/**
 * 攔截器 請求引數簽名校驗
 * Created by jiyang on 14:47 2017/12/14
 */
@Component
@Slf4j
public class ParameterInterceptor implements HandlerInterceptor {

    public static final String VERIFY_FAIL_MSG = "The request parameter signature verification failed!";

    @Autowired
    private ChannelService channelService;


    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object o) throws Exception {
        // 渠道編號
        String channelCode = request.getParameter("channelCode");
        // 簽名
        String signStr = request.getParameter("sign");

        if (StringUtils.isBlank(channelCode) || StringUtils.isBlank(signStr)) {
            log.warn(VERIFY_FAIL_MSG);
            response.setStatus(HttpStatus.SC_BAD_REQUEST);
            return false;
        }

        Channel channel = channelService.selectByChannelCode(channelCode);
        if (channel == null) {
            log.warn(VERIFY_FAIL_MSG);
            response.setStatus(HttpStatus.SC_BAD_REQUEST);
            return false;
        }

        boolean right = MD5Util.verifySign(channel.getEncryptKey(), request);
        if (right) {
            return true;
        }

        log.warn(VERIFY_FAIL_MSG);
        response.setStatus(HttpStatus.SC_FORBIDDEN);
        return false;
    }


    @Override
    public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) {
        return ;
    }

    @Override
    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) {
        return ;
    }

}
 

public class MD5Util {

    public static String md5(String string) {
        byte[] hash;
        try {
            hash = MessageDigest.getInstance("MD5").digest(string.getBytes("UTF-8"));
        } catch (UnsupportedEncodingException e) {
            throw new RuntimeException("UTF-8 is unsupported", e);
        } catch (NoSuchAlgorithmException e) {
            throw new RuntimeException("MessageDigest不支援MD5Util", e);
        }
        StringBuilder hex = new StringBuilder(hash.length * 2);
        for (byte b : hash) {
            if ((b & 0xFF) < 0x10) hex.append("0");
            hex.append(Integer.toHexString(b & 0xFF));
        }
        return hex.toString();
    }


    /**
     * md5簽名
     *
     * 按引數名稱升序，將引數值進行連線 簽名
     * @param appSecret
     * @param params
     * @return
     */
    public static String sign(String appSecret, TreeMap<String, String> params) {
        StringBuilder paramValues = new StringBuilder();
        params.put("appSecret", appSecret);

        for (Map.Entry<String, String> entry : params.entrySet()) {
            paramValues.append(entry.getValue());
        }
        System.out.println(md5(paramValues.toString()));
        return md5(paramValues.toString());
    }


    /**
     * 請求引數簽名驗證
     *
     * @param appSecret
     * @param request
     * @return true 驗證通過 false 驗證失敗
     * @throws Exception
     */
    public static boolean verifySign(String appSecret, HttpServletRequest request) throws Exception {
        TreeMap<String, String> params = new TreeMap<String, String>();

        String signStr = request.getParameter("sign");
        if(StringUtils.isBlank(signStr)){
            throw new RuntimeException("There is no signature field in the request parameter!");
        }

        Enumeration<String> enu = request.getParameterNames();
        while (enu.hasMoreElements()) {
            String paramName = enu.nextElement().trim();
            if (!paramName.equals("sign")) {
                params.put(paramName, URLDecoder.decode(request.getParameter(paramName), "UTF-8"));
            }
        }

        if (!sign(appSecret, params).equals(signStr)) {
            return false;
        }
        return true;
    }
    
}
 

/**
 * 攔截器
 */
@Configuration
public class IntercepterConfig extends WebMvcConfigurerAdapter {

    @Value("${longdai.core.token}")
    private String token;

    @Value("${app.profile}")
    private String profile;

    @Override
    public void addInterceptors(InterceptorRegistry registry) {

        //registry.addInterceptor(new SwaggerInterceptor()).addPathPatterns("/v2/api-docs/**");
        // Token 驗證(僅生產)
        if (!("dev".equals(profile.trim()) || "dohko".equals(profile.trim()))) {
            registry.addInterceptor(new TokenInterceptor(token)).addPathPatterns("/**").excludePathPatterns("/health/core/ping");
        }

        // 簽名校驗
        registry.addInterceptor(getParameterInterceptor()).addPathPatterns("/v3/thirdParty/**");
    }


    @Bean
    public HandlerInterceptor getParameterInterceptor(){
        return new ParameterInterceptor();
    }
}