Configure Spring Security to return 403 for REST URLs and redirect to login for other URLs

Question

My web application has a bunch "normal" resources (html pages etc) and also some REST resources which are called from JavaScript by the previously mentioned html pages.

If there is a session timeout the user gets redirected to the login form. That's great for the "normal" resources, but not for the REST resources. I'll just need a 403 response there so that the JavaScript can take over and ask the user to reauthenticate.

There are countless examples on the web how to configure each of those, but I could not find an example on how to combine the methods. All my API URLs start with "/api/", so I'll need the 403 for all those URLs and the redirect for all the remaining URLs. How do I set this up?

Answer 1

It took me a little bit of Spring source code study to get this to work. You can set up an authentication entry point as follows:

<bean id="authenticationEntryPoint" class="org.springframework.security.web.authentication.DelegatingAuthenticationEntryPoint">
     <!-- this is the configuration for /api/ URLs -->
     <constructor-arg>
         <map>
             <entry>
                <key>
                    <bean class="org.springframework.security.web.util.matcher.RegexRequestMatcher">
                        <constructor-arg value="^/api/.*" /><!-- match URLs starting with "/api/" -->
                        <constructor-arg><null /></constructor-arg><!-- no matter what the HTTP method is -->
                    </bean>
                </key>
                <!-- if the key above has matched, send 403 response -->
                <bean class="org.springframework.security.web.authentication.Http403ForbiddenEntryPoint" />
             </entry>
         </map>
     </constructor-arg>

     <!-- and in the default case just redirect to login form -->
     <property name="defaultEntryPoint">
        <bean class="org.springframework.security.web.authentication.LoginUrlAuthenticationEntryPoint">
            <constructor-arg value="/spring_security_login" />
        </bean>
     </property>
 </bean>

This can then be used in the Sping Security configuration:

<http ... entry-point-ref="authenticationEntryPoint">