数字签名 Signature 的使用

1、**的获取

package cn.snowpa.common;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.security.KeyFactory;
import java.security.KeyStore;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.Base64;
import java.util.Enumeration;

@Component
public class MiSecretKey {
    /**
     * 加***
     */
    private static String signaturePublic;
    
    @Value("${signature.public}")
    public void setSignaturePublic(String signaturePublic) {
        MiSecretKey.signaturePublic = signaturePublic;
    }
    
    /**
     * 加***
     */
    private static String signaturePrivate;
    
    @Value("${signature.private}")
    public void setSignaturePrivate(String signaturePrivate) {
        MiSecretKey.signaturePrivate = signaturePrivate;
    }
    
    /**
     * 从文件中获取公钥(公钥的比特编码是X.509格式)
     *
     * @return
     * @throws Exception
     */
    public PublicKey getPublicKeyByFile() throws Exception {
        //建立文件对象
        File file = new File(signaturePublic);
        FileInputStream fis = new FileInputStream(file);
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        byte[] buffer = new byte[1024];
        int len;
        while ((len = fis.read(buffer)) > 0) {
            bos.write(buffer, 0, len);
        }
        byte[] pbks = Base64.getDecoder().decode(bos.toByteArray());
        X509EncodedKeySpec encodedKeySpec = new X509EncodedKeySpec(pbks);
        PublicKey newPbk = KeyFactory.getInstance("RSA").generatePublic(encodedKeySpec);
        return newPbk;
    }
    
    /**
     * 从文件中获取公钥(私钥的比特编码是pkcs8格式)
     *
     * @return
     * @throws Exception
     */
    public PrivateKey getPrivateKeyByFile() throws Exception {
        //建立文件对象
        File file = new File(signaturePrivate);
        FileInputStream fis = new FileInputStream(file);
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        byte[] buffer = new byte[1024];
        int len = 0;
        while ((len = fis.read(buffer)) > 0) {
            bos.write(buffer, 0, len);
        }
        byte[] prks = Base64.getDecoder().decode(bos.toByteArray());
        /**/
        PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(prks);
        PrivateKey newPrk = KeyFactory.getInstance("RSA").generatePrivate(pkcs8EncodedKeySpec);
        return newPrk;
    }
    
}

2、生成签名和验证

package cn.snowpa.common;

import com.alibaba.fastjson.JSONObject;
import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

import java.io.IOException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Map;
import java.util.TreeMap;

public class MiSignature {

    /**
     * 签名算法
     */
    public static final String SIGN_ALGORITHMS = "SHA1WithRSA";

    /**
     * 签名算法
     */
    public static final String ENCODE = "utf-8";

    /**
     * RSA签名
     *
     * @param content    待签名数据
     * @param privateKey 私钥
     * @return 签名值
     */
    public static String sign(String content, PrivateKey privateKey) {
        try {
            Signature signature = Signature.getInstance(SIGN_ALGORITHMS);
            signature.initSign(privateKey);
            signature.update(content.getBytes(ENCODE));
            byte[] signed = signature.sign();
            return byte2Base64 (signed);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * 验签
     *
     * @param content 待签名数据
     * @param sign    签名值
     * @param pubKey  公钥
     * @return 失败时，返回false。
     */
    public static boolean verifySignature (String content, String sign, PublicKey pubKey) {
        if (null == content || null == sign || "".equals(content) || "".equals(sign)) {
            return false;
        }
        try {
            byte[] signed = base642Byte(sign);
            Signature signatureChecker = Signature.getInstance(SIGN_ALGORITHMS);
            signatureChecker.initVerify(pubKey);
            signatureChecker.update(content.getBytes());
            // 验证签名是否正常
            return signatureChecker.verify(signed);
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    public static String byte2Base64(byte[] bytes) {
        BASE64Encoder encoder = new BASE64Encoder();
        return encoder.encode(bytes);
    }

    public static byte[] base642Byte(String base64Key) throws IOException {
        BASE64Decoder decoder = new BASE64Decoder();
        return decoder.decodeBuffer(base64Key);
    }

    // 使json-lib来进行json到map的转换，fastjson有排序问题，不能用
    public static Map<String, String> jsonToMap (JSONObject json) {
        Map<String, String> map = new HashMap<>();
        for (Object key : json.keySet()) {
            if("sign".equals(key)){
                continue;
            }
            String value = json.getString((String) key);
            map.put((String) key, value);
        }
        Map<String, String> resultMap = sortMapByKey(map);    //按Key进行排序
        return resultMap;
    }

    /**
     * 使用 Map按key进行排序
     * @param map
     * @return
     */

    public static Map<String, String> sortMapByKey(Map<String, String> map) {
        if (map == null || map.isEmpty()) {
            return null;
        }
        Map<String, String> sortMap = new TreeMap<String, String>(new MapKeyComparator());
        sortMap.putAll(map);
        return sortMap;
    }

    static class MapKeyComparator implements Comparator<String> {
        @Override
        public int compare(String str1, String str2) {
            return str1.compareTo(str2);
        }
    }

    public static void main(String[] args) {
        try {
            // 随机生成一对非对称加密的秘钥对
            MiSecretKey keyPair = new MiSecretKey();
            String content = "helloWord123" + ("测试内容");
            System.out.println("验签内容：" + content);
            String sign = MiSignature.sign(content, keyPair.getPrivateKeyByFile() );
            System.out.println("签名结果=" + sign);
            boolean verify = MiSignature.verifySignature(content, sign, keyPair.getPublicKeyByFile());
            System.out.println("验签结果="+verify);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

3、自定义拦截器验证签名

package cn.snowpa.interceptor;

import cn.snowpa.common.MiSecretKey;
import cn.snowpa.common.MiSignature;
import cn.snowpa.utils.JsonUtils;
import cn.snowpa.utils.ResultUtil;
import cn.snowpa.utils.StringUtil;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.servlet.HandlerInterceptor;

import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Map;

@Slf4j
public class SystemApiInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        try {
            JSONObject paramsJson = getRequestParams(request);
            Map<String,String> content_map = MiSignature.jsonToMap(paramsJson);
            String sign = paramsJson.getString("sign");
            log.info("sign:"+sign);
            String content = content_map.toString();
            log.info("content:"+content);
            if (StringUtil.isEmpty(sign))  {
                write(request, response, JsonUtils.toJson(ResultUtil.error(500,"签名异常")));
                return false;
            }
            MiSecretKey keyPair = new MiSecretKey();
            boolean verify = MiSignature.verifySignature(content, sign, keyPair.getPublicKeyByFile());
            log.info("验签结果:"+verify);
            if(!verify){
                write(request, response, JsonUtils.toJson(ResultUtil.error(500,"签名异常")));
                return false;
            }
            return true;
        }catch (Exception e){
            log.info("异常信息："+e.getMessage());
            write(request, response, JsonUtils.toJson(ResultUtil.error(500,"签名异常")));
            return false;
        }
    }

    // 获取HttpServletRequest里面的参数，并decode
    private JSONObject getRequestParams(HttpServletRequest request)  throws Exception {
        ServletInputStream servletInputStream = request.getInputStream();
        ServletInputStream inputStream = servletInputStream;
        StringBuilder content = new StringBuilder();
        byte[] b = new byte[1024];
        int lens;
        while ((lens = inputStream.read(b)) > 0) {
            content.append(new String(b, 0, lens));
        }
        String strContent = content.toString(); // 请求体内容
        log.info("请求体：{}", strContent);
        JSONObject params = JSON.parseObject(strContent);
        return params;
    }

    /**
     * 通过response返回错误信息给前端
     *
     * @param request 请求
     * @param response 响应
     * @param content 响应内容
     */
    private void write (HttpServletRequest request, HttpServletResponse response, String content) throws IOException {
        String origin = request.getHeader("Origin");
        response.setHeader("Access-Control-Allow-Origin", origin);
        response.setCharacterEncoding("UTF-8");
        response.setContentType("application/json; charset=utf-8");
        response.getWriter().write(content);
    }
}

4、拦截器的配置-配置拦截URL

package cn.snowpa.interceptor;

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
public class WebMvcConfig implements WebMvcConfigurer {

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new SystemApiInterceptor())
                .addPathPatterns("/systemApi/**");
    }

}

 

5、解决请求体的数据只能获取一次的问题

5.1  请求体数据的处理

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

public class BodyReaderHttpServletRequestWrapper extends HttpServletRequestWrapper {


    private final byte[] body;
    private String bodyStr;

    public BodyReaderHttpServletRequestWrapper(HttpServletRequest request) throws IOException {
        super(request);
        String bodyString = getBodyString(request);
        body = bodyString.getBytes(Charset.forName("UTF-8"));
        bodyStr=bodyString;
    }

    public String getBodyStr() {
        return bodyStr;
    }

    @Override
    public ServletInputStream getInputStream() throws IOException {
        final ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(body);

        return new ServletInputStream() {
            @Override
            public int read() throws IOException {
                return byteArrayInputStream.read();
            }

            @Override
            public boolean isFinished() {
                return false;
            }

            @Override
            public boolean isReady() {
                return false;
            }

            @Override
            public void setReadListener(ReadListener readListener) {
            }
        };
    }


    public  String getBodyString(HttpServletRequest request) throws IOException {
        StringBuilder sb = new StringBuilder();
        InputStream inputStream = null;
        BufferedReader reader = null;
        try {
            inputStream = request.getInputStream();
            reader = new BufferedReader(
                    new InputStreamReader(inputStream, Charset.forName("UTF-8")));

            char[] bodyCharBuffer = new char[1024];
            int len = 0;
            while ((len = reader.read(bodyCharBuffer)) != -1) {
                sb.append(new String(bodyCharBuffer, 0, len));
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (inputStream != null) {
                try {
                    inputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (reader != null) {
                try {
                    reader.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return sb.toString();
    }
}

5.2  过滤器调用处理请求体的数据

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;

@WebFilter(filterName = "httpServletRequestWrapperFilter", urlPatterns = {"/*"})
public class HttpServletRequestWrapperFilter implements Filter {

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

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

        ServletRequest requestWrapper = null;

        if (request instanceof HttpServletRequest) {
            HttpServletRequest httpRequest = (HttpServletRequest) request;
            //遇到post方法才对request进行包装
            String methodType = httpRequest.getMethod();
            if ("POST".equals(methodType)) {
                requestWrapper = new BodyReaderHttpServletRequestWrapper(
                        (HttpServletRequest) request);
            }
        }
        if (null == requestWrapper) {
            chain.doFilter(request, response);
        } else {
            chain.doFilter(requestWrapper, response);
        }
    }

    @Override
    public void destroy() {

    }
}