Spring Security 实现“记住我”功能及原理解析

这章继续扩展功能，来一个“记住我”的功能实现，就是说用户在登录一次以后，系统会记住这个用户一段时间，这段时间内用户不需要重新登录就可以使用系统。

记住我功能基本原理

原理说明

• 用户登录发送认证请求的时候会被UsernamePasswordAuthenticationFilter认证拦截，认证成功以后会调用一个RememberMeService服务，服务里面有一个TokenRepository，这个服务会生成一个Token，然后将Token写入到浏览器的Cookie同时会使用TokenRepository把生成的Token写到数据库里面，因为这个动作是在认证成功以后做的，所以在Token写入数据库的时候会把用户名同时写入数据库。
• 假如浏览器关了重新访问系统，用户不需要再次登录就可以访问，这个时候请求在过滤器链上会经过RememberMeAuthenticationFilter，这个过滤器的作用是读取Cookie中的Token交给RemeberMeService，RemeberMeService会用TokenRepository到数据库里去查这个Token在数据库里有没有记录，如果有记录就会把用户名取出来，取出来以后会进行各种校验然后生成新Token再调用之前的UserDetAIlService，去获取用户的信息，然后把用户信息放到SecurityContext里面，到这里就把用户给登录上了。

图解说明

RememberMeAuthenticationFilter位于过滤器链的哪一环？

图解

首先其他认证过滤器会先进行认证，当其他过滤器都无法认证时，RememberMeAuthenticationFilter会尝试去做认证。

记住我功能具体实现

前端页面

登录的时候加上一行记住我的勾选按钮，这里要注意，name一定要是remember-me，下面源码部分会提到。

<tr>
				<td colspan='2'><input name="remember-me" type="checkbox" value="true" />记住我</td>
			</tr>

后台

首先配置TokenRepositoryBean

/**
	 * 记住我功能的Token存取器配置
	 * 
	 * @return
	 */
	@Bean
	public PersistentTokenRepository persistentTokenRepository() {
		JdbcTokenRepositoryImpl tokenRepository = new JdbcTokenRepositoryImpl();
		tokenRepository.setDataSource(dataSource);
		// 启动的时候自动创建表，建表语句 JdbcTokenRepositoryImpl 已经都写好了
		tokenRepository.setCreateTableOnStartup(true);
		return tokenRepository;
	}

然后需要在 configure 配置方法那边进行记住我功能所有组件的配置

protected void configure(HttpSecurity http) throws Exception {
		ValidateCodeFilter validateCodeFilter = new ValidateCodeFilter();
		http.addFilterBefore(validateCodeFilter, UsernamePasswordAuthenticationFilter.class)
				.formLogin()
				.loginPage("/authentication/require")
				.loginProcessingUrl("/authentication/form")
				.successHandler(meicloudAuthenticationSuccessHandler)
				.failureHandler(meicloudAuthenticationFailureHandler)
				// 配置记住我功能
				.and()
				.rememberMe()
				// 配置TokenRepository
				.tokenRepository(persistentTokenRepository())
				// 配置Token过期时间
				.tokenValiditySeconds(3600)
				// 最终拿到用户名之后，使用UserDetailsService去做登录
				.userDetailsService(userDetailsService)
				.and()
				.authorizeRequests()
				.antMatchers("/authentication/require", securityProperties.getBrowser().getSignInPage(), "/code/image").permitAll()
				.anyRequest()
				.authenticated()
				.and()
				.csrf().disable();

	}

记住我功能Spring Security源码解析

登录之前“记住我”源码流程

在认证成功之后，会调用successfulAuthentication方法（这些第五章源码部分已经学习过），在将认证信息保存到Context后，RememberMeServices就会调用它的loginSuccess方法。

 protected void successfulAuthentication(HttpServletRequest request, HttpServletResponse response, FilterChain chain, Authentication authResult) throws IOException, ServletException {
 if (this.logger.isDebugEnabled()) {
  this.logger.debug("Authentication success. Updating SecurityContextHolder to contain: " + authResult);
 }

 SecurityContextHolder.getContext().setAuthentication(authResult);
 this.rememberMeServices.loginSuccess(request, response, authResult);
 if (this.eventPublisher != null) {
  this.eventPublisher.publishEvent(new InteractiveAuthenticationSuccessEvent(authResult, this.getClass()));
 }

 this.successHandler.onAuthenticationSuccess(request, response, authResult);
 }

loginSuccess方法里面会先检查请求中是否有name为remember-me的参数，有才进行下一步。

 public final void loginSuccess(HttpServletRequest request, HttpServletResponse response, Authentication successfulAuthentication) {
 	// this.parameter = "remember-me"
 if (!this.rememberMeRequested(request, this.parameter)) {
  this.logger.debug("Remember-me login not requested.");
 } else {
  this.onLoginSuccess(request, response, successfulAuthentication);
 }
 }

再进入onLoginSuccess方法，里面主要就是进行写库和写Cookie的操作。

 protected void onLoginSuccess(HttpServletRequest request, HttpServletResponse response, Authentication successfulAuthentication) {
 String username = successfulAuthentication.getName();
 this.logger.debug("Creating new persistent login for user " + username);
 // 生成Token
 PersistentRememberMeToken persistentToken = new PersistentRememberMeToken(username, this.generateSeriesData(), this.generateTokenData(), new Date());
 try {
 	// 将Token和userName插入数据库
  this.tokenRepository.createNewToken(persistentToken);
  // 将Token写到Cookie中
  this.addCookie(persistentToken, request, response);
 } catch (Exception var7) {
  this.logger.error("Failed to save persistent token ", var7);
 }
 }

登录之后“记住我”源码流程

首先会进入RememberMeAuthenticationFilter，会先判断前面的过滤器是否进行过认证（Context中是否有认证信息），未进行过认证的话会调用RememberMeServices的autoLogin方法。

public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
 HttpServletRequest request = (HttpServletRequest)req;
 HttpServletResponse response = (HttpServletResponse)res;
 if (SecurityContextHolder.getContext().getAuthentication() == null) {
  Authentication rememberMeAuth = this.rememberMeServices.autoLogin(request, response);
  if (rememberMeAuth != null) {
  try {
   rememberMeAuth = this.authenticationManager.authenticate(rememberMeAuth);
   SecurityContextHolder.getContext().setAuthentication(rememberMeAuth);
   this.onSuccessfulAuthentication(request, response, rememberMeAuth);
   if (this.logger.isDebugEnabled()) {
   this.logger.debug("SecurityContextHolder populated with remember-me token: '" + SecurityContextHolder.getContext().getAuthentication() + "'");
   }

   if (this.eventPublisher != null) {
   this.eventPublisher.publishEvent(new InteractiveAuthenticationSuccessEvent(SecurityContextHolder.getContext().getAuthentication(), this.getClass()));
   }

   if (this.successHandler != null) {
   this.successHandler.onAuthenticationSuccess(request, response, rememberMeAuth);
   return;
   }
  } catch (AuthenticationException var8) {
   if (this.logger.isDebugEnabled()) {
   this.logger.debug("SecurityContextHolder not populated with remember-me token, as AuthenticationManager rejected Authentication returned by RememberMeServices: '" + rememberMeAuth + "'; invalidating remember-me token", var8);
   }

   this.rememberMeServices.loginFail(request, response);
   this.onUnsuccessfulAuthentication(request, response, var8);
  }
  }
  chain.doFilter(request, response);
 } else {
  if (this.logger.isDebugEnabled()) {
  this.logger.debug("SecurityContextHolder not populated with remember-me token, as it already contained: '" + SecurityContextHolder.getContext().getAuthentication() + "'");
  }
  chain.doFilter(request, response);
 }
 }

autoLogin方法里面，主要调用this.processAutoLoginCookie(cookieTokens, request, response)这个方法获取数据库中的用户信息，其步骤是：

• 解析前端传来的Cookie，里面包含了Token和seriesId，它会使用seriesId查找数据库的Token
• 检查Cookie中的Token和数据库查出来的Token是否一样
• 一样的话再检查数据库中的Token是否已过期
• 如果以上都符合的话，会使用旧的用户名和series重新new一个Token，这时过期时间也重新刷新
• 然后将新的Token保存回数据库，同时添加回Cookie中
• 最后再调用UserDetailsService的loadUserByUsername方法返回UserDetails

protected UserDetails processAutoLoginCookie(String[] cookieTokens, HttpServletRequest request, HttpServletResponse response) {
 if (cookieTokens.length != 2) {
  throw new InvalidCookieException("Cookie token did not contain 2 tokens, but contained '" + Arrays.asList(cookieTokens) + "'");
 } else {
  String presentedSeries = cookieTokens[0];
  String presentedToken = cookieTokens[1];
  PersistentRememberMeToken token = this.tokenRepository.getTokenForSeries(presentedSeries);
  if (token == null) {
  throw new RememberMeAuthenticationException("No persistent token found for series id: " + presentedSeries);
  } else if (!presentedToken.equals(token.getTokenValue())) {
  this.tokenRepository.removeUserTokens(token.getUsername());
  throw new CookieTheftException(this.messages.getMessage("PersistentTokenBasedRememberMeServices.cookieStolen", "Invalid remember-me token (Series/token) mismatch. Implies previous cookie theft attack."));
  } else if (token.getDate().getTime() + (long)this.getTokenValiditySeconds() * 1000L < System.currentTimeMillis()) {
  throw new RememberMeAuthenticationException("Remember-me login has expired");
  } else {
  if (this.logger.isDebugEnabled()) {
   this.logger.debug("Refreshing persistent login token for user '" + token.getUsername() + "', series '" + token.getSeries() + "'");
  }
  PersistentRememberMeToken newToken = new PersistentRememberMeToken(token.getUsername(), token.getSeries(), this.generateTokenData(), new Date());
  try {
   this.tokenRepository.updateToken(newToken.getSeries(), newToken.getTokenValue(), newToken.getDate());
   this.addCookie(newToken, request, response);
  } catch (Exception var9) {
   this.logger.error("Failed to update token: ", var9);
   throw new RememberMeAuthenticationException("Autologin failed due to data access problem");
  }

  return this.getUserDetailsService().loadUserByUsername(token.getUsername());
  }
 }
 }

回到RememberMeAuthenticationFilter，在调用了autoLogin方法之后得到了rememberMeAuth，然后再对其进行一个认证，认证成功之后保存到SecurityContext中，至此整个RememberMe自动登录流程源码结束。