springboot情操陶冶-web配置(八)
本文关注应用的安全方面,涉及校验以及授权方面,以springboot自带的security板块作为讲解的内容
实例
建议用户可直接路由至博主的先前博客spring security整合cas方案。本文则针对相关的源码作下简单的分析,方便笔者以及读者更深入的了解spring的security板块
@EnableWebSecurity
这个注解很精髓,基本上可以作为security的入口,笔者贴一下它的源码
@Retention(value = java.lang.annotation.RetentionPolicy.RUNTIME)
@Target(value = { java.lang.annotation.ElementType.TYPE })
@Documented
@Import({ WebSecurityConfiguration.class,
SpringWebMvcImportSelector.class })
@EnableGlobalAuthentication
@Configuration
public @interface EnableWebSecurity {
/**
* Controls debugging support for Spring Security. Default is false.
* @return if true, enables debug support with Spring Security
*/
boolean debug() default false;
}
可以分为三个部分来分析,
SpringWebMvcImportSelector
-支持mvc的参数安全校验,替代了@EnableWebMvcSecurity注解
WebSecurityConfiguration
-Web的安全配置
@EnableGlobalAuthentication
-支持公共的认证校验
SpringWebMvcImportSelector
首先先看下其如何整合mvc的安全校验,其是一个ImportSelector接口,观察下其复写的方法
public String[] selectImports(AnnotationMetadata importingClassMetadata) {
boolean webmvcPresent = ClassUtils.isPresent(
"org.springframework.web.servlet.DispatcherServlet",
getClass().getClassLoader());
return webmvcPresent
? new String[] {
"org.springframework.security.config.annotation.web.configuration.WebMvcSecurityConfiguration" }
: new String[] {};
}
由上述代码可知,在classpath环境中存在mvc的关键类DispatcherServlet时便会引入WebMvcSecurityConfiguration类,那么此类又配置了什么东西呢?
里面的代码很简单,但关键是其是WebMvcConfigurer接口的实现类,根据之前的文章提到,该接口主要是用于配置MVC的相关功能,比如参数处理器、返回值处理器、异常处理器等等。
而该类只是扩展了相应的参数处理器,我们可以看下源码
@Override
@SuppressWarnings("deprecation")
public void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
// 支持@AuthenticationPrinciple参数注解校验
AuthenticationPrincipalArgumentResolver authenticationPrincipalResolver = new AuthenticationPrincipalArgumentResolver();
authenticationPrincipalResolver.setBeanResolver(beanResolver);
argumentResolvers.add(authenticationPrincipalResolver);
// 废弃
argumentResolvers
.add(new org.springframework.security.web.bind.support.AuthenticationPrincipalArgumentResolver());
// csrf token参数
argumentResolvers.add(new CsrfTokenArgumentResolver());
}
针对@AuthenticationPrinciple
注解的参数校验,本文不展开了,这里作下归纳
- 带有@AuthenticationPrinciple注解的参数其值会从SecurityContext的上下文读取相应的Authentication校验信息
- 有一个要求,被该注解修饰的参数须同SecurityContext的上下文存放的Authentication信息为同一接口,否则则会返回null。如果设置了errorOnInvalidType属性为true,则会抛异常
- 综上所述,该注解主要是方便将校验通过的Token用于参数赋值,其它的作用也不是很大
@EnableGlobalAuthentication
再来分析下springboot-security的公共认证校验是什么概念,贴下源码
@Retention(value = java.lang.annotation.RetentionPolicy.RUNTIME)
@Target(value = { java.lang.annotation.ElementType.TYPE })
@Documented
@Import(AuthenticationConfiguration.class)
@Configuration
public @interface EnableGlobalAuthentication {
}
OK,直接进入相应的AuthenticationConfiguration类进行具体的分析
1.其引入了ObjectPostProcessorConfiguration配置用于创建AutowireBeanFactoryObjectPostProcessor类,作用应该是通过Spring上下文实例相应的实体类并注册到bean工厂中
@Bean
public ObjectPostProcessor<Object> objectPostProcessor(
AutowireCapableBeanFactory beanFactory) {
return new AutowireBeanFactoryObjectPostProcessor(beanFactory);
}
2.创建基于密码机制的认证管理器Bean,类型为DefaultPasswordEncoderAuthenticationManagerBuilder
@Bean
public AuthenticationManagerBuilder authenticationManagerBuilder(
ObjectPostProcessor<Object> objectPostProcessor, ApplicationContext context) {
// 密码加密器
LazyPasswordEncoder defaultPasswordEncoder = new LazyPasswordEncoder(context);
// 认证事件传播器
AuthenticationEventPublisher authenticationEventPublisher = getBeanOrNull(context, AuthenticationEventPublisher.class);
// 默认的认证管理器
DefaultPasswordEncoderAuthenticationManagerBuilder result = new DefaultPasswordEncoderAuthenticationManagerBuilder(objectPostProcessor, defaultPasswordEncoder);
if (authenticationEventPublisher != null) {
result.authenticationEventPublisher(authenticationEventPublisher);
}
return result;
}
上述的密码加密器支持多种方式的加密,比如bcrypt(默认)/ladp/md5/sha-1等,感兴趣的读者可自行阅读。用户也可多用此Bean作额外的扩展,例如官方建议的如下代码
@Configuration
@EnableGlobalAuthentication
public class MyGlobalAuthenticationConfiguration {
@Autowired
public void configureGlobal(AuthenticationManagerBuilder auth) {
auth.inMemoryAuthentication().withUser("user").password("password").roles("USER")
.and().withUser("admin").password("password").roles("ADMIN,USER");
}
}
3.创建基于UserDetails的认证器,用于管理用户的授权信息
@Bean
public static InitializeUserDetailsBeanManagerConfigurer initializeUserDetailsBeanManagerConfigurer(ApplicationContext context) {
return new InitializeUserDetailsBeanManagerConfigurer(context);
}
其会创建基于Datasource源的DaoAuthenticationProvider认证校验器,前提是ApplicationContext上下文存在UserDetailsServiceBean对象,否则会不创建。如果用户想基于数据库或者其他数据源的可尝试复写UserDetailsService接口
@Configuration
public class DaoUserDetailsServiceConfig {
/**
* load user info by dao
*
* @see org.springframework.security.authentication.dao.DaoAuthenticationProvider
*/
@Configuration
public static class DefaultUserDetailsService implements UserDetailsService {
private static final String DEFAULT_PASS = "defaultPass";
// admin authority
private Collection<? extends GrantedAuthority> adminAuthority;
@Resource
private PasswordEncoder defaultPasswordEncoder;
public DefaultUserDetailsService() {
SimpleGrantedAuthority authority = new SimpleGrantedAuthority("ROLE_ADMIN");
List<GrantedAuthority> authorities = new ArrayList<>();
authorities.add(authority);
adminAuthority = Collections.unmodifiableList(authorities);
}
@Override
public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
User userdetails = new User(username, defaultPasswordEncoder.encode(DEFAULT_PASS), adminAuthority);
return userdetails;
}
@Bean
public PasswordEncoder daoPasswordEncoder() {
PasswordEncoder passwordEncoder = new BCryptPasswordEncoder();
return passwordEncoder;
}
}
}
注意:实现UserDetailsService的自定义实例请确保只有一个注册至ApplicationContext上,否则上述的基于数据源配置无法自动化配置;但也可通过AuthenticationManagerBuilder#userDetailsService()方法来进行相应的配置
4.创建AuthenticationProvider认证器,用于用户信息的校验
@Bean
public static InitializeAuthenticationProviderBeanManagerConfigurer initializeAuthenticationProviderBeanManagerConfigurer(ApplicationContext context) {
return new InitializeAuthenticationProviderBeanManagerConfigurer(context);
}
同第三点,只是它就配置简单的AuthenticationProvider至相应的AuthenticationManagerBuilderBean中
所以综上所述,@EnableGlobalAuthentication注解的主要目的是配置认证管理器,里面包含了加密器以及相应的认证器
WebSecurityConfiguration
web方面的安全配置,笔者也根据加载的顺序来进行分析
1.获取WebSecurityConfigurer接口bean集合的AutowiredWebSecurityConfigurersIgnoreParents类
@Bean
public static AutowiredWebSecurityConfigurersIgnoreParents autowiredWebSecurityConfigurersIgnoreParents(
ConfigurableListableBeanFactory beanFactory) {
return new AutowiredWebSecurityConfigurersIgnoreParents(beanFactory);
}
此Bean用于获取所有注册在bean工厂上的WebSecurityConfigurer接口,用户也一般通过此接口的抽象类WebSecurityConfigurerAdapter来进行相应的扩展
2.设置Security的Filter过滤链配置,提前为创建过滤链作准备
@Autowired(required = false)
public void setFilterChainProxySecurityConfigurer(
ObjectPostProcessor<Object> objectPostProcessor,
@Value("#{@autowiredWebSecurityConfigurersIgnoreParents.getWebSecurityConfigurers()}") List<SecurityConfigurer<Filter, WebSecurity>> webSecurityConfigurers)
throws Exception {
// WebSecurity创建
webSecurity = objectPostProcessor
.postProcess(new WebSecurity(objectPostProcessor));
if (debugEnabled != null) {
webSecurity.debug(debugEnabled);
}
// 根据@Order属性排序
Collections.sort(webSecurityConfigurers, AnnotationAwareOrderComparator.INSTANCE);
Integer previousOrder = null;
Object previousConfig = null;
// 校验Order对应的值,不允许相同,否则会抛出异常
for (SecurityConfigurer<Filter, WebSecurity> config : webSecurityConfigurers) {
Integer order = AnnotationAwareOrderComparator.lookupOrder(config);
if (previousOrder != null && previousOrder.equals(order)) {
throw new IllegalStateException(
"@Order on WebSecurityConfigurers must be unique. Order of "
+ order + " was already used on " + previousConfig + ", so it cannot be used on "
+ config + " too.");
}
previousOrder = order;
previousConfig = config;
}
// 对排序过的SecurityConfigurer依次放入WebSecurity对象中
for (SecurityConfigurer<Filter, WebSecurity> webSecurityConfigurer : webSecurityConfigurers) {
webSecurity.apply(webSecurityConfigurer);
}
this.webSecurityConfigurers = webSecurityConfigurers;
}
这里便提一下,我们在继承WebSecurityConfigurerAdapter抽象类的时候,记得在其头上加上@Order属性,并且保证值唯一
3.创建Security过滤链
@Bean(name = AbstractSecurityWebApplicationInitializer.DEFAULT_FILTER_NAME)
public Filter springSecurityFilterChain() throws Exception {
// 如果用户没有配置WebSecurityConfigurer接口,则创建一个空的
boolean hasConfigurers = webSecurityConfigurers != null
&& !webSecurityConfigurers.isEmpty();
if (!hasConfigurers) {
WebSecurityConfigurerAdapter adapter = objectObjectPostProcessor
.postProcess(new WebSecurityConfigurerAdapter() {
});
webSecurity.apply(adapter);
}
// create Filter
return webSecurity.build();
}
看来Filter拦截器的配置是通过WebSecurity这个类来完成的,限于里面的代码过于复杂,本文就不展开了,感兴趣的读者可以重点关注下此类。由此可以得出Springboot的安全校验是通过过滤链的设计方式来完成的
4.URI权限校验Bean,其依赖于第三点的配置
@Bean
@DependsOn(AbstractSecurityWebApplicationInitializer.DEFAULT_FILTER_NAME)
public WebInvocationPrivilegeEvaluator privilegeEvaluator() throws Exception {
return webSecurity.getPrivilegeEvaluator();
}
5.安全校验表达式验证Bean,其也依赖于第三点的配置,应该是与第四点搭配使用
@Bean
@DependsOn(AbstractSecurityWebApplicationInitializer.DEFAULT_FILTER_NAME)
public SecurityExpressionHandler<FilterInvocation> webSecurityExpressionHandler() {
return webSecurity.getExpressionHandler();
}
小结
Springboot整合的Security板块内容很多,本文也展示不完,不过值得关注的是以下几个方面
1)WebSecurity的个性化配置类,一般是复写抽象接口WebSecurityConfigurerAdapter,再加上@EnableWebSecurity注解便可
2)AuthenticationManagerBuilder认证校验器,重点关注其中的密码校验器,用于密码的加密解密,默认使用bcrypt方式。如果用户想通过其他数据源获取用户信息,可以关注UserDetailsService接口。推荐用户均使用AuthenticationManagerBuilder类配置认证机制!
3)WebSecurity类,此类是Springboot Security模块的核心类,具体的过滤链配置均是由此类得到的。读者以及笔者应该对此加以关注