webauthn: use DefaultResourcesFilter#webauthn

- Unconditionally use the DefaultResourcesFilter, because the javascript file is required by the
  DefaultWebAythnPageGeneratingFilter, which is always registered.

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

@@ -16,17 +16,13 @@
 
 package org.springframework.security.config.annotation.web.configurers;
 
-import java.lang.reflect.Constructor;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
 
 import org.springframework.beans.factory.NoSuchBeanDefinitionException;
 import org.springframework.context.ApplicationContext;
-import org.springframework.core.io.ClassPathResource;
-import org.springframework.http.HttpMethod;
-import org.springframework.http.MediaType;
 import org.springframework.security.authentication.ProviderManager;
 import org.springframework.security.config.annotation.web.HttpSecurityBuilder;
 import org.springframework.security.core.userdetails.UserDetailsService;
@@ -35,8 +31,6 @@
 import org.springframework.security.web.authentication.ui.DefaultResourcesFilter;
 import org.springframework.security.web.authentication.www.BasicAuthenticationFilter;
 import org.springframework.security.web.csrf.CsrfToken;
-import org.springframework.security.web.util.matcher.AntPathRequestMatcher;
-import org.springframework.security.web.util.matcher.RequestMatcher;
 import org.springframework.security.web.webauthn.api.PublicKeyCredentialRpEntity;
 import org.springframework.security.web.webauthn.authentication.PublicKeyCredentialRequestOptionsFilter;
 import org.springframework.security.web.webauthn.authentication.WebAuthnAuthenticationFilter;
@@ -51,8 +45,6 @@
 import org.springframework.security.web.webauthn.registration.PublicKeyCredentialCreationOptionsFilter;
 import org.springframework.security.web.webauthn.registration.WebAuthnRegistrationFilter;
 
-import static org.springframework.security.web.util.matcher.AntPathRequestMatcher.antMatcher;
-
 /**
  * Configures WebAuthn for Spring Security applications
  *
@@ -127,26 +119,15 @@ public void configure(H http) throws Exception {
 		http.addFilterBefore(webAuthnAuthnFilter, BasicAuthenticationFilter.class);
 		http.addFilterAfter(new WebAuthnRegistrationFilter(userCredentials, rpOperations), AuthorizationFilter.class);
 		http.addFilterBefore(new PublicKeyCredentialCreationOptionsFilter(rpOperations), AuthorizationFilter.class);
+		http.addFilter(DefaultResourcesFilter.webauthn());
 		http.addFilterAfter(new DefaultWebAuthnRegistrationPageGeneratingFilter(userEntities, userCredentials),
 				AuthorizationFilter.class);
 		http.addFilterBefore(new PublicKeyCredentialRequestOptionsFilter(rpOperations), AuthorizationFilter.class);
 		DefaultLoginPageGeneratingFilter loginPageGeneratingFilter = http
 			.getSharedObject(DefaultLoginPageGeneratingFilter.class);
 		if (loginPageGeneratingFilter != null) {
-			ClassPathResource webauthn = new ClassPathResource(
-					"org/springframework/security/spring-security-webauthn.js");
-			AntPathRequestMatcher matcher = antMatcher(HttpMethod.GET, "/login/webauthn.js");
-
-			Constructor<DefaultResourcesFilter> constructor = DefaultResourcesFilter.class
-				.getDeclaredConstructor(RequestMatcher.class, ClassPathResource.class, MediaType.class);
-			constructor.setAccessible(true);
-			DefaultResourcesFilter resourcesFilter = constructor.newInstance(matcher, webauthn,
-					MediaType.parseMediaType("text/javascript"));
-			http.addFilter(resourcesFilter);
-			DefaultLoginPageGeneratingFilter loginGeneratingFilter = http
-				.getSharedObject(DefaultLoginPageGeneratingFilter.class);
-			loginGeneratingFilter.setPasskeysEnabled(true);
-			loginGeneratingFilter.setResolveHeaders((request) -> {
+			loginPageGeneratingFilter.setPasskeysEnabled(true);
+			loginPageGeneratingFilter.setResolveHeaders((request) -> {
 				CsrfToken csrfToken = (CsrfToken) request.getAttribute(CsrfToken.class.getName());
 				return Map.of(csrfToken.getHeaderName(), csrfToken.getToken());
 			});

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

@@ -0,0 +1,77 @@
+/*
+ * Copyright 2002-2024 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 org.springframework.security.config.annotation.web.configurers;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+
+import org.springframework.beans.factory.annotation.Autowired;
+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.annotation.web.configuration.EnableWebSecurity;
+import org.springframework.security.config.test.SpringTestContext;
+import org.springframework.security.config.test.SpringTestContextExtension;
+import org.springframework.security.core.userdetails.UserDetailsService;
+import org.springframework.security.provisioning.InMemoryUserDetailsManager;
+import org.springframework.security.web.SecurityFilterChain;
+import org.springframework.test.web.servlet.MockMvc;
+
+import static org.hamcrest.Matchers.containsString;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.header;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+/**
+ * @author Daniel Garnier-Moiroux
+ */
+@ExtendWith(SpringTestContextExtension.class)
+public class WebAuthnConfigurerTests {
+
+	public final SpringTestContext spring = new SpringTestContext(this);
+
+	@Autowired
+	MockMvc mvc;
+
+	@Test
+	public void javascriptWhenWebauthnConfiguredThenServesJavascript() throws Exception {
+		this.spring.register(DefaultWebauthnConfiguration.class).autowire();
+		this.mvc.perform(get("/login/webauthn.js"))
+			.andExpect(status().isOk())
+			.andExpect(header().string("content-type", "text/javascript;charset=UTF-8"))
+			.andExpect(content().string(containsString("async function authenticate(")));
+	}
+
+	@Configuration
+	@EnableWebSecurity
+	static class DefaultWebauthnConfiguration {
+
+		@Bean
+		UserDetailsService userDetailsService() {
+			return new InMemoryUserDetailsManager();
+		}
+
+		@Bean
+		SecurityFilterChain securityFilterChain(HttpSecurity http) throws Exception {
+			return http.webAuthn(Customizer.withDefaults()).build();
+		}
+
+	}
+
+}