LDAP - AD Username Password configuration for context-source - spring-mvc

Question

I am using Spring Security to authenticate against Active Directory using LDAP protocol. Following code works well in authentication and setting up LDAP templates too (springSecurity.xml) :
<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns="http://www.springframework.org/schema/security"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:beans="http://www.springframework.org/schema/beans"
xmlns:ldap="http://www.springframework.org/schema/ldap"
xsi:schemaLocation="
http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-3.1.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/ldap
http://www.springframework.org/schema/ldap/spring-ldap.xsd">
<http use-expressions="true">
<intercept-url pattern="/login" access="permitAll" />
<intercept-url pattern="/authenticated" access="isAuthenticated()" />
<form-login login-page="/login" default-target-url="/authenticated"
authentication-failure-url="/login?error=true" />
<logout />
</http>
<beans:bean
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<beans:property name="location">
<beans:value>classpath:/ldap.properties</beans:value>
</beans:property>
<beans:property name="SystemPropertiesMode">
<beans:value>2</beans:value> <!-- OVERRIDE is 2 -->
</beans:property>
</beans:bean>
<beans:bean id="adAuthenticationProvider"
class="org.springframework.security.ldap.authentication.ad.ActiveDirectoryLdapAuthenticationProvider">
<beans:constructor-arg value="${sample.ldap.domain}" />
<beans:constructor-arg value="${sample.ldap.url}" />
<beans:property name="useAuthenticationRequestCredentials"
value="true" />
<beans:property name="convertSubErrorCodesToExceptions"
value="true" />
</beans:bean>
<authentication-manager>
<authentication-provider ref="adAuthenticationProvider" />
</authentication-manager>
<!-- Ldap after authentication -->
<context:property-placeholder location="classpath:/ldap.properties"
system-properties-mode="OVERRIDE" />
<context:annotation-config />
<ldap:context-source id="contextSource"
password="${sample.ldap.password}"
url="${sample.ldap.url}"
username="${sample.ldap.userDn}"
base="${sample.ldap.base}"
referral="follow" />
<ldap:ldap-template id="ldapTemplate"
context-source-ref="contextSource" />
<ldap:repositories base-package="com.domain" />
<beans:bean class="com.service.UserService">
<beans:property name="directoryType" value="${sample.ldap.directory.type}" />
</beans:bean>
<!-- Required to make sure BaseLdapName is populated in UserService -->
<beans:bean
class="org.springframework.ldap.core.support.BaseLdapPathBeanPostProcessor" />
</beans:beans>
Authentication works fine while fetching j_username and j_password from login.jsp. To set up the ldap template i am using username and password attribute defined in properties file, but i wish to use same username and password from spring security. Please guide me as how to bind the Username and Password attribute properties in ldap:context-source id="contextSource" to spring security credentials.
The code is little messy, any input for improvement is welcomed.

Answer 1

As specified in the Configuration chapter of the reference documentation, you can use the Spring Security authentication for the ContextSource by specifying a custom authentication-source-ref in the the configuration element of the ContextSource. In your case you would use the a SpringSecurityAuthenticationSource, shipped with Spring Security.
<ldap:context-source id="contextSource"
url="${sample.ldap.url}"
base="${sample.ldap.base}"
referral="follow"
authentication-source-ref="authenticationSource"/>
<bean id="authenticationSource"
class="org.springframework.security.ldap.authentication.SpringSecurityAuthenticationSource" />