Custom Authentication provider with Spring Security and Java Config

Question

How can I define a custom Authentication provider by using Spring Security with Java Configurations? I would like to perform a login checking credentials on my own database.

Answer 1

The following does what you need (CustomAuthenticationProvider is your implementation which needs to be managed by Spring)

@Configuration
@EnableWebMvcSecurity
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

    @Autowired
    private CustomAuthenticationProvider customAuthenticationProvider;

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        /**
         * Do your stuff here
         */
    }

    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
        auth.authenticationProvider(customAuthenticationProvider);
    }
}

Answer 2

As shown on baeldung.com, define your authentication provider as follow:

@Component
public class CustomAuthenticationProvider implements AuthenticationProvider {

    @Override
    public Authentication authenticate(Authentication authentication) 
      throws AuthenticationException {

        String name = authentication.getName();
        String password = authentication.getCredentials().toString();

        if (shouldAuthenticateAgainstThirdPartySystem(username, password)) {

            // use the credentials
            // and authenticate against the third-party system
            return new UsernamePasswordAuthenticationToken(
              name, password, new ArrayList<>());
        } else {
            return null;
        }
    }

    @Override
    public boolean supports(Class<?> authentication) {
        return authentication.equals(
          UsernamePasswordAuthenticationToken.class);
    }
}

and following code is corresponding java config:

@Configuration
@EnableWebSecurity
@ComponentScan("org.project.security")
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    @Autowired
    private CustomAuthenticationProvider authProvider;

    @Override
    protected void configure(
      AuthenticationManagerBuilder auth) throws Exception {

        auth.authenticationProvider(authProvider);
    }

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.authorizeRequests().anyRequest().authenticated()
            .and()
            .httpBasic();
    }
}