C# AES 加密解密，微信敏感数据解密

/// AES加密解密方式
/// ECB模式不许偏移量iv
/// 提供输出base64和Hex 16进制格式

public class AES_Cipher
    {
        /// <summary>
        /// AES 算法加密(ECB模式) 将明文加密，加密后进行Hex编码，返回密文
        /// </summary>
        /// <param name="str">明文</param>
        /// <param name="key">密钥</param>
        /// <returns>加密后Hex编码的密文</returns>
        public static string AesEncryptor_ECB_Hex(string str, string key)
        {
            if (string.IsNullOrEmpty(str)) return null;
            Byte[] toEncryptArray = Encoding.UTF8.GetBytes(str);

            RijndaelManaged rm = new RijndaelManaged
            {
                //Key = StrToHexByte(key),  //把key转成16进制
                Key = Encoding.UTF8.GetBytes(key),
                Mode = CipherMode.ECB,
                Padding = PaddingMode.PKCS7
            };

            ICryptoTransform cTransform = rm.CreateEncryptor();
            Byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);

            return ToHexString(resultArray);
        }


        /// <summary>
        ///AES 算法解密(ECB模式) 将密文Hex解码后进行解密，返回明文
        /// </summary>
        /// <param name="str">密文</param>
        /// <param name="key">密钥</param>
        /// <returns>明文</returns>
        public static string AesDecryptor_ECB_Hex(string str, string key)
        {
            if (string.IsNullOrEmpty(str)) return null;
            Byte[] toEncryptArray = StrToHexByte(str);

            RijndaelManaged rm = new RijndaelManaged
            {
                //Key = StrToHexByte(key), //key16进制解码
                Key = Encoding.UTF8.GetBytes(key),
                Mode = CipherMode.ECB,
                Padding = PaddingMode.PKCS7
            };

            ICryptoTransform cTransform = rm.CreateDecryptor();
            Byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);

            return Encoding.UTF8.GetString(resultArray);
        }

        /// <summary>
        /// byte数组Hex编码
        /// </summary>
        /// <param name="bytes">需要进行编码的byte[]</param>
        /// <returns></returns>
        public static string ToHexString(byte[] bytes)
        {
            string hexString = string.Empty;
            if (bytes != null)
            {
                StringBuilder strB = new StringBuilder();
                for (int i = 0; i < bytes.Length; i++)
                {
                    strB.Append(bytes[i].ToString("X2"));
                }
                hexString = strB.ToString();
            }
            return hexString;
        }
        /// <summary> 
        /// 字符串进行Hex解码(Hex.decodeHex())
        /// </summary> 
        /// <param name="hexString">需要进行解码的字符串</param> 
        /// <returns></returns> 
        public static byte[] StrToHexByte(string hexString)
        {
            hexString = hexString.Replace(" ", "");
            if ((hexString.Length % 2) != 0)
                hexString += " ";
            byte[] returnBytes = new byte[hexString.Length / 2];
            for (int i = 0; i < returnBytes.Length; i++)
                returnBytes[i] = Convert.ToByte(hexString.Substring(i * 2, 2), 16);
            return returnBytes;
        }


        /// <summary>
        /// AES 算法加密(ECB模式) 将明文加密，加密后进行Base64编码，返回密文
        /// </summary>
        /// <param name="str">明文</param>
        /// <param name="key">密钥</param>
        /// <returns>加密后Base64编码的密文</returns>
        public static string AesEncryptor_ECB_Base64(string str, string key)
        {
            if (string.IsNullOrEmpty(str)) return null;
            Byte[] toEncryptArray = Encoding.UTF8.GetBytes(str);

            RijndaelManaged rm = new RijndaelManaged
            {
                //Key = Convert.FromBase64String(key), //如果key是base64编码过的就解码转换,如果按照规范明文和key都应该传入base64
                Key = Encoding.UTF8.GetBytes(key),
                Mode = CipherMode.ECB,
                Padding = PaddingMode.PKCS7
            };

            ICryptoTransform cTransform = rm.CreateEncryptor();
            Byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);

            return Convert.ToBase64String(resultArray);
        }

        /// <summary>
        ///AES 算法解密(ECB模式) 将密文Base64解码后进行解密，返回明文
        /// </summary>
        /// <param name="base64Str">密文(base64编码格式)</param>
        /// <param name="key">密钥</param>
        /// <returns>明文</returns>
        public static string AesDecryptor_ECB_Base64(string base64Str, string key)
        {
            if (string.IsNullOrEmpty(base64Str)) return null;
            Byte[] toEncryptArray = Convert.FromBase64String(base64Str);

            RijndaelManaged rm = new RijndaelManaged
            {
                //Key = Convert.FromBase64String(key), //如果key是base64编码过的就解码转换,如果按照规范密文和key都应该传入base64
                Key = Encoding.UTF8.GetBytes(key),
                Mode = CipherMode.ECB,
                Padding = PaddingMode.PKCS7
            };

            ICryptoTransform cTransform = rm.CreateDecryptor();
            Byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);

            return Encoding.UTF8.GetString(resultArray);
        }

微信敏感数据解密

        /// <summary>
        /// 微信敏感数据解密
        /// </summary>
        /// <param name="encryptedData">密文</param>
        /// <param name="iv">加密算法的初始向量</param>
        /// <param name="sessionKey">登录获取的session_key</param>
        /// <returns></returns>
        public static string AESDecrypt(string encryptedData, string iv, string sessionKey)
        {
            var encryptedDataByte = Convert.FromBase64String(encryptedData);
            var rijndaelCipher = new RijndaelManaged
            {
                Key = Convert.FromBase64String(sessionKey),
                IV = Convert.FromBase64String(iv),
                Mode = CipherMode.CBC,
                Padding = PaddingMode.PKCS7
            };

            var transform = rijndaelCipher.CreateDecryptor();
            var plainText = transform.TransformFinalBlock(encryptedDataByte, 0, encryptedDataByte.Length);
            var result = Encoding.UTF8.GetString(plainText);
            return result;
        }