c# Desc 和Aes

    private static string DescEncrypt(string str)
        {
            string key = "12345678";///必须是8位
            byte[] p_byte_key = System.Text.Encoding.Default.GetBytes(key);
            byte[] p_byte_key2 = System.Text.Encoding.Default.GetBytes(key);
            byte[] p_byte_data = System.Text.Encoding.Default.GetBytes(str);
            try
            {
                MemoryStream p_stream_ms = new MemoryStream();
                CryptoStream p_cryptstream_stream = new CryptoStream(p_stream_ms, new DESCryptoServiceProvider().CreateEncryptor(p_byte_key, p_byte_key2), CryptoStreamMode.Write);
                p_cryptstream_stream.Write(p_byte_data, 0, p_byte_data.Length);
                p_cryptstream_stream.FlushFinalBlock();
                byte[] p_bt_temp = p_stream_ms.ToArray();
                string p_str = Convert.ToBase64String(p_bt_temp);
                return p_str;
            }
            catch
            {

                return null;
            }
        }
        private static string DescDecrypt(string str)
        {
            try
            {
                string key = "12345678";///必须是8位
                byte[] p_byte_key = System.Text.Encoding.Default.GetBytes(key);
                byte[] p_byte_key2 = System.Text.Encoding.Default.GetBytes(key);
                byte[] p_byte_data2 = Convert.FromBase64String(str);///变换
                MemoryStream p_stream_msold = new MemoryStream(p_byte_data2);///内存
                CryptoStream p_cryptstream_stream = new CryptoStream(p_stream_msold, new DESCryptoServiceProvider().CreateDecryptor(p_byte_key, p_byte_key2), CryptoStreamMode.Read);//解密
                byte[] p_bt_temp = new byte[200];
                MemoryStream p_stream_ms = new MemoryStream();
                int i = 0;
                ///按照内存数组大小读取数据    如果有值那就可以处理了.
                while ((i = p_cryptstream_stream.Read(p_bt_temp, 0, p_bt_temp.Length)) > 0)
                {
                    p_stream_ms.Write(p_bt_temp, 0, i);///放到内存里了。
                }
                string p_strs = Encoding.Default.GetString(p_stream_ms.ToArray());
                return p_strs;
            }
            catch (Exception e)
            {

                return null;
            }
           
        }

   ////必须是32位byte

    public static string AesEncrypt(string str, string key)
        {
            if (string.IsNullOrEmpty(str)) return null;
            Byte[] toEncryptArray = Encoding.UTF8.GetBytes(str);

            System.Security.Cryptography.RijndaelManaged rm = new System.Security.Cryptography.RijndaelManaged
            {
                Key = Encoding.UTF8.GetBytes(key),
                Mode = System.Security.Cryptography.CipherMode.ECB,
                Padding = System.Security.Cryptography.PaddingMode.PKCS7
            };

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

            return Convert.ToBase64String(resultArray, 0, resultArray.Length);
        }
        /// <summary>
        ///  AES 解密
        /// </summary>
        /// <param name="str">明文（待解密）</param>
        /// <param name="key">密文 必须是32位byte</param>
        /// <returns></returns>
        public static string AesDecrypt(string str, string key)
        {
            if (string.IsNullOrEmpty(str)) return null;
            Byte[] toEncryptArray = Convert.FromBase64String(str);

            System.Security.Cryptography.RijndaelManaged rm = new System.Security.Cryptography.RijndaelManaged
            {
                Key = Encoding.UTF8.GetBytes(key),
                Mode = System.Security.Cryptography.CipherMode.ECB,
                Padding = System.Security.Cryptography.PaddingMode.PKCS7
            };

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

            return Encoding.UTF8.GetString(resultArray);
        }