Java中解密微信加密数据工具类

偏执的太偏执、 2022-10-07 00:50 183阅读 0赞

**当我们开发微信公众号，小程序等，微信返回给我们的数据往往是经过加密的，我们需要使用 sessionKey 配合解密，才能得到我们想要的数据**

*  1、引入依赖

<dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <optional>true</optional>
    </dependency>
    
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>fastjson</artifactId>
        <version>1.2.60</version>
    </dependency>
    
    <dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-lang3</artifactId>
        <version>3.8.1</version>
    </dependency>
    
    <dependency>
        <groupId>org.bouncycastle</groupId>
        <artifactId>bcprov-jdk15on</artifactId>
        <version>1.55</version>
    </dependency>

*  2、解密工具类

import com.alibaba.fastjson.JSONObject;
    import com.sun.org.apache.xerces.internal.impl.dv.util.Base64;
    import lombok.extern.slf4j.Slf4j;
    import org.apache.commons.lang3.StringUtils;
    import org.bouncycastle.jce.provider.BouncyCastleProvider;
    
    import javax.crypto.Cipher;
    import javax.crypto.spec.IvParameterSpec;
    import javax.crypto.spec.SecretKeySpec;
    import java.security.AlgorithmParameters;
    import java.security.Security;
    import java.util.Arrays;
    
    /**
     * 解密微信加密数据工具类
     */
    @Slf4j
    public class WechatUtils {
    
        /**
         * 解密微信加密数据
         *
         * @param encryptedData
         * @param iv
         * @param sessionkey
         * @return
         */
        public static JSONObject decryptWechatData(String encryptedData, String iv, String sessionkey) {
            // 被加密的数据
            byte[] dataByte = Base64.decode(encryptedData);
            // 加密秘钥
            byte[] keyByte = Base64.decode(sessionkey);
            // 偏移量
            byte[] ivByte = Base64.decode(iv);
            try {
                int base = 16;
                if (keyByte.length % base != 0) {
                    int groups = keyByte.length / base + (keyByte.length % base != 0 ? 1 : 0);
                    byte[] temp = new byte[groups * base];
                    Arrays.fill(temp, (byte) 0);
                    System.arraycopy(keyByte, 0, temp, 0, keyByte.length);
                    keyByte = temp;
                }
                Security.addProvider(new BouncyCastleProvider());
                Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding", "BC");
                SecretKeySpec spec = new SecretKeySpec(keyByte, "AES");
                AlgorithmParameters parameters = AlgorithmParameters.getInstance("AES");
                parameters.init(new IvParameterSpec(ivByte));
                cipher.init(Cipher.DECRYPT_MODE, spec, parameters);
                byte[] resultByte = cipher.doFinal(dataByte);
                if (null != resultByte && resultByte.length > 0) {
                    String result = new String(resultByte, "UTF-8");
                    if (StringUtils.isNotBlank(result)) {
                        log.info("----------解密微信数据成功----------");
                        return JSONObject.parseObject(result);
                    }
                }
            } catch (Exception e) {
                e.printStackTrace();
                log.info("----------解密微信数据失败----------");
            }
            return null;
        }
    }

这样，我们将微信加密的数据，转化成了 JSON 对象，就得到了我们想要的数据了

如您在阅读中发现不足，欢迎留言！！！