asp.net core 解密微信小程序中的encryptedData

直接上代码：

       /// 

        /// 微信小程序 encryptedData 解密
        /// 
        /// 
        /// session_key
        /// iv
        /// 
        public string AES_decrypt22(string encryptedDataStr, string key, string iv)
        {
            var rijalg = Aes.Create();
           // RijndaelManaged rijalg = new RijndaelManaged();
            //----------------- 
            //设置 cipher 格式 AES-128-CBC 

            rijalg.KeySize = 128;

            rijalg.Padding = PaddingMode.PKCS7;
            rijalg.Mode = CipherMode.CBC;

            rijalg.Key = Convert.FromBase64String(key);
            rijalg.IV = Convert.FromBase64String(iv);


            byte[] encryptedData = Convert.FromBase64String(encryptedDataStr);
            //解密 
            ICryptoTransform decryptor = rijalg.CreateDecryptor(rijalg.Key, rijalg.IV);

            string result;

            using (MemoryStream msDecrypt = new MemoryStream(encryptedData))
            {
                using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
                {
                    using (StreamReader srDecrypt = new StreamReader(csDecrypt))
                    {

                        result = srDecrypt.ReadToEnd();
                    }
                }
            }
            return result;
        }