Spring Security登陸流程講解
在Spring Security中,認證授權都是通過過濾器來實現的。
當開始登陸的時候,有一個關鍵的過濾器UsernamePasswordAuthenticationFilter,該類繼承抽象類AbstractAuthenticationProcessingFilter,在AbstractAuthenticationProcessingFilter裡有一個doFilter方法,一切先從這裡說起。
private void doFilter(HttpServletRequest request, HttpServletResponse response, FilterChain chain) throws IOException, ServletException { if (!requiresAuthentication(request, response)) { chain.doFilter(request, response); return; } try { Authentication authenticationResult = attemptAuthentication(request, response); if (authenticationResult == null) { // return immediately as subclass has indicated that it hasn't completed return; } this.sessionStrategy.onAuthentication(authenticationResult, request, response); // Authentication success if (this.continueChainBeforeSuccessfulAuthentication) { chain.doFilter(request, response); } successfulAuthentication(request, response, chain, authenticationResult); } catch (InternalAuthenticationServiceException failed) { this.logger.error("An internal error occurred while trying to authenticate the user.", failed); unsuccessfulAuthentication(request, response, failed); } catch (AuthenticationException ex) { // Authentication failed unsuccessfulAuthentication(request, response, ex); } }
首先requiresAuthentication先判斷是否嘗試校驗,通過後調用attemptAuthentication方法,這個方法也就是UsernamePasswordAuthenticationFilter 中的attemptAuthentication方法。
public Authentication attemptAuthentication(HttpServletRequest request, HttpServletResponse response) throws AuthenticationException { if (this.postOnly && !request.getMethod().equals("POST")) { throw new AuthenticationServiceException("Authentication method not supported: " + request.getMethod()); } String username = obtainUsername(request); username = (username != null) ? username : ""; username = username.trim(); String password = obtainPassword(request); password = (password != null) ? password : ""; UsernamePasswordAuthenticationToken authRequest = new UsernamePasswordAuthenticationToken(username, password); // Allow subclasses to set the "details" property setDetails(request, authRequest); return this.getAuthenticationManager().authenticate(authRequest); }
1.在UsernamePasswordAuthenticationFilter 的attemptAuthentication方法中,先是驗證請求的類型,是否是POST請求,如果不是的話,拋出異常。(PS:登陸肯定要用POST方法瞭)
2.然後拿到username和password。這裡使用的是obtainUsername方法,也就是get方法。
@Nullable protected String obtainPassword(HttpServletRequest request) { return request.getParameter(this.passwordParameter); } @Nullable protected String obtainUsername(HttpServletRequest request) { return request.getParameter(this.usernameParameter); }
由此我們知道瞭Spring Security中是通過get方法來拿到參數,所以在進行前後端分離的時候是無法接受JSON數據,處理方法就是自定義一個Filter來繼承UsernamePasswordAuthenticationFilter,重寫attemptAuthentication方法,然後創建一個Filter實例寫好登陸成功和失敗的邏輯處理,在HttpSecurity參數的configure中通過addFilterAt來替換Spring Security官方提供的過濾器。
3.創建一個UsernamePasswordAuthenticationToken 實例。
4.設置Details,在這裡關鍵的是在WebAuthenticationDetails類中記錄瞭用戶的remoteAddress和sessionId。
public WebAuthenticationDetails(HttpServletRequest request) { this.remoteAddress = request.getRemoteAddr(); HttpSession session = request.getSession(false); this.sessionId = (session != null) ? session.getId() : null; }
5.拿到一個AuthenticationManager通過authenticate方法進行校驗,這裡以實現類ProviderManager為例。
@Override public Authentication authenticate(Authentication authentication) throws AuthenticationException { //獲取Authentication的運行時類 Class<? extends Authentication> toTest = authentication.getClass(); AuthenticationException lastException = null; AuthenticationException parentException = null; Authentication result = null; Authentication parentResult = null; int currentPosition = 0; int size = this.providers.size(); for (AuthenticationProvider provider : getProviders()) { //判斷是否支持處理該類別的provider if (!provider.supports(toTest)) { continue; } if (logger.isTraceEnabled()) { logger.trace(LogMessage.format("Authenticating request with %s (%d/%d)", provider.getClass().getSimpleName(), ++currentPosition, size)); } try { //獲取用戶的信息 result = provider.authenticate(authentication); if (result != null) { copyDetails(authentication, result); break; } } catch (AccountStatusException | InternalAuthenticationServiceException ex) { prepareException(ex, authentication); // SEC-546: Avoid polling additional providers if auth failure is due to // invalid account status throw ex; } catch (AuthenticationException ex) { lastException = ex; } } //不支持的話跳出循環再次執行 if (result == null && this.parent != null) { // Allow the parent to try. try { parentResult = this.parent.authenticate(authentication); result = parentResult; } catch (ProviderNotFoundException ex) { // ignore as we will throw below if no other exception occurred prior to // calling parent and the parent // may throw ProviderNotFound even though a provider in the child already // handled the request } catch (AuthenticationException ex) { parentException = ex; lastException = ex; } } if (result != null) { //擦除用戶的憑證 也就是密碼 if (this.eraseCredentialsAfterAuthentication && (result instanceof CredentialsContainer)) { // Authentication is complete. Remove credentials and other secret data // from authentication ((CredentialsContainer) result).eraseCredentials(); } // If the parent AuthenticationManager was attempted and successful then it // will publish an AuthenticationSuccessEvent // This check prevents a duplicate AuthenticationSuccessEvent if the parent // AuthenticationManager already published it if (parentResult == null) { //公示登陸成功 this.eventPublisher.publishAuthenticationSuccess(result); } return result; } // Parent was null, or didn't authenticate (or throw an exception). if (lastException == null) { lastException = new ProviderNotFoundException(this.messages.getMessage("ProviderManager.providerNotFound", new Object[] { toTest.getName() }, "No AuthenticationProvider found for {0}")); } // If the parent AuthenticationManager was attempted and failed then it will // publish an AbstractAuthenticationFailureEvent // This check prevents a duplicate AbstractAuthenticationFailureEvent if the // parent AuthenticationManager already published it if (parentException == null) { prepareException(lastException, authentication); } throw lastException; }
6.經過一系列校驗,此時登陸校驗基本完成,當驗證通過後會執行doFilter中的successfulAuthentication方法,跳轉到我們設置的登陸成功界面,驗證失敗會執行unsuccessfulAuthentication方法,跳轉到我們設置的登陸失敗界面。
到此這篇關於Spring Security登陸流程講解的文章就介紹到這瞭,更多相關Spring Security登陸內容請搜索WalkonNet以前的文章或繼續瀏覽下面的相關文章希望大傢以後多多支持WalkonNet!
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