How to Over ride BindAuthenticator handleBindException for Spring LDAP Authentication setup in Spring Boot - spring

Question

For Spring security setup in Spring Boot. The LDAP Authentication provider is configured by default to use BindAuthenticator class.
This Class contains method
/**
* Allows subclasses to inspect the exception thrown by an attempt to bind with a
* particular DN. The default implementation just reports the failure to the debug
* logger.
*/
protected void handleBindException(String userDn, String username, Throwable cause) {
if (logger.isDebugEnabled()) {
logger.debug("Failed to bind as " + userDn + ": " + cause);
}
}
This Method is to handle the authentication related Exceptions like invalid credentials.
I want to over-ride this method so i can handle this issue and return proper error message on the basis of error codes returned by LDAP. like invalid password or the account is locked.
Current LDAP implementation always returns "Bad Credentials" that does not give the right picture that why my credentials are invalid. i want to cover the cases
where the account is Locked
password is expired so i can redirect to change password
account locked due to number of invalid password retries
Please help

Answer 1

The issue i fixed by defining the LDAP context instead of using the Spring Boot LDAPAuthenticationProviderConfigurer.
Then created the FilterBasedLdapUserSearch and Over-written the BindAuthentication with my ConnectBindAuthenticator.
i created a separate LDAPConfiguration class for spring boot configuration and registered all these custom objects as Beans.
From the above Objects i created LDAPAuthenticationProvider by passing my Custom Objects to constructor
The Config is as below
#Bean
public DefaultSpringSecurityContextSource contextSource() {
DefaultSpringSecurityContextSource contextSource = new DefaultSpringSecurityContextSource(env.getProperty("ldap.url"));
contextSource.setBase(env.getProperty("ldap.base"));
contextSource.setUserDn(env.getProperty("ldap.managerDn"));
contextSource.setPassword(env.getProperty("ldap.managerPassword"));
return contextSource;
}
#Bean
public ConnectBindAuthenticator bindAuthenticator() {
ConnectBindAuthenticator connectBindAuthenticator = new ConnectBindAuthenticator(contextSource());
connectBindAuthenticator.setUserSearch(ldapUserSearch());
connectBindAuthenticator.setUserDnPatterns(new String[]{env.getProperty("ldap.managerDn")});
return connectBindAuthenticator;
}
#Bean
public LdapUserSearch ldapUserSearch() {
return new FilterBasedLdapUserSearch("", env.getProperty("ldap.userSearchFilter"), contextSource());
}

Answer 2

You have to change your spring security configuration to add your extension of BindAuthenticator:
CustomBindAuthenticator.java
public class CustomBindAuthenticator extends BindAuthenticator {
public CustomBindAuthenticator(BaseLdapPathContextSource contextSource) {
super(contextSource);
}
#Override
protected void handleBindException(String userDn, String username, Throwable cause) {
// TODO: Include here the logic of your custom BindAuthenticator
if (somethingHappens()) {
throw new MyCustomException("Custom error message");
}
super.handleBindException(userDn, username, cause);
}
}
spring-security.xml
<beans:bean id="contextSource"
class="org.springframework.security.ldap.DefaultSpringSecurityContextSource">
<beans:constructor-arg value="LDAP_URL" />
<beans:property name="userDn" value="USER_DN" />
<beans:property name="password" value="PASSWORD" />
</beans:bean>
<beans:bean id="userSearch"
class="org.springframework.security.ldap.search.FilterBasedLdapUserSearch">
<beans:constructor-arg index="0" value="USER_SEARCH_BASE" />
<beans:constructor-arg index="1" value="USER_SEARCH_FILTER" />
<beans:constructor-arg index="2" ref="contextSource" />
</beans:bean>
<beans:bean id="ldapAuthProvider"
class="org.springframework.security.ldap.authentication.LdapAuthenticationProvider">
<beans:constructor-arg>
<beans:bean class="com.your.project.CustomBindAuthenticator">
<beans:constructor-arg ref="contextSource" />
<beans:property name="userSearch" ref="userSearch" />
</beans:bean>
</beans:constructor-arg>
</beans:bean>
<security:authentication-manager alias="authenticationManager">
<security:authentication-provider ref="ldapAuthProvider" />
</security:authentication-manager>
Hope it's helpful.