Create our own SessionCreationPolicy enum

Update `ManagementServerProperties` so that `security.sessions` no
longer uses `SessionCreationPolicy` from Spring Security. We now
use our own enun which allows `management.security.*` properties to
be set without the risk of a `ClassNotFoundException`.

Fixes gh-3888

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/autoconfigure/ManagementServerProperties.java

@@ -20,6 +20,7 @@ import java.net.InetAddress;
 import java.util.Arrays;
 import java.util.List;
 
+import javax.servlet.http.HttpSession;
 import javax.validation.constraints.NotNull;
 
 import org.springframework.boot.autoconfigure.security.SecurityPrerequisite;
@@ -28,8 +29,6 @@ import org.springframework.boot.autoconfigure.web.ServerProperties;
 import org.springframework.boot.context.embedded.Ssl;
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.boot.context.properties.NestedConfigurationProperty;
-import org.springframework.security.config.http.SessionCreationPolicy;
-import org.springframework.util.ClassUtils;
 import org.springframework.util.StringUtils;
 
 /**
@@ -43,8 +42,6 @@ import org.springframework.util.StringUtils;
 @ConfigurationProperties(prefix = "management", ignoreUnknownFields = true)
 public class ManagementServerProperties implements SecurityPrerequisite {
 
-	private static final String SECURITY_CHECK_CLASS = "org.springframework.security.config.http.SessionCreationPolicy";
-
 	/**
 	 * Order applied to the WebSecurityConfigurerAdapter that is used to configure basic
 	 * authentication for management endpoints. If you want to add your own authentication
@@ -89,14 +86,7 @@ public class ManagementServerProperties implements SecurityPrerequisite {
 	 */
 	private boolean addApplicationContextHeader = true;
 
-	private final Security security = maybeCreateSecurity();
-
-	private Security maybeCreateSecurity() {
-		if (ClassUtils.isPresent(SECURITY_CHECK_CLASS, null)) {
-			return new Security();
-		}
-		return null;
-	}
+	private final Security security = new Security();
 
 	/**
 	 * Returns the management port or {@code null} if the
@@ -181,7 +171,8 @@ public class ManagementServerProperties implements SecurityPrerequisite {
 		private List<String> roles = Arrays.asList("ADMIN");
 
 		/**
-		 * Session creating policy to use (always, never, if_required, stateless).
+		 * Session creating policy for security use (always, never, if_required,
+		 * stateless).
 		 */
 		private SessionCreationPolicy sessions = SessionCreationPolicy.STATELESS;
 
@@ -216,4 +207,29 @@ public class ManagementServerProperties implements SecurityPrerequisite {
 
 	}
 
+	public enum SessionCreationPolicy {
+
+		/**
+		 * Always create an {@link HttpSession}.
+		 */
+		ALWAYS,
+
+		/**
+		 * Never create an {@link HttpSession}, but use any {@link HttpSession} that
+		 * already exists.
+		 */
+		NEVER,
+
+		/**
+		 * Only create an {@link HttpSession} if required.
+		 */
+		IF_REQUIRED,
+
+		/**
+		 * Never create an {@link HttpSession}.
+		 */
+		STATELESS
+
+	}
+
 }

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/autoconfigure/ManagementWebSecurityAutoConfiguration.java

@@ -64,6 +64,7 @@ import org.springframework.security.config.annotation.web.configuration.EnableWe
 import org.springframework.security.config.annotation.web.configuration.WebSecurityConfiguration;
 import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
 import org.springframework.security.config.annotation.web.configurers.ExpressionUrlAuthorizationConfigurer;
+import org.springframework.security.config.http.SessionCreationPolicy;
 import org.springframework.security.web.AuthenticationEntryPoint;
 import org.springframework.security.web.authentication.www.BasicAuthenticationEntryPoint;
 import org.springframework.security.web.util.matcher.AntPathRequestMatcher;
@@ -274,13 +275,22 @@ public class ManagementWebSecurityAutoConfiguration {
 				http.httpBasic().authenticationEntryPoint(entryPoint);
 				// No cookies for management endpoints by default
 				http.csrf().disable();
-				http.sessionManagement().sessionCreationPolicy(
-						this.management.getSecurity().getSessions());
+				http.sessionManagement()
+						.sessionCreationPolicy(asSpringSecuritySessionCreationPolicy(
+								this.management.getSecurity().getSessions()));
 				SpringBootWebSecurityConfiguration.configureHeaders(http.headers(),
 						this.security.getHeaders());
 			}
 		}
 
+		private SessionCreationPolicy asSpringSecuritySessionCreationPolicy(
+				Enum<?> value) {
+			if (value == null) {
+				return SessionCreationPolicy.STATELESS;
+			}
+			return SessionCreationPolicy.valueOf(value.name());
+		}
+
 		private RequestMatcher getRequestMatcher() {
 			if (this.management.getSecurity().isEnabled()) {
 				return LazyEndpointPathRequestMatcher

spring-boot-samples/pom.xml

@@ -25,6 +25,7 @@
 		<module>spring-boot-sample-activemq</module>
 		<module>spring-boot-sample-actuator</module>
 		<module>spring-boot-sample-actuator-log4j2</module>
+		<module>spring-boot-sample-actuator-no-security</module>
 		<module>spring-boot-sample-actuator-noweb</module>
 		<module>spring-boot-sample-actuator-ui</module>
 		<module>spring-boot-sample-amqp</module>

spring-boot-samples/spring-boot-sample-actuator-no-security/pom.xml

@@ -0,0 +1,44 @@
+<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<!-- Your own application should inherit from spring-boot-starter-parent -->
+		<groupId>org.springframework.boot</groupId>
+		<artifactId>spring-boot-samples</artifactId>
+		<version>1.4.2.BUILD-SNAPSHOT</version>
+	</parent>
+	<artifactId>spring-boot-sample-actuator-no-security</artifactId>
+	<name>Spring Boot Actuator UI Sample</name>
+	<description>Spring Boot Actuator UI Sample</description>
+	<url>http://projects.spring.io/spring-boot/</url>
+	<organization>
+		<name>Pivotal Software, Inc.</name>
+		<url>http://www.spring.io</url>
+	</organization>
+	<properties>
+		<main.basedir>${basedir}/../..</main.basedir>
+	</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-freemarker</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+			</plugin>
+		</plugins>
+	</build>
+</project>

spring-boot-samples/spring-boot-sample-actuator-no-security/src/main/java/sample/actuator/nosecurity/SampleActuatorNoSecurityApplication.java

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2012-2016 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.actuator.nosecurity;
+
+import java.util.Date;
+import java.util.Map;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+
+@SpringBootApplication
+@Controller
+public class SampleActuatorNoSecurityApplication {
+
+	@GetMapping("/")
+	public String home(Map<String, Object> model) {
+		model.put("message", "Hello World");
+		model.put("title", "Hello Home");
+		model.put("date", new Date());
+		return "home";
+	}
+
+	@RequestMapping("/foo")
+	public String foo() {
+		throw new RuntimeException("Expected exception in controller");
+	}
+
+	public static void main(String[] args) throws Exception {
+		SpringApplication.run(SampleActuatorNoSecurityApplication.class, args);
+	}
+
+}

spring-boot-samples/spring-boot-sample-actuator-no-security/src/main/resources/application.properties

@@ -0,0 +1,2 @@
+health.diskspace.enabled=false
+management.security.role=superuser

spring-boot-samples/spring-boot-sample-actuator-no-security/src/main/resources/templates/error.ftl

@@ -0,0 +1,32 @@
+<#import "/spring.ftl" as spring />
+<!DOCTYPE html>
+<html>
+<head>
+<title>Error</title>
+<#assign home><@spring.url relativeUrl="/"/></#assign>
+<#assign bootstrap><@spring.url relativeUrl="/css/bootstrap.min.css"/></#assign>
+<link rel="stylesheet" href="${bootstrap}" />
+</head>
+<body>
+	<div class="container">
+		<div class="navbar">
+			<div class="navbar-inner">
+				<a class="brand" href="http://freemarker.org/"> FreeMarker -
+					Plain </a>
+				<ul class="nav">
+					<li><a href="${home}"> Home </a></li>
+				</ul>
+			</div>
+		</div>
+		<h1>Error Page</h1>
+		<div id="created">${timestamp?datetime}</div>
+		<div>
+			There was an unexpected error (type=${error}, status=${status}).
+		</div>
+		<div>${message}</div>
+		<div>
+			Please contact the operator with the above information.
+		</div>
+	</div>
+</body>
+</html>

spring-boot-samples/spring-boot-sample-actuator-no-security/src/main/resources/templates/home.ftl

@@ -0,0 +1,26 @@
+<#import "/spring.ftl" as spring />
+<!DOCTYPE html>
+<html>
+<head>
+<title>${title}</title>
+<#assign home><@spring.url relativeUrl="/"/></#assign>
+<#assign bootstrap><@spring.url relativeUrl="/css/bootstrap.min.css"/></#assign>
+<link rel="stylesheet" href="${bootstrap}" />
+</head>
+<body>
+	<div class="container">
+		<div class="navbar">
+			<div class="navbar-inner">
+				<a class="brand" href="http://freemarker.org/"> FreeMarker -
+					Plain </a>
+				<ul class="nav">
+					<li><a href="${home}"> Home </a></li>
+				</ul>
+			</div>
+		</div>
+		<h1>${title}</h1>
+		<div>${message}</div>
+		<div id="created">${date?datetime}</div>
+	</div>
+</body>
+</html>

spring-boot-samples/spring-boot-sample-actuator-no-security/src/test/java/sample/actuator/nosecurity/SampleActuatorNoSecurityApplicationTests.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2012-2016 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.actuator.nosecurity;
+
+import java.util.Arrays;
+import java.util.Map;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
+import org.springframework.boot.test.web.client.TestRestTemplate;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpMethod;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Basic integration tests for demo application.
+ *
+ * @author Phillip Webb
+ */
+@RunWith(SpringRunner.class)
+@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
+@DirtiesContext
+public class SampleActuatorNoSecurityApplicationTests {
+
+	@Autowired
+	private TestRestTemplate restTemplate;
+
+	@Test
+	public void testHome() throws Exception {
+		HttpHeaders headers = new HttpHeaders();
+		headers.setAccept(Arrays.asList(MediaType.TEXT_HTML));
+		ResponseEntity<String> entity = this.restTemplate.exchange("/", HttpMethod.GET,
+				new HttpEntity<Void>(headers), String.class);
+		assertThat(entity.getStatusCode()).isEqualTo(HttpStatus.OK);
+		assertThat(entity.getBody()).contains("<title>Hello");
+	}
+
+	@Test
+	public void testMetrics() throws Exception {
+		@SuppressWarnings("rawtypes")
+		ResponseEntity<Map> entity = this.restTemplate.getForEntity("/metrics",
+				Map.class);
+		assertThat(entity.getStatusCode()).isEqualTo(HttpStatus.OK);
+	}
+
+}