Spring SAML 扩展和 Spring Security CSRF 保护冲突

我们有一个带有 Spring Security (3.2.4) 的 Spring MVC (4.0.5) 应用程序，其中包括运行良好的 CSRF 保护。我们现在添加 SAML 安全扩展 (spring-security-saml2-core 1.0.0)，这会导致 CSRF 保护出现问题。

元数据已在 SSOCircle 上配置并尝试访问http://localhost:8080/myapp定向至 SSOCircle 上的登录页面。身份验证后，浏览器重定向到http://localhost:8080/myapp/saml/SSO并产生错误：

HTTP 状态 403 - 未找到预期的 CSRF 令牌。您的会话已过期吗？

如果我们关闭 CSRF 保护，一切正常。我们如何在维持 CSRF 保护的同时仍然使用 SAML 扩展？

在设置 SAML 扩展之前，我们使用了登录表单，并且 CSRF 保护有效，并且我们在登录 JSP 上没有收到错误，并且它没有令牌。

SAML 之前的代码：

@Override
protected void configure(HttpSecurity httpSecurity) throws Exception {
    httpSecurity.authorizeRequests()
            .antMatchers("/login", "/login.request", "/logout").permitAll()
            .anyRequest()
                .hasAnyAuthority("MyRole")
                    .and().formLogin()
            .loginPage("/login.request").loginProcessingUrl("/login")
            .failureUrl("/login.request?error").permitAll().and().logout()
            .logoutUrl("/logout").permitAll()
            .logoutSuccessUrl("/login.request");
}

使用 SAML 的代码：

@Override
protected void configure(HttpSecurity http) throws Exception {
    //http.csrf().disable();

    http.httpBasic().authenticationEntryPoint(samlEntryPoint());

    http.addFilterBefore(metadataGeneratorFilter(),
            ChannelProcessingFilter.class).addFilterAfter(samlFilter(),
            BasicAuthenticationFilter.class);

    http
        .authorizeRequests()
            .antMatchers("/error").permitAll()
            .antMatchers("/saml/**").permitAll()
            .anyRequest()
                .hasAnyAuthority("MyRole")
            .anyRequest().authenticated();

    http.logout().logoutSuccessUrl("/");
}

UPDATE

重新启用 CSRF 保护并将日志记录设置为 DEBUG 后，以下是成功身份验证后立即出现的日志：

22.10.2014 16:54:17.374 [http-bio-8080-exec-8] DEBUG o.s.w.m.support.MultipartFilter -
                Using MultipartResolver 'filterMultipartResolver' for MultipartFilter

22.10.2014 16:54:17.377 [http-bio-8080-exec-8] DEBUG o.s.b.f.s.DefaultListableBeanFactory -
                Returning cached instance of singleton bean 'filterMultipartResolver'

22.10.2014 16:54:17.788 [http-bio-8080-exec-8] DEBUG o.s.w.m.support.MultipartFilter -
                Request [/epass/saml/SSO] is not a multipart request

22.10.2014 16:54:17.790 [http-bio-8080-exec-8] DEBUG o.s.s.w.u.m.AntPathRequestMatcher -
                Checking match of request : '/saml/sso'; against '/resources/**'

22.10.2014 16:54:17.791 [http-bio-8080-exec-8] DEBUG o.s.security.web.FilterChainProxy -
                /saml/SSO at position 1 of 14 in additional filter chain; firing Filter: 'MetadataGeneratorFilter'

22.10.2014 16:54:17.793 [http-bio-8080-exec-8] DEBUG o.s.security.web.FilterChainProxy -
                /saml/SSO at position 2 of 14 in additional filter chain; firing Filter: 'WebAsyncManagerIntegrationFilter'

22.10.2014 16:54:17.795 [http-bio-8080-exec-8] DEBUG o.s.security.web.FilterChainProxy -
                /saml/SSO at position 3 of 14 in additional filter chain; firing Filter: 'SecurityContextPersistenceFilter'

22.10.2014 16:54:17.797 [http-bio-8080-exec-8] DEBUG o.s.s.w.c.HttpSessionSecurityContextRepository -
                HttpSession returned null object for SPRING_SECURITY_CONTEXT

22.10.2014 16:54:17.798 [http-bio-8080-exec-8] DEBUG o.s.s.w.c.HttpSessionSecurityContextRepository -
                No SecurityContext was available from the HttpSession: org.apache.catalina.session.StandardSessionFacade@b08c9c9. A new one will be created.

22.10.2014 16:54:17.800 [http-bio-8080-exec-8] DEBUG o.s.security.web.FilterChainProxy -
                /saml/SSO at position 4 of 14 in additional filter chain; firing Filter: 'HeaderWriterFilter'

22.10.2014 16:54:17.801 [http-bio-8080-exec-8] DEBUG o.s.s.w.h.writers.HstsHeaderWriter -
                Not injecting HSTS header since it did not match the requestMatcher org.springframework.security.web.header.writers.HstsHeaderWriter$SecureRequestMatcher@244a79ef

22.10.2014 16:54:17.802 [http-bio-8080-exec-8] DEBUG o.s.security.web.FilterChainProxy -
                /saml/SSO at position 5 of 14 in additional filter chain; firing Filter: 'CsrfFilter'
22.10.2014 16:54:17.805 [http-bio-8080-exec-8] DEBUG o.s.security.web.csrf.CsrfFilter -
                Invalid CSRF token found for `http://localhost:8080/myapp/saml/SSO`

22.10.2014 16:54:17.807 [http-bio-8080-exec-8] DEBUG o.s.s.w.c.HttpSessionSecurityContextRepository -
                SecurityContext is empty or contents are anonymous - context will not be stored in HttpSession.

22.10.2014 16:54:17.808 [http-bio-8080-exec-8] DEBUG o.s.s.w.c.SecurityContextPersistenceFilter -
                SecurityContextHolder now cleared, as request processing completed

你至少有两个选择。

一是实施定制RequestMatcher (org.springframework.security.web.util.RequestMatcher），这与 Spring SAML URL 不匹配，并将其提供给 csrf 配置：

http.csrf().requireCsrfProtectionMatcher(matcher);

另一种更简单的方法是在单独的 http 配置中定义 Spring SAML 端点，该配置不会启用 csrf 保护。

执行此操作的 XML 配置类似于：

<!-- SAML processing endpoints -->
<security:http pattern="/saml/**" entry-point-ref="samlEntryPoint">
    <security:custom-filter before="FIRST" ref="metadataGeneratorFilter"/>
    <security:custom-filter after="BASIC_AUTH_FILTER" ref="samlFilter"/>
</security:http>

<!-- Secured pages with SAML as entry point -->
<security:http entry-point-ref="samlEntryPoint">
    <security:csrf />
    <security:intercept-url pattern="/**" access="IS_AUTHENTICATED_FULLY"/>
    <security:custom-filter before="FIRST" ref="metadataGeneratorFilter"/>
</security:http>

对于 Java 配置，类似这样的内容应该有效：

@Configuration
@EnableWebSecurity
public class MutlipleHttpConfigurationConfig {

    @Configuration
    @Order(1)
    public static class SAMLWebSecurityConfigurationAdapter extends WebSecurityConfigurerAdapter {
        protected void configure(HttpSecurity http) throws Exception {
            http.antMatcher("/saml/**");
            http.csrf().disable();
            http.httpBasic().authenticationEntryPoint(samlEntryPoint());
            http.addFilterBefore(metadataGeneratorFilter(),
                    ChannelProcessingFilter.class).addFilterAfter(samlFilter(),
                    BasicAuthenticationFilter.class);
        }
    }

    @Configuration
    public static class BasicWebSecurityConfigurationAdapter extends WebSecurityConfigurerAdapter {
        protected void configure(HttpSecurity http) throws Exception {
            http.httpBasic().authenticationEntryPoint(samlEntryPoint());
            http.addFilterBefore(metadataGeneratorFilter(), ChannelProcessingFilter.class);
            http
                    .authorizeRequests()
                    .antMatchers("/error").permitAll()
                    .anyRequest()
                    .hasAnyAuthority("MyRole")
                    .anyRequest().authenticated();

            http.logout().logoutSuccessUrl("/");
        }
    }
}

有关使用 Java 配置定义多个 http 配置的详细信息，请参阅Spring安全手册 http://docs.spring.io/spring-security/site/docs/3.2.x/reference/htmlsingle/#multiple-httpsecurity.