/*
 * Copyright 2017-2018 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.web.SecurityFilterChain;
import org.springframework.security.web.authentication.Http403ForbiddenEntryPoint;

/**
 * Sample custom {@link SecurityFilterChain} that applies OAuth Resource Server
 * pre-authentication, and rejects unauthenticated requests to a single page, {@code /topsecret}.
 * All other pages are unsecured.
 *
 * <p>Because of {@code spring-cloud-gcp-starter-security-iap} dependency, the secure token will be
 * retrieved from Google Cloud IAP header {@code x-goog-iap-jwt-assertion}, and not from the
 * standard OAuth Bearer header.
 *
 * @since 1.1
 */
@Configuration
@EnableWebSecurity
public class SecurityConfigurer {

  @Bean
  public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
    http.authorizeHttpRequests()
        .requestMatchers("/topsecret")
        .authenticated()
        .and()
        .oauth2ResourceServer()
        .jwt()
        .and()
        .authenticationEntryPoint(new Http403ForbiddenEntryPoint());

    return http.build();
  }
}
