I had the same banging-my-head-against-the-wall experience you did, and ended up writing a custom authentication provider that does an LDAP query against the Active Directory server.
So my security-related beans are:
<beans:bean id="contextSource"
class="org.springframework.security.ldap.DefaultSpringSecurityContextSource">
<beans:constructor-arg value="ldap://hostname.queso.com:389/" />
</beans:bean>
<beans:bean id="ldapAuthenticationProvider"
class="org.queso.ad.service.authentication.LdapAuthenticationProvider">
<beans:property name="authenticator" ref="ldapAuthenticator" />
<custom-authentication-provider />
</beans:bean>
<beans:bean id="ldapAuthenticator"
class="org.queso.ad.service.authentication.LdapAuthenticatorImpl">
<beans:property name="contextFactory" ref="contextSource" />
<beans:property name="principalPrefix" value="QUESO\" />
</beans:bean>
Then the LdapAuthenticationProvider class:
/**
* Custom Spring Security authentication provider which tries to bind to an LDAP server with
* the passed-in credentials; of note, when used with the custom {@link LdapAuthenticatorImpl},
* does <strong>not</strong> require an LDAP username and password for initial binding.
*
* @author Jason
*/
public class LdapAuthenticationProvider implements AuthenticationProvider {
private LdapAuthenticator authenticator;
public Authentication authenticate(Authentication auth) throws AuthenticationException {
// Authenticate, using the passed-in credentials.
DirContextOperations authAdapter = authenticator.authenticate(auth);
// Creating an LdapAuthenticationToken (rather than using the existing Authentication
// object) allows us to add the already-created LDAP context for our app to use later.
LdapAuthenticationToken ldapAuth = new LdapAuthenticationToken(auth, "ROLE_USER");
InitialLdapContext ldapContext = (InitialLdapContext) authAdapter
.getObjectAttribute("ldapContext");
if (ldapContext != null) {
ldapAuth.setContext(ldapContext);
}
return ldapAuth;
}
public boolean supports(Class clazz) {
return (UsernamePasswordAuthenticationToken.class.isAssignableFrom(clazz));
}
public LdapAuthenticator getAuthenticator() {
return authenticator;
}
public void setAuthenticator(LdapAuthenticator authenticator) {
this.authenticator = authenticator;
}
}
Then the LdapAuthenticatorImpl class:
/**
* Custom Spring Security LDAP authenticator which tries to bind to an LDAP server using the
* passed-in credentials; does <strong>not</strong> require "master" credentials for an
* initial bind prior to searching for the passed-in username.
*
* @author Jason
*/
public class LdapAuthenticatorImpl implements LdapAuthenticator {
private DefaultSpringSecurityContextSource contextFactory;
private String principalPrefix = "";
public DirContextOperations authenticate(Authentication authentication) {
// Grab the username and password out of the authentication object.
String principal = principalPrefix + authentication.getName();
String password = "";
if (authentication.getCredentials() != null) {
password = authentication.getCredentials().toString();
}
// If we have a valid username and password, try to authenticate.
if (!("".equals(principal.trim())) && !("".equals(password.trim()))) {
InitialLdapContext ldapContext = (InitialLdapContext) contextFactory
.getReadWriteContext(principal, password);
// We need to pass the context back out, so that the auth provider can add it to the
// Authentication object.
DirContextOperations authAdapter = new DirContextAdapter();
authAdapter.addAttributeValue("ldapContext", ldapContext);
return authAdapter;
} else {
throw new BadCredentialsException("Blank username and/or password!");
}
}
/**
* Since the InitialLdapContext that's stored as a property of an LdapAuthenticationToken is
* transient (because it isn't Serializable), we need some way to recreate the
* InitialLdapContext if it's null (e.g., if the LdapAuthenticationToken has been serialized
* and deserialized). This is that mechanism.
*
* @param authenticator
* the LdapAuthenticator instance from your application's context
* @param auth
* the LdapAuthenticationToken in which to recreate the InitialLdapContext
* @return
*/
static public InitialLdapContext recreateLdapContext(LdapAuthenticator authenticator,
LdapAuthenticationToken auth) {
DirContextOperations authAdapter = authenticator.authenticate(auth);
InitialLdapContext context = (InitialLdapContext) authAdapter
.getObjectAttribute("ldapContext");
auth.setContext(context);
return context;
}
public DefaultSpringSecurityContextSource getContextFactory() {
return contextFactory;
}
/**
* Set the context factory to use for generating a new LDAP context.
*
* @param contextFactory
*/
public void setContextFactory(DefaultSpringSecurityContextSource contextFactory) {
this.contextFactory = contextFactory;
}
public String getPrincipalPrefix() {
return principalPrefix;
}
/**
* Set the string to be prepended to all principal names prior to attempting authentication
* against the LDAP server. (For example, if the Active Directory wants the domain-name-plus
* backslash prepended, use this.)
*
* @param principalPrefix
*/
public void setPrincipalPrefix(String principalPrefix) {
if (principalPrefix != null) {
this.principalPrefix = principalPrefix;
} else {
this.principalPrefix = "";
}
}
}
And finally, the LdapAuthenticationToken class:
/**
* <p>
* Authentication token to use when an app needs further access to the LDAP context used to
* authenticate the user.
* </p>
*
* <p>
* When this is the Authentication object stored in the Spring Security context, an application
* can retrieve the current LDAP context thusly:
* </p>
*
* <pre>
* LdapAuthenticationToken ldapAuth = (LdapAuthenticationToken) SecurityContextHolder
* .getContext().getAuthentication();
* InitialLdapContext ldapContext = ldapAuth.getContext();
* </pre>
*
* @author Jason
*
*/
public class LdapAuthenticationToken extends AbstractAuthenticationToken {
private static final long serialVersionUID = -5040340622950665401L;
private Authentication auth;
transient private InitialLdapContext context;
private List<GrantedAuthority> authorities = new ArrayList<GrantedAuthority>();
/**
* Construct a new LdapAuthenticationToken, using an existing Authentication object and
* granting all users a default authority.
*
* @param auth
* @param defaultAuthority
*/
public LdapAuthenticationToken(Authentication auth, GrantedAuthority defaultAuthority) {
this.auth = auth;
if (auth.getAuthorities() != null) {
this.authorities.addAll(Arrays.asList(auth.getAuthorities()));
}
if (defaultAuthority != null) {
this.authorities.add(defaultAuthority);
}
super.setAuthenticated(true);
}
/**
* Construct a new LdapAuthenticationToken, using an existing Authentication object and
* granting all users a default authority.
*
* @param auth
* @param defaultAuthority
*/
public LdapAuthenticationToken(Authentication auth, String defaultAuthority) {
this(auth, new GrantedAuthorityImpl(defaultAuthority));
}
public GrantedAuthority[] getAuthorities() {
GrantedAuthority[] authoritiesArray = this.authorities.toArray(new GrantedAuthority[0]);
return authoritiesArray;
}
public void addAuthority(GrantedAuthority authority) {
this.authorities.add(authority);
}
public Object getCredentials() {
return auth.getCredentials();
}
public Object getPrincipal() {
return auth.getPrincipal();
}
/**
* Retrieve the LDAP context attached to this user's authentication object.
*
* @return the LDAP context
*/
public InitialLdapContext getContext() {
return context;
}
/**
* Attach an LDAP context to this user's authentication object.
*
* @param context
* the LDAP context
*/
public void setContext(InitialLdapContext context) {
this.context = context;
}
}
You'll notice that there are a few bits in there that you might not need.
For example, my app needed to retain the successfully-logged-in LDAP context for further use by the user once logged in -- the app's purpose is to let users log in via their AD credentials and then perform further AD-related functions. So because of that, I have a custom authentication token, LdapAuthenticationToken, that I pass around (rather than Spring's default Authentication token) which allows me to attach the LDAP context. In LdapAuthenticationProvider.authenticate(), I create that token and pass it back out; in LdapAuthenticatorImpl.authenticate(), I attach the logged-in context to the return object so that it can be added to the user's Spring authentication object.
Also, in LdapAuthenticationProvider.authenticate(), I assign all logged-in users the ROLE_USER role -- that's what lets me then test for that role in my intercept-url elements. You'll want to make this match whatever role you want to test for, or even assign roles based on Active Directory groups or whatever.
Finally, and a corollary to that, the way I implemented LdapAuthenticationProvider.authenticate() gives all users with valid AD accounts the same ROLE_USER role. Obviously, in that method, you can perform further tests on the user (i.e., is the user in a specific AD group?) and assign roles that way, or even test for some condition before even granting the user access at all.
