/*
 * Copyright 2002-2018 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
 *
 *      http://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 sample;

import java.security.KeyFactory;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.X509EncodedKeySpec;
import java.util.Base64;

import org.springframework.context.annotation.Bean;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.security.oauth2.jwt.JwtDecoder;
import org.springframework.security.oauth2.jwt.JwtProcessors;
import org.springframework.security.oauth2.jwt.NimbusJwtDecoder;

/**
 * @author Josh Cummings
 */
@EnableWebSecurity
public class OAuth2ResourceServerSecurityConfiguration extends WebSecurityConfigurerAdapter {

	@Override
	protected void configure(HttpSecurity http) throws Exception {
		// @formatter:off
		http
			.authorizeRequests()
				.antMatchers("/message/**").hasAuthority("SCOPE_message:read")
				.anyRequest().authenticated()
				.and()
			.oauth2ResourceServer()
				.jwt()
					.decoder(jwtDecoder());
		// @formatter:on
	}

	@Bean
	JwtDecoder jwtDecoder() throws Exception {
		return new NimbusJwtDecoder(JwtProcessors.withPublicKey(key()).build());
	}

	private RSAPublicKey key() throws Exception {
		String encoded = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDdlatRjRjogo3WojgGHFHYLugd" +
				"UWAY9iR3fy4arWNA1KoS8kVw33cJibXr8bvwUAUparCwlvdbH6dvEOfou0/gCFQs" +
				"HUfQrSDv+MuSUMAe8jzKE4qW+jK+xQU9a03GUnKHkkle+Q0pX/g6jXZ7r1/xAK5D" +
				"o2kQ+X5xK9cipRgEKwIDAQAB";
		byte[] bytes = Base64.getDecoder().decode(encoded.getBytes());
		return (RSAPublicKey) KeyFactory.getInstance("RSA")
				.generatePublic(new X509EncodedKeySpec(bytes));
	}
}