Disable default logout page when logout disabled

Closes gh-9475

config/src/main/java/org/springframework/security/config/annotation/web/configurers/DefaultLoginPageConfigurer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -97,7 +97,10 @@ public final class DefaultLoginPageConfigurer<H extends HttpSecurityBuilder<H>>
 		if (this.loginPageGeneratingFilter.isEnabled() && authenticationEntryPoint == null) {
 			this.loginPageGeneratingFilter = postProcess(this.loginPageGeneratingFilter);
 			http.addFilter(this.loginPageGeneratingFilter);
-			http.addFilter(this.logoutPageGeneratingFilter);
+			LogoutConfigurer<H> logoutConfigurer = http.getConfigurer(LogoutConfigurer.class);
+			if (logoutConfigurer != null) {
+				http.addFilter(this.logoutPageGeneratingFilter);
+			}
 		}
 	}
 

config/src/main/java/org/springframework/security/config/web/server/ServerHttpSecurity.java

@@ -2224,7 +2224,10 @@ public class ServerHttpSecurity {
 			}
 			if (loginPage != null) {
 				http.addFilterAt(loginPage, SecurityWebFiltersOrder.LOGIN_PAGE_GENERATING);
-				http.addFilterAt(new LogoutPageGeneratingWebFilter(), SecurityWebFiltersOrder.LOGOUT_PAGE_GENERATING);
+				if (http.logout != null) {
+					http.addFilterAt(new LogoutPageGeneratingWebFilter(),
+							SecurityWebFiltersOrder.LOGOUT_PAGE_GENERATING);
+				}
 			}
 		}
 

config/src/test/java/org/springframework/security/config/annotation/web/configurers/DefaultLoginPageConfigurerTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -46,11 +46,14 @@ import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.verify;
+import static org.springframework.security.config.Customizer.withDefaults;
 import static org.springframework.security.test.web.servlet.request.SecurityMockMvcRequestPostProcessors.csrf;
+import static org.springframework.security.test.web.servlet.request.SecurityMockMvcRequestPostProcessors.user;
 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.content;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.redirectedUrl;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
 
 /**
  * Tests for {@link DefaultLoginPageConfigurer}
@@ -375,6 +378,18 @@ public class DefaultLoginPageConfigurerTests {
 						.isZero();
 	}
 
+	@Test
+	public void formLoginWhenLogoutEnabledThenCreatesDefaultLogoutPage() throws Exception {
+		this.spring.register(DefaultLogoutPageConfig.class).autowire();
+		this.mvc.perform(get("/logout").with(user("user"))).andExpect(status().isOk());
+	}
+
+	@Test
+	public void formLoginWhenLogoutDisabledThenDefaultLogoutPageDoesNotExist() throws Exception {
+		this.spring.register(LogoutDisabledConfig.class).autowire();
+		this.mvc.perform(get("/logout").with(user("user"))).andExpect(status().isNotFound());
+	}
+
 	@EnableWebSecurity
 	static class DefaultLoginPageConfig extends WebSecurityConfigurerAdapter {
 
@@ -533,6 +548,41 @@ public class DefaultLoginPageConfigurerTests {
 
 	}
 
+	@EnableWebSecurity
+	static class DefaultLogoutPageConfig extends WebSecurityConfigurerAdapter {
+
+		@Override
+		protected void configure(HttpSecurity http) throws Exception {
+			// @formatter:off
+			http
+				.authorizeRequests((authorize) -> authorize
+					.anyRequest().authenticated()
+				)
+				.formLogin(withDefaults());
+			// @formatter:on
+		}
+
+	}
+
+	@EnableWebSecurity
+	static class LogoutDisabledConfig extends WebSecurityConfigurerAdapter {
+
+		@Override
+		protected void configure(HttpSecurity http) throws Exception {
+			// @formatter:off
+			http
+					.authorizeRequests((authorize) -> authorize
+							.anyRequest().authenticated()
+					)
+					.formLogin(withDefaults())
+					.logout((logout) -> logout
+							.disable()
+					);
+			// @formatter:on
+		}
+
+	}
+
 	static class ReflectingObjectPostProcessor implements ObjectPostProcessor<Object> {
 
 		@Override

config/src/test/java/org/springframework/security/config/web/server/LogoutSpecTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -26,7 +26,10 @@ import org.springframework.security.web.server.SecurityWebFilterChain;
 import org.springframework.security.web.server.context.WebSessionServerSecurityContextRepository;
 import org.springframework.security.web.server.util.matcher.ServerWebExchangeMatchers;
 import org.springframework.test.web.reactive.server.WebTestClient;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.springframework.security.config.Customizer.withDefaults;
 
 /**
@@ -146,7 +149,7 @@ public class LogoutSpecTests {
 	}
 
 	@Test
-	public void logoutWhenDisabledThenPostToLogoutDoesNothing() {
+	public void logoutWhenDisabledThenDefaultLogoutPageDoesNotExist() {
 		// @formatter:off
 		SecurityWebFilterChain securityWebFilter = this.http
 				.authorizeExchange()
@@ -156,7 +159,7 @@ public class LogoutSpecTests {
 				.logout().disable()
 				.build();
 		WebTestClient webTestClient = WebTestClientBuilder
-				.bindToWebFilters(securityWebFilter)
+				.bindToControllerAndWebFilters(HomeController.class, securityWebFilter)
 				.build();
 		WebDriver driver = WebTestClientHtmlUnitDriverBuilder
 				.webTestClientSetup(webTestClient)
@@ -171,8 +174,8 @@ public class LogoutSpecTests {
 				.submit(FormLoginTests.HomePage.class);
 		// @formatter:on
 		homePage.assertAt();
-		FormLoginTests.DefaultLogoutPage.to(driver).assertAt().logout();
-		homePage.assertAt();
+		FormLoginTests.DefaultLogoutPage.to(driver);
+		assertThat(driver.getPageSource()).isEmpty();
 	}
 
 	@Test
@@ -208,4 +211,14 @@ public class LogoutSpecTests {
 		FormLoginTests.HomePage.to(driver, FormLoginTests.DefaultLoginPage.class).assertAt();
 	}
 
+	@RestController
+	public static class HomeController {
+
+		@GetMapping("/")
+		public String ok() {
+			return "ok";
+		}
+
+	}
+
 }