简介

现在越来越多人关注接口安全，传统的接口在传输的过程中，容易被抓包然后更改里面的参数值达到某些目的。
传统的做法是用安全框架或者在代码里面做验证，但是有些系统是不需要登录的，随时可以调。
这时候我们可以通过对参数进行签名验证，如果参数与签名值不匹配，则请求不通过，直接返回错误信息。

项目代码地址：

https://github.com/MrXuan3168/sign_server

测试

启动项目
GET请求可以用浏览器直接访问 http://localhost:8080/signTest?sign=A0161DC47118062053567CDD10FBACC6&username=admin&password=admin
- A0161DC47118062053567CDD10FBACC6 是 username=admin&password=admin MD5加密后的结果。可以打开 https://md5jiami.51240.com/ 然后输入 {"password":"admin","username":"admin"} 进行加密验证，json字符串里面，必须保证字段是按照 ascll码进行排序的,username的ascll码比 password的ascll码大，所以要放在后面。
打开 postman 进行POST请求测试，请求Url为 http://localhost:8080/signTest?sign=A0161DC47118062053567CDD10FBACC6 参数为
```
  {
      "username":"admin",
      "password":"admin"
  }
```

调用过程

涉及第三方技术

前端：js-md5(vue md5-npm包)、axios(vue ajax请求npm包)
- 安装命令
```
 npm install js-md5
 npm install axios
```

后端: fastjson、lombok

     <dependency>
         <groupId>org.projectlombok</groupId>
         <artifactId>lombok</artifactId>
         <optional>true</optional>
     </dependency>
     <dependency>
         <groupId>com.alibaba</groupId>
         <artifactId>fastjson</artifactId>
         <version>1.2.47</version>
         <scope>compile</scope>
     </dependency>

签名逻辑

前端（客户端）： 1.不管GET Url 还是 POST Body 的参数，都转换成 json 对象，用 ascll码排序对参数排序。 2.排序后对参数进行MD5加密，存入 sign 值。 3.把 sign 值放在请求URL 后面或者 Head头里面(该项目直接放在URL后面)。
后端（服务端）： 1.把参数接收，转成 json对象，用 ascll码排序 2.排序后对参数进行MD5加密，存入 paramsSign 值。 3.和请求URL 中的 sign值做对比，相同则请求通过。

前端代码

加密工具类

import md5 from 'js-md5'

export default class signMd5Utils {
    /**
     * json参数升序
     * @param jsonObj 发送参数
     */

    static sortAsc(jsonObj) {
        let arr = new Array();
        let num = 0;
        for (let i in jsonObj) {
            arr[num] = i;
            num++;
        }
        let sortArr = arr.sort();
        let sortObj = {};
        for (let i in sortArr) {
            sortObj[sortArr[i]] = jsonObj[sortArr[i]];
        }
        return sortObj;
    }


    /**
     * @param url 请求的url,应该包含请求参数(url的?后面的参数)
     * @param requestParams 请求参数(POST的JSON参数)
     * @returns {string} 获取签名
     */
    static getSign(url, requestParams) {
        let urlParams = this.parseQueryString(url);
        let jsonObj = this.mergeObject(urlParams, requestParams);
        let requestBody = this.sortAsc(jsonObj);
        return md5(JSON.stringify(requestBody)).toUpperCase();
    }

    /**
     * @param url 请求的url
     * @returns {{}} 将url中请求参数组装成json对象(url的?后面的参数)
     */
    static parseQueryString(url) {
        let urlReg = /^[^\?]+\?([\w\W]+)$/,
            paramReg = /([^&=]+)=([\w\W]*?)(&|$|#)/g,
            urlArray = urlReg.exec(url),
            result = {};
        if (urlArray && urlArray[1]) {
            let paramString = urlArray[1], paramResult;
            while ((paramResult = paramReg.exec(paramString)) != null) {
                result[paramResult[1]] = paramResult[2];
            }
        }
        return result;
    }

    /**
     * @returns {*} 将两个对象合并成一个
     */
    static mergeObject(objectOne, objectTwo) {
        if (Object.keys(objectTwo).length > 0) {
            for (let key in objectTwo) {
                if (objectTwo.hasOwnProperty(key) === true) {
                    objectOne[key] = objectTwo[key];
                }
            }
        }
        return objectOne;
    }

    static urlEncode(param, key, encode) {
        if (param == null) return '';
        let paramStr = '';
        let t = typeof (param);
        if (t == 'string' || t == 'number' || t == 'boolean') {
            paramStr += '&' + key + '=' + ((encode == null || encode) ? encodeURIComponent(param) : param);
        } else {
            for (let i in param) {
                let k = key == null ? i : key + (param instanceof Array ? '[' + i + ']' : '.' + i);
                paramStr += this.urlEncode(param[i], k, encode);
            }
        }
        return paramStr;
    };
}

发送请求类

import axios from 'axios';
import signMd5Utils from "../utils/signMd5Utils"
// var config = require('../../config')
//config = process.env.NODE_ENV === 'development' ? config.dev : config.build
//let apiUrl = config.apiUrl;
//var qs = require('qs');
const instance = axios.create({
    baseURL: 'http://localhost:8080/',
    // timeout: 1000 * 30,
    // 允许跨域带token
    xhrFields: {
        withCredentials: false
    },
    crossDomain: true,
    emulateJSON: true
});
export default instance
export function signTestPost(query) {

    let url = 'signTest';
    let sign = signMd5Utils.getSign(url, query);
    let requestUrl = url + "?sign=" + sign;  //将签名添加在请求参数后面去请求接口
    return instance({
        url: requestUrl,
        method: 'post',
        data: query
    })
}
export function signTestGet(query) {

    let url = 'signTest';
    let urlParams = signMd5Utils.urlEncode(query);
    let sign = signMd5Utils.getSign(url, query);
    let requestUrl = url + "?sign=" + sign + urlParams;  //将签名添加在请求参数后面去请求接口
    return instance({
        url: requestUrl,
        method: 'get',
    })
}

调用请求

let user = {
    "username": "admin",
    "password": "admin",
};
signTestPost(user).then(r => {
    console.log(r)
});

signTestGet(user).then(r => {
    console.log(r)
})

后端代码

过滤器(到达 Controller 前执行)

import com.alibaba.fastjson.JSONObject;
import com.show.sign.utils.HttpUtils;
import com.show.sign.utils.SignUtil;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.SortedMap;

/**
 * 签名过滤器
 * @author show
 * @date 10:03 2019/5/30
 * @Component 注册 Filter 组件
 */
@Slf4j
@Component 
public class SignAuthFilter implements Filter {
    static final String FAVICON = "/favicon.ico";

    @Override
    public void init(FilterConfig filterConfig) {

        log.info("初始化 SignAuthFilter");
    }

    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {

        HttpServletResponse response = (HttpServletResponse) res;
        // 防止流读取一次后就没有了, 所以需要将流继续写出去
        HttpServletRequest request = (HttpServletRequest) req;
        HttpServletRequest requestWrapper = new BodyReaderHttpServletRequestWrapper(request);
        //获取图标不需要验证签名
        if (FAVICON.equals(requestWrapper.getRequestURI())) {
            chain.doFilter(request, response);
        } else {
            //获取全部参数(包括URL和body上的)
            SortedMap<String, String> allParams = HttpUtils.getAllParams(requestWrapper);
            //对参数进行签名验证
            boolean isSigned = SignUtil.verifySign(allParams);
            if (isSigned) {
                log.info("签名通过");
                chain.doFilter(requestWrapper, response);
            } else {
                log.info("参数校验出错");
                //校验失败返回前端
                response.setCharacterEncoding("UTF-8");
                response.setContentType("application/json; charset=utf-8");
                PrintWriter out = response.getWriter();
               JSONObject resParam = new JSONObject();
                resParam.put("msg", "参数校验出错");
                resParam.put("success", "false");
                out.append(resParam.toJSONString());
            }
        }
    }

    @Override
    public void destroy() {

        log.info("销毁 SignAuthFilter");
    }
}

BodyReaderHttpServletRequestWrapper 类主要作用是复制 HttpServletRequest 的输入流，不然你拿出 body 参数后验签后，到 Controller 时，接收参数会为 null

import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.*;
import java.nio.charset.Charset;

/**
 * 保存过滤器里面的流
 * @author show
 * @date 10:03 2019/5/30
 */
public class BodyReaderHttpServletRequestWrapper extends HttpServletRequestWrapper {

    private final byte[] body;

    public BodyReaderHttpServletRequestWrapper(HttpServletRequest request) {

        super(request);
        String sessionStream = getBodyString(request);
        body = sessionStream.getBytes(Charset.forName("UTF-8"));
    }

    /**
     * 获取请求Body
     *
     * @param request
     * @return
     */
    public String getBodyString(final ServletRequest request) {

        StringBuilder sb = new StringBuilder();
        try (
            InputStream inputStream = cloneInputStream(request.getInputStream());
            BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream, Charset.forName("UTF-8")))
        ) {
            String line;
            while ((line = reader.readLine()) != null) {
                sb.append(line);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return sb.toString();
    }

    /**
     * Description: 复制输入流</br>
     *
     * @param inputStream
     * @return</br>
     */
    public InputStream cloneInputStream(ServletInputStream inputStream) {

        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        byte[] buffer = new byte[1024];
        int len;
        try {
            while ((len = inputStream.read(buffer)) > -1) {
                byteArrayOutputStream.write(buffer, 0, len);
            }
            byteArrayOutputStream.flush();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return new ByteArrayInputStream(byteArrayOutputStream.toByteArray());
    }

    @Override
    public BufferedReader getReader() {

        return new BufferedReader(new InputStreamReader(getInputStream()));
    }

    @Override
    public ServletInputStream getInputStream() {

        final ByteArrayInputStream bais = new ByteArrayInputStream(body);
        return new ServletInputStream() {

            @Override
            public int read() {

                return bais.read();
            }

            @Override
            public boolean isFinished() {

                return false;
            }

            @Override
            public boolean isReady() {

                return false;
            }

            @Override
            public void setReadListener(ReadListener readListener) {

            }
        };
    }
}

签名工具类

import com.alibaba.fastjson.JSONObject;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.DigestUtils;
import org.springframework.util.StringUtils;

import java.util.SortedMap;

/**
 * 签名工具类
 * @author show
 * @date 10:01 2019/5/30
 */
@Slf4j
public class SignUtil {

    /**
     * @param params 所有的请求参数都会在这里进行排序加密
     * @return 验证签名结果
     */
    public static boolean verifySign(SortedMap<String, String> params) {

        String urlSign = params.get("sign");
        log.info("Url Sign : {}", urlSign);
        if (params == null || StringUtils.isEmpty(urlSign)) {
            return false;
        }
        //把参数加密
        String paramsSign = getParamsSign(params);
        log.info("Param Sign : {}", paramsSign);
        return !StringUtils.isEmpty(paramsSign) && urlSign.equals(paramsSign);
    }

    /**
     * @param params 所有的请求参数都会在这里进行排序加密
     * @return 得到签名
     */
    public static String getParamsSign(SortedMap<String, String> params) {
        //要先去掉 Url 里的 Sign
        params.remove("sign");
        String paramsJsonStr = JSONObject.toJSONString(params);
        return DigestUtils.md5DigestAsHex(paramsJsonStr.getBytes()).toUpperCase();
    }
}

http工具类获取请求中的数据

import com.alibaba.fastjson.JSONObject;
import org.springframework.http.HttpMethod;

import javax.servlet.http.HttpServletRequest;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.util.HashMap;
import java.util.Map;
import java.util.SortedMap;
import java.util.TreeMap;

/**
 * http 工具类 获取请求中的参数
 * @author show
 * @date 14:23 2019/5/29
 */
public class HttpUtils {
    /**
     * 将URL的参数和body参数合并
     * @author show
     * @date 14:24 2019/5/29
     * @param request
     */
    public static SortedMap<String, String> getAllParams(HttpServletRequest request) throws IOException {

        SortedMap<String, String> result = new TreeMap<>();
        //获取URL上的参数
        Map<String, String> urlParams = getUrlParams(request);
        for (Map.Entry entry : urlParams.entrySet()) {
            result.put((String) entry.getKey(), (String) entry.getValue());
        }
        Map<String, String> allRequestParam = new HashMap<>(16);
        // get请求不需要拿body参数
        if (!HttpMethod.GET.name().equals(request.getMethod())) {
            allRequestParam = getAllRequestParam(request);
        }
        //将URL的参数和body参数进行合并
        if (allRequestParam != null) {
            for (Map.Entry entry : allRequestParam.entrySet()) {
                result.put((String) entry.getKey(), (String) entry.getValue());
            }
        }
        return result;
    }

    /**
     * 获取 Body 参数
     * @author show
     * @date 15:04 2019/5/30
     * @param request
     */
    public static Map<String, String> getAllRequestParam(final HttpServletRequest request) throws IOException {

        BufferedReader reader = new BufferedReader(new InputStreamReader(request.getInputStream()));
        String str = "";
        StringBuilder wholeStr = new StringBuilder();
        //一行一行的读取body体里面的内容；
        while ((str = reader.readLine()) != null) {
            wholeStr.append(str);
        }
        //转化成json对象
        return JSONObject.parseObject(wholeStr.toString(), Map.class);
    }

    /**
     * 将URL请求参数转换成Map
     * @author show
     * @param request
     */
    public static Map<String, String> getUrlParams(HttpServletRequest request) {

        String param = "";
        try {
            param = URLDecoder.decode(request.getQueryString(), "utf-8");
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        Map<String, String> result = new HashMap<>(16);
        String[] params = param.split("&");
        for (String s : params) {
            int index = s.indexOf("=");
            result.put(s.substring(0, index), s.substring(index + 1));
        }
        return result;
    }
}