企业微信开启接收消息+验证URL有效性

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@[toc]

简介

前期准备

• 一个备案的域名。
• 可线上部署的应用，与域名对应。

2.3使用到的示例代码来源企业微信-开发者中心

• 访问地址：

  https://developer.work.weixin.qq.com/document/path/90468
  

• 示例代码下载链接：

  https://open.work.weixin.qq.com/wwopen/downloadfile/java.zip
  

关于企业微信的开启接收信息的文档

https://developer.work.weixin.qq.com/document/10514

本文关键词

企业微信开启接收消息、验证URL有效性、SHA1、提供接收和推送给企业微信消息的加解密接口、计算消息签名接口

实现步骤

1 开启接收消息

1.1 设置接收消息的参数

在企业的管理端后台，进入需要设置接收消息的目标应用，点击“接收消息”的“设置API接收”按钮，进入配置页面。

用的URL、Token、EncodingAESKey三个参数

• URL是企业后台接收企业微信推送请求的访问协议和地址，支持http或https协议。
• Token可由企业任意填写，用于生成签名。
• EncodingAESKey用于消息体的加密，是AES密钥的Base64编码。

这三个参数需要在下面代码中使用到。

2 验证URL有效性

2.1 官方说明

当点击“保存”提交以上信息时，企业微信会发送一条验证消息到填写的URL，发送方法为GET。
企业的接收消息服务器接收到验证请求后，需要作出正确的响应才能通过URL验证。

假设接收消息地址设置为：http://api.3dept.com/，企业微信将向该地址发送如下验证请求：

请求方式：GET
请求地址：

http://api.3dept.com/?msg_signature=ASDFQWEXZCVAQFASDFASDFSS&timestamp=13500001234&nonce=123412323&echostr=ENCRYPT_STR

参数说明

企业后台收到请求后，需要做如下操作：

1. 对收到的请求做Urldecode处理
2. 通过参数msg_signature对请求进行校验，确认调用者的合法性。
3. 解密echostr参数得到消息内容(即msg字段)
4. 在1秒内原样返回明文消息内容(不能加引号，不能带bom头，不能带换行符)

2.2 Java代码

控制器层代码：QYWeiXinLoginController.java

package com.ruoyi.project.controller;


import com.ruoyi.project.tx.qyweixin.service.IQYWeiXinLoginService;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;


@RestController
@RequestMapping("/wechat/info")
public class QYWechatInfoController {
   
   

    @Resource
    private IQYWeiXinLoginService qyWeiXinLoginService;

    /**
     * 验证URL有效性
     *
     */
    @RequestMapping(value = "/verifyURLValidity", method = RequestMethod.GET)
    public void verifyURLValidity(@RequestParam(value = "msg_signature", required = true) String msgSignature,
                                  @RequestParam(value = "timestamp", required = true) String timestamp,
                                  @RequestParam(value = "nonce", required = true) String nonce,
                                  @RequestParam(value = "echostr", required = true) String echostr,
                                  HttpServletResponse response) {
   
   
        String msg = qyWeiXinLoginService.verifyURLValidity(msgSignature, timestamp, nonce, echostr);
        try {
   
   
            response.getWriter().print(msg);
        } catch (IOException e) {
   
   
            throw new RuntimeException(e);
        }
    }

}

业务接口：IQYWeiXinLoginService.java

package com.ruoyi.project.tx.qyweixin.service;


public interface IQYWeiXinLoginService {
   
   
    String verifyURLValidity(String msgSignature, String timestamp, String nonce, String echostr);
}

业务接口实现：QYWeiXinLoginServiceImpl.java

package com.ruoyi.project.tx.qyweixin.service.impl;


import com.ruoyi.project.tx.qyweixin.service.IQYWeiXinLoginService;
import com.ruoyi.project.utils.aes.AesException;
import com.ruoyi.project.utils.aes.WXBizMsgCrypt;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Service;

@Service
public class QYWeiXinLoginServiceImpl implements IQYWeiXinLoginService {
   
   
    private static final Logger logger = LoggerFactory.getLogger(QYWeiXinLoginServiceImpl.class);

    @Override
    public String  verifyURLValidity(String msgSignature, String timestamp, String nonce, String echostr) {
   
   
        logger.info("企业微信登录获取到的参数：msgSignature:{},timestamp:{},nonce:{},echostr:{}:",msgSignature,timestamp,nonce,echostr);
        //token
        String TOKEN = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
        // encodingAESKey
        String ENCODINGAES_KEY = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
        //企业ID
        String CORP_ID = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";

        // 通过检验msg_signature对请求进行校验，若校验成功则原样返回echostr，表示接入成功，否则接入失败
        String result = null;
        try {
   
   
            WXBizMsgCrypt wxcpt = new WXBizMsgCrypt(TOKEN, ENCODINGAES_KEY, CORP_ID);
            result = wxcpt.VerifyURL(msgSignature, timestamp, nonce, echostr);
        } catch (AesException e) {
   
   
            e.printStackTrace();
        }
        logger.info("----------微信接口访问结束----------");
        return result;
    }
}

2.3 使用到的示例代码

提供接收和推送给企业微信消息的加解密接口：WXBizMsgCrypt.java

/**
 * 对企业微信发送给企业后台的消息加解密示例代码.
 *
 * @copyright Copyright (c) 1998-2014 Tencent Inc.
 */

// ------------------------------------------------------------------------

/**
 * 针对org.apache.commons.codec.binary.Base64，
 * 需要导入架包commons-codec-1.9（或commons-codec-1.8等其他版本）
 * 官方下载地址：http://commons.apache.org/proper/commons-codec/download_codec.cgi
 */
package com.ruoyi.project.utils.aes;

import java.nio.charset.Charset;
import java.util.Arrays;
import java.util.Random;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

import org.apache.commons.codec.binary.Base64;

/**
 * 提供接收和推送给企业微信消息的加解密接口(UTF8编码的字符串).
 * <ol>
 *     <li>第三方回复加密消息给企业微信</li>
 *     <li>第三方收到企业微信发送的消息，验证消息的安全性，并对消息进行解密。</li>
 * </ol>
 * 说明：异常java.security.InvalidKeyException:illegal Key Size的解决方案
 * <ol>
 *     <li>在官方网站下载JCE无限制权限策略文件（JDK7的下载地址：
 *      http://www.oracle.com/technetwork/java/javase/downloads/jce-7-download-432124.html</li>
 *     <li>下载后解压，可以看到local_policy.jar和US_export_policy.jar以及readme.txt</li>
 *     <li>如果安装了JRE，将两个jar文件放到%JRE_HOME%\lib\security目录下覆盖原来的文件</li>
 *     <li>如果安装了JDK，将两个jar文件放到%JDK_HOME%\jre\lib\security目录下覆盖原来文件</li>
 * </ol>
 */
public class WXBizMsgCrypt {
   
   
    static Charset CHARSET = Charset.forName("utf-8");
    Base64 base64 = new Base64();
    byte[] aesKey;
    String token;
    String receiveid;

    /**
     * 构造函数
     * @param token 企业微信后台，开发者设置的token
     * @param encodingAesKey 企业微信后台，开发者设置的EncodingAESKey
     * @param receiveid, 不同场景含义不同，详见文档
     *
     * @throws AesException 执行失败，请查看该异常的错误码和具体的错误信息
     */
    public WXBizMsgCrypt(String token, String encodingAesKey, String receiveid) throws AesException {
   
   
        if (encodingAesKey.length() != 43) {
   
   
            throw new AesException(AesException.IllegalAesKey);
        }

        this.token = token;
        this.receiveid = receiveid;
        aesKey = Base64.decodeBase64(encodingAesKey + "=");
    }

    // 生成4个字节的网络字节序
    byte[] getNetworkBytesOrder(int sourceNumber) {
   
   
        byte[] orderBytes = new byte[4];
        orderBytes[3] = (byte) (sourceNumber & 0xFF);
        orderBytes[2] = (byte) (sourceNumber >> 8 & 0xFF);
        orderBytes[1] = (byte) (sourceNumber >> 16 & 0xFF);
        orderBytes[0] = (byte) (sourceNumber >> 24 & 0xFF);
        return orderBytes;
    }

    // 还原4个字节的网络字节序
    int recoverNetworkBytesOrder(byte[] orderBytes) {
   
   
        int sourceNumber = 0;
        for (int i = 0; i < 4; i++) {
   
   
            sourceNumber <<= 8;
            sourceNumber |= orderBytes[i] & 0xff;
        }
        return sourceNumber;
    }

    // 随机生成16位字符串
    String getRandomStr() {
   
   
        String base = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
        Random random = new Random();
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < 16; i++) {
   
   
            int number = random.nextInt(base.length());
            sb.append(base.charAt(number));
        }
        return sb.toString();
    }

    /**
     * 对明文进行加密.
     *
     * @param text 需要加密的明文
     * @return 加密后base64编码的字符串
     * @throws AesException aes加密失败
     */
    String encrypt(String randomStr, String text) throws AesException {
   
   
        ByteGroup byteCollector = new ByteGroup();
        byte[] randomStrBytes = randomStr.getBytes(CHARSET);
        byte[] textBytes = text.getBytes(CHARSET);
        byte[] networkBytesOrder = getNetworkBytesOrder(textBytes.length);
        byte[] receiveidBytes = receiveid.getBytes(CHARSET);

        // randomStr + networkBytesOrder + text + receiveid
        byteCollector.addBytes(randomStrBytes);
        byteCollector.addBytes(networkBytesOrder);
        byteCollector.addBytes(textBytes);
        byteCollector.addBytes(receiveidBytes);

        // ... + pad: 使用自定义的填充方式对明文进行补位填充
        byte[] padBytes = PKCS7Encoder.encode(byteCollector.size());
        byteCollector.addBytes(padBytes);

        // 获得最终的字节流, 未加密
        byte[] unencrypted = byteCollector.toBytes();

        try {
   
   
            // 设置加密模式为AES的CBC模式
            Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
            SecretKeySpec keySpec = new SecretKeySpec(aesKey, "AES");
            IvParameterSpec iv = new IvParameterSpec(aesKey, 0, 16);
            cipher.init(Cipher.ENCRYPT_MODE, keySpec, iv);

            // 加密
            byte[] encrypted = cipher.doFinal(unencrypted);

            // 使用BASE64对加密后的字符串进行编码
            String base64Encrypted = base64.encodeToString(encrypted);

            return base64Encrypted;
        } catch (Exception e) {
   
   
            e.printStackTrace();
            throw new AesException(AesException.EncryptAESError);
        }
    }

    /**
     * 对密文进行解密.
     *
     * @param text 需要解密的密文
     * @return 解密得到的明文
     * @throws AesException aes解密失败
     */
    String decrypt(String text) throws AesException {
   
   
        byte[] original;
        try {
   
   
            // 设置解密模式为AES的CBC模式
            Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
            SecretKeySpec key_spec = new SecretKeySpec(aesKey, "AES");
            IvParameterSpec iv = new IvParameterSpec(Arrays.copyOfRange(aesKey, 0, 16));
            cipher.init(Cipher.DECRYPT_MODE, key_spec, iv);

            // 使用BASE64对密文进行解码
            byte[] encrypted = Base64.decodeBase64(text);

            // 解密
            original = cipher.doFinal(encrypted);
        } catch (Exception e) {
   
   
            e.printStackTrace();
            throw new AesException(AesException.DecryptAESError);
        }

        String xmlContent, from_receiveid;
        try {
   
   
            // 去除补位字符
            byte[] bytes = PKCS7Encoder.decode(original);

            // 分离16位随机字符串,网络字节序和receiveid
            byte[] networkOrder = Arrays.copyOfRange(bytes, 16, 20);

            int xmlLength = recoverNetworkBytesOrder(networkOrder);

            xmlContent = new String(Arrays.copyOfRange(bytes, 20, 20 + xmlLength), CHARSET);
            from_receiveid = new String(Arrays.copyOfRange(bytes, 20 + xmlLength, bytes.length),
                    CHARSET);
        } catch (Exception e) {
   
   
            e.printStackTrace();
            throw new AesException(AesException.IllegalBuffer);
        }

        // receiveid不相同的情况
        if (!from_receiveid.equals(receiveid)) {
   
   
            throw new AesException(AesException.ValidateCorpidError);
        }
        return xmlContent;

    }

    /**
     * 将企业微信回复用户的消息加密打包.
     * <ol>
     *     <li>对要发送的消息进行AES-CBC加密</li>
     *     <li>生成安全签名</li>
     *     <li>将消息密文和安全签名打包成xml格式</li>
     * </ol>
     *
     * @param replyMsg 企业微信待回复用户的消息，xml格式的字符串
     * @param timeStamp 时间戳，可以自己生成，也可以用URL参数的timestamp
     * @param nonce 随机串，可以自己生成，也可以用URL参数的nonce
     *
     * @return 加密后的可以直接回复用户的密文，包括msg_signature, timestamp, nonce, encrypt的xml格式的字符串
     * @throws AesException 执行失败，请查看该异常的错误码和具体的错误信息
     */
    public String EncryptMsg(String replyMsg, String timeStamp, String nonce) throws AesException {
   
   
        // 加密
        String encrypt = encrypt(getRandomStr(), replyMsg);

        // 生成安全签名
        if (timeStamp == "") {
   
   
            timeStamp = Long.toString(System.currentTimeMillis());
        }

        String signature = SHA1.getSHA1(token, timeStamp, nonce, encrypt);

        // System.out.println("发送给平台的签名是: " + signature[1].toString());
        // 生成发送的xml
        String result = XMLParse.generate(encrypt, signature, timeStamp, nonce);
        return result;
    }

    /**
     * 检验消息的真实性，并且获取解密后的明文.
     * <ol>
     *     <li>利用收到的密文生成安全签名，进行签名验证</li>
     *     <li>若验证通过，则提取xml中的加密消息</li>
     *     <li>对消息进行解密</li>
     * </ol>
     *
     * @param msgSignature 签名串，对应URL参数的msg_signature
     * @param timeStamp 时间戳，对应URL参数的timestamp
     * @param nonce 随机串，对应URL参数的nonce
     * @param postData 密文，对应POST请求的数据
     *
     * @return 解密后的原文
     * @throws AesException 执行失败，请查看该异常的错误码和具体的错误信息
     */
    public String DecryptMsg(String msgSignature, String timeStamp, String nonce, String postData)
            throws AesException {
   
   

        // 密钥，公众账号的app secret
        // 提取密文
        Object[] encrypt = XMLParse.extract(postData);

        // 验证安全签名
        String signature = SHA1.getSHA1(token, timeStamp, nonce, encrypt[1].toString());

        // 和URL中的签名比较是否相等
        // System.out.println("第三方收到URL中的签名：" + msg_sign);
        // System.out.println("第三方校验签名：" + signature);
        if (!signature.equals(msgSignature)) {
   
   
            throw new AesException(AesException.ValidateSignatureError);
        }

        // 解密
        String result = decrypt(encrypt[1].toString());
        return result;
    }

    /**
     * 验证URL
     * @param msgSignature 签名串，对应URL参数的msg_signature
     * @param timeStamp 时间戳，对应URL参数的timestamp
     * @param nonce 随机串，对应URL参数的nonce
     * @param echoStr 随机串，对应URL参数的echostr
     *
     * @return 解密之后的echostr
     * @throws AesException 执行失败，请查看该异常的错误码和具体的错误信息
     */
    public String VerifyURL(String msgSignature, String timeStamp, String nonce, String echoStr)
            throws AesException {
   
   
        String signature = SHA1.getSHA1(token, timeStamp, nonce, echoStr);

        if (!signature.equals(msgSignature)) {
   
   
            throw new AesException(AesException.ValidateSignatureError);
        }

        String result = decrypt(echoStr);
        return result;
    }

}

加解密异常类：AesException.java

package com.ruoyi.project.utils.aes;

/**
 * 加解密异常类
 */
public class AesException extends Exception {
   
   
    public final static int OK = 0;
    public final static int ValidateSignatureError = -40001;
    public final static int ParseXmlError = -40002;
    public final static int ComputeSignatureError = -40003;
    public final static int IllegalAesKey = -40004;
    public final static int ValidateCorpidError = -40005;
    public final static int EncryptAESError = -40006;
    public final static int DecryptAESError = -40007;
    public final static int IllegalBuffer = -40008;
//public final static int EncodeBase64Error = -40009;
//public final static int DecodeBase64Error = -40010;
//public final static int GenReturnXmlError = -40011;
    private int code;

    private static String getMessage(int code) {
   
   
        switch (code) {
   
   
            case ValidateSignatureError:
                return "签名验证错误";
            case ParseXmlError:
                return "xml解析失败";
            case ComputeSignatureError:
                return "sha加密生成签名失败";
            case IllegalAesKey:
                return "SymmetricKey非法";
            case ValidateCorpidError:
                return "corpid校验失败";
            case EncryptAESError:
                return "aes加密失败";
            case DecryptAESError:
                return "aes解密失败";
            case IllegalBuffer:
                return "解密后得到的buffer非法";
//        case EncodeBase64Error:
//            return "base64加密错误";
//        case DecodeBase64Error:
//            return "base64解密错误";
//        case GenReturnXmlError:
//            return "xml生成失败";
            default:
                return null; // cannot be
        }
    }
    public int getCode() {
   
   
        return code;
    }
    AesException(int code) {
   
   
        super(getMessage(code));
        this.code = code;
    }
}

ByteGroup.java

package com.ruoyi.project.utils.aes;

import java.util.ArrayList;

class ByteGroup {
   
   
    ArrayList<Byte> byteContainer = new ArrayList<Byte>();

    public byte[] toBytes() {
   
   
        byte[] bytes = new byte[byteContainer.size()];
        for (int i = 0; i < byteContainer.size(); i++) {
   
   
            bytes[i] = byteContainer.get(i);
        }
        return bytes;
    }

    public ByteGroup addBytes(byte[] bytes) {
   
   
        for (byte b : bytes) {
   
   
            byteContainer.add(b);
        }
        return this;
    }

    public int size() {
   
   
        return byteContainer.size();
    }
}

提供基于PKCS7算法的加解密接口：PKCS7Encoder.java

package com.ruoyi.project.utils.aes;

import java.nio.charset.Charset;
import java.util.Arrays;

/**
 * 提供基于PKCS7算法的加解密接口.
 */
class PKCS7Encoder {
   
   
    static Charset CHARSET = Charset.forName("utf-8");
    static int BLOCK_SIZE = 32;

    /**
     * 获得对明文进行补位填充的字节.
     *
     * @param count 需要进行填充补位操作的明文字节个数
     * @return 补齐用的字节数组
     */
    static byte[] encode(int count) {
   
   
        // 计算需要填充的位数
        int amountToPad = BLOCK_SIZE - (count % BLOCK_SIZE);
        if (amountToPad == 0) {
   
   
            amountToPad = BLOCK_SIZE;
        }
        // 获得补位所用的字符
        char padChr = chr(amountToPad);
        String tmp = new String();
        for (int index = 0; index < amountToPad; index++) {
   
   
            tmp += padChr;
        }
        return tmp.getBytes(CHARSET);
    }

    /**
     * 删除解密后明文的补位字符
     *
     * @param decrypted 解密后的明文
     * @return 删除补位字符后的明文
     */
    static byte[] decode(byte[] decrypted) {
   
   
        int pad = (int) decrypted[decrypted.length - 1];
        if (pad < 1 || pad > 32) {
   
   
            pad = 0;
        }
        return Arrays.copyOfRange(decrypted, 0, decrypted.length - pad);
    }

    /**
     * 将数字转化成ASCII码对应的字符，用于对明文进行补码
     *
     * @param a 需要转化的数字
     * @return 转化得到的字符
     */
    static char chr(int a) {
   
   
        byte target = (byte) (a & 0xFF);
        return (char) target;
    }

}

计算消息签名接口：SHA1.java

package com.ruoyi.project.utils.aes;

import java.security.MessageDigest;
import java.util.Arrays;
/**
 * 对企业微信发送给企业后台的消息加解密示例代码.
 *
 * @copyright Copyright (c) 1998-2014 Tencent Inc.
 */
/**
 * SHA1 class
 *
 * 计算消息签名接口.
 */
public class SHA1 {
   
   

    /**
     * 用SHA1算法生成安全签名
     * @param token 票据
     * @param timestamp 时间戳
     * @param nonce 随机字符串
     * @param encrypt 密文
     * @return 安全签名
     * @throws AesException
     */
    public static String getSHA1(String token, String timestamp, String nonce, String encrypt) throws AesException
              {
   
   
        try {
   
   
            String[] array = new String[] {
   
    token, timestamp, nonce, encrypt };
            StringBuffer sb = new StringBuffer();
            // 字符串排序
            Arrays.sort(array);
            for (int i = 0; i < 4; i++) {
   
   
                sb.append(array[i]);
            }
            String str = sb.toString();
            // SHA1签名生成
            MessageDigest md = MessageDigest.getInstance("SHA-1");
            md.update(str.getBytes());
            byte[] digest = md.digest();

            StringBuffer hexstr = new StringBuffer();
            String shaHex = "";
            for (int i = 0; i < digest.length; i++) {
   
   
                shaHex = Integer.toHexString(digest[i] & 0xFF);
                if (shaHex.length() < 2) {
   
   
                    hexstr.append(0);
                }
                hexstr.append(shaHex);
            }
            return hexstr.toString();
        } catch (Exception e) {
   
   
            e.printStackTrace();
            throw new AesException(AesException.ComputeSignatureError);
        }
    }
}

提供提取消息格式中的密文及生成回复消息格式的接口：XMLParse.java

/**
 * 对企业微信发送给企业后台的消息加解密示例代码.
 *
 * @copyright Copyright (c) 1998-2014 Tencent Inc.
 */

// ------------------------------------------------------------------------

package com.ruoyi.project.utils.aes;

import java.io.StringReader;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;

/**
 * XMLParse class
 *
 * 提供提取消息格式中的密文及生成回复消息格式的接口.
 */
class XMLParse {
   
   

    /**
     * 提取出xml数据包中的加密消息
     * @param xmltext 待提取的xml字符串
     * @return 提取出的加密消息字符串
     * @throws AesException
     */
    public static Object[] extract(String xmltext) throws AesException     {
   
   
        Object[] result = new Object[3];
        try {
   
   
            DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();

            String FEATURE = null;
            // This is the PRIMARY defense. If DTDs (doctypes) are disallowed, almost all XML entity attacks are prevented
            // Xerces 2 only - http://xerces.apache.org/xerces2-j/features.html#disallow-doctype-decl
            FEATURE = "http://apache.org/xml/features/disallow-doctype-decl";
            dbf.setFeature(FEATURE, true);

            // If you can't completely disable DTDs, then at least do the following:
            // Xerces 1 - http://xerces.apache.org/xerces-j/features.html#external-general-entities
            // Xerces 2 - http://xerces.apache.org/xerces2-j/features.html#external-general-entities
            // JDK7+ - http://xml.org/sax/features/external-general-entities
            FEATURE = "http://xml.org/sax/features/external-general-entities";
            dbf.setFeature(FEATURE, false);

            // Xerces 1 - http://xerces.apache.org/xerces-j/features.html#external-parameter-entities
            // Xerces 2 - http://xerces.apache.org/xerces2-j/features.html#external-parameter-entities
            // JDK7+ - http://xml.org/sax/features/external-parameter-entities
            FEATURE = "http://xml.org/sax/features/external-parameter-entities";
            dbf.setFeature(FEATURE, false);

            // Disable external DTDs as well
            FEATURE = "http://apache.org/xml/features/nonvalidating/load-external-dtd";
            dbf.setFeature(FEATURE, false);

            // and these as well, per Timothy Morgan's 2014 paper: "XML Schema, DTD, and Entity Attacks"
            dbf.setXIncludeAware(false);
            dbf.setExpandEntityReferences(false);

            // And, per Timothy Morgan: "If for some reason support for inline DOCTYPEs are a requirement, then
            // ensure the entity settings are disabled (as shown above) and beware that SSRF attacks
            // (http://cwe.mitre.org/data/definitions/918.html) and denial
            // of service attacks (such as billion laughs or decompression bombs via "jar:") are a risk."

            // remaining parser logic
            DocumentBuilder db = dbf.newDocumentBuilder();
            StringReader sr = new StringReader(xmltext);
            InputSource is = new InputSource(sr);
            Document document = db.parse(is);

            Element root = document.getDocumentElement();
            NodeList nodelist1 = root.getElementsByTagName("Encrypt");
            result[0] = 0;
            result[1] = nodelist1.item(0).getTextContent();
            return result;
        } catch (Exception e) {
   
   
            e.printStackTrace();
            throw new AesException(AesException.ParseXmlError);
        }
    }

    /**
     * 生成xml消息
     * @param encrypt 加密后的消息密文
     * @param signature 安全签名
     * @param timestamp 时间戳
     * @param nonce 随机字符串
     * @return 生成的xml字符串
     */
    public static String generate(String encrypt, String signature, String timestamp, String nonce) {
   
   

        String format = "<xml>\n" + "<Encrypt><![CDATA[%1$s]]></Encrypt>\n"
                + "<MsgSignature><![CDATA[%2$s]]></MsgSignature>\n"
                + "<TimeStamp>%3$s</TimeStamp>\n" + "<Nonce><![CDATA[%4$s]]></Nonce>\n" + "</xml>";
        return String.format(format, encrypt, signature, timestamp, nonce);

    }
}