Spring Security常用過濾器實例解析
Spring Security常見的15個攔截器
1 . org.springframework.security.web.context.SecurityContextPersistenceFilter
首當其沖的一個過濾器,作用之重要,自不必多言。
SecurityContextPersistenceFilter主要是使用SecurityContextRepository在session中保存或更新一個 SecurityContext,并將SecurityContext給以后的過濾器使用,來為后續filter建立所需的上下文。 SecurityContext中存儲了當前用戶的認證以及權限信息。2 . org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter
此過濾器用于集成SecurityContext到Spring異步執行機制中的WebAsyncManager
3 . org.springframework.security.web.header.HeaderWriterFilter
向請求的Header中添加相應的信息,可在http標簽內部使用security:headers來控制
4 . org.springframework.security.web.csrf.CsrfFilter
csrf又稱跨域請求偽造,SpringSecurity會對所有post請求驗證是否包含系統生成的csrf的token信息,
如果不包含,則報錯。起到防止csrf攻擊的效果。
5. org.springframework.security.web.authentication.logout.LogoutFilter
匹配 URL為/logout的請求,實現用戶退出,清除認證信息。
6 . org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter
認證操作全靠這個過濾器,默認匹配URL為/login且必須為POST請求。
7 . org.springframework.security.web.authentication.ui.DefaultLoginPageGeneratingFilter
如果沒有在配置文件中指定認證頁面,則由該過濾器生成一個默認認證頁面。
8 . org.springframework.security.web.authentication.ui.DefaultLogoutPageGeneratingFilter
由此過濾器可以生產一個默認的退出登錄頁面
9 . org.springframework.security.web.authentication.www.BasicAuthenticationFilter
此過濾器會自動解析HTTP請求中頭部名字為Authentication,且以Basic開頭的頭信息。
10 . org.springframework.security.web.savedrequest.RequestCacheAwareFilter
通過HttpSessionRequestCache內部維護了一個RequestCache,用于緩存HttpServletRequest
11 . org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter
針對ServletRequest進行了一次包裝,使得request具有更加豐富的API
12 . org.springframework.security.web.authentication.AnonymousAuthenticationFilter
當SecurityContextHolder中認證信息為空,則會創建一個匿名用戶存入到SecurityContextHolder中。
spring security為了兼容未登錄的訪問,也走了一套認證流程,只不過是一個匿名的身份。
13 . org.springframework.security.web.session.SessionManagementFilter
SecurityContextRepository限制同一用戶開啟多個會話的數量
14 . org.springframework.security.web.access.ExceptionTranslationFilter
異常轉換過濾器位于整個springSecurityFilterChain的后方,用來轉換整個鏈路中出現的異常
15 . org.springframework.security.web.access.intercept.FilterSecurityInterceptor
獲取所配置資源訪問的授權信息,根據SecurityContextHolder中存儲的用戶信息來決定其是否有權限。
那么,是不是spring security一共就這么多過濾器呢?答案是否定的!隨著spring-security.xml配置的添加,還會出現新的過濾器。
那么,是不是spring security每次都會加載這些過濾器呢?答案也是否定的!隨著spring-security.xml配置的修改,有些過濾器可能會被去掉。
spring security 過濾器鏈加載原理
public class DelegatingFilterProxy extends GenericFilterBean {@Nullableprivate String contextAttribute;@Nullableprivate WebApplicationContext webApplicationContext;@Nullableprivate String targetBeanName;private boolean targetFilterLifecycle;@Nullableprivate volatile Filter delegate;//注:這個過濾器才是真正加載的過濾器private final Object delegateMonitor;//注:doFilter才是過濾器的入口,直接從這看!public void doFilter(ServletRequest request, ServletResponse response, FilterChainfilterChain) throws ServletException, IOException {Filter delegateToUse = this.delegate;if (delegateToUse == null) {synchronized(this.delegateMonitor) {delegateToUse = this.delegate;if (delegateToUse == null) {WebApplicationContext wac = this.findWebApplicationContext();if (wac == null) {throw new IllegalStateException('No WebApplicationContext found: noContextLoaderListener or DispatcherServlet registered?');}//第一步:doFilter中最重要的一步,初始化上面私有過濾器屬性delegatedelegateToUse = this.initDelegate(wac);}this.delegate = delegateToUse;}}//第三步:執行FilterChainProxy過濾器this.invokeDelegate(delegateToUse, request, response, filterChain);}//第二步:直接看最終加載的過濾器到底是誰protected Filter initDelegate(WebApplicationContext wac) throws ServletException {//debug得知targetBeanName為:springSecurityFilterChainString targetBeanName = this.getTargetBeanName();Assert.state(targetBeanName != null, 'No target bean name set');//debug得知delegate對象為:FilterChainProxyFilter delegate = (Filter)wac.getBean(targetBeanName, Filter.class);if (this.isTargetFilterLifecycle()) {delegate.init(this.getFilterConfig());}return delegate;}protected void invokeDelegate(Filter delegate, ServletRequest request, ServletResponseresponse, FilterChain filterChain) throws ServletException, IOException {delegate.doFilter(request, response, filterChain);}}
第二步debug結果如下:
由此可知, DelegatingFilterProxy通過springSecurityFilterChain這個名稱,得到了一個FilterChainProxy過濾器,最終在第三步執行了這個過濾器。
FilterChainProxy
public class FilterChainProxy extends GenericFilterBean {private static final Log logger = LogFactory.getLog(FilterChainProxy.class);private static final String FILTER_APPLIED =FilterChainProxy.class.getName().concat('.APPLIED');private List<SecurityFilterChain> filterChains;private FilterChainProxy.FilterChainValidator filterChainValidator;private HttpFirewall firewall;//咿!?可以通過一個叫SecurityFilterChain的對象實例化出一個FilterChainProxy對象//這FilterChainProxy又是何方神圣?會不會是真正的過濾器鏈對象呢?先留著這個疑問!public FilterChainProxy(SecurityFilterChain chain) {this(Arrays.asList(chain));}//又是SecurityFilterChain這家伙!嫌疑更大了!public FilterChainProxy(List<SecurityFilterChain> filterChains) {this.filterChainValidator = new FilterChainProxy.NullFilterChainValidator();this.firewall = new StrictHttpFirewall();this.filterChains = filterChains;}//注:直接從doFilter看public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)throws IOException, ServletException {boolean clearContext = request.getAttribute(FILTER_APPLIED) == null;if (clearContext) {try {request.setAttribute(FILTER_APPLIED, Boolean.TRUE);this.doFilterInternal(request, response, chain);} finally {SecurityContextHolder.clearContext();request.removeAttribute(FILTER_APPLIED);}} else {//第一步:具體操作調用下面的doFilterInternal方法了this.doFilterInternal(request, response, chain);}}private void doFilterInternal(ServletRequest request, ServletResponse response, FilterChainchain) throws IOException, ServletException {FirewalledRequest fwRequest =this.firewall.getFirewalledRequest((HttpServletRequest)request);HttpServletResponse fwResponse =this.firewall.getFirewalledResponse((HttpServletResponse)response);//第二步:封裝要執行的過濾器鏈,那么多過濾器就在這里被封裝進去了!List<Filter> filters = this.getFilters((HttpServletRequest)fwRequest);if (filters != null && filters.size() != 0) {FilterChainProxy.VirtualFilterChain vfc = newFilterChainProxy.VirtualFilterChain(fwRequest, chain, filters);//第四步:加載過濾器鏈vfc.doFilter(fwRequest, fwResponse);} else {if (logger.isDebugEnabled()) {logger.debug(UrlUtils.buildRequestUrl(fwRequest) + (filters == null ? ' has nomatching filters' : ' has an empty filter list'));}fwRequest.reset();chain.doFilter(fwRequest, fwResponse);}}private List<Filter> getFilters(HttpServletRequest request) {Iterator var2 = this.filterChains.iterator();//第三步:封裝過濾器鏈到SecurityFilterChain中!SecurityFilterChain chain;do {if (!var2.hasNext()) {return null;}chain = (SecurityFilterChain)var2.next();} while(!chain.matches(request));return chain.getFilters();}}
SecurityFilterChain
最后看SecurityFilterChain,這是個接口,實現類也只有一個,這才是web.xml中配置的過濾器鏈對象!
public interface SecurityFilterChain { boolean matches(HttpServletRequest request); List<Filter> getFilters();}
public final class DefaultSecurityFilterChain implements SecurityFilterChain { private static final Log logger = LogFactory.getLog(DefaultSecurityFilterChain.class); private final RequestMatcher requestMatcher; private final List<Filter> filters; public DefaultSecurityFilterChain(RequestMatcher requestMatcher, Filter... filters) { this(requestMatcher, Arrays.asList(filters)); } public DefaultSecurityFilterChain(RequestMatcher requestMatcher, List<Filter> filters) { logger.info('Creating filter chain: ' + requestMatcher + ', ' + filters); this.requestMatcher = requestMatcher; this.filters = new ArrayList<>(filters); } public RequestMatcher getRequestMatcher() { return requestMatcher; } public List<Filter> getFilters() { return filters; } public boolean matches(HttpServletRequest request) { return requestMatcher.matches(request); } @Override public String toString() { return '[ ' + requestMatcher + ', ' + filters + ']'; }}
以上就是本文的全部內容,希望對大家的學習有所幫助,也希望大家多多支持好吧啦網。
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