SpringCloud中Gateway实现JWT认证（一）

一、目的

1.不需要每个微服务都实现鉴权逻辑导致重复编码

2.每个微服务都需要知道秘钥，这样不安全

二、GlobalFilter实现跳过登录接口、Token验证

@Component
public class AuthFilter implements GlobalFilter, Ordered
{
    private static final Logger log = LoggerFactory.getLogger(AuthFilter.class);

    // 排除过滤的 uri 地址，nacos自行添加
    @Autowired
    private IgnoreWhiteProperties ignoreWhite;

    @Autowired
    private RedisService redisService;


    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain)
    {
        ServerHttpRequest request = exchange.getRequest();
        ServerHttpRequest.Builder mutate = request.mutate();

        String url = request.getURI().getPath();
        // 跳过不需要验证的路径
        if (StringUtils.matches(url, ignoreWhite.getWhites()))
        {
            return chain.filter(exchange);
        }
        String token = getToken(request);
        if (StringUtils.isEmpty(token))
        {
            return unauthorizedResponse(exchange, "令牌不能为空");
        }
        Claims claims = JwtUtils.parseToken(token);
        if (claims == null)
        {
            return unauthorizedResponse(exchange, "令牌已过期或验证不正确！");
        }
        String userkey = JwtUtils.getUserKey(claims);
        boolean islogin = redisService.hasKey(getTokenKey(userkey));
        if (!islogin)
        {
            return unauthorizedResponse(exchange, "登录状态已过期");
        }
        String userid = JwtUtils.getUserId(claims);
        String username = JwtUtils.getUserName(claims);
        if (StringUtils.isEmpty(userid) || StringUtils.isEmpty(username))
        {
            return unauthorizedResponse(exchange, "令牌验证失败");
        }

        // 设置用户信息到请求
        addHeader(mutate, SecurityConstants.USER_KEY, userkey);
        addHeader(mutate, SecurityConstants.DETAILS_USER_ID, userid);
        addHeader(mutate, SecurityConstants.DETAILS_USERNAME, username);
        // 内部请求来源参数清除
        removeHeader(mutate, SecurityConstants.FROM_SOURCE);
        return chain.filter(exchange.mutate().request(mutate.build()).build());
    }

    private void addHeader(ServerHttpRequest.Builder mutate, String name, Object value)
    {
        if (value == null)
        {
            return;
        }
        String valueStr = value.toString();
        String valueEncode = ServletUtils.urlEncode(valueStr);
        mutate.header(name, valueEncode);
    }

    private void removeHeader(ServerHttpRequest.Builder mutate, String name)
    {
        mutate.headers(httpHeaders -> httpHeaders.remove(name)).build();
    }

    private Mono<Void> unauthorizedResponse(ServerWebExchange exchange, String msg)
    {
        log.error("[鉴权异常处理]请求路径:{}", exchange.getRequest().getPath());
        return ServletUtils.webFluxResponseWriter(exchange.getResponse(), msg, HttpStatus.UNAUTHORIZED);
    }

    /**
     * 获取缓存key
     */
    private String getTokenKey(String token)
    {
        return CacheConstants.LOGIN_TOKEN_KEY + token;
    }

    /**
     * 获取请求token
     */
    private String getToken(ServerHttpRequest request)
    {
        String token = request.getHeaders().getFirst(TokenConstants.AUTHENTICATION);
        // 如果前端设置了令牌前缀，则裁剪掉前缀
        if (StringUtils.isNotEmpty(token) && token.startsWith(TokenConstants.PREFIX))
        {
            token = token.replaceFirst(TokenConstants.PREFIX, StringUtils.EMPTY);
        }
        return token;
    }

    @Override
    public int getOrder()
    {
        return -200;
    }

1.放行白名单，如登录、注册

/**
 * 放行白名单配置
 * 
 * @author yuankai
 */
@Configuration
@RefreshScope
@ConfigurationProperties(prefix = "security.ignore")
public class IgnoreWhiteProperties
{
    /**
     * 放行白名单配置，网关不校验此处的白名单
     */
    private List<String> whites = new ArrayList<>();

    public List<String> getWhites()
    {
        return whites;
    }

    public void setWhites(List<String> whites)
    {
        this.whites = whites;
    }
}

三、将用户信息封装到SecurityContextHolder（由于web线程池是复用的，因此在下一个请求请移除ThreadLocal里面中的值）

public class HeaderInterceptor implements AsyncHandlerInterceptor
{
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception
    {
        if (!(handler instanceof HandlerMethod))
        {
            return true;
        }

        SecurityContextHolder.setUserId(ServletUtils.getHeader(request, SecurityConstants.DETAILS_USER_ID));
        SecurityContextHolder.setUserName(ServletUtils.getHeader(request, SecurityConstants.DETAILS_USERNAME));
        SecurityContextHolder.setUserKey(ServletUtils.getHeader(request, SecurityConstants.USER_KEY));

        String token = SecurityUtils.getToken();
        if (StringUtils.isNotEmpty(token))
        {
            LoginUser loginUser = AuthUtil.getLoginUser(token);
            if (StringUtils.isNotNull(loginUser))
            {
                AuthUtil.verifyLoginUserExpire(loginUser);
                SecurityContextHolder.set(SecurityConstants.LOGIN_USER, loginUser);
            }
        }
        return true;
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
            throws Exception
    {
        SecurityContextHolder.remove();
    }
}

四、jwt安全策略

1.目的：jwt的使用过程中，为了降低被他们使用的可能性，通过refreshToken的方式，使得token在超过期限后失效

2.大概流程图

3.登录时创建token存储到redis中，并设置过期时间为720分钟（即使token被窃取，其有效期也会受到限制）

    /**
     * 刷新令牌有效期
     *
     * @param loginUser 登录信息
     */
    public void refreshToken(LoginUser loginUser)
    {
        loginUser.setLoginTime(System.currentTimeMillis());
        loginUser.setExpireTime(loginUser.getLoginTime() + expireTime * MILLIS_MINUTE);
        // 根据uuid将loginUser缓存
        String userKey = getTokenKey(loginUser.getToken());
        redisService.setCacheObject(userKey, loginUser, expireTime, TimeUnit.MINUTES);
    }

4.在GlobalFilter中登录状态是否过期

        boolean islogin = redisService.hasKey(getTokenKey(userkey));
        if (!islogin)
        {
            return unauthorizedResponse(exchange, "登录状态已过期");
        }

5.在拦截器中验证当前用户并刷新有效期（刷新缓存的目的是为了避免用户在使用过程中突然下线）

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception
    {
        if (!(handler instanceof HandlerMethod))
        {
            return true;
        }

        SecurityContextHolder.setUserId(ServletUtils.getHeader(request, SecurityConstants.DETAILS_USER_ID));
        SecurityContextHolder.setUserName(ServletUtils.getHeader(request, SecurityConstants.DETAILS_USERNAME));
        SecurityContextHolder.setUserKey(ServletUtils.getHeader(request, SecurityConstants.USER_KEY));

        String token = SecurityUtils.getToken();
        if (StringUtils.isNotEmpty(token))
        {
            LoginUser loginUser = AuthUtil.getLoginUser(token);
            if (StringUtils.isNotNull(loginUser))
            {
                AuthUtil.verifyLoginUserExpire(loginUser);
                SecurityContextHolder.set(SecurityConstants.LOGIN_USER, loginUser);
            }
        }
        return true;
    }

    /**
     * 验证令牌有效期，相差不足120分钟，自动刷新缓存
     *
     * @param loginUser
     */
    public void verifyToken(LoginUser loginUser)
    {
        long expireTime = loginUser.getExpireTime();
        long currentTime = System.currentTimeMillis();
        if (expireTime - currentTime <= MILLIS_MINUTE_TEN)
        {
            refreshToken(loginUser);
        }
    }

6.当用户登出后，redis删除过期信息（当用户登出后删除过期信息，避免登出后jwt被盗所使用）

    /**
     * 删除用户缓存信息
     */
    public void delLoginUser(String token)
    {
        if (StringUtils.isNotEmpty(token))
        {
            String userkey = JwtUtils.getUserKey(token);
            redisService.deleteObject(getTokenKey(userkey));
        }
    }

7.假设用户在登录过程中，并没有点击登出，而是直接关闭了浏览器，在这段时间内jwt被盗取怎么办？

①实施主动登出机制，使得当用户在另一个设备或位置登录时，之前的JWT令牌自动失效。可以通过在服务端存储每个用户的登录信息，包括设备信息、IP地址等，当用户的新登录请求出现时，比对新旧登录信息，若发现异常则主动让旧令牌失效

② 在JWT 的Payload部分可以包含一些信息，例如IP地址、User-Agent等，可以通过验证这些信息来限制令牌的使用范围，如果JWT令牌被用于不符合条件的请求，可以主动使令牌失效