Spring Security前后端分离最佳实践(登录+JWT)

Spring Security前后端分离最佳实践(登录+JWT)

现在前后端分离的Web应用越来越流行，后端提供一系列API，前端通过调用这些API完成系统的各个需求的呈现。那么这篇文章主要讲一讲在前后端分离的开发场景中，后端使用Spring Security如何实现登录以及API请求时的身份和权限校验。

Spring Security的核心就是各种Filter的运用，我们需要设计两个主要的Filter

• LoginAuthenticationFilter
  • 限定只支持POST的登录请求
  • 用于处理登录逻辑
• JwtTokenAuthenticationFilter
  • 支持忽略不需要校验的path请求
  • 从请求头获取JWT进行校验

开发环境

    <parent>
        <groupId>org.springframework.bootgroupId>
        <artifactId>spring-boot-starter-parentartifactId>
        <version>2.6.3version>
    parent>

jar包依赖

    <dependencies>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-securityartifactId>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>
    dependencies>

Spring Security配置

继承WebSecurityConfigurerAdapter

为了便于大家理解，我尽量让演示代码精简。定义一个类继承WebSecurityConfigurerAdapter，完整代码如下:

@Component
public class DemoWen3Security extends WebSecurityConfigurerAdapter {

  @Override
  protected void configure(HttpSecurity http) throws Exception {
    http.authorizeRequests()
            // 需要忽略的请求，不校验，直接放行
            .requestMatchers(new AntPathRequestMatcher("/**/test")).permitAll()
            .anyRequest().authenticated();

    // 登录过滤器
    http.addFilterBefore(new LoginAuthenticationFilter(), UsernamePasswordAuthenticationFilter.class);
    // token校验过滤器
    http.addFilterBefore(new JwtTokenAuthenticationFilter(), UsernamePasswordAuthenticationFilter.class);

    // 禁用表单提交
    http.formLogin().disable();
    // 禁用注销
    http.logout().disable();
    // 禁用csrf功能，方便使用curl或postman测试
    http.csrf().disable();
  }
}

• 这个配置项还有非常丰富的功能，比如未登录状态下请求了受保护的资源的处理逻辑
• 还有权限不足时的处理逻辑
• 示例代码没有把所有的配置项逐一演示，有兴趣的小伙伴欢迎继续沟通交流

登录过滤器LoginAuthenticationFilter

代码中已经有关键注释对逻辑进行说明，完成代码如下:

public class LoginAuthenticationFilter extends UsernamePasswordAuthenticationFilter {

  public LoginAuthenticationFilter() {
    // 根据需要自定义处理登录请求的Action
    setFilterProcessesUrl("/user/login");
    // 校验用户名密码
    setAuthenticationManager(new AuthenticationManager() {
      @Override
      public Authentication authenticate(Authentication authentication) throws AuthenticationException {
        UsernamePasswordAuthenticationToken token = (UsernamePasswordAuthenticationToken)authentication;
        if("xxx".equals(token.getPrincipal()) &&
                "xxx".equals(token.getCredentials())) {
          return new TestingAuthenticationToken("xxx", "xxx");
        }
        throw new BadCredentialsException("用户名密码错误");
      }
    });
    // 登录成功处理逻辑
    setAuthenticationSuccessHandler(new AuthenticationSuccessHandler() {
      @Override
      public void onAuthenticationSuccess(HttpServletRequest request, HttpServletResponse response, Authentication authentication) throws IOException, ServletException {
        response.getWriter().write("login successfully, token:" + UUID.randomUUID().toString());
      }
    });
    // 登录失败处理逻辑
    setAuthenticationFailureHandler(new AuthenticationFailureHandler() {
      @Override
      public void onAuthenticationFailure(HttpServletRequest request, HttpServletResponse response, AuthenticationException exception) throws IOException, ServletException {
        response.getWriter().write("login fail:" + exception.getMessage());
      }
    });
  }
}

• Spring Security提供了非常丰富的功能，校验用户名密码有很多种实现方式，示例代码只是其中的一种
• 登录成功和失败可以根据需要返回自定义JSON数据

token校验过滤器JwtTokenAuthenticationFilter

代码中已经有关键注释对逻辑进行说明，完成代码如下:

public class JwtTokenAuthenticationFilter extends UsernamePasswordAuthenticationFilter {

  public JwtTokenAuthenticationFilter() {
    // token校验逻辑
    setAuthenticationManager(new AuthenticationManager() {
      @Override
      public Authentication authenticate(Authentication authentication) throws AuthenticationException {
        TestingAuthenticationToken token = (TestingAuthenticationToken)authentication;
        String accessToken = (String)token.getCredentials();
        // 校验token逻辑，这里演示只是判空
        if(StringUtils.isNoneBlank(accessToken)) {
          return new TestingAuthenticationToken("xxx", "xxx", AuthorityUtils.createAuthorityList(new String[]{"admin"}));
        }
        throw new BadCredentialsException("token is empty");
      }
    });
    // 校验失败处理逻辑
    setAuthenticationFailureHandler(new AuthenticationFailureHandler() {
      @Override
      public void onAuthenticationFailure(HttpServletRequest request, HttpServletResponse response, AuthenticationException exception) throws IOException, ServletException {
        response.setStatus(HttpStatus.UNAUTHORIZED.value());
        response.getWriter().write("401 token is invalid:" + exception.getMessage());
      }
    });
  }

  // 获取token并触发校验
  @Override
  public Authentication attemptAuthentication(HttpServletRequest request, HttpServletResponse response) throws AuthenticationException {
    // 从请求头获取token
    String token = request.getHeader(HttpHeaders.AUTHORIZATION);
    if(StringUtils.isBlank(token)) {
      throw new BadCredentialsException("token is empty");
    }
    TestingAuthenticationToken testingAuthenticationToken = new TestingAuthenticationToken(token, token);
    return this.getAuthenticationManager().authenticate(testingAuthenticationToken);
  }

  // 判断当前请求是否需要进行token校验
  @Override
  protected boolean requiresAuthentication(HttpServletRequest request, HttpServletResponse response) {
    // 不需要校验的请求直接忽略放行
    if(new AntPathRequestMatcher("/**/test").matches(request)) {
      return false;
    }
    // 如果已经校验通过，不重复校验
    Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
    if(null!=authentication && authentication.isAuthenticated()) {
      return false;
    }
    return true;
  }

  // 校验通过后的处理逻辑
  @Override
  protected void successfulAuthentication(HttpServletRequest request, HttpServletResponse response, FilterChain chain, Authentication authResult) throws IOException, ServletException {
    // 把身份数据放入上下文，后续代码可以随时通过静态方法获取SecurityContextHolder.getContext().getAuthentication()
    SecurityContextHolder.getContext().setAuthentication(authResult);
    // 继续往下进入controller或其它被访问的资源
    chain.doFilter(request, response);
  }
}

• Spring Security对token的校验也提供了多种校验方式
• 示例代码只是展示了一种最简单直接的方式

main()函数启动类

@SpringBootApplication
public class DemoSpringSecurityApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoSpringSecurityApplication.class, args);
    }
}

测试验证

• 使用curl命令进行测试
  curl -ik -XPOST "http://localhost:8080/user/login?username=xxx&password=xxx"
• 响应结果

$ curl -ik -XPOST "http://localhost:8080/user/login?username=xxx&password=xxx"
HTTP/1.1 200
X-Content-Type-Options: nosniff
X-XSS-Protection: 1; mode=block
Cache-Control: no-cache, no-store, max-age=0, must-revalidate
Pragma: no-cache
Expires: 0
X-Frame-Options: DENY
Set-Cookie: JSESSIONID=D5240B930D22093D35DFC10A5860CD14; Path=/; HttpOnly
Content-Length: 62
Date: Thu, 31 Mar 2022 15:29:22 GMT

login successfully, token:44a3e490-06ef-4b18-aec5-ad3e7511e3bd

• 登录成功，并返回了token
• 继续请求，带token请求API
  curl -ik -XGET -H "Authorization: 44a3e490-06ef-4b18-aec5-ad3e7511e3bd" "http://localhost:8080/getUser"
• 请求成功，响应如下

HTTP/1.1 404
Set-Cookie: JSESSIONID=E701BA24983F2463C4FFD0AC7EEF72E4; Path=/; HttpOnly
Vary: Origin
Vary: Access-Control-Request-Method
Vary: Access-Control-Request-Headers
X-Content-Type-Options: nosniff
X-XSS-Protection: 1; mode=block
Cache-Control: no-cache, no-store, max-age=0, must-revalidate
Pragma: no-cache
Expires: 0
X-Frame-Options: DENY
Content-Type: application/json
Transfer-Encoding: chunked
Date: Thu, 31 Mar 2022 15:36:47 GMT

{"timestamp":"2022-03-31T15:36:47.504+00:00","status":404,"error":"Not Found","path":"/getUser"}

• 为什么返回404呢？因为我们并没有定义/getUser这个API，因为是演示token的校验机制，所以可以看到请求的校验也是通过了的
• 试试不带token的请求
  curl -ik -XGET "http://localhost:8080/getUser"
• 后端的响应如下

HTTP/1.1 401
X-Content-Type-Options: nosniff
X-XSS-Protection: 1; mode=block
Cache-Control: no-cache, no-store, max-age=0, must-revalidate
Pragma: no-cache
Expires: 0
X-Frame-Options: DENY
Content-Length: 35
Date: Thu, 31 Mar 2022 15:41:00 GMT

401 token is invalid:token is empty

• 返回了401，符合我们的预期
• 至此，我们对登录、token的校验的演示就全部完成了

总结

Spring Security功能很强大，对安全认证这一块提供了非常丰富的支持，篇幅有限，只是演示了非常基础的功能。如果大家在进行前后端分离的开发时，后端也想集成Spring Security，相信通过这篇文章的介绍，可以帮助大家解决一定的困惑。

本人对Spring Security的研究非常深入，几乎翻看了底层所有的源码，熟悉Spring Security运行的机制、原理，如果大家在使用Spring Security的过程中遇到什么难题，欢迎进一步沟通、交流。