Why Spring Security permitAll() is not working with OAuth2.0?

TheCoder :

I have a REST API secured with OAuth2.0 I am able to get the access-token using http://localhost:8085/auth/token?grant_type=password&[email protected]&password=mypass(along with username pass basic auth).
But when I am trying to access http://localhost:8085/api/v1/signup , API returns a 401 unauthorized error.
Though I have used antMatchers("/signup").permitAll(), why API is expecting a access-token to access this resource? Passing access-token along with this request would signup a user.
This is my resource server configuration

@Configuration
@EnableResourceServer
public class ResourceServerConfig extends ResourceServerConfigurerAdapter {

//require beans and methods here

@Autowired
public void configureGlobal(final AuthenticationManagerBuilder auth) {
    auth.authenticationProvider(authProvider());
}

@Override
public void configure(final HttpSecurity http) throws Exception {
    http
    .authorizeRequests()
    .antMatchers("/signup").permitAll()
    .anyRequest().authenticated()
    .and()
    .sessionManagement().sessionCreationPolicy(SessionCreationPolicy.STATELESS).and()
    .csrf().disable();
}
}

Update: As suggested by this thread, I ignored /signup at ``, but that also didn't worked.

@Configuration
@EnableWebSecurity
@EnableGlobalMethodSecurity(securedEnabled = true, prePostEnabled = true)
@ComponentScan(basePackages = { "com.sample.rest.security" })
@Order(2)
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    //other Beans & methods

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        List<RequestMatcher> requestMatchers = new ArrayList<RequestMatcher>();
        requestMatchers.add(new AntPathRequestMatcher("/signup/**"));

        http.
        requestMatcher(new OrRequestMatcher(requestMatchers)).
        authorizeRequests().antMatchers("/signup/**")
        .permitAll();
    }

}

TheCoder :

I got the issue. It was the context path which was causing the issue. I am having a dispatcher servlet defined with a mapping URL /api/v1/* and as one can see my signup request, it contains a context path i.e http://localhost:8085/api/v1/signup

For OAuth2 configuration in Spring, we need to take extra care of context path. First, it should be defined in the AuthorizationServer

@Configuration
@EnableAuthorizationServer
public class AuthorizationServerConfig extends AuthorizationServerConfigurerAdapter {
  @Override
  public void configure(final AuthorizationServerEndpointsConfigurer endpoints) { 
        endpoints
        .prefix("/api/v1") //here
        .tokenStore(tokenStore())
        .accessTokenConverter(accessTokenConverter())
        .authenticationManager(authenticationManager)
        .allowedTokenEndpointRequestMethods(HttpMethod.GET, HttpMethod.POST);
  }

Then, the context must be added to the permitAll() path like this

@Override
public void configure(final HttpSecurity http) throws Exception {
    http
    .authorizeRequests()
    .antMatchers("/api/v1/signup").permitAll()  //context path here
    .anyRequest().authenticated();
}

Up till now, the signup request is still expected to pass a access token with it. For removing the OAuth security from signup, we need to remove security at the WebSecurity, which can be done using WebSecurityConfigurerAdapter

@EnableWebSecurity
@EnableGlobalMethodSecurity
@ComponentScan(basePackages = { "com.sample.rest.security" })
public class SecurityConfig extends WebSecurityConfigurerAdapter {

     @Override
     public void configure(WebSecurity webSecurity) throws Exception {
        webSecurity.ignoring().antMatchers("/signup");
     }
 //////////// OR use below method ///////////
/*  @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.
        authorizeRequests().antMatchers("/signup/**").permitAll();
    }
*/
}

Note, there is no use to add context path to the WebSecurityConfigurerAdapter configuration.