1、简介

本文主要讲述如何通过SpringSecurity+CAS在springboot项目中实现单点登录和单点注销的功能。

参考内容有Spring Security官方文档中的

本文为Jaune161的原创文章。原文地址http://blog.csdn.net/jaune161/article/details/78060780，转载请注明出处。

2、项目依赖

主要依赖如下

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-security</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.security</groupId>
    <artifactId>spring-security-cas</artifactId>
</dependency>
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <optional>true</optional>
</dependency>

3、项目配置

Application配置。

@SpringBootApplication(scanBasePackages = "com.wawscm")
@EnableWebSecurity
public class Application {

    public static void main(String[] args) {
        new SpringApplicationBuilder(Application.class).web(true).run(args);
    }

}

增加CAS参数配置

这里分为CASServer配置和CASService配置。其中Server是CAS服务的配置，Service是我们自己服务的配置。

@Data
@ConfigurationProperties(prefix = "security.cas.server")
public class CasServerConfig {
    private String host;
    private String login;
    private String logout;

}

@Data
@ConfigurationProperties(prefix = "security.cas.service")
public class CasServiceConfig {
    private String host;
    private String login;
    private String logout;
    private Boolean sendRenew = false;
}

配置内容如下

security:
  cas:
    server:
      host: http://192.168.1.202:9082/cas
      login: ${security.cas.server.host}/login
      logout: ${security.cas.server.host}/logout
    service:
      host: http://localhost:9088
      login: /login/cas
      logout: /logout

后面需要根据实际配置再拼接参数。

SpringSecurity Bean配置

@Configuration
@EnableConfigurationProperties({CasServerConfig.class, CasServiceConfig.class})
public class SecurityConfiguration {

    @Autowired
    private CasServerConfig casServerConfig;

    @Autowired
    private CasServiceConfig casServiceConfig;

    @Bean
    public ServiceProperties serviceProperties() {
        ServiceProperties serviceProperties = new ServiceProperties();
        serviceProperties.setService(this.casServiceConfig.getHost() + this.casServiceConfig.getLogin());
        serviceProperties.setSendRenew(this.casServiceConfig.getSendRenew());
        return serviceProperties;
    }

    @Bean
    public CasAuthenticationFilter casAuthenticationFilter(AuthenticationManager authenticationManager, ServiceProperties serviceProperties) {
        CasAuthenticationFilter casAuthenticationFilter = new CasAuthenticationFilter();
        casAuthenticationFilter.setAuthenticationManager(authenticationManager);
        casAuthenticationFilter.setServiceProperties(serviceProperties);
        casAuthenticationFilter.setFilterProcessesUrl(this.casServiceConfig.getLogin());
        casAuthenticationFilter.setContinueChainBeforeSuccessfulAuthentication(false);
        casAuthenticationFilter.setAuthenticationSuccessHandler(
                new SimpleUrlAuthenticationSuccessHandler("/")
        );
        return casAuthenticationFilter;
    }

    @Bean
    public CasAuthenticationEntryPoint casAuthenticationEntryPoint(ServiceProperties serviceProperties) {
        CasAuthenticationEntryPoint entryPoint = new CasAuthenticationEntryPoint();
        entryPoint.setLoginUrl(this.casServerConfig.getLogin());
        entryPoint.setServiceProperties(serviceProperties);
        return entryPoint;
    }

    @Bean
    public Cas20ServiceTicketValidator cas20ServiceTicketValidator() {
        return new Cas20ServiceTicketValidator(this.casServerConfig.getHost());
    }

    @Bean
    public CasAuthenticationProvider casAuthenticationProvider(
            AuthenticationUserDetailsService<CasAssertionAuthenticationToken> userDetailsService,
            ServiceProperties serviceProperties, Cas20ServiceTicketValidator ticketValidator) {
        CasAuthenticationProvider provider = new CasAuthenticationProvider();
        provider.setKey("casProvider");
        provider.setServiceProperties(serviceProperties);
        provider.setTicketValidator(ticketValidator);
        provider.setAuthenticationUserDetailsService(userDetailsService);

        return provider;
    }

    @Bean
    public LogoutFilter logoutFilter() {
        String logoutRedirectPath = this.casServerConfig.getLogout() + "?service=" +
                this.casServiceConfig.getHost();
        LogoutFilter logoutFilter = new LogoutFilter(logoutRedirectPath, new SecurityContextLogoutHandler());
        logoutFilter.setFilterProcessesUrl(this.casServiceConfig.getLogout());
        return logoutFilter;
    }
}

ServiceProperties ：服务配置，我们自己的服务。 CasAuthenticationFilter：CAS认证过滤器，主要实现票据认证和认证成功后的跳转。 LogoutFilter：注销功能

Spring Security配置

@Configuration
@Order(SecurityProperties.ACCESS_OVERRIDE_ORDER)
public class CasWebSecurityConfiguration extends WebSecurityConfigurerAdapter {

    @Autowired
    private CasAuthenticationEntryPoint casAuthenticationEntryPoint;

    @Autowired
    private CasAuthenticationProvider casAuthenticationProvider;

    @Autowired
    private CasAuthenticationFilter casAuthenticationFilter;

    @Autowired
    private LogoutFilter logoutFilter;

    @Autowired
    private CasServerConfig casServerConfig;

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.headers().frameOptions().disable();

        http.csrf().disable();

        http.authorizeRequests()
                .requestMatchers(CorsUtils::isPreFlightRequest).permitAll()
                .antMatchers("/static/**").permitAll() // 不拦截静态资源
                .antMatchers("/api/**").permitAll()  // 不拦截对外API
                    .anyRequest().authenticated();  // 所有资源都需要登陆后才可以访问。

        http.logout().permitAll();  // 不拦截注销

        http.exceptionHandling().authenticationEntryPoint(casAuthenticationEntryPoint);
        // 单点注销的过滤器，必须配置在SpringSecurity的过滤器链中，如果直接配置在Web容器中，貌似是不起作用的。我自己的是不起作用的。
        SingleSignOutFilter singleSignOutFilter = new SingleSignOutFilter();
        singleSignOutFilter.setCasServerUrlPrefix(this.casServerConfig.getHost());

        http.addFilter(casAuthenticationFilter)
                .addFilterBefore(logoutFilter, LogoutFilter.class)
                .addFilterBefore(singleSignOutFilter, CasAuthenticationFilter.class);

        http.antMatcher("/**");
    }

    @Autowired
    public void configureGlobal(AuthenticationManagerBuilder auth) throws Exception {
        auth.authenticationProvider(casAuthenticationProvider);
    }

    @Bean
    public ServletListenerRegistrationBean<SingleSignOutHttpSessionListener> singleSignOutHttpSessionListener(){
        ServletListenerRegistrationBean<SingleSignOutHttpSessionListener> servletListenerRegistrationBean =
                new ServletListenerRegistrationBean<>();
        servletListenerRegistrationBean.setListener(new SingleSignOutHttpSessionListener());
        return servletListenerRegistrationBean;
    }

}

到此SpringBoot、SpringSecurity、CAS集成结束。但是这样配置有一个问题，那就是如果我们登录之前的请求是带参数的，或者跳转的不是首页，那么就会出现登录成功之后直接跳转到主页，而不是我们想要访问的页面，参数也丢失了。下面我们来解决这个问题。

4 、处理回跳地址

处理的思路是，在登录之前记住访问地址及请求参数，在登录成功之后再取到这个地址然后回跳到对应的地址。

首先我们需要写一个过滤器来获取我们的请求地址，并放到Session中。

public class HttpParamsFilter implements Filter {
    public String REQUESTED_URL = "CasRequestedUrl";

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain)
            throws IOException, ServletException {
        final HttpServletRequest request = (HttpServletRequest) servletRequest;
        final HttpServletResponse response = (HttpServletResponse) servletResponse;
        HttpSession session = request.getSession();

        String requestPath = WebUtils.getFullPath(request);

        session.setAttribute(REQUESTED_URL, requestPath);

        chain.doFilter(request, response);
    }

    @Override
    public void destroy() {

    }
}

然后在CasWebSecurityConfiguration中增加对应的配置。

@Bean
public FilterRegistrationBean httpParamsFilter() {
    FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean();
    filterRegistrationBean.setFilter(new HttpParamsFilter());
    filterRegistrationBean.setOrder(-999);
    filterRegistrationBean.addUrlPatterns("/"); 
    return filterRegistrationBean;
}

然后扩展SimpleUrlAuthenticationSuccessHandler来实现我们的功能。

public class MyUrlAuthenticationSuccessHandler extends SimpleUrlAuthenticationSuccessHandler {

    public NeteaseUrlAuthenticationSuccessHandler() {
        super();
    }

    public NeteaseUrlAuthenticationSuccessHandler(String defaultTargetUrl) {
        super(defaultTargetUrl);
    }

    @Override
    protected String determineTargetUrl(HttpServletRequest request, HttpServletResponse response) {
        if (isAlwaysUseDefaultTargetUrl()) {
            return this.getDefaultTargetUrl();
        }

        // Check for the parameter and use that if available
        String targetUrl = null;

        if (this.getTargetUrlParameter() != null) {
            targetUrl = request.getParameter(this.getTargetUrlParameter());

            if (StringUtils.hasText(targetUrl)) {
                logger.debug("Found targetUrlParameter in request: " + targetUrl);

                return targetUrl;
            }
        }

        if (!StringUtils.hasText(targetUrl)) {
            HttpSession session = request.getSession();
            targetUrl = (String) session.getAttribute(HttpParamsFilter.REQUESTED_URL);
        }

        if (!StringUtils.hasText(targetUrl)) {
            targetUrl = this.getDefaultTargetUrl();
            logger.debug("Using default Url: " + targetUrl);
        }

        return targetUrl;
    }
}

最后将CasAuthenticationFilter中的SimpleUrlAuthenticationSuccessHandler替换为MyUrlAuthenticationSuccessHandler就可以了。

这里需要注意一个问题，由于CAS回调是访问的/login/cas(这里是我的配置)，所以过滤器一定不能拦截/login/cas否则HttpParamsFilter会将/login/cas放到Session中，就出现了无限循环。

1. 访问http://host/?id=1 -- session: /?id=1
2. CAS登录成功,然后回跳到login/cas?ticket=xxx -- session: login/cas?ticket=xxx
3. 验证票据成功NeteaseUrlAuthenticationSuccessHandler处理跳转，从session中获取跳转地址：login/cas?ticket=xxx
4. 跳转到`login/cas?ticket=xxx`然后重复步骤 2-4

主要是我们保留了请求中的参数，所以一直会有票据信息。所以就出现了无限循环。如果没有保留票据信息，就直接报错了，因为第二次访问的时候票据丢了。

由于我的是单页应用，所以我直接拦截主页就可以了。另一种处理方法是在HttpParamsFilter判断访问地址，如果是login/cas就不更新Session中的值。