Spring 3.0 Security - Authorization with Authentication - spring-security

Question

I am new to Spring and my requirement is that I do not want to authenticate the user with username and password.
The user is authenticate is some other application and my app get the request with folloing details:
User name
Roles
I just want use Spring Security to secure the pages according to the roles in the request.
I've given a thought about writing UserDetailService, but that only add request-data, Spring still ask for authentication information.
Then I thought about writing something like the following:
public class UserLogin {
/*
#Resource(name = "userDetailsService")
private UserDetailsService userDetailsService;
*/
#Resource(name = "authenticationManager")
private AuthenticationManager authenticationManager;
public boolean login(UserEntity user) {
//UserDetails ud = userDetailsService.loadUserByUsername(username);
Collection<GrantedAuthority> authorities = new ArrayList<GrantedAuthority>();
for (String role : user.getAuthorities()) {
authorities.add(new GrantedAuthorityImpl(role));
}
UsernamePasswordAuthenticationToken token = new UsernamePasswordAuthenticationToken(user.getUsername(), user.getPassword(), authorities);
try {
Authentication auth = authenticationManager.authenticate(token);
SecurityContext securityContext = new SecurityContextImpl();
// Places in ThredLocal for future retrieval
SecurityContextHolder.setContext(securityContext);
SecurityContextHolder.getContext().setAuthentication(auth);
} catch (AuthenticationException e) {
return false;
}
return true;
}
}
Am I going in the right direction. If so, how to configure the whole thing .. in spring-xml .

Answer 1

You're in what's called a Pre-Authentication scenario, where you configure Spring Security to only Authorize access, not Authenticate access. See http://static.springsource.org/spring-security/site/docs/3.0.x/reference/preauth.html. Here is a full configuration, where you need to implement AbstractPreAuthenticatedProcessingFilter to grep your authentication scheme's UserPrincipal, and the custom UserDetailsService you mention above.
<?xml version="1.0" encoding="UTF-8"?>
<beans:beans
xmlns:security="http://www.springframework.org/schema/security"
xmlns:beans="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-3.0.xsd">
<security:global-method-security secured-annotations="enabled" />
<beans:bean id="preAuthenticatedProcessingFilterEntryPoint" class="org.springframework.security.web.authentication.Http403ForbiddenEntryPoint" />
<security:http auto-config="false" entry-point-ref="preAuthenticatedProcessingFilterEntryPoint">
<security:custom-filter position="PRE_AUTH_FILTER" ref="myCustomPreAuthFilter" />
</security:http>
<beans:bean id="myCustomPreAuthFilter" class="com.mypackage.MyCustomPreAuthFilter">
<beans:property name="authenticationManager" ref="authenticationManager" />
</beans:bean>
<security:authentication-manager alias="authenticationManager">
<security:authentication-provider ref="preauthAuthProvider" />
</security:authentication-manager>
<beans:bean id="preauthAuthProvider" class="org.springframework.security.web.authentication.preauth.PreAuthenticatedAuthenticationProvider">
<beans:property name="preAuthenticatedUserDetailsService">
<beans:bean id="userDetailsServiceWrapper" class="org.springframework.security.core.userdetails.UserDetailsByNameServiceWrapper">
<beans:property name="userDetailsService" ref="myCustomUserDetailsService"/>
</beans:bean>
</beans:property>
</beans:bean>