前言
本文是接上一章Spring Security系列之認證過程(六)進一步分析Spring Security使用者名稱密碼登入授權是如何實現得;
類圖
除錯過程
使用debug方式啟動https://github.com/longfeizheng/logback該專案,瀏覽器輸入http://localhost:8080/persons,使用者名稱隨意,密碼123456即可;
原始碼分析
如圖所示,顯示了登入認證過程中的 filters
相關的呼叫流程,將幾個自認為重要的 filters 標註了出來,
UsernamePasswordAuthenticationFilter
,AnonymousAuthenticationFilter
,ExceptionTranslationFilter
,FilterSecurityInterceptor
以及相關的處理流程如下所述;
UsernamePasswordAuthenticationFilter
整個呼叫流程是,先呼叫其父類 AbstractAuthenticationProcessingFilter.doFilter() 方法,然後再執行 UsernamePasswordAuthenticationFilter.attemptAuthentication() 方法進行驗證;
AbstractAuthenticationProcessingFilter
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
throws IOException, ServletException {
HttpServletRequest request = (HttpServletRequest) req;
HttpServletResponse response = (HttpServletResponse) res;
#1.判斷當前的filter是否可以處理當前請求,不可以的話則交給下一個filter處理
if (!requiresAuthentication(request, response)) {
chain.doFilter(request, response);
return;
}
if (logger.isDebugEnabled()) {
logger.debug("Request is to process authentication");
}
Authentication authResult;
try {
#2.抽象方法由子類UsernamePasswordAuthenticationFilter實現
authResult = attemptAuthentication(request, response);
if (authResult == null) {
// return immediately as subclass has indicated that it hasn't completed
// authentication
return;
}
#2.認證成功後,處理一些與session相關的方法
sessionStrategy.onAuthentication(authResult, request, response);
}
catch (InternalAuthenticationServiceException failed) {
logger.error(
"An internal error occurred while trying to authenticate the user.",
failed);
#3.認證失敗後的的一些操作
unsuccessfulAuthentication(request, response, failed);
return;
}
catch (AuthenticationException failed) {
// Authentication failed
unsuccessfulAuthentication(request, response, failed);
return;
}
// Authentication success
if (continueChainBeforeSuccessfulAuthentication) {
chain.doFilter(request, response);
}
#3. 認證成功後的相關回撥方法 主要將當前的認證放到SecurityContextHolder中
successfulAuthentication(request, response, chain, authResult);
}
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整個程式的執行流程如下:
- 判斷filter是否可以處理當前的請求,如果不可以則放行交給下一個filter
- 呼叫抽象方法attemptAuthentication進行驗證,該方法由子類UsernamePasswordAuthenticationFilter實現
- 認證成功以後,回撥一些與 session 相關的方法;
- 認證成功以後,認證成功後的相關回撥方法;認證成功以後,認證成功後的相關回撥方法;
protected void successfulAuthentication(HttpServletRequest request, HttpServletResponse response, FilterChain chain, Authentication authResult) throws IOException, ServletException { if (logger.isDebugEnabled()) { logger.debug("Authentication success. Updating SecurityContextHolder to contain: " + authResult); } SecurityContextHolder.getContext().setAuthentication(authResult); rememberMeServices.loginSuccess(request, response, authResult); // Fire event if (this.eventPublisher != null) { eventPublisher.publishEvent(new InteractiveAuthenticationSuccessEvent( authResult, this.getClass())); } successHandler.onAuthenticationSuccess(request, response, authResult); } 複製程式碼
- 將當前認證成功的 Authentication 放置到 SecurityContextHolder 中;
- 將當前認證成功的 Authentication 放置到 SecurityContextHolder 中;
- 呼叫其它可擴充套件的 handlers 繼續處理該認證成功以後的回撥事件;(實現AuthenticationSuccessHandler介面即可)
UsernamePasswordAuthenticationFilter
public Authentication attemptAuthentication(HttpServletRequest request,
HttpServletResponse response) throws AuthenticationException {
#1.判斷請求的方法必須為POST請求
if (postOnly && !request.getMethod().equals("POST")) {
throw new AuthenticationServiceException(
"Authentication method not supported: " + request.getMethod());
}
#2.從request中獲取username和password
String username = obtainUsername(request);
String password = obtainPassword(request);
if (username == null) {
username = "";
}
if (password == null) {
password = "";
}
username = username.trim();
#3.構建UsernamePasswordAuthenticationToken(兩個引數的構造方法setAuthenticated(false))
UsernamePasswordAuthenticationToken authRequest = new UsernamePasswordAuthenticationToken(
username, password);
// Allow subclasses to set the "details" property
setDetails(request, authRequest);
#4. 呼叫 AuthenticationManager 進行驗證(子類ProviderManager遍歷所有的AuthenticationProvider認證)
return this.getAuthenticationManager().authenticate(authRequest);
}
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- 認證請求的方法必須為POST
- 從request中獲取 username 和 password
- 封裝Authenticaiton的實現類UsernamePasswordAuthenticationToken,(UsernamePasswordAuthenticationToken呼叫兩個引數的構造方法setAuthenticated(false))
- 呼叫 AuthenticationManager 的 authenticate 方法進行驗證;可參考ProviderManager部分;
AnonymousAuthenticationFilter
從上圖中過濾器的執行順序圖中可以看出AnonymousAuthenticationFilter
過濾器是在UsernamePasswordAuthenticationFilter
等過濾器之後,如果它前面的過濾器都沒有認證成功,Spring Security則為當前的SecurityContextHolder
中新增一個Authenticaiton
的匿名實現類AnonymousAuthenticationToken
;
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
throws IOException, ServletException {
#1.如果前面的過濾器都沒認證通過,則SecurityContextHolder中Authentication為空
if (SecurityContextHolder.getContext().getAuthentication() == null) {
#2.為當前的SecurityContextHolder中新增一個匿名的AnonymousAuthenticationToken
SecurityContextHolder.getContext().setAuthentication(
createAuthentication((HttpServletRequest) req));
if (logger.isDebugEnabled()) {
logger.debug("Populated SecurityContextHolder with anonymous token: '"
+ SecurityContextHolder.getContext().getAuthentication() + "'");
}
}
else {
if (logger.isDebugEnabled()) {
logger.debug("SecurityContextHolder not populated with anonymous token, as it already contained: '"
+ SecurityContextHolder.getContext().getAuthentication() + "'");
}
}
chain.doFilter(req, res);
}
#3.建立匿名的AnonymousAuthenticationToken
protected Authentication createAuthentication(HttpServletRequest request) {
AnonymousAuthenticationToken auth = new AnonymousAuthenticationToken(key,
principal, authorities);
auth.setDetails(authenticationDetailsSource.buildDetails(request));
return auth;
}
/**
* Creates a filter with a principal named "anonymousUser" and the single authority
* "ROLE_ANONYMOUS".
*
* @param key the key to identify tokens created by this filter
*/
##.建立一個使用者名稱為anonymousUser 授權為ROLE_ANONYMOUS
public AnonymousAuthenticationFilter(String key) {
this(key, "anonymousUser", AuthorityUtils.createAuthorityList("ROLE_ANONYMOUS"));
}
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- 判斷
SecurityContextHolder
中Authentication
為否為空; - 如果空則為當前的
SecurityContextHolder
中新增一個匿名的AnonymousAuthenticationToken
(使用者名稱為 anonymousUser 的AnonymousAuthenticationToken)
ExceptionTranslationFilter
ExceptionTranslationFilter
異常處理過濾器,該過濾器用來處理在系統認證授權過程中丟擲的異常(也就是下一個過濾器FilterSecurityInterceptor
),主要是處理 AuthenticationException
和AccessDeniedException
。
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
throws IOException, ServletException {
HttpServletRequest request = (HttpServletRequest) req;
HttpServletResponse response = (HttpServletResponse) res;
try {
chain.doFilter(request, response);
logger.debug("Chain processed normally");
}
catch (IOException ex) {
throw ex;
}
catch (Exception ex) {
// Try to extract a SpringSecurityException from the stacktrace
#.判斷是不是AuthenticationException
Throwable[] causeChain = throwableAnalyzer.determineCauseChain(ex);
RuntimeException ase = (AuthenticationException) throwableAnalyzer
.getFirstThrowableOfType(AuthenticationException.class, causeChain);
if (ase == null) {
#. 判斷是不是AccessDeniedException
ase = (AccessDeniedException) throwableAnalyzer.getFirstThrowableOfType(
AccessDeniedException.class, causeChain);
}
if (ase != null) {
handleSpringSecurityException(request, response, chain, ase);
}
else {
// Rethrow ServletExceptions and RuntimeExceptions as-is
if (ex instanceof ServletException) {
throw (ServletException) ex;
}
else if (ex instanceof RuntimeException) {
throw (RuntimeException) ex;
}
// Wrap other Exceptions. This shouldn't actually happen
// as we've already covered all the possibilities for doFilter
throw new RuntimeException(ex);
}
}
}
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FilterSecurityInterceptor
此過濾器為認證授權過濾器鏈中最後一個過濾器,該過濾器之後就是請求真正的/persons
服務
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
FilterInvocation fi = new FilterInvocation(request, response, chain);
invoke(fi);
}
public void invoke(FilterInvocation fi) throws IOException, ServletException {
if ((fi.getRequest() != null)
&& (fi.getRequest().getAttribute(FILTER_APPLIED) != null)
&& observeOncePerRequest) {
// filter already applied to this request and user wants us to observe
// once-per-request handling, so don't re-do security checking
fi.getChain().doFilter(fi.getRequest(), fi.getResponse());
}
else {
// first time this request being called, so perform security checking
if (fi.getRequest() != null) {
fi.getRequest().setAttribute(FILTER_APPLIED, Boolean.TRUE);
}
#1. before invocation重要
InterceptorStatusToken token = super.beforeInvocation(fi);
try {
#2. 可以理解開始請求真正的 /persons 服務
fi.getChain().doFilter(fi.getRequest(), fi.getResponse());
}
finally {
super.finallyInvocation(token);
}
#3. after Invocation
super.afterInvocation(token, null);
}
}
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- before invocation重要
- 請求真正的 /persons 服務
- after Invocation
三個部分中,最重要的是 #1,該過程中會呼叫 AccessDecisionManager 來驗證當前已認證成功的使用者是否有許可權訪問該資源;
AccessDecisionManager: beforeInvocation
protected InterceptorStatusToken beforeInvocation(Object object) {
...
Collection<ConfigAttribute> attributes = this.obtainSecurityMetadataSource()
.getAttributes(object);
...
Authentication authenticated = authenticateIfRequired();
// Attempt authorization
try {
#1.重點
this.accessDecisionManager.decide(authenticated, object, attributes);
}
catch (AccessDeniedException accessDeniedException) {
publishEvent(new AuthorizationFailureEvent(object, attributes, authenticated,accessDeniedException));
throw accessDeniedException;
}
...
}
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authenticated
就是當前認證的Authentication
,那麼object 和attributes又是什麼呢?
attributes和object 是什麼?
Collection<ConfigAttribute> attributes = this.obtainSecurityMetadataSource()
.getAttributes(object);
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除錯
我們發現object
為當前請求的 url:/persons
, 那麼getAttributes
方法就是使用當前的訪問資源路徑去匹配我們自己定義的匹配規則。
protected void configure(HttpSecurity http) throws Exception {
http.formLogin()//使用表單登入,不再使用預設httpBasic方式
.loginPage(SecurityConstants.DEFAULT_UNAUTHENTICATION_URL)//如果請求的URL需要認證則跳轉的URL
.loginProcessingUrl(SecurityConstants.DEFAULT_SIGN_IN_PROCESSING_URL_FORM)//處理表單中自定義的登入URL
.and()
.authorizeRequests().antMatchers(SecurityConstants.DEFAULT_UNAUTHENTICATION_URL,
SecurityConstants.DEFAULT_SIGN_IN_PROCESSING_URL_FORM,
SecurityConstants.DEFAULT_REGISTER_URL,
"/**/*.js",
"/**/*.css",
"/**/*.jpg",
"/**/*.png",
"/**/*.woff2")
.permitAll()//以上的請求都不需要認證
.anyRequest()//剩下的請求
.authenticated()//都需要認證
.and()
.csrf().disable()//關閉csrd攔截
;
}
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0-7
返回 permitALL
即不需要認證 ,8
對應anyRequest
返回 authenticated
即當前請求需要認證;
authenticated
為匿名AnonymousAuthentication
使用者名稱為anonymousUser
AccessDecisionManager 是如何授權的?
Spring Security預設使用AffirmativeBased
實現 AccessDecisionManager
的 decide
方法來實現授權
public void decide(Authentication authentication, Object object,
Collection<ConfigAttribute> configAttributes) throws AccessDeniedException {
int deny = 0;
#1.呼叫AccessDecisionVoter 進行vote(投票)
for (AccessDecisionVoter voter : getDecisionVoters()) {
int result = voter.vote(authentication, object, configAttributes);
if (logger.isDebugEnabled()) {
logger.debug("Voter: " + voter + ", returned: " + result);
}
switch (result) {
#1.1只要有voter投票為ACCESS_GRANTED,則通過 直接返回
case AccessDecisionVoter.ACCESS_GRANTED://1
return;
@#1.2只要有voter投票為ACCESS_DENIED,則記錄一下
case AccessDecisionVoter.ACCESS_DENIED://-1
deny++;
break;
default:
break;
}
}
if (deny > 0) {
#2.如果有兩個及以上AccessDecisionVoter(姑且稱之為投票者吧)都投ACCESS_DENIED,則直接就不通過了
throw new AccessDeniedException(messages.getMessage(
"AbstractAccessDecisionManager.accessDenied", "Access is denied"));
}
// To get this far, every AccessDecisionVoter abstained
checkAllowIfAllAbstainDecisions();
}
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- 呼叫AccessDecisionVoter 進行vote(投票)
- 只要有投通過(ACCESS_GRANTED)票,則直接判為通過。
- 如果沒有投通過則 deny++ ,最後判斷if(deny>0 丟擲AccessDeniedException(未授權)
WebExpressionVoter.vote()
public int vote(Authentication authentication, FilterInvocation fi,
Collection<ConfigAttribute> attributes) {
assert authentication != null;
assert fi != null;
assert attributes != null;
WebExpressionConfigAttribute weca = findConfigAttribute(attributes);
if (weca == null) {
return ACCESS_ABSTAIN;
}
EvaluationContext ctx = expressionHandler.createEvaluationContext(authentication,
fi);
ctx = weca.postProcess(ctx, fi);
return ExpressionUtils.evaluateAsBoolean(weca.getAuthorizeExpression(), ctx) ? ACCESS_GRANTED
: ACCESS_DENIED;
}
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到此位置authentication
當前使用者資訊,fl
當前訪問的資源路徑及attributes
當前資源路徑的決策(即是否需要認證)。剩下就是判斷當前使用者的角色Authentication.authorites
是否許可權訪問決策訪問當前資源fi。
時序圖
文章來源`