the proper objects.

Updating the the newer ldap-authn-config.xml

While the older, longer file should work in most cases, it is a good idea to look at updating to the new file from the distribution.

Having said that, copying the new file in will break initially unless you also explicitly define the bean called shibboleth.authn.Password.Validators (shown above), which is present by default in password-authn-config.xml in new installs. For LDAP alone, the example above generally suffices.

One issue that does come up with the older file: the defaults around pooling validation in V3 were expressed numerically in seconds, and these numbers are interpreted in V4 as milliseconds. The proper syntax is really XML Duration syntax (PT5M == 5 minutes) and not numerically, but out of the box using the old file with V4 and not setting some of the pooling properties will result in dramatically frequent pool validation on the order of every half second. The logs will be very noisy so it's quite obvious.

To correct this, either update to the V4 file (and define the new bean noted above), or change the property defaults in the old file, or actually set the properties themselves rather than leaving them commented.

Configuring LDAP as a back-end relies on beans internally that are configured using ldap.properties (defined separately from other properties because they are sometimes shared for LDAPConnector configuration). Older releases included an authn/ldap-authn-config.xml file; this remains supported but is no longer required or provided.

The properties in ldap.properties do most of the work out of the box. Adding additional beans may be needed in very advanced cases where a higher degree of control is required, and you are welcome to place them within authn/password-authn-config.xml.

The properties act as global defaults that can be overridden on specific instances of beans inheriting from shibboleth.LDAPValidator defined in authn/password-authn-config.xml in the shibboleth.authn.Password.Validators bean.

In the simple case of LDAP used alone:

Defining use of LDAP in password-authn-config.xml

It's possible to directly configure the various settings within the validator bean instead of or in addition to relying on the defaults. Typically this involves injecting a bean based on shibboleth.LDAPAuthenticationFactory into the validator bean’s authenticator property. This is a large factory class of type net.shibboleth.idp.authn.config.LDAPAuthenticationFactoryBean that includes most common LDAP settings.

As an example, you could chain together multiple LDAP servers (rather than hoping the client library will do it for you) like this:

Chaining LDAP validators

Note Regarding Upgrades

The ldap-authn-config.xml file from V3 has been removed, with the associated objects declared internally and using a large set of properties that will generally auto-configure the proper objects.

Updating from the older ldap-authn-config.xml

While the older, longer file should work in most cases, it is a good idea to consider removing the file from the distribution.

Having said that, removing the file will break initially unless you also explicitly define the bean called shibboleth.authn.Password.Validators (shown above), which is present by default in password-authn-config.xml in new installs. For LDAP alone, the example above generally suffices.

One issue that does come up with the older file: the defaults around pooling validation in V3 were expressed numerically in seconds, and these numbers are interpreted in V4 as milliseconds. The proper syntax is really XML Duration syntax (PT5M == 5 minutes) and not numerically, but out of the box using the old file with V4 and not setting some of the pooling properties will result in dramatically frequent pool validation on the order of every half second. The logs will be very noisy so it's quite obvious.

To correct this, either remove the old file (and define the new bean noted above), or change the property defaults in the old file, or actually set the properties themselves rather than leaving them commented.

The following sections describe how to configure a single instance of an LDAP CredentialValidator using the beans and properties that were available in V3 and are used by default in V4.

Authenticator Configuration

The idp.authn.LDAP.authenticator property controls the workflow for how authentication occurs against the LDAP directory for most “simple” cases by automatically configuring a number of underlying objects based on a set of built-in “authenticator types” supported by the ldaptive library.

anonSearchAuthenticator	Performs an anonymous search for the user's DN
bindSearchAuthenticator	Binds with a configured DN as a service account, then searches for the user's DN
directAuthenticator	User DNs are of a known format. i.e. CN=user_name,ou=accounts,dc=domain,dc=edu. No DN search is performed.
adAuthenticator	Configuration that leverages the AD specific @domain.com format. No DN search is performed since AD supports binding directly with that user name.

Depending on the choice above, various other properties must be set (see the reference section below).

Connection Configuration

Use the following properties to configure basic connection information for the LDAP directory:

idp.authn.LDAP.ldapURL
idp.authn.LDAP.useStartTLS
idp.authn.LDAP.connectTimeout

A connection pool is used, and there are several properties used to configure pool behavior (see the reference below).

SSL Configuration

If StartTLS or SSL are used, a source of trust anchors must be configured to control certificate validation, using the idp.authn.LDAP.sslConfig property:

certificateTrust	Uses the idp.authn.LDAP.trustCertificates property to load a resource containing the trust anchors (such as a file of PEM-format certificates)
keyStoreTrust	Uses the idp.authn.LDAP.trustStore property to load a keystore containing the trust anchors
jvmTrust	Uses the default JVM trust anchors (the JVM-wide "cacerts" file)
disabled ^4.3	Does not allow SSL or startTLS connections.

We have tentative plans to deprecate the “jvmTrust” option, which has already been removed from the attribute resolution side of the software, as it is bad practice and has been a source of serious security flaws.

Reference

A number of properties are found in ldap.properties to configure LDAP authentication global defaults. Most of the time, this is sufficient to deal with most configurations without having to delve into modifying any beans, unless you're trying to chain together separately configured back-ends.

Note that the big "override everything" hook tends to be the idp.authn.LDAP.authenticator property, as most of the other properties auto-configure specific aspects of one of the built-in Authenticator beans.

Property	Type	Default	Function

Property	Type	Default	Function
idp.authn.LDAP.authenticator	Enumeration	anonSearchAuthenticator	Controls the workflow for how authentication occurs against the LDAP, one of: anonSearchAuthenticator, bindSearchAuthenticator, directAuthenticator, adAuthenticator
idp.authn.LDAP.ldapURL	LDAP URI		Connection URI for LDAP directory.
idp.authn.LDAP.useStartTLS	Boolean	true	Whether StartTLS should be used after connecting with LDAP alone.
idp.authn.LDAP.useSSL	Boolean	false	DEPRECATED. To use LDAPS, specify ldaps:// in the idp.authn.LDAP.ldapURL property.
idp.authn.LDAP.connectTimeout	Duration	PT3S	Time to wait for the TCP connection to occur.
idp.authn.LDAP.responseTimeout	Duration	PT3S	Time to wait for an LDAP response message. (Applies to every request.)
idp.authn.LDAP.connectionStrategy	Enumeration	ACTIVE_PASSIVE	Connection strategy to use when multiple URLs are supplied, one of ACTIVE_PASSIVE, ROUND_ROBIN, RANDOM
idp.authn.LDAP.sslConfig	Enumeration	certificateTrust	How to establish trust in the server's TLS certificate, one of: jvmTrust, certificateTrust, or keyStoreTrust
idp.authn.LDAP.trustCertificates	Resource path		A resource to load trust anchors from, usually a local file in %{idp.home}/credentials
idp.authn.LDAP.trustStore	Resource path		A resource to load a Java keystore containing trust anchors, usually a local file in %{idp.home}/credentials
idp.authn.LDAP.returnAttributes	Comma-sep'd Strings		List of attributes to request during authentication
idp.authn.LDAP.baseDN	String		Base DN to search against, used by anonSearchAuthenticator, bindSearchAuthenticator
idp.authn.LDAP.subtreeSearch	Boolean	false	Whether to search recursively, used by anonSearchAuthenticator, bindSearchAuthenticator
idp.authn.LDAP.userFilter	String		LDAP search filter, used by anonSearchAuthenticator, bindSearchAuthenticator
idp.authn.LDAP.bindDN	String		DN to bind with during search, used by bindSearchAuthenticator
idp.authn.LDAP.bindDNCredential	String		Password to bind with during search, used by bindSearchAuthenticator, usually set via %{idp.home}/credentials/secrets.properties
idp.authn.LDAP.dnFormat	String		A formatting string to generate the user DNs to authenticate, used by directAuthenticator, adAuthenticator
idp.authn.LDAP.resolveEntryOnFailure	Boolean	false	Whether the user's LDAP entry should be returned in the authentication response even when the user bind fails.
idp.authn.LDAP.resolveEntryWithBindDN	Boolean	false	Whether the user's LDAP entry should be resolved with the bindDN credentials rather than as the authenticated user.
idp.authn.LDAP.usePasswordPolicy	Boolean	false	Whether to use the Password Policy Control.
idp.authn.LDAP.usePasswordExpiration	Boolean	false	Whether to use the Password Expired Control.
idp.authn.LDAP.activeDirectory	Boolean	false	If you are using Active Directory, this switch will attempt to use the account states defined by AD. Note that this flag is unnecessary if you are using the 'adAuthenticator'. It is meant to be specified with one of the other authenticator types.
idp.authn.LDAP.freeIPADirectory	Boolean	false	If you are using the FreeIPA LDAP, this switch will attempt to use the account states defined by that product.
idp.authn.LDAP.eDirectory	Boolean	false	If you are using the EDirectory LDAP, this switch will attempt to use the account states defined by that product.
idp.authn.LDAP.disablePooling	Boolean	false	Whether connection pools should be used for LDAP connections used for authentication.
idp.pool.LDAP.minSize	Integer	3	Minimum LDAP connection pool size
idp.pool.LDAP.maxSize	Integer	10	Maximum LDAP connection pool size
idp.pool.LDAP.validateOnCheckout	Boolean	false	Whether to validate connections when checking them out of the pool
idp.pool.LDAP.validatePeriodically	Boolean	true	Whether to validate connections in the background
idp.pool.LDAP.validatePeriod	Duration	PT5M	Duration between validation, if idp.pool.LDAP.validatePeriodically is true
idp.pool.LDAP.validateDN^4.0.1	String		DN to search with the validateFilter, default is the rootDSE
idp.pool.LDAP.validateFilter^4.0.1	String	(objectClass=*)	Search filter to execute in order to validate a pooled connection
idp.pool.LDAP.prunePeriod	Duration	PT5M	Duration between looking for idle connections to reduce the pool back to its minimum size
idp.pool.LDAP.idleTime	Duration	PT10M	Duration connections must be idle to be eligible for pruning
idp.pool.LDAP.blockWaitTime	Duration	PT3S	Duration to wait for a free connection in the pool
idp.authn.LDAP.bindPoolPassivator^4.0.1	Enumeration	none	Controls how connections in the bind pool are passivated. Connections in the bind pool may be in an authenticated state that will not allow validation searches to succeed. This property controls how bind connections are placed back into the pool. If your directory requires searches to be performed by the idp.authn.LDAP.bindDN or anonymously, this property controls that behavior. one of: none, bind, anonymousBind.

Properties can be used to configure all of the built-in beans used for this feature, so the only bean of relevance is below.

Bean ID	Type	Function

Bean ID	Type	Function
shibboleth.LDAPAuthenticationFactory	LDAPAuthenticationFactoryBean	Factory bean parent for defining new instances of the org.ldaptive.auth.Authenticator class if required

Advanced Features

Note that for some advanced use cases, it may be necessary to dig deeply into the Ldaptive documentation and wire up custom objects using, or based on beans in the older V3 version of authn/ldap-authn-config.xml, ultimately installing an instance of org.ldaptive.auth.Authenticator into the "authenticator" property of a particular LDAPCredentialValidator bean. Most of the flexibility comes from all the various types of objects that can be injected into instances of the Authenticator class.

LDAP attributes are returned as part of the authentication process and exposed in the LDAPResponseContext.

Property	Sample	Result

Property	Sample	Result
idp.authn.LDAP.returnAttributes	uid, eduPersonAffiliation	Returns the uid and eduPersonAffiliation attributes.
	*	Returns all user attributes on the entry.
	*,+	Returns all user and operational attributes on the entry.
	1.1	No attribute returned. No search performed.

By default, attributes will be searched for using the same connection the user authenticated on. Therefore the user must have read on any attributes for those to be returned.

If you need access to attributes that user does not have read access to, then you must configure a connection pool that is authorized to read that data. The following configuration demonstrates how to add a new connection pool for that purpose.

Spring Configuration

Add the idp.authn.LDAP.entryResolver.bindDN and idp.authn.LDAP.entryResolver.bindDNCredential properties to conf/ldap.properties and credentials/secrets.properties respectively. Then set idp.authn.LDAP.authenticator to anonSearchAuthenticator. to complete the configuration.

Note: if you're using the bindSearchAuthenticator and those credentials can be reused for entry resolution, then this configuration can be shortened by wiring the bindPooledConnectionFactory to the entry resolver.