Spring Security原理学习--用户名和密码认证(三)

╰+攻爆jí腚メ 2022-05-08 14:18 221阅读 0赞

在上一篇博客[Spring Security原理学习--核心过滤器Filter(二)][Spring Security_--_Filter]中我们已经了解到Spring Security相关业务处理的Filter，这篇博客我们通过代码完整的将Spring Security登录、验证和退出的流程了解一下。

### 一、登录请求 ###

1、Spring Security默认提供了一个登录页面，默认请求地址 GET：[http://localhost:8080/login][http_localhost_8080_login]，当请求为GET时最终请求被DefaultLoginPageGeneratingFilter拦截进行处理，返回默认的登录页面

在isLoginUrlRequest(request)方法中，如果判断是/login请求则接下来生成默认的登录页面返回

private boolean isLoginUrlRequest(HttpServletRequest request) {
    		return matches(request, loginPageUrl);
    	}
    private boolean matches(HttpServletRequest request, String url) {
            //首先判断是不是GET请求
    		if (!"GET".equals(request.getMethod()) || url == null) {
    			return false;
    		}
    		String uri = request.getRequestURI();
    		int pathParamIndex = uri.indexOf(';');
    
    		if (pathParamIndex > 0) {
    			// strip everything after the first semi-colon
    			uri = uri.substring(0, pathParamIndex);
    		}
    
    		if (request.getQueryString() != null) {
    			uri += "?" + request.getQueryString();
    		}
    
    		if ("".equals(request.getContextPath())) {
    			return uri.equals(url);
    		}
    
    		return uri.equals(request.getContextPath() + url);
    	}

generateLoginPageHtml方法中生成默认登录页面

private String generateLoginPageHtml(HttpServletRequest request, boolean loginError,
    			boolean logoutSuccess) {
    		String errorMsg = "none";
    
    		if (loginError) {
    			HttpSession session = request.getSession(false);
    
    			if (session != null) {
    				AuthenticationException ex = (AuthenticationException) session
    						.getAttribute(WebAttributes.AUTHENTICATION_EXCEPTION);
    				errorMsg = ex != null ? ex.getMessage() : "none";
    			}
    		}
    
    		StringBuilder sb = new StringBuilder();
    
    		sb.append("<html><head><title>Login Page</title></head>");
    
    		if (formLoginEnabled) {
    			sb.append("<body onload='document.f.").append(usernameParameter)
    					.append(".focus();'>\n");
    		}
    
    		if (loginError) {
    			sb.append("<p><font color='red'>Your login attempt was not successful, try again.<br/><br/>Reason: ");
    			sb.append(errorMsg);
    			sb.append("</font></p>");
    		}
    
    		if (logoutSuccess) {
    			sb.append("<p><font color='green'>You have been logged out</font></p>");
    		}
    
    		if (formLoginEnabled) {
    			sb.append("<h3>Login with Username and Password</h3>");
    			sb.append("<form name='f' action='").append(request.getContextPath())
    					.append(authenticationUrl).append("' method='POST'>\n");
    			sb.append("<table>\n");
    			sb.append("	<tr><td>User:</td><td><input type='text' name='");
    			sb.append(usernameParameter).append("' value='").append("'></td></tr>\n");
    			sb.append("	<tr><td>Password:</td><td><input type='password' name='")
    					.append(passwordParameter).append("'/></td></tr>\n");
    
    			if (rememberMeParameter != null) {
    				sb.append("	<tr><td><input type='checkbox' name='")
    						.append(rememberMeParameter)
    						.append("'/></td><td>Remember me on this computer.</td></tr>\n");
    			}
    
    			sb.append("	<tr><td colspan='2'><input name=\"submit\" type=\"submit\" value=\"Login\"/></td></tr>\n");
    			renderHiddenInputs(sb, request);
    			sb.append("</table>\n");
    			sb.append("</form>");
    		}
    
    		if (openIdEnabled) {
    			sb.append("<h3>Login with OpenID Identity</h3>");
    			sb.append("<form name='oidf' action='").append(request.getContextPath())
    					.append(openIDauthenticationUrl).append("' method='POST'>\n");
    			sb.append("<table>\n");
    			sb.append("	<tr><td>Identity:</td><td><input type='text' size='30' name='");
    			sb.append(openIDusernameParameter).append("'/></td></tr>\n");
    
    			if (openIDrememberMeParameter != null) {
    				sb.append("	<tr><td><input type='checkbox' name='")
    						.append(openIDrememberMeParameter)
    						.append("'></td><td>Remember me on this computer.</td></tr>\n");
    			}
    
    			sb.append("	<tr><td colspan='2'><input name=\"submit\" type=\"submit\" value=\"Login\"/></td></tr>\n");
    			sb.append("</table>\n");
    			renderHiddenInputs(sb, request);
    			sb.append("</form>");
    		}
    
    		sb.append("</body></html>");
    
    		return sb.toString();
    	}

2、当请求地址为POST：[http://localhost:8080/login][http_localhost_8080_login]时则为登录操作，POST请求会提交用户名和密码登录信息，此时由UsernamePasswordAuthenticationFilter的父类AbstractAuthenticationProcessingFilter处理，简单来说就是从请求request中获取用户名和密码进行认证操作。

public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
    			throws IOException, ServletException {
    
    		HttpServletRequest request = (HttpServletRequest) req;
    		HttpServletResponse response = (HttpServletResponse) res;
    		
    		//当不是登录请求 POST:/login时则直接跳过
    		if (!requiresAuthentication(request, response)) {
    			chain.doFilter(request, response);
    
    			return;
    		}
    		//如果是登录请求 POST:/login则进行验证处理
    		if (logger.isDebugEnabled()) {
    			logger.debug("Request is to process authentication");
    		}
    
    		Authentication authResult;
    
    		try {
    			//从请求中获取用户名密码进行校验
    			authResult = attemptAuthentication(request, response);
    			if (authResult == null) {
    				// return immediately as subclass has indicated that it hasn't completed
    				// authentication
    				return;
    			}
    			sessionStrategy.onAuthentication(authResult, request, response);
    		}
    		catch (InternalAuthenticationServiceException failed) {
    			logger.error(
    					"An internal error occurred while trying to authenticate the user.",
    					failed);
    			//校验失败则跳转到登录页面
    			unsuccessfulAuthentication(request, response, failed);
    
    			return;
    		}
    		catch (AuthenticationException failed) {
    			// Authentication failed
    			//校验失败则跳转到登录页面
    			unsuccessfulAuthentication(request, response, failed);
    
    			return;
    		}
    
    		// Authentication success
    		if (continueChainBeforeSuccessfulAuthentication) {
    			chain.doFilter(request, response);
    		}
    		//校验成功则跳转到成功之后页面
    		successfulAuthentication(request, response, chain, authResult);
    	}

（1）在doFilter方法中，首先会调用requiresAuthentication方法判断是不是登录请求，如果不是则直接跳过这个Filter，如果是则进行身份验证

![70][]

（2）如果请求是登录操作，则接下来进行身份验证相关的操作

调用authResult = attemptAuthentication(request, response)方法进行验证，在attemptAuthentication中会从请求中获取用户名和密码构建UsernamePasswordAuthenticationToken对象，然后调用接口AuthenticationManager的authenticate进行验证返回Authentication

public Authentication attemptAuthentication(HttpServletRequest request,
    			HttpServletResponse response) throws AuthenticationException {
    		if (postOnly && !request.getMethod().equals("POST")) {
    			throw new AuthenticationServiceException(
    					"Authentication method not supported: " + request.getMethod());
    		}
            //获取用户名密码
    		String username = obtainUsername(request);
    		String password = obtainPassword(request);
    
    		if (username == null) {
    			username = "";
    		}
    
    		if (password == null) {
    			password = "";
    		}
    
    		username = username.trim();
    
    		UsernamePasswordAuthenticationToken authRequest = new UsernamePasswordAuthenticationToken(
    				username, password);
    
    		// Allow subclasses to set the "details" property
    		setDetails(request, authRequest);
            //调用AuthenticationManager的实现类进行校验
    		return this.getAuthenticationManager().authenticate(authRequest);
    	}

在接口AuthenticationManager的实现类ProviderManager调用authenticate方法进行校验操作。在authenticate方法中提供了一个List<AuthenticationProvider>，开发者可以提供不同的校验方式（用户名密码、手机号密码、邮箱密码等）只要其中有一个AutenticationProvider调用authenticate方法校验通过即可，当校验不通过时会抛出AuthenticationException ，当所有的AuthenticationProvider校验不通过时，直接抛出异常由ExceptionTranslationFilter捕捉处理，跳转到登录页面。

public Authentication authenticate(Authentication authentication)
    			throws AuthenticationException {
    		Class<? extends Authentication> toTest = authentication.getClass();
    		AuthenticationException lastException = null;
    		Authentication result = null;
    		boolean debug = logger.isDebugEnabled();
            //可以提供多个验证器，只要其中有一个校验通过接口
    		for (AuthenticationProvider provider : getProviders()) {
    			if (!provider.supports(toTest)) {
    				continue;
    			}
    
    			if (debug) {
    				logger.debug("Authentication attempt using "
    						+ provider.getClass().getName());
    			}
    
    			try {
                    //进行校验，校验不通过则直接抛出AuthenticationException 
    				result = provider.authenticate(authentication);
    
    				if (result != null) {
    					copyDetails(authentication, result);
    					break;
    				}
    			}
    			catch (AccountStatusException e) {
    				prepareException(e, authentication);
    				// SEC-546: Avoid polling additional providers if auth failure is due to
    				// invalid account status
    				throw e;
    			}
    			catch (InternalAuthenticationServiceException e) {
    				prepareException(e, authentication);
    				throw e;
    			}
    			catch (AuthenticationException e) {
    				lastException = e;
    			}
    		}
    
    		if (result == null && parent != null) {
    			// Allow the parent to try.
    			try {
    				result = parent.authenticate(authentication);
    			}
    			catch (ProviderNotFoundException e) {
    				// 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 e) {
    				lastException = e;
    			}
    		}
    
    		if (result != null) {
    			if (eraseCredentialsAfterAuthentication
    					&& (result instanceof CredentialsContainer)) {
    				// Authentication is complete. Remove credentials and other secret data
    				// from authentication
    				((CredentialsContainer) result).eraseCredentials();
    			}
    
    			eventPublisher.publishAuthenticationSuccess(result);
    			return result;
    		}
            
    		// Parent was null, or didn't authenticate (or throw an exception).
            //最终校验不通过则抛出异常，由ExceptionTranslationFilter捕捉处理
    		if (lastException == null) {
    			lastException = new ProviderNotFoundException(messages.getMessage(
    					"ProviderManager.providerNotFound",
    					new Object[] { toTest.getName() },
    					"No AuthenticationProvider found for {0}"));
    		}
    
    		prepareException(lastException, authentication);
    
    		throw lastException;
    	}

在接口AuthenticationProvider的实现类AbstractUserDetailsAuthenticationProvider中调用authenticate进行用户名密码等的校验

（1）首先从缓存userCahce中获取，如果获取到从子类DaoAuthenticationProvider的retirveUser方法中获取

（2）如果获取不到则直接抛出异常

（3）如果匹配成功调用createSuccessAuthentication方法创建Authentication返回。

public Authentication authenticate(Authentication authentication)
    			throws AuthenticationException {
    		Assert.isInstanceOf(UsernamePasswordAuthenticationToken.class, authentication,
    				messages.getMessage(
    						"AbstractUserDetailsAuthenticationProvider.onlySupports",
    						"Only UsernamePasswordAuthenticationToken is supported"));
    
    		// Determine username
    		String username = (authentication.getPrincipal() == null) ? "NONE_PROVIDED"
    				: authentication.getName();
    
    		boolean cacheWasUsed = true;
    		UserDetails user = this.userCache.getUserFromCache(username);
    
    		if (user == null) {
    			cacheWasUsed = false;
    
    			try {
    				user = retrieveUser(username,
    						(UsernamePasswordAuthenticationToken) authentication);
    			}
    			catch (UsernameNotFoundException notFound) {
    				logger.debug("User '" + username + "' not found");
    
    				if (hideUserNotFoundExceptions) {
    					throw new BadCredentialsException(messages.getMessage(
    							"AbstractUserDetailsAuthenticationProvider.badCredentials",
    							"Bad credentials"));
    				}
    				else {
    					throw notFound;
    				}
    			}
    
    			Assert.notNull(user,
    					"retrieveUser returned null - a violation of the interface contract");
    		}
    
    		try {
    			preAuthenticationChecks.check(user);
                //判断用户名和密码等信息是否完全匹配
    			additionalAuthenticationChecks(user,
    					(UsernamePasswordAuthenticationToken) authentication);
    		}
    		catch (AuthenticationException exception) {
    			if (cacheWasUsed) {
    				// There was a problem, so try again after checking
    				// we're using latest data (i.e. not from the cache)
    				cacheWasUsed = false;
    				user = retrieveUser(username,
    						(UsernamePasswordAuthenticationToken) authentication);
    				preAuthenticationChecks.check(user);
    				additionalAuthenticationChecks(user,
    						(UsernamePasswordAuthenticationToken) authentication);
    			}
    			else {
    				throw exception;
    			}
    		}
    
    		postAuthenticationChecks.check(user);
    
    		if (!cacheWasUsed) {
    			this.userCache.putUserInCache(user);
    		}
    
    		Object principalToReturn = user;
    
    		if (forcePrincipalAsString) {
    			principalToReturn = user.getUsername();
    		}
    
    		return createSuccessAuthentication(principalToReturn, authentication, user);
    	}

在子类DaoAuthenticationProvider中调用接口的UserDetailsService的loadUserByUsername方法根据用户名来查找用户信息(在正式项目中实现此接口来完成从数据库等中查找)，如果查找不到还是直接抛出异常，由上层去处理。

protected final UserDetails retrieveUser(String username,
    			UsernamePasswordAuthenticationToken authentication)
    			throws AuthenticationException {
    		UserDetails loadedUser;
    
    		try {
                //调用默认实现InMemoryUserDetailsManager查找用户名密码
    			loadedUser = this.getUserDetailsService().loadUserByUsername(username);
    		}
    		catch (UsernameNotFoundException notFound) {
    			if (authentication.getCredentials() != null) {
    				String presentedPassword = authentication.getCredentials().toString();
    				passwordEncoder.isPasswordValid(userNotFoundEncodedPassword,
    						presentedPassword, null);
    			}
    			throw notFound;
    		}
    		catch (Exception repositoryProblem) {
    			throw new InternalAuthenticationServiceException(
    					repositoryProblem.getMessage(), repositoryProblem);
    		}
    
    		if (loadedUser == null) {
    			throw new InternalAuthenticationServiceException(
    					"UserDetailsService returned null, which is an interface contract violation");
    		}
    		return loadedUser;
    	}

当找到用户信息后，还需要根据用户信息和password字段进行匹配，在additionalAuthenticationChecks中完成完整的用户名和密码认证。

protected void additionalAuthenticationChecks(UserDetails userDetails,
    			UsernamePasswordAuthenticationToken authentication)
    			throws AuthenticationException {
    		Object salt = null;
    
    		if (this.saltSource != null) {
    			salt = this.saltSource.getSalt(userDetails);
    		}
    
    		if (authentication.getCredentials() == null) {
    			logger.debug("Authentication failed: no credentials provided");
    
    			throw new BadCredentialsException(messages.getMessage(
    					"AbstractUserDetailsAuthenticationProvider.badCredentials",
    					"Bad credentials"));
    		}
    
    		String presentedPassword = authentication.getCredentials().toString();
    
    		if (!passwordEncoder.isPasswordValid(userDetails.getPassword(),
    				presentedPassword, salt)) {
    			logger.debug("Authentication failed: password does not match stored value");
    
    			throw new BadCredentialsException(messages.getMessage(
    					"AbstractUserDetailsAuthenticationProvider.badCredentials",
    					"Bad credentials"));
    		}
    	}

在UserDetailService的实现类InMemoryUserDetailsManager中根据用户名获取用户信息。

//根据用户名获取用户信息，最终生成用户名密码和权限等信息
    public UserDetails loadUserByUsername(String username)
    			throws UsernameNotFoundException {
    		UserDetails user = users.get(username.toLowerCase());
    
    		if (user == null) {
    			throw new UsernameNotFoundException(username);
    		}
    
    		return new User(user.getUsername(), user.getPassword(), user.isEnabled(),
    				user.isAccountNonExpired(), user.isCredentialsNonExpired(),
    				user.isAccountNonLocked(), user.getAuthorities());
    	}

总结：Spring Security的用户名和密码认证主要是在UsernamePasswordAuthenticationFilter进行处理的，在这中间过程中如果认证失败则抛出异常，认证成功则返回Authentication，当然这并接下来还有一个重要的就是角色权限验证，接下来我们用一篇博客进行分析。

[Spring Security_--_Filter]: https://blog.csdn.net/qq924862077/article/details/83040564
[http_localhost_8080_login]: http://localhost:8080/login
[70]: /images/20220508/feb1e166016442af84d0eab53d1cec91.png