小程序登录，服务器解密数据失败，卡在“pad block corrupted”

解密敏感数据

1. 对称解密使用的算法为AES-128-CBC，数据采用PKCS#7填充。
2. 对称解密的目标密文为encryptedData。
3. 对称解密秘钥aeskey = Base64_Decode(session_key), aeskey长度为 16Byte。
4. 对称解密算法初始向量为Base64_Decode(iv)。

根据以上描述，写了相应的解密算法，发现一直卡在这里，错误如下：{"code":1,"msg":"javax.crypto.BadPaddingException: pad block corrupted"}

解密 代码如下：

public Result aesDecryptData(String encryptedData, String sessionKey, String iv) {
        // refer: https://developers.weixin.qq.com/miniprogram/dev/framework/open-ability/signature.html

        if (sessionKey.length() != 24)            return new Result(ErrorCode.WxIllegalAesKey);

        if (iv.length() != 24)            return new Result(ErrorCode.WxIllegalIv);

        Security.addProvider(new BouncyCastleProvider());

        var decoder = Base64.getDecoder();
        var aesKey = decoder.decode(sessionKey);
        var aesIv = decoder.decode(iv);
        var cipher = decoder.decode(encryptedData);

        try {            var skeySpec = new SecretKeySpec(aesKey, "AES");
            var ivSpec = new IvParameterSpec(aesIv);
            var dcipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
//            var dcipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
//            var dcipher = Cipher.getInstance("AES/CBC/PKCS7Padding", "BC");

//            var params = AlgorithmParameters.getInstance("AES");
//            params.init(ivSpec);
//            dcipher.init(Cipher.DECRYPT_MODE, skeySpec, params);
            dcipher.init(Cipher.DECRYPT_MODE, skeySpec, ivSpec);

//            var res = new String(dcipher.doFinal(cipher));

            var res = decodeSecData(cipher, aesIv, aesKey);
            log.debug("aesDecryptData: res={}", res);

            var j = JSONUtil.parse(res);
//            if (j == null || !j.getJSONObject("watermark").getString("appid").equals(weapp.get("appid"))) {
//                return new Result(ErrorCode.WxIllegalBuffer);
//            }

//            var unionId = j.getString("unionId");
//            redis.set("user:session_key:" + unionId, sessionKey);

//            return new Result(ErrorCode.Success, null, j);
            return new Result(ErrorCode.Success, j);
        } catch (Exception e) {            log.info("aesDecryptData fail: e={}", e.getMessage());
            return new Result(ErrorCode.Fail, e.getMessage());
        }    }