Spring Security - Run-As 认证

1. Overview

In this tutorial, we'll illustrate how to use Run-As authentication in Spring Security with a simple scenario.

The very high-level explanation about Run-As is as follows: a user can execute some piece of logic as another principal with different privileges.

2. The RunAsManager

The first thing we'll need to do is set up our GlobalMethodSecurity and inject a RunAsManager.

This is responsible for providing the temporary Authentication object with extra privileges:

@Configuration
@EnableGlobalMethodSecurity(securedEnabled = true)
public class MethodSecurityConfig extends GlobalMethodSecurityConfiguration {
    @Override
    protected RunAsManager runAsManager() {
        RunAsManagerImpl runAsManager = new RunAsManagerImpl();
        runAsManager.setKey("MyRunAsKey");
        return runAsManager;
    }
}

By overriding runAsManager, we're replacing the default implementation in the base class – which simply returns a null.

Also notice the key property – the framework uses that to secure/verify temporary Authentication objects (created via this manager).

Finally – the resulting Authentication object is a RunAsUserToken.

3. Security Configuration

To authenticate our temporary Authentication object, we'll set up a RunAsImplAuthenticationProvider:

@Autowired
public void configureGlobal(AuthenticationManagerBuilder auth) throws Exception {
    ...
    auth.authenticationProvider(runAsAuthenticationProvider());
}

@Bean
public AuthenticationProvider runAsAuthenticationProvider() {
    RunAsImplAuthenticationProvider authProvider = new RunAsImplAuthenticationProvider();
    authProvider.setKey("MyRunAsKey");
    return authProvider;
}

We're of course setting this up with the same key we used in the manager – so that the provider can check that the RunAsUserToken authentication object is created using the same key.

4. The Controller With @Secured

Now – let's see how to use Run-As Authentication replacement:

@Controller
@RequestMapping("/runas")
class RunAsController {

    @Secured({ "ROLE_USER", "RUN_AS_REPORTER" })
    @RequestMapping
    @ResponseBody
    public String tryRunAs() {
        Authentication auth = SecurityContextHolder.getContext().getAuthentication();
        return "Current User Authorities inside this RunAS method only " + 
          auth.getAuthorities().toString();
    }

}

The core thing here is the new role – RUN_AS_REPORTER. This is the trigger of the Run-As functionality – as the framework deals with it differently because of the prefix.

When a request executes through this logic, we'll have:

The current user authorities before tryRunAs() method are [ROLE_USER]
The current user authorities inside tryRunAs() method are [ROLE_USER, ROLE_RUN_AS_REPORTER]
The temporary Authentication object replaces the existing Authentication object for the duration of the tryRunAS() method invocation only

5. The Service

Finally, let's implement the actual logic – a simple service layer that's also secured:

@Service
public class RunAsService {

    @Secured({ "ROLE_RUN_AS_REPORTER" })
    public Authentication getCurrentUser() {
        Authentication authentication = 
          SecurityContextHolder.getContext().getAuthentication();
        return authentication;
    }
}

Note that:

To access getCurrentUser() method, we need to ROLE_RUN_AS_REPORTER
So we can only call getCurrentUser() method inside our tryRunAs() controller method

6. The Front-End

Next, we will use a simple front-end to test our Run-As feature:

<html>
<body>
Current user authorities: 
    <span sec:authentication="principal.authorities">user</span>
<br/>
<span id="temp"></span>
<a href="#" onclick="tryRunAs()">Generate Report As Super User</a>
             
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.2/jquery.min.js"></script>
<script type="text/javascript">
function tryRunAs(){
    $.get( "/runas" , function( data ) {
         $("#temp").html(data);
    });
}
</script>
</body>
</html>

So now, when a user triggers the “Generate Report As Super User” action – they'll obtain the temporary ROLE_RUN_AS_REPORTER authority.

7. Conclusion

In this quick tutorial, we explored a simple example using the Spring Security Run-As authentication replacement feature.

This tutorial is based on the codebase available on GitHub.

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Security