feat(ap3): add oauth2Login session BFF

.gitignore

@@ -4,6 +4,7 @@
 *.iml
 
 backend/target/
+bff/target/
 **/node_modules/
 frontend/dist/
 build/

README.md

@@ -97,16 +97,16 @@ Keycloak을 잠시 중지하고 export한 뒤 자동으로 다시 올립니다.
 runtime export에는 실제 client secret과 credential hash가 포함될 수 있어
 gitignored `build/keycloak-export/`에 권한 `0600`으로만 저장됩니다.
 
-## AP1: SPA Direct + Resource Server
+## AP3: Backend-for-Frontend
 
-`develop-keycloak-pattern1`은 vanilla JavaScript SPA가 `spa-public` client로
-Authorization Code + PKCE S256 로그인을 수행하는 패턴입니다. access/refresh
-token은 명시적인 in-memory store에만 보관되므로 새로고침하면 사라집니다.
+`develop-keycloak-pattern3`의 Spring BFF는 `http://localhost:8083`에서
+실행됩니다. 브라우저에는 HttpOnly session cookie만 두고 access/refresh
+token은 BFF가 서버에 보관합니다. `/bff/api/me`는 BFF가 보유 access
+token을 붙여 Resource Server로 proxy합니다.
 
 ```bash
-./scripts/verify-pattern1.sh
+./scripts/verify-pattern3.sh
 ```
 
-브라우저에서 `http://localhost:8088`을 열어 로그인한 뒤 보호 API를 호출할 수
-있습니다. SPA는 `http://localhost:8081/api/me`를 직접 호출하며 Spring
-Resource Server가 Bearer JWT를 검증합니다.
+자세한 경계와 session 저장소 trade-off는
+[`docs/ap3-bff-boundary.md`](docs/ap3-bff-boundary.md)를 참고하세요.

backend/src/main/java/com/example/keycloakpattern/AudienceValidator.java

@@ -0,0 +1,29 @@
+package com.example.keycloakpattern;
+
+import org.springframework.security.oauth2.core.OAuth2Error;
+import org.springframework.security.oauth2.core.OAuth2TokenValidator;
+import org.springframework.security.oauth2.core.OAuth2TokenValidatorResult;
+import org.springframework.security.oauth2.jwt.Jwt;
+
+final class AudienceValidator implements OAuth2TokenValidator<Jwt> {
+
+    private static final OAuth2Error MISSING_AUDIENCE = new OAuth2Error(
+        "invalid_token",
+        "The required resource audience is missing",
+        null
+    );
+
+    private final String expectedAudience;
+
+    AudienceValidator(String expectedAudience) {
+        this.expectedAudience = expectedAudience;
+    }
+
+    @Override
+    public OAuth2TokenValidatorResult validate(Jwt jwt) {
+        if (jwt.getAudience().contains(expectedAudience)) {
+            return OAuth2TokenValidatorResult.success();
+        }
+        return OAuth2TokenValidatorResult.failure(MISSING_AUDIENCE);
+    }
+}

backend/src/main/java/com/example/keycloakpattern/JwtDecoderConfig.java

@@ -0,0 +1,31 @@
+package com.example.keycloakpattern;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.security.oauth2.core.DelegatingOAuth2TokenValidator;
+import org.springframework.security.oauth2.core.OAuth2TokenValidator;
+import org.springframework.security.oauth2.jwt.Jwt;
+import org.springframework.security.oauth2.jwt.JwtDecoder;
+import org.springframework.security.oauth2.jwt.JwtValidators;
+import org.springframework.security.oauth2.jwt.NimbusJwtDecoder;
+
+@Configuration
+public class JwtDecoderConfig {
+
+    @Bean
+    JwtDecoder jwtDecoder(
+        @Value("${spring.security.oauth2.resourceserver.jwt.issuer-uri}") String issuer,
+        @Value("${spring.security.oauth2.resourceserver.jwt.jwk-set-uri}") String jwkSetUri,
+        @Value("${security.expected-audience}") String expectedAudience
+    ) {
+        NimbusJwtDecoder decoder = NimbusJwtDecoder.withJwkSetUri(jwkSetUri).build();
+        OAuth2TokenValidator<Jwt> issuerAndTimestamp =
+            JwtValidators.createDefaultWithIssuer(issuer);
+        OAuth2TokenValidator<Jwt> audience = new AudienceValidator(expectedAudience);
+        decoder.setJwtValidator(
+            new DelegatingOAuth2TokenValidator<>(issuerAndTimestamp, audience)
+        );
+        return decoder;
+    }
+}

backend/src/main/java/com/example/keycloakpattern/SecurityConfig.java

@@ -1,16 +1,11 @@
 package com.example.keycloakpattern;
 
-import java.util.List;
-
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.security.config.Customizer;
 import org.springframework.security.config.annotation.web.builders.HttpSecurity;
 import org.springframework.security.config.http.SessionCreationPolicy;
 import org.springframework.security.web.SecurityFilterChain;
-import org.springframework.web.cors.CorsConfiguration;
-import org.springframework.web.cors.CorsConfigurationSource;
-import org.springframework.web.cors.UrlBasedCorsConfigurationSource;
 
 @Configuration
 public class SecurityConfig {
@@ -18,7 +13,6 @@ public class SecurityConfig {
     @Bean
     SecurityFilterChain apiSecurity(HttpSecurity http) throws Exception {
         return http
-            .cors(Customizer.withDefaults())
             .csrf(csrf -> csrf.disable())
             .sessionManagement(session ->
                 session.sessionCreationPolicy(SessionCreationPolicy.STATELESS))
@@ -30,19 +24,4 @@ public class SecurityConfig {
             .oauth2ResourceServer(oauth2 -> oauth2.jwt(Customizer.withDefaults()))
             .build();
     }
-
-    @Bean
-    CorsConfigurationSource corsConfigurationSource() {
-        CorsConfiguration configuration = new CorsConfiguration();
-        configuration.setAllowedOrigins(List.of(
-            "http://localhost:8088",
-            "http://127.0.0.1:8088"
-        ));
-        configuration.setAllowedMethods(List.of("GET", "OPTIONS"));
-        configuration.setAllowedHeaders(List.of("Authorization", "Content-Type"));
-
-        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
-        source.registerCorsConfiguration("/api/**", configuration);
-        return source;
-    }
 }

backend/src/main/resources/application.yml

@@ -11,6 +11,9 @@ spring:
           issuer-uri: ${SPRING_SECURITY_OAUTH2_RESOURCESERVER_JWT_ISSUER_URI:http://localhost:8080/realms/keycloak-patterns}
           jwk-set-uri: ${SPRING_SECURITY_OAUTH2_RESOURCESERVER_JWT_JWK_SET_URI:http://localhost:8080/realms/keycloak-patterns/protocol/openid-connect/certs}
 
+security:
+  expected-audience: ${SECURITY_EXPECTED_AUDIENCE:keycloak-pattern-api}
+
 management:
   endpoint:
     health:

backend/src/test/java/com/example/keycloakpattern/AudienceValidatorTest.java

@@ -0,0 +1,49 @@
+package com.example.keycloakpattern;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.time.Instant;
+import java.util.List;
+import java.util.Map;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.security.oauth2.core.OAuth2TokenValidatorResult;
+import org.springframework.security.oauth2.jwt.Jwt;
+
+class AudienceValidatorTest {
+
+    private final AudienceValidator validator =
+        new AudienceValidator("keycloak-pattern-api");
+
+    @Test
+    void acceptsRequiredAudience() {
+        OAuth2TokenValidatorResult result = validator.validate(jwtWithAudience(
+            List.of("account", "keycloak-pattern-api")
+        ));
+
+        assertThat(result.hasErrors()).isFalse();
+    }
+
+    @Test
+    void rejectsForeignAudience() {
+        OAuth2TokenValidatorResult result = validator.validate(jwtWithAudience(
+            List.of("another-resource")
+        ));
+
+        assertThat(result.hasErrors()).isTrue();
+        assertThat(result.getErrors())
+            .extracting(error -> error.getErrorCode())
+            .containsExactly("invalid_token");
+    }
+
+    private Jwt jwtWithAudience(List<String> audience) {
+        Instant now = Instant.now();
+        return new Jwt(
+            "test-token",
+            now,
+            now.plusSeconds(300),
+            Map.of("alg", "none"),
+            Map.of("sub", "test-subject", "aud", audience)
+        );
+    }
+}

bff/.dockerignore

@@ -0,0 +1 @@
+target/

bff/Dockerfile

@@ -0,0 +1,14 @@
+FROM maven:3.9.11-eclipse-temurin-21-alpine AS build
+WORKDIR /workspace
+COPY pom.xml .
+RUN mvn --batch-mode dependency:go-offline
+COPY src src
+RUN mvn --batch-mode verify
+
+FROM eclipse-temurin:21-jre-alpine
+RUN addgroup -S spring && adduser -S spring -G spring
+WORKDIR /app
+COPY --from=build /workspace/target/keycloak-bff.jar app.jar
+USER spring:spring
+EXPOSE 8083
+ENTRYPOINT ["java", "-jar", "/app/app.jar"]

bff/pom.xml

@@ -0,0 +1,58 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>3.5.16</version>
+        <relativePath/>
+    </parent>
+
+    <groupId>com.example</groupId>
+    <artifactId>keycloak-bff</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>keycloak-bff</name>
+
+    <properties>
+        <java.version>21</java.version>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-actuator</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-oauth2-client</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.security</groupId>
+            <artifactId>spring-security-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <finalName>keycloak-bff</finalName>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+</project>

bff/src/main/java/com/example/keycloakpattern/bff/BffApplication.java

@@ -0,0 +1,12 @@
+package com.example.keycloakpattern.bff;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class BffApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(BffApplication.class, args);
+    }
+}

bff/src/main/java/com/example/keycloakpattern/bff/BffController.java

@@ -0,0 +1,112 @@
+package com.example.keycloakpattern.bff;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicReference;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.http.CacheControl;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.ResponseEntity;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.oauth2.client.OAuth2AuthorizeRequest;
+import org.springframework.security.oauth2.client.OAuth2AuthorizedClient;
+import org.springframework.security.oauth2.client.OAuth2AuthorizedClientManager;
+import org.springframework.security.oauth2.client.OAuth2AuthorizedClientService;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.client.RestClient;
+import org.springframework.web.server.ResponseStatusException;
+
+import static org.springframework.http.HttpStatus.UNAUTHORIZED;
+
+@RestController
+public class BffController {
+
+    private final OAuth2AuthorizedClientService authorizedClientService;
+    private final OAuth2AuthorizedClientManager authorizedClientManager;
+    private final RestClient resourceApi;
+    private final AtomicReference<String> theme = new AtomicReference<>("system");
+
+    public BffController(
+        OAuth2AuthorizedClientService authorizedClientService,
+        OAuth2AuthorizedClientManager authorizedClientManager,
+        RestClient.Builder restClientBuilder,
+        @Value("${resource-api.base-url}") String resourceApiBaseUrl
+    ) {
+        this.authorizedClientService = authorizedClientService;
+        this.authorizedClientManager = authorizedClientManager;
+        this.resourceApi = restClientBuilder.baseUrl(resourceApiBaseUrl).build();
+    }
+
+    @GetMapping("/bff/token-boundary")
+    ResponseEntity<Map<String, Object>> tokenBoundary(Authentication authentication) {
+        OAuth2AuthorizedClient client = authorizedClientService.loadAuthorizedClient(
+            "keycloak",
+            authentication.getName()
+        );
+
+        Map<String, Object> response = new LinkedHashMap<>();
+        response.put("pattern", "AP3-backend-for-frontend");
+        response.put("principal", authentication.getName());
+        response.put("accessTokenStoredOnServer", client != null
+            && client.getAccessToken() != null);
+        response.put("refreshTokenStoredOnServer", client != null
+            && client.getRefreshToken() != null);
+        response.put("browserTokenCount", 0);
+        response.put("csrfProtectionEnabled", false);
+
+        return ResponseEntity.ok()
+            .cacheControl(CacheControl.noStore())
+            .header("Pragma", "no-cache")
+            .body(response);
+    }
+
+    @GetMapping("/bff/api/me")
+    ResponseEntity<?> currentUser(Authentication authentication) {
+        OAuth2AuthorizedClient client = authorizedClient(authentication);
+        return resourceApi.get()
+            .uri("/api/me")
+            .header(
+                HttpHeaders.AUTHORIZATION,
+                "Bearer " + client.getAccessToken().getTokenValue()
+            )
+            .retrieve()
+            .toEntity(Map.class);
+    }
+
+    @PostMapping("/bff/api/preferences")
+    Map<String, Object> updatePreference(
+        Authentication authentication,
+        @RequestParam(defaultValue = "system") String theme
+    ) {
+        this.theme.set(theme);
+        return Map.of(
+            "updated", true,
+            "theme", this.theme.get(),
+            "principal", authentication.getName()
+        );
+    }
+
+    @GetMapping("/bff/api/preferences")
+    Map<String, String> preference() {
+        return Map.of("theme", theme.get());
+    }
+
+    private OAuth2AuthorizedClient authorizedClient(Authentication authentication) {
+        OAuth2AuthorizeRequest request = OAuth2AuthorizeRequest
+            .withClientRegistrationId("keycloak")
+            .principal(authentication)
+            .build();
+        OAuth2AuthorizedClient client = authorizedClientManager.authorize(request);
+        if (client == null || client.getAccessToken() == null) {
+            throw new ResponseStatusException(
+                UNAUTHORIZED,
+                "No authorized Keycloak client is available"
+            );
+        }
+        return client;
+    }
+}

bff/src/main/java/com/example/keycloakpattern/bff/SecurityConfig.java

@@ -0,0 +1,73 @@
+package com.example.keycloakpattern.bff;
+
+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.oauth2.client.AuthorizedClientServiceOAuth2AuthorizedClientManager;
+import org.springframework.security.oauth2.client.OAuth2AuthorizedClientManager;
+import org.springframework.security.oauth2.client.OAuth2AuthorizedClientProvider;
+import org.springframework.security.oauth2.client.OAuth2AuthorizedClientProviderBuilder;
+import org.springframework.security.oauth2.client.OAuth2AuthorizedClientService;
+import org.springframework.security.oauth2.client.registration.ClientRegistrationRepository;
+import org.springframework.security.oauth2.client.web.DefaultOAuth2AuthorizationRequestResolver;
+import org.springframework.security.oauth2.client.web.OAuth2AuthorizationRequestCustomizers;
+import org.springframework.security.web.SecurityFilterChain;
+
+@Configuration
+public class SecurityConfig {
+
+    @Bean
+    SecurityFilterChain bffSecurity(
+        HttpSecurity http,
+        ClientRegistrationRepository clientRegistrationRepository
+    ) throws Exception {
+        DefaultOAuth2AuthorizationRequestResolver authorizationRequestResolver =
+            new DefaultOAuth2AuthorizationRequestResolver(
+                clientRegistrationRepository,
+                "/oauth2/authorization"
+            );
+        authorizationRequestResolver.setAuthorizationRequestCustomizer(
+            OAuth2AuthorizationRequestCustomizers.withPkce()
+        );
+
+        return http
+            .csrf(csrf -> csrf.disable())
+            .authorizeHttpRequests(authorize -> authorize
+                .requestMatchers(
+                    "/",
+                    "/index.html",
+                    "/app.js",
+                    "/favicon.ico",
+                    "/actuator/health",
+                    "/actuator/health/**"
+                )
+                .permitAll()
+                .anyRequest()
+                .authenticated())
+            .oauth2Login(oauth2 -> oauth2
+                .authorizationEndpoint(endpoint -> endpoint
+                    .authorizationRequestResolver(authorizationRequestResolver))
+                .defaultSuccessUrl("/", true))
+            .build();
+    }
+
+    @Bean
+    OAuth2AuthorizedClientManager authorizedClientManager(
+        ClientRegistrationRepository clientRegistrationRepository,
+        OAuth2AuthorizedClientService authorizedClientService
+    ) {
+        OAuth2AuthorizedClientProvider authorizedClientProvider =
+            OAuth2AuthorizedClientProviderBuilder.builder()
+                .authorizationCode()
+                .refreshToken()
+                .build();
+
+        AuthorizedClientServiceOAuth2AuthorizedClientManager manager =
+            new AuthorizedClientServiceOAuth2AuthorizedClientManager(
+                clientRegistrationRepository,
+                authorizedClientService
+            );
+        manager.setAuthorizedClientProvider(authorizedClientProvider);
+        return manager;
+    }
+}

bff/src/main/resources/application.yml

@@ -0,0 +1,46 @@
+server:
+  port: ${SERVER_PORT:8083}
+  servlet:
+    session:
+      cookie:
+        name: AP3_SESSION
+        http-only: true
+
+spring:
+  application:
+    name: keycloak-bff
+  security:
+    oauth2:
+      client:
+        registration:
+          keycloak:
+            provider: keycloak
+            client-id: bff-confidential
+            client-secret: ${KEYCLOAK_CLIENT_SECRET}
+            client-authentication-method: client_secret_basic
+            authorization-grant-type: authorization_code
+            redirect-uri: "{baseUrl}/login/oauth2/code/{registrationId}"
+            scope:
+              - openid
+              - profile
+              - email
+        provider:
+          keycloak:
+            authorization-uri: http://localhost:8080/realms/keycloak-patterns/protocol/openid-connect/auth
+            token-uri: http://keycloak:8080/realms/keycloak-patterns/protocol/openid-connect/token
+            jwk-set-uri: http://keycloak:8080/realms/keycloak-patterns/protocol/openid-connect/certs
+            user-info-uri: http://keycloak:8080/realms/keycloak-patterns/protocol/openid-connect/userinfo
+            user-name-attribute: preferred_username
+
+resource-api:
+  base-url: ${RESOURCE_API_BASE_URL:http://localhost:8081}
+
+management:
+  endpoint:
+    health:
+      probes:
+        enabled: true
+  endpoints:
+    web:
+      exposure:
+        include: health,info

bff/src/main/resources/static/app.js

@@ -0,0 +1,39 @@
+const result = document.querySelector("#result");
+
+function render(value) {
+  result.textContent = JSON.stringify(value, null, 2);
+}
+
+async function request(path, options = {}) {
+  const response = await fetch(path, {
+    ...options,
+    headers: { Accept: "application/json", ...options.headers },
+  });
+  if (response.redirected || response.status === 401) {
+    window.location.assign("/oauth2/authorization/keycloak");
+    return null;
+  }
+  const body = await response.json();
+  render({ status: response.status, ...body });
+  return { response, body };
+}
+
+document.querySelector("#login").addEventListener("click", () => {
+  window.location.assign("/oauth2/authorization/keycloak");
+});
+
+document.querySelector("#inspect").addEventListener("click", () => {
+  void request("/bff/token-boundary");
+});
+
+document.querySelector("#call-bff").addEventListener("click", () => {
+  void request("/bff/api/me");
+});
+
+document.querySelector("#change-without-csrf").addEventListener("click", () => {
+  void request("/bff/api/preferences", {
+    method: "POST",
+    body: new URLSearchParams({ theme: "dark" }),
+    headers: { "Content-Type": "application/x-www-form-urlencoded" },
+  });
+});

bff/src/main/resources/static/index.html

@@ -0,0 +1,31 @@
+<!doctype html>
+<html lang="ko">
+<head>
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1">
+  <title>AP3 · Backend-for-Frontend</title>
+  <style>
+    :root { color-scheme: light dark; font-family: system-ui, sans-serif; }
+    body { max-width: 58rem; margin: 6vh auto; padding: 0 1.5rem; line-height: 1.6; }
+    button { margin: 0 0.5rem 0.5rem 0; padding: 0.6rem 0.9rem; cursor: pointer; }
+    pre { min-height: 9rem; padding: 1rem; border-radius: 0.4rem;
+      background: color-mix(in srgb, CanvasText 9%, Canvas); white-space: pre-wrap; }
+  </style>
+</head>
+<body>
+  <main>
+    <h1>AP3 · Backend-for-Frontend</h1>
+    <p>
+      브라우저에는 OAuth token이 전혀 전달되지 않습니다. HttpOnly session
+      cookie로 BFF만 호출하고, BFF가 서버 보관 access token을 Resource
+      Server 요청에 붙입니다.
+    </p>
+    <button id="login" type="button">Keycloak 로그인</button>
+    <button id="inspect" type="button">token 경계 확인</button>
+    <button id="call-bff" type="button">BFF 경유 API 호출</button>
+    <button id="change-without-csrf" type="button">CSRF token 없이 상태 변경</button>
+    <pre id="result" aria-live="polite"></pre>
+  </main>
+  <script type="module" src="/app.js"></script>
+</body>
+</html>

bff/src/test/java/com/example/keycloakpattern/bff/BffControllerTest.java

@@ -0,0 +1,69 @@
+package com.example.keycloakpattern.bff;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+import static org.springframework.security.test.web.servlet.request.SecurityMockMvcRequestPostProcessors.oidcLogin;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.header;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.security.oauth2.client.OAuth2AuthorizedClient;
+import org.springframework.security.oauth2.client.OAuth2AuthorizedClientManager;
+import org.springframework.security.oauth2.client.OAuth2AuthorizedClientService;
+import org.springframework.security.oauth2.core.OAuth2AccessToken;
+import org.springframework.security.oauth2.core.OAuth2RefreshToken;
+import org.springframework.test.context.bean.override.mockito.MockitoBean;
+import org.springframework.test.web.servlet.MockMvc;
+
+@SpringBootTest(properties = {
+    "KEYCLOAK_CLIENT_SECRET=test-only-secret",
+    "resource-api.base-url=http://127.0.0.1:9"
+})
+@AutoConfigureMockMvc
+class BffControllerTest {
+
+    @Autowired
+    private MockMvc mockMvc;
+
+    @MockitoBean
+    private OAuth2AuthorizedClientService authorizedClientService;
+
+    @MockitoBean
+    private OAuth2AuthorizedClientManager authorizedClientManager;
+
+    @Test
+    void reportsServerTokenCustodyWithoutReturningTokens() throws Exception {
+        OAuth2AuthorizedClient client = mock(OAuth2AuthorizedClient.class);
+        when(client.getAccessToken()).thenReturn(mock(OAuth2AccessToken.class));
+        when(client.getRefreshToken()).thenReturn(mock(OAuth2RefreshToken.class));
+        when(authorizedClientService.loadAuthorizedClient("keycloak", "test-subject"))
+            .thenReturn(client);
+
+        mockMvc.perform(get("/bff/token-boundary").with(oidcLogin()
+                .idToken(token -> token.subject("test-subject"))))
+            .andExpect(status().isOk())
+            .andExpect(header().string("Cache-Control", "no-store"))
+            .andExpect(jsonPath("$.accessTokenStoredOnServer").value(true))
+            .andExpect(jsonPath("$.refreshTokenStoredOnServer").value(true))
+            .andExpect(jsonPath("$.browserTokenCount").value(0))
+            .andExpect(jsonPath("$.csrfProtectionEnabled").value(false))
+            .andExpect(jsonPath("$.access_token").doesNotExist())
+            .andExpect(jsonPath("$.refresh_token").doesNotExist());
+    }
+
+    @Test
+    void demonstratesStateChangeWithoutCsrfProtection() throws Exception {
+        mockMvc.perform(post("/bff/api/preferences")
+                .param("theme", "attacker")
+                .with(oidcLogin().idToken(token -> token.subject("test-subject"))))
+            .andExpect(status().isOk())
+            .andExpect(jsonPath("$.updated").value(true))
+            .andExpect(jsonPath("$.theme").value("attacker"));
+    }
+}

docker-compose.yml

@@ -86,6 +86,32 @@ services:
       - keycloak-net
     restart: unless-stopped
 
+  bff:
+    build:
+      context: ./bff
+    environment:
+      SERVER_PORT: "8083"
+      KEYCLOAK_CLIENT_SECRET: ${BFF_CLIENT_SECRET:?set BFF_CLIENT_SECRET in .env}
+      RESOURCE_API_BASE_URL: http://app:8081
+    ports:
+      - "127.0.0.1:8083:8083"
+    depends_on:
+      keycloak:
+        condition: service_healthy
+      app:
+        condition: service_healthy
+    healthcheck:
+      test:
+        - CMD-SHELL
+        - wget -q -O - http://127.0.0.1:8083/actuator/health | grep -q '"status":"UP"'
+      interval: 10s
+      timeout: 5s
+      retries: 12
+      start_period: 20s
+    networks:
+      - keycloak-net
+    restart: unless-stopped
+
   nginx:
     build:
       context: ./frontend

docs/ap3-bff-boundary.md

@@ -0,0 +1,28 @@
+# AP3 · Backend-for-Frontend
+
+## 요청과 token 경계
+
+1. 브라우저는 BFF의 `/oauth2/authorization/keycloak`로 로그인을 시작합니다.
+2. Spring `oauth2Login`은 PKCE S256 authorization code flow를 수행합니다.
+3. BFF가 client secret으로 code를 교환하고 access/refresh token을 서버의
+   `OAuth2AuthorizedClientService`에 보관합니다.
+4. 브라우저에는 OAuth token 대신 HttpOnly `AP3_SESSION` 식별자만 남습니다.
+5. 브라우저가 `/bff/api/me`를 cookie로 호출하면 BFF가 access token을
+   `Authorization: Bearer`로 붙여 Resource Server에 fan-out합니다.
+
+Resource Server는 `aud=keycloak-pattern-api`를 검증합니다. 브라우저에서는
+8081로 직접 요청하거나 Keycloak token endpoint를 호출하지 않습니다.
+
+학습용 구성은 단일 인스턴스 메모리에 session과 authorized client를
+보관합니다. BFF를 재시작하면 세션이 사라집니다. 다중 인스턴스 운영에서는
+Spring Session/Redis 같은 공유 저장소와 저장 token 암호화 정책이 필요합니다.
+
+## 방어 전 CSRF 재현
+
+이 feature 브랜치에서는 다음 CSRF 방어 feature와 비교하기 위해 CSRF를
+의도적으로 끕니다. 다른 origin의 자동 제출 form이 브라우저 cookie를
+자동으로 포함해 `/bff/api/preferences` 상태를 바꾸는 것을 E2E에서
+재현합니다.
+
+이 취약 상태는 `feature/keycloak-bff-csrf-samesite-defense`에서 Spring
+CSRF token과 명시적 SameSite=Lax를 적용해 차단합니다.

e2e/package.json

@@ -4,7 +4,7 @@
   "version": "1.0.0",
   "type": "module",
   "scripts": {
-    "test:pattern1": "node pattern1.mjs"
+    "test:pattern3": "node pattern3.mjs"
   },
   "devDependencies": {
     "playwright-core": "1.62.0"

e2e/pattern1.mjs

@@ -1,71 +0,0 @@
-import assert from "node:assert/strict";
-import { chromium } from "playwright-core";
-
-const username = process.env.E2E_USERNAME ?? "regular-user";
-const password = process.env.E2E_PASSWORD;
-
-assert.ok(password, "E2E_PASSWORD must be set");
-
-const browser = await chromium.launch({
-  executablePath: process.env.CHROME_BIN ?? "/usr/bin/google-chrome",
-  headless: true,
-  args: ["--no-sandbox"],
-});
-
-try {
-  const context = await browser.newContext();
-  const page = await context.newPage();
-  let authorizationUrl;
-
-  page.on("request", (request) => {
-    if (request.url().includes("/protocol/openid-connect/auth")) {
-      authorizationUrl = new URL(request.url());
-    }
-  });
-
-  await page.goto("http://localhost:8088");
-  await page.locator("#login").click();
-  await page.waitForURL(/localhost:8080/u);
-  await page.locator("#username").fill(username);
-  await page.locator("#password").fill(password);
-  await page.locator("#kc-login").click();
-  await page.waitForURL("http://localhost:8088/");
-  await page.locator('[data-authenticated="true"]').waitFor();
-
-  assert.equal(authorizationUrl?.searchParams.get("response_type"), "code");
-  assert.equal(authorizationUrl?.searchParams.get("code_challenge_method"), "S256");
-  assert.ok(authorizationUrl?.searchParams.get("code_challenge"));
-
-  const accessToken = await page.evaluate(() => window.__pattern1.getAccessToken());
-  assert.ok(accessToken, "access token must exist in browser memory");
-
-  const storageSnapshot = await page.evaluate(() => ({
-    localStorage: Object.values(localStorage),
-    sessionStorage: Object.values(sessionStorage),
-  }));
-  assert.equal(
-    JSON.stringify(storageSnapshot).includes(accessToken),
-    false,
-    "access token must not be persisted in Web Storage",
-  );
-
-  await page.locator("#call-api").click();
-  await page.waitForFunction(() => {
-    const text = document.querySelector("#result")?.textContent ?? "";
-    return text.includes('"httpStatus": 200');
-  });
-
-  await page.reload();
-  await page.locator('[data-authenticated="false"]').waitFor();
-  assert.equal(
-    await page.evaluate(() => window.__pattern1.getAccessToken()),
-    null,
-    "reload must clear the memory-only token",
-  );
-
-  console.log(
-    "pattern1 browser verified: code+PKCE S256, protected API 200, Web Storage token 0, reload clears token",
-  );
-} finally {
-  await browser.close();
-}

e2e/pattern3.mjs

@@ -0,0 +1,140 @@
+import assert from "node:assert/strict";
+import { chromium } from "playwright-core";
+
+const password = process.env.E2E_PASSWORD;
+assert.ok(password, "E2E_PASSWORD must be set");
+
+async function completeKeycloakLogin(page) {
+  for (let attempt = 1; attempt <= 2; attempt += 1) {
+    await page.locator("#username").fill(
+      process.env.E2E_USERNAME ?? "regular-user",
+    );
+    await page.locator("#password").fill(password);
+    await page.locator("#kc-login").click();
+    await page.waitForLoadState("domcontentloaded");
+
+    if (page.url() === "http://localhost:8083/") {
+      return;
+    }
+    if (attempt === 1) {
+      await page.goto(
+        "http://localhost:8083/oauth2/authorization/keycloak",
+      );
+      await page.waitForURL(/localhost:8080/u);
+    }
+  }
+  throw new Error(`Keycloak login did not return to AP3: ${page.url()}`);
+}
+
+const browser = await chromium.launch({
+  executablePath: process.env.CHROME_BIN ?? "/usr/bin/google-chrome",
+  headless: true,
+  args: ["--no-sandbox"],
+});
+
+try {
+  const context = await browser.newContext();
+  const page = await context.newPage();
+  const browserRequests = [];
+  page.on("request", (request) => browserRequests.push(request.url()));
+
+  await page.goto("http://localhost:8083");
+  const authorizationRequestPromise = page.waitForRequest((request) =>
+    request.url().includes(
+      "/protocol/openid-connect/auth?response_type=code",
+    ),
+  );
+  await page.locator("#login").click();
+  const authorizationRequest = await authorizationRequestPromise;
+  const authorizationUrl = new URL(authorizationRequest.url());
+  assert.equal(authorizationUrl.searchParams.get("client_id"), "bff-confidential");
+  assert.equal(authorizationUrl.searchParams.get("code_challenge_method"), "S256");
+  assert.ok(authorizationUrl.searchParams.get("code_challenge"));
+
+  await page.waitForURL(/localhost:8080/u);
+  await completeKeycloakLogin(page);
+  const callbackRequest = browserRequests.find((url) =>
+    url.startsWith("http://localhost:8083/login/oauth2/code/keycloak?"),
+  );
+  assert.ok(callbackRequest, "authorization response must use the BFF callback");
+
+  const boundaryResponsePromise = page.waitForResponse((response) =>
+    response.url().endsWith("/bff/token-boundary"),
+  );
+  await page.locator("#inspect").click();
+  const boundaryResponse = await boundaryResponsePromise;
+  assert.equal(boundaryResponse.status(), 200);
+  const boundary = await boundaryResponse.json();
+  assert.equal(boundary.accessTokenStoredOnServer, true);
+  assert.equal(boundary.refreshTokenStoredOnServer, true);
+  assert.equal(boundary.browserTokenCount, 0);
+  assert.equal(boundary.csrfProtectionEnabled, false);
+  assert.equal(JSON.stringify(boundary).includes("access_token"), false);
+  assert.equal(JSON.stringify(boundary).includes("refresh_token"), false);
+
+  const proxyResponsePromise = page.waitForResponse((response) =>
+    response.url().endsWith("/bff/api/me"),
+  );
+  await page.locator("#call-bff").click();
+  const proxyResponse = await proxyResponsePromise;
+  assert.equal(proxyResponse.status(), 200);
+  const resource = await proxyResponse.json();
+  assert.equal(resource.username, "regular-user");
+  assert.ok(resource.audience.includes("keycloak-pattern-api"));
+
+  assert.equal(
+    browserRequests.some((url) => url.startsWith("http://localhost:8081/")),
+    false,
+    "the browser must not bypass the BFF",
+  );
+  assert.equal(
+    browserRequests.some((url) =>
+      url.includes("/protocol/openid-connect/token"),
+    ),
+    false,
+    "the token exchange must be server-to-server",
+  );
+
+  const cookies = await context.cookies("http://localhost:8083/");
+  const sessionCookie = cookies.find((cookie) => cookie.name === "AP3_SESSION");
+  assert.ok(sessionCookie);
+  assert.equal(sessionCookie.httpOnly, true);
+
+  const storage = await page.evaluate(() => ({
+    localStorage: Object.values(localStorage),
+    sessionStorage: Object.values(sessionStorage),
+    readableCookies: document.cookie,
+  }));
+  assert.deepEqual(storage.localStorage, []);
+  assert.deepEqual(storage.sessionStorage, []);
+  assert.equal(storage.readableCookies.includes("AP3_SESSION"), false);
+
+  await page.goto("http://localhost:8088");
+  const forgedResponsePromise = page.waitForResponse(
+    (response) =>
+      response.url() === "http://localhost:8083/bff/api/preferences" &&
+      response.request().method() === "POST",
+  );
+  await page.evaluate(() => {
+    const form = document.createElement("form");
+    form.method = "POST";
+    form.action = "http://localhost:8083/bff/api/preferences";
+    const input = document.createElement("input");
+    input.name = "theme";
+    input.value = "attacker";
+    form.append(input);
+    document.body.append(form);
+    form.submit();
+  });
+  const forgedResponse = await forgedResponsePromise;
+  assert.equal(forgedResponse.status(), 200);
+  const forgedResult = await forgedResponse.json();
+  assert.equal(forgedResult.updated, true);
+  assert.equal(forgedResult.theme, "attacker");
+
+  console.log(
+    "pattern3 BFF verified: browser token 0, session-only proxy 200, pre-defense CSRF reproduced",
+  );
+} finally {
+  await browser.close();
+}

frontend/Dockerfile

@@ -1,16 +1,4 @@
-FROM node:24-alpine AS build
-
-WORKDIR /workspace
-
-COPY package.json package-lock.json ./
-RUN npm ci
-
-COPY src ./src
-COPY test ./test
-RUN npm test && npm run build
-
 FROM nginx:1.29-alpine
 
 COPY nginx.conf /etc/nginx/conf.d/default.conf
 COPY index.html /usr/share/nginx/html/index.html
-COPY --from=build /workspace/dist/app.js /usr/share/nginx/html/app.js

frontend/index.html

@@ -3,66 +3,31 @@
 <head>
   <meta charset="utf-8">
   <meta name="viewport" content="width=device-width, initial-scale=1">
-  <meta name="referrer" content="no-referrer">
-  <title>AP1 · SPA Direct + Resource Server</title>
+  <title>Keycloak Authentication Patterns</title>
   <style>
     :root {
       color-scheme: light dark;
       font-family: system-ui, sans-serif;
     }
     body {
-      max-width: 56rem;
-      margin: 6vh auto;
+      max-width: 48rem;
+      margin: 8vh auto;
       padding: 0 1.5rem;
-      line-height: 1.55;
-    }
-    button {
-      margin: 0 0.5rem 0.5rem 0;
-      padding: 0.6rem 0.9rem;
-      cursor: pointer;
-    }
-    code, pre {
-      border-radius: 0.35rem;
-      background: color-mix(in srgb, CanvasText 9%, Canvas);
+      line-height: 1.6;
     }
     code {
-      padding: 0.1rem 0.3rem;
-    }
-    pre {
-      min-height: 8rem;
-      padding: 1rem;
-      overflow: auto;
-      white-space: pre-wrap;
-    }
-    .notice {
-      border-left: 0.3rem solid #e09f3e;
-      padding-left: 1rem;
+      padding: 0.15rem 0.35rem;
+      border-radius: 0.25rem;
+      background: color-mix(in srgb, CanvasText 10%, Canvas);
     }
   </style>
 </head>
 <body>
-  <main>
-    <h1>AP1 · SPA Direct + Resource Server</h1>
-    <p>
-      바닐라 JavaScript SPA가 <code>spa-public</code> client로 Authorization
-      Code + PKCE를 수행하고, access token을 직접 Spring Resource Server에
-      전달합니다.
-    </p>
-    <p class="notice">
-      access/refresh token은 메모리에만 존재합니다. 새로고침하면 사라지는 것이
-      이 패턴의 의도된 보안 경계입니다.
-    </p>
-
-    <section>
-      <button id="login" type="button">Keycloak 로그인</button>
-      <button id="call-api" type="button" disabled>보호 API 호출</button>
-      <button id="pkce-demo" type="button">수동 PKCE 생성</button>
-      <button id="logout" type="button" disabled>로그아웃</button>
-    </section>
-
-    <p id="session-state" data-authenticated="false">세션 확인 중…</p>
-    <pre id="result" aria-live="polite"></pre>
-  </main>
-  <script type="module" src="/app.js"></script>
+  <h1>Keycloak Authentication Patterns</h1>
+  <p>공통 Docker Compose baseline이 실행 중입니다.</p>
+  <p>
+    공개 API는 <code>/api/public</code>, 보호 API는
+    <code>/api/me</code>에서 확인할 수 있습니다.
+  </p>
 </body>
 </html>

frontend/nginx.conf

@@ -21,7 +21,6 @@ server {
     }
 
     location / {
-        add_header Cache-Control "no-store";
         try_files $uri $uri/ /index.html;
     }
 }

frontend/package-lock.json

@@ -1,523 +0,0 @@
-{
-  "name": "keycloak-pattern1-spa",
-  "version": "1.0.0",
-  "lockfileVersion": 3,
-  "requires": true,
-  "packages": {
-    "": {
-      "name": "keycloak-pattern1-spa",
-      "version": "1.0.0",
-      "dependencies": {
-        "oidc-client-ts": "3.5.0"
-      },
-      "devDependencies": {
-        "esbuild": "0.28.1"
-      }
-    },
-    "node_modules/@esbuild/aix-ppc64": {
-      "version": "0.28.1",
-      "resolved": "https://registry.npmjs.org/@esbuild/aix-ppc64/-/aix-ppc64-0.28.1.tgz",
-      "integrity": "sha512-Svl7tq8k/08+p6CXPpRjQ1fKX+1odH/BQbb48fV6fj3CWHhsoIOoY87w1oHXm0qEpkIK3ZfVgp0hed3XBXzXMQ==",
-      "cpu": [
-        "ppc64"
-      ],
-      "dev": true,
-      "license": "MIT",
-      "optional": true,
-      "os": [
-        "aix"
-      ],
-      "engines": {
-        "node": ">=18"
-      }
-    },
-    "node_modules/@esbuild/android-arm": {
-      "version": "0.28.1",
-      "resolved": "https://registry.npmjs.org/@esbuild/android-arm/-/android-arm-0.28.1.tgz",
-      "integrity": "sha512-0k2F129Xdio1TdJfzJ8sy1Q47vUD2NnwdhiAf7drUN1EBTfPf4hsFCtmMgu/6m8JSzsBrlmVjudMBQqOfG8usQ==",
-      "cpu": [
-        "arm"
-      ],
-      "dev": true,
-      "license": "MIT",
-      "optional": true,
-      "os": [
-        "android"
-      ],
-      "engines": {
-        "node": ">=18"
-      }
-    },
-    "node_modules/@esbuild/android-arm64": {
-      "version": "0.28.1",
-      "resolved": "https://registry.npmjs.org/@esbuild/android-arm64/-/android-arm64-0.28.1.tgz",
-      "integrity": "sha512-34EGEbCIAgosYz6goLcopX6Mo7NyGv9tfwEM2/7Ce2VcVRk568iSvniGWcUXIy7wEDR1wzolcxcriFVrWYcwBg==",
-      "cpu": [
-        "arm64"
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-      "dev": true,
-      "license": "MIT",
-      "optional": true,
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-        "android"
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-      "engines": {
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-      }
-    },
-    "node_modules/@esbuild/android-x64": {
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-      "resolved": "https://registry.npmjs.org/@esbuild/android-x64/-/android-x64-0.28.1.tgz",
-      "integrity": "sha512-dbwY7ltSMDWsRatcRpCnES4F+im88OCUgGZjy52shC7GqHRE/cYlxNbB4Z4UpJswpcc4Qxd2oE/ufM0p61IKng==",
-      "cpu": [
-        "x64"
-      ],
-      "dev": true,
-      "license": "MIT",
-      "optional": true,
-      "os": [
-        "android"
-      ],
-      "engines": {
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-      }
-    },
-    "node_modules/@esbuild/darwin-arm64": {
-      "version": "0.28.1",
-      "resolved": "https://registry.npmjs.org/@esbuild/darwin-arm64/-/darwin-arm64-0.28.1.tgz",
-      "integrity": "sha512-TZbWkQY7kvTAXbXUT7uVACR5cMHsDiSz9z7ZKAX/RTq/WJEk3QyRr0wZpNhBDX+/0CtdqUIJlOiodQcta6tY3Q==",
-      "cpu": [
-        "arm64"
-      ],
-      "dev": true,
-      "license": "MIT",
-      "optional": true,
-      "os": [
-        "darwin"
-      ],
-      "engines": {
-        "node": ">=18"
-      }
-    },
-    "node_modules/@esbuild/darwin-x64": {
-      "version": "0.28.1",
-      "resolved": "https://registry.npmjs.org/@esbuild/darwin-x64/-/darwin-x64-0.28.1.tgz",
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-      "dev": true,
-      "license": "MIT",
-      "optional": true,
-      "os": [
-        "darwin"
-      ],
-      "engines": {
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-      }
-    },
-    "node_modules/@esbuild/freebsd-arm64": {
-      "version": "0.28.1",
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-      "dev": true,
-      "license": "MIT",
-      "optional": true,
-      "os": [
-        "freebsd"
-      ],
-      "engines": {
-        "node": ">=18"
-      }
-    },
-    "node_modules/@esbuild/freebsd-x64": {
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-      "license": "MIT",
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-      "version": "3.5.0",
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frontend/package.json

@@ -1,16 +0,0 @@
-{
-  "name": "keycloak-pattern1-spa",
-  "private": true,
-  "version": "1.0.0",
-  "type": "module",
-  "scripts": {
-    "build": "esbuild src/app.js --bundle --format=esm --outfile=dist/app.js --minify --sourcemap",
-    "test": "node --test test/*.test.mjs"
-  },
-  "dependencies": {
-    "oidc-client-ts": "3.5.0"
-  },
-  "devDependencies": {
-    "esbuild": "0.28.1"
-  }
-}

frontend/src/app.js

@@ -1,138 +0,0 @@
-import {
-  InMemoryWebStorage,
-  UserManager,
-  WebStorageStateStore,
-} from "oidc-client-ts";
-
-import { createPkcePair } from "./pkce.js";
-
-const authority = "http://localhost:8080/realms/keycloak-patterns";
-const backendBaseUrl = "http://localhost:8081";
-
-const userManager = new UserManager({
-  authority,
-  client_id: "spa-public",
-  redirect_uri: "http://localhost:8088/callback.html",
-  post_logout_redirect_uri: "http://localhost:8088/",
-  response_type: "code",
-  scope: "openid profile email",
-  automaticSilentRenew: true,
-  monitorSession: false,
-  loadUserInfo: false,
-  userStore: new WebStorageStateStore({
-    store: new InMemoryWebStorage(),
-  }),
-  stateStore: new WebStorageStateStore({
-    store: window.sessionStorage,
-  }),
-});
-
-const loginButton = document.querySelector("#login");
-const logoutButton = document.querySelector("#logout");
-const apiButton = document.querySelector("#call-api");
-const pkceButton = document.querySelector("#pkce-demo");
-const sessionState = document.querySelector("#session-state");
-const result = document.querySelector("#result");
-
-let currentUser = null;
-
-function renderJson(value) {
-  result.textContent = JSON.stringify(value, null, 2);
-}
-
-function tokenMetadata(user) {
-  return {
-    subject: user.profile.sub,
-    username: user.profile.preferred_username,
-    expiresAt: new Date(user.expires_at * 1000).toISOString(),
-    accessTokenHeldBy: "browser memory",
-    refreshTokenHeldBy: user.refresh_token ? "browser memory" : "not issued",
-  };
-}
-
-function renderSession(user) {
-  currentUser = user;
-  const authenticated = Boolean(user && !user.expired);
-  sessionState.dataset.authenticated = String(authenticated);
-  sessionState.textContent = authenticated
-    ? `${user.profile.preferred_username} 로그인됨 · token은 메모리에만 보관`
-    : "로그인되지 않음 · 브라우저 저장소에 token 없음";
-  loginButton.disabled = authenticated;
-  logoutButton.disabled = !authenticated;
-  apiButton.disabled = !authenticated;
-
-  if (authenticated) {
-    renderJson(tokenMetadata(user));
-  }
-}
-
-async function finishSigninCallback() {
-  const params = new URLSearchParams(window.location.search);
-  const isCallback = window.location.pathname === "/callback.html"
-    && (params.has("code") || params.has("error"));
-
-  if (!isCallback) {
-    return null;
-  }
-
-  const user = await userManager.signinRedirectCallback();
-  window.history.replaceState({}, document.title, "/");
-  return user;
-}
-
-async function callProtectedApi() {
-  if (!currentUser || currentUser.expired) {
-    throw new Error("로그인이 필요합니다.");
-  }
-
-  const response = await fetch(`${backendBaseUrl}/api/me`, {
-    headers: {
-      Authorization: `Bearer ${currentUser.access_token}`,
-    },
-  });
-  const body = await response.json();
-  renderJson({
-    httpStatus: response.status,
-    resourceServerResponse: body,
-    tokenBoundary: tokenMetadata(currentUser),
-  });
-
-  if (!response.ok) {
-    throw new Error(`보호 API가 ${response.status}를 반환했습니다.`);
-  }
-}
-
-loginButton.addEventListener("click", () => userManager.signinRedirect());
-logoutButton.addEventListener("click", () => userManager.signoutRedirect());
-apiButton.addEventListener("click", () => {
-  callProtectedApi().catch((error) => renderJson({ error: error.message }));
-});
-pkceButton.addEventListener("click", () => {
-  createPkcePair()
-    .then(({ verifier, challenge, method }) => renderJson({
-      method,
-      verifierLength: verifier.length,
-      challengeLength: challenge.length,
-      note: "실제 로그인에서는 oidc-client-ts가 같은 S256 단계를 수행합니다.",
-    }))
-    .catch((error) => renderJson({ error: error.message }));
-});
-
-userManager.events.addUserLoaded(renderSession);
-userManager.events.addUserUnloaded(() => renderSession(null));
-userManager.events.addAccessTokenExpired(() => renderSession(null));
-
-window.__pattern1 = {
-  getAccessToken: () => currentUser?.access_token ?? null,
-  getRefreshToken: () => currentUser?.refresh_token ?? null,
-  getIdToken: () => currentUser?.id_token ?? null,
-  callProtectedApi,
-};
-
-try {
-  const callbackUser = await finishSigninCallback();
-  renderSession(callbackUser ?? await userManager.getUser());
-} catch (error) {
-  renderSession(null);
-  renderJson({ error: error.message });
-}

frontend/src/pkce.js

@@ -1,26 +0,0 @@
-function base64Url(bytes) {
-  let binary = "";
-  for (const byte of bytes) {
-    binary += String.fromCharCode(byte);
-  }
-  return btoa(binary)
-    .replaceAll("+", "-")
-    .replaceAll("/", "_")
-    .replace(/=+$/u, "");
-}
-
-export async function createPkcePair(cryptoApi = globalThis.crypto) {
-  const verifierBytes = new Uint8Array(32);
-  cryptoApi.getRandomValues(verifierBytes);
-  const verifier = base64Url(verifierBytes);
-  const digest = await cryptoApi.subtle.digest(
-    "SHA-256",
-    new TextEncoder().encode(verifier),
-  );
-
-  return {
-    verifier,
-    challenge: base64Url(new Uint8Array(digest)),
-    method: "S256",
-  };
-}

frontend/test/pkce.test.mjs

@@ -1,18 +0,0 @@
-import assert from "node:assert/strict";
-import { webcrypto } from "node:crypto";
-import test from "node:test";
-
-globalThis.btoa = (value) => Buffer.from(value, "binary").toString("base64");
-
-const { createPkcePair } = await import("../src/pkce.js");
-
-test("manual PKCE helper creates an RFC 7636 S256 pair", async () => {
-  const pair = await createPkcePair(webcrypto);
-
-  assert.equal(pair.method, "S256");
-  assert.equal(pair.verifier.length, 43);
-  assert.equal(pair.challenge.length, 43);
-  assert.match(pair.verifier, /^[A-Za-z0-9_-]+$/u);
-  assert.match(pair.challenge, /^[A-Za-z0-9_-]+$/u);
-  assert.notEqual(pair.verifier, pair.challenge);
-});

keycloak/import/keycloak-patterns-realm.json

@@ -98,8 +98,24 @@
         "http://localhost:8083"
       ],
       "attributes": {
+        "pkce.code.challenge.method": "S256",
         "post.logout.redirect.uris": "http://localhost:8083/*"
-      }
+      },
+      "protocolMappers": [
+        {
+          "name": "keycloak-pattern-api-audience",
+          "protocol": "openid-connect",
+          "protocolMapper": "oidc-audience-mapper",
+          "consentRequired": false,
+          "config": {
+            "included.custom.audience": "keycloak-pattern-api",
+            "id.token.claim": "false",
+            "access.token.claim": "true",
+            "userinfo.token.claim": "false",
+            "introspection.token.claim": "true"
+          }
+        }
+      ]
     },
     {
       "clientId": "edge-proxy",

scripts/verify-pattern3.sh

@@ -2,7 +2,7 @@
 set -eu
 
 if [ ! -f .env ]; then
-  echo "missing .env; copy .env.example and set local-only values" >&2
+  echo "missing .env; copy .env.example and set development values" >&2
   exit 1
 fi
 
@@ -16,6 +16,6 @@ docker compose up --build -d --wait
 npm --prefix e2e ci
 E2E_USERNAME=regular-user \
 E2E_PASSWORD="$REGULAR_USER_PASSWORD" \
-  npm --prefix e2e run test:pattern1
+  npm --prefix e2e run test:pattern3
 
-echo "AP1 verified end to end"
+echo "AP3 BFF session and CSRF behavior verified"