Add Support for Clear Site Data on Logout

Added an implementation of HeaderWriter for Clear-Site-Data HTTP
response header as welll as an implementation of LogoutHanlder
that accepts an implementation of HeaderWriter to write headers.

- Added ClearSiteDataHeaderWriter and HeaderWriterLogoutHandler
that implements HeaderWriter and LogoutHandler respectively
- Added unit tests for both implementations's behaviours
- Integration tests for HeaderWriterLogoutHandler that uses
ClearSiteDataHeaderWriter
- Updated the documentation to include link to
HeaderWriterLogoutHandler

Fixes spring-projectsgh-4187

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

@@ -0,0 +1,99 @@
+/*
+ * Copyright 2002-2019 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 org.springframework.security.config.annotation.web.configurers;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+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.config.test.SpringTestRule;
+import org.springframework.security.test.context.annotation.SecurityTestExecutionListeners;
+import org.springframework.security.test.context.support.WithMockUser;
+import org.springframework.security.web.authentication.logout.HeaderWriterLogoutHandler;
+import org.springframework.security.web.header.writers.ClearSiteDataHeaderWriter;
+import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.test.web.servlet.MockMvc;
+
+import static org.springframework.security.test.web.servlet.request.SecurityMockMvcRequestPostProcessors.csrf;
+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;
+
+/**
+ *
+ * Tests for {@link HeaderWriterLogoutHandler} that passing {@link ClearSiteDataHeaderWriter}
+ * implementation.
+ *
+ * @author Rafiullah Hamedy
+ *
+ */
+@RunWith(SpringRunner.class)
+@SecurityTestExecutionListeners
+public class LogoutConfigurerClearSiteDataTests {
+
+	private static final String CLEAR_SITE_DATA_HEADER = "Clear-Site-Data";
+
+	private static final String[] SOURCE = {"cache", "cookies", "storage", "executionContexts"};
+
+	private static final String HEADER_VALUE = "\"cache\", \"cookies\", \"storage\", \"executionContexts\"";
+
+	@Rule
+	public final SpringTestRule spring = new SpringTestRule();
+
+	@Autowired
+	MockMvc mvc;
+
+	@Test
+	@WithMockUser
+	public void logoutWhenRequestTypeGetThenHeaderNotPresentt() throws Exception {
+		this.spring.register(HttpLogoutConfig.class).autowire();
+
+		this.mvc.perform(get("/logout").secure(true).with(csrf()))
+			.andExpect(header().doesNotExist(CLEAR_SITE_DATA_HEADER));
+	}
+
+	@Test
+	@WithMockUser
+	public void logoutWhenRequestTypePostAndNotSecureThenHeaderNotPresent() throws Exception {
+		this.spring.register(HttpLogoutConfig.class).autowire();
+
+		this.mvc.perform(post("/logout").with(csrf()))
+			.andExpect(header().doesNotExist(CLEAR_SITE_DATA_HEADER));
+	}
+
+	@Test
+	@WithMockUser
+	public void logoutWhenRequestTypePostAndSecureThenHeaderIsPresent() throws Exception {
+		this.spring.register(HttpLogoutConfig.class).autowire();
+
+		this.mvc.perform(post("/logout").secure(true).with(csrf()))
+			.andExpect(header().stringValues(CLEAR_SITE_DATA_HEADER, HEADER_VALUE));
+	}
+
+	@EnableWebSecurity
+	static class HttpLogoutConfig extends WebSecurityConfigurerAdapter {
+		@Override
+		protected void configure(HttpSecurity http) throws Exception {
+			http
+				.logout()
+					.addLogoutHandler(new HeaderWriterLogoutHandler(new ClearSiteDataHeaderWriter(SOURCE)));
+		}
+	}
+}

docs/manual/src/docs/asciidoc/_includes/servlet/preface/java-configuration.adoc

@@ -343,6 +343,7 @@ Various implementations are provided:
 - {security-api-url}org/springframework/security/web/authentication/logout/CookieClearingLogoutHandler.html[CookieClearingLogoutHandler]
 - {security-api-url}org/springframework/security/web/csrf/CsrfLogoutHandler.html[CsrfLogoutHandler]
 - {security-api-url}org/springframework/security/web/authentication/logout/SecurityContextLogoutHandler.html[SecurityContextLogoutHandler]
+- {security-api-url}org/springframework/security/web/authentication/logout/HeaderWriterLogoutHandler.html[HeaderWriterLogoutHandler]
 
 Please see <<remember-me-impls>> for details.
 

web/src/main/java/org/springframework/security/web/authentication/logout/HeaderWriterLogoutHandler.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2002-2019 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 org.springframework.security.web.authentication.logout;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import org.springframework.security.core.Authentication;
+import org.springframework.security.web.header.HeaderWriter;
+import org.springframework.util.Assert;
+
+/**
+ *
+ * @author Rafiullah Hamedy
+ * @since 5.2
+ */
+public final class HeaderWriterLogoutHandler implements LogoutHandler {
+	private final HeaderWriter headerWriter;
+
+	/**
+	 * Constructs a new instance using the passed {@link HeaderWriter} implementation
+	 *
+	 * @param headerWriter
+	 * @throws {@link IllegalArgumentException} if headerWriter is null.
+	 */
+	public HeaderWriterLogoutHandler(HeaderWriter headerWriter) {
+		Assert.notNull(headerWriter, "headerWriter cannot be null.");
+		this.headerWriter = headerWriter;
+	}
+
+	@Override
+	public void logout(HttpServletRequest request, HttpServletResponse response,
+			Authentication authentication) {
+		this.headerWriter.writeHeaders(request, response);
+	}
+}

web/src/main/java/org/springframework/security/web/header/writers/ClearSiteDataHeaderWriter.java

@@ -0,0 +1,101 @@
+/*
+ * Copyright 2002-2019 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 org.springframework.security.web.header.writers;
+
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.springframework.security.web.header.HeaderWriter;
+import org.springframework.security.web.util.matcher.RequestMatcher;
+import org.springframework.util.Assert;
+
+/**
+ * Provides support for <a href="https://w3c.github.io/webappsec-clear-site-data/">Clear
+ * Site Data</a>.
+ *
+ * <p>
+ * Developers may instruct a user agent to clear various types of relevant data by delivering
+ * a Clear-Site-Data HTTP response header in response to a request.
+ * <p>
+ *
+ * <p>
+ * Due to <a href="https://w3c.github.io/webappsec-clear-site-data/#incomplete">Incomplete Clearing</a>
+ * section the header is only applied if the request is secure.
+ * </p>
+ *
+ * @author Rafiullah Hamedy
+ * @since 5.2
+ */
+public final class ClearSiteDataHeaderWriter implements HeaderWriter {
+
+	private static final String CLEAR_SITE_DATA_HEADER = "Clear-Site-Data";
+
+	private final Log logger = LogFactory.getLog(getClass());
+
+	private final RequestMatcher requestMatcher;
+
+	private String headerValue;
+
+	/**
+	 * <p>
+	 * Creates a new instance of {@link ClearSiteDataHeaderWriter} with given sources.
+	 * The constructor also initializes <b>requestMatcher</b> with a new instance of
+	 * <b>SecureRequestMatcher</b> to ensure that header is only applied if and when
+	 * the request is secure as per the <b>Incomplete Clearing</b> section.
+	 * </p>
+	 *
+	 * @param sources (i.e. "cache", "cookies", "storage", "executionContexts" or "*")
+	 * @throws {@link IllegalArgumentException} if sources is null or empty.
+	 */
+	public ClearSiteDataHeaderWriter(String ...sources) {
+		Assert.notEmpty(sources, "Sources cannot be empty or null.");
+		this.requestMatcher = new SecureRequestMatcher();
+		this.headerValue = Stream.of(sources).map(this::quote).collect(Collectors.joining(", "));
+	}
+
+	@Override
+	public void writeHeaders(HttpServletRequest request, HttpServletResponse response) {
+		if (this.requestMatcher.matches(request)) {
+			if (!response.containsHeader(CLEAR_SITE_DATA_HEADER)) {
+				response.setHeader(CLEAR_SITE_DATA_HEADER, this.headerValue);
+			}
+		} else if (logger.isDebugEnabled()) {
+			logger.debug("Not injecting Clear-Site-Data header since it did not match the "
+						+ "requestMatcher " + this.requestMatcher);
+		}
+	}
+
+	private static final class SecureRequestMatcher implements RequestMatcher {
+		public boolean matches(HttpServletRequest request) {
+			return request.isSecure();
+		}
+	}
+
+	private String quote(String source) {
+		return "\"" + source + "\"";
+	}
+
+	@Override
+	public String toString() {
+		return getClass().getName() + " [headerValue=" + this.headerValue + "]";
+	}
+}

web/src/test/java/org/springframework/security/web/authentication/logout/HeaderWriterLogoutHandlerTests.java

@@ -0,0 +1,104 @@
+/*
+ * Copyright 2002-2019 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 org.springframework.security.web.authentication.logout;
+
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.springframework.mock.web.MockHttpServletRequest;
+import org.springframework.mock.web.MockHttpServletResponse;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.web.header.writers.ClearSiteDataHeaderWriter;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.header;
+
+/**
+ *
+ * @author Rafiullah Hamedy
+ *
+ * @see {@link HeaderWriterLogoutHandler}
+ */
+public class HeaderWriterLogoutHandlerTests {
+	private static final String HEADER_NAME = "Clear-Site-Data";
+
+	private MockHttpServletResponse response;
+	private MockHttpServletRequest request;
+
+	@Rule
+	public ExpectedException thrown = ExpectedException.none();
+
+	@Before
+	public void setup() {
+		this.response = new MockHttpServletResponse();
+		this.request = new MockHttpServletRequest();
+	}
+
+	@Test
+	public void createInstanceWhenHeaderWriterIsNullThenThrowsException() {
+		this.thrown.expect(IllegalArgumentException.class);
+		this.thrown.expectMessage("headerWriter cannot be null.");
+
+		new HeaderWriterLogoutHandler(null);
+	}
+
+	@Test
+	public void createInstanceWhenSourceIsNullThenThrowsException() {
+		this.thrown.expect(IllegalArgumentException.class);
+		this.thrown.expectMessage("Sources cannot be empty or null.");
+
+		new HeaderWriterLogoutHandler(new ClearSiteDataHeaderWriter());
+	}
+
+	@Test
+	public void logoutWhenRequestIsNotSecureThenHeaderIsNotPresent() {
+		HeaderWriterLogoutHandler handler = new HeaderWriterLogoutHandler(
+				new ClearSiteDataHeaderWriter("cache"));
+
+		handler.logout(request, response, mock(Authentication.class));
+
+		assertThat(header().doesNotExist(HEADER_NAME));
+	}
+
+	@Test
+	public void logoutWhenRequestIsSecureThenHeaderIsPresentMatchesWildCardSource() {
+		HeaderWriterLogoutHandler handler = new HeaderWriterLogoutHandler(
+				new ClearSiteDataHeaderWriter("*"));
+
+		this.request.setSecure(true);
+
+		handler.logout(request, response, mock(Authentication.class));
+
+		assertThat(header().stringValues(HEADER_NAME, "\"*\""));
+	}
+
+	@Test
+	public void logoutWhenRequestIsSecureThenHeaderValueMatchesSource() {
+		HeaderWriterLogoutHandler handler = new HeaderWriterLogoutHandler(
+				new ClearSiteDataHeaderWriter("cache", "cookies", "storage",
+						"executionContexts"));
+
+		this.request.setSecure(true);
+
+		handler.logout(request, response, mock(Authentication.class));
+
+		assertThat(header().stringValues(HEADER_NAME, "\"cache\", \"cookies\", \"storage\", "
+				+ "\"executionContexts\""));
+	}
+}