com.foxinmy.weixin4j.util.MessageUtil Maven / Gradle / Ivy
The newest version!
package com.foxinmy.weixin4j.util;
import java.util.Arrays;
import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import com.foxinmy.weixin4j.base64.Base64;
/**
* 消息工具类
*
* @className MessageUtil
* @author jinyu([email protected])
* @date 2014年10月31日
* @since JDK 1.6
* @see
*/
public final class MessageUtil {
/**
* 验证微信签名
*
* @param signature
* 微信加密签名，signature结合了开发者填写的token参数和请求中的timestamp参数、nonce参数
* @return 开发者通过检验signature对请求进行相关校验。若确认此次GET请求来自微信服务器
* 请原样返回echostr参数内容，则接入生效 成为开发者成功，否则接入失败
* @see 接入指南
*/
public static String signature(String... para) {
Arrays.sort(para);
StringBuffer sb = new StringBuffer();
for (String str : para) {
sb.append(str);
}
return ServerToolkits.digestSHA1(sb.toString());
}
/**
* 对xml消息加密
*
* @param appId
* 应用ID
* @param encodingAesKey
* 加密密钥
* @param xmlContent
* 原始消息体
* @return aes加密后的消息体
* @throws WeixinException
*/
public static String aesEncrypt(String appId, String encodingAesKey, String xmlContent) {
/**
* 其中，msg_encrypt=Base64_Encode(AES_Encrypt [random(16B)+ msg_len(4B) +
* msg + $AppId])
*
* random(16B)为16字节的随机字符串；msg_len为msg长度，占4个字节(网络字节序)，$AppId为公众账号的AppId
*/
byte[] randomBytes = ServerToolkits.getBytesUtf8(ServerToolkits.generateRandomString(16));
byte[] xmlBytes = ServerToolkits.getBytesUtf8(xmlContent);
int xmlLength = xmlBytes.length;
byte[] orderBytes = new byte[4];
orderBytes[3] = (byte) (xmlLength & 0xFF);
orderBytes[2] = (byte) (xmlLength >> 8 & 0xFF);
orderBytes[1] = (byte) (xmlLength >> 16 & 0xFF);
orderBytes[0] = (byte) (xmlLength >> 24 & 0xFF);
byte[] appidBytes = ServerToolkits.getBytesUtf8(appId);
int byteLength = randomBytes.length + xmlLength + orderBytes.length + appidBytes.length;
// ... + pad: 使用自定义的填充方式对明文进行补位填充
byte[] padBytes = PKCS7Encoder.encode(byteLength);
// random + endian + xml + appid + pad 获得最终的字节流
byte[] unencrypted = new byte[byteLength + padBytes.length];
byteLength = 0;
// src:源数组;srcPos:源数组要复制的起始位置;dest:目的数组;destPos:目的数组放置的起始位置;length:复制的长度
System.arraycopy(randomBytes, 0, unencrypted, byteLength, randomBytes.length);
byteLength += randomBytes.length;
System.arraycopy(orderBytes, 0, unencrypted, byteLength, orderBytes.length);
byteLength += orderBytes.length;
System.arraycopy(xmlBytes, 0, unencrypted, byteLength, xmlBytes.length);
byteLength += xmlBytes.length;
System.arraycopy(appidBytes, 0, unencrypted, byteLength, appidBytes.length);
byteLength += appidBytes.length;
System.arraycopy(padBytes, 0, unencrypted, byteLength, padBytes.length);
try {
byte[] aesKey = Base64.decodeBase64(encodingAesKey + "=");
// 设置加密模式为AES的CBC模式
Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
SecretKeySpec keySpec = new SecretKeySpec(aesKey, ServerToolkits.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
// return Base64.encodeBase64String(encrypted);
return Base64.encodeBase64String(encrypted);
} catch (Exception e) {
throw new RuntimeException("-40006,AES加密失败:" + e.getMessage());
}
}
/**
* 对AES消息解密
*
* @param appId
* @param encodingAesKey
* aes加密的密钥
* @param encryptContent
* 加密的消息体
* @return 解密后的字符
* @throws WeixinException
*/
public static String aesDecrypt(String appId, String encodingAesKey, String encryptContent) {
byte[] aesKey = Base64.decodeBase64(encodingAesKey + "=");
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, ServerToolkits.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(encryptContent);
// 解密
original = cipher.doFinal(encrypted);
} catch (Exception e) {
throw new RuntimeException("-40007,AES解密失败:" + e.getMessage());
}
String xmlContent, fromAppId;
try {
// 去除补位字符
byte[] bytes = PKCS7Encoder.decode(original);
/**
* AES加密的buf由16个字节的随机字符串、4个字节的msg_len(网络字节序)、msg和$AppId组成，
* 其中msg_len为msg的长度，$AppId为公众帐号的AppId
*/
// 获取表示xml长度的字节数组
byte[] lengthByte = Arrays.copyOfRange(bytes, 16, 20);
// 获取xml消息主体的长度(byte[]2int)
// http://my.oschina.net/u/169390/blog/97495
int xmlLength = lengthByte[3] & 0xff | (lengthByte[2] & 0xff) << 8 | (lengthByte[1] & 0xff) << 16
| (lengthByte[0] & 0xff) << 24;
xmlContent = ServerToolkits.newStringUtf8(Arrays.copyOfRange(bytes, 20, 20 + xmlLength));
fromAppId = ServerToolkits.newStringUtf8(Arrays.copyOfRange(bytes, 20 + xmlLength, bytes.length));
} catch (Exception e) {
throw new RuntimeException("-40008,xml内容不合法:" + e.getMessage());
}
// 校验appId是否一致
if (appId != null && !fromAppId.trim().equals(appId)) {
throw new RuntimeException("-40005,校验AppID失败,expect " + appId + ",but actual is " + fromAppId);
}
return xmlContent;
}
}