Spring OAuth2 - There is no client authentication. Try adding an appropriate authentication filter

Question

We have an application which is using spring-security-oauth2:1.0. I was trying to change it to a newer version, spring-security-oauth2:2.0.7.RELEASE. Some classes were removed, some package structure is changed, I managed to sort out all those things and I was able to start the server without any issue. But I am facing a strange issue here.

With OAuth2 - 1.0 version, when the user logs in we used to do a GET request on /oauth/token, For example :

http://localhost:8080/echo/oauth/token?grant_type=password&client_id=ws&client_secret=secret&scope=read,write&[email protected]&password=password123

and It used to work just fine.

When I try the same thing, First of all I am not able to make a GET request because of the logic in TokenEndPoint.java

private Set<HttpMethod> allowedRequestMethods = new HashSet<HttpMethod>(Arrays.asList(HttpMethod.POST));

@RequestMapping(value = "/oauth/token", method=RequestMethod.GET)
public ResponseEntity<OAuth2AccessToken> getAccessToken(Principal principal, @RequestParam
Map<String, String> parameters) throws HttpRequestMethodNotSupportedException {
    if (!allowedRequestMethods.contains(HttpMethod.GET)) {
        throw new HttpRequestMethodNotSupportedException("GET");
    }
    return postAccessToken(principal, parameters);
}

I have tried to make a POST request same as above URL, but I get InsufficientAuthenticationException with the error message

There is no client authentication. Try adding an appropriate authentication filter

This is because of the following POST request controller in TokenEndpoint.java. When I debug, I see that principal is null.

@RequestMapping(value = "/oauth/token", method=RequestMethod.POST)
    public ResponseEntity<OAuth2AccessToken> postAccessToken(Principal principal, @RequestParam
    Map<String, String> parameters) throws HttpRequestMethodNotSupportedException {
        //principal is null here
        if (!(principal instanceof Authentication)) {
            throw new InsufficientAuthenticationException(
                    "There is no client authentication. Try adding an appropriate authentication filter.");
        }
     .............
 }

I have an authentication filter and it worked well when I used version 1.0. This is the relevant prats of my config:

    <authentication-manager xmlns="http://www.springframework.org/schema/security">
        <authentication-provider user-service-ref="userDetailsService"/>
    </authentication-manager>

   <bean id="userDetailsService" class="com.hcl.nc.service.UserDetailsService">
        <constructor-arg><ref bean="sessionFactory" /></constructor-arg>
    </bean>

I always thought that the request will be authenticated by authentication-provider and goes to token-endpoint but that does not seem to be the correct flow. After debugging the application with version 2.0.7, now I really doubt my understanding about the flow.

Could somebody please explain why it worked in previous version and why it's not working now?

Do I have do to something different to get a OAuth token??

NOTE: I have already checked these questions : here, here, here. But I was not able to find the correct solution.

Answer 1

I don't know the previous version, but I know a bit about 2.0.7.

I suspect your problem is that your TokenEndpoint security tries to authenticate your clients against your user service.

The TokenEndpoint is protected by a BasicAuthenticationFilter. By default this filter would use an AuthenticationManager instance, which itself holds an AuthenticationProvider, which itself depends on an instance of UserDetailsService. The trick is that this particular instance of UserDetailsService must be client based, not user based : that's why there is a ClientDetailsUserDetailsService, which adapts ClientDetailsService to UserDetailsService.

Normally all this stuff is already done by default when you use the framework's configuration classes AuthorizationServerConfigurerAdapter, @EnableAuthorizationServer, etc..