MD5和DES加密方法

    /// <summary>

        /// MD5加密

        /// </summary>

        /// <param name="EncryptString"></param>

        /// <returns></returns>

        public string MD5Encrypt(string EncryptString)

        {

            if (string.IsNullOrEmpty(EncryptString)) { throw (new Exception(" 密文不得为空 ")); }

            System.Security.Cryptography.MD5 md5 = new MD5CryptoServiceProvider();

            string m_strEncrypt = "";

            try

            {

                m_strEncrypt = BitConverter.ToString(md5.ComputeHash(Encoding.Default.GetBytes(EncryptString))).Replace("-", "");

            }

            catch (ArgumentException ex) { throw ex; }

            catch (CryptographicException ex) { throw ex; }

            catch (Exception ex) { throw ex; }

            finally { md5.Clear(); }

            return m_strEncrypt;

        }

DES加密解密

/// <summary>

        /// 解密

        /// </summary>

        /// <param name="str"></param>

        /// <returns></returns>

        private static string DecryptCookie(string str)

        {

            if (string.IsNullOrEmpty(str))

            {

                return null;

            }

            DESCryptoServiceProvider provider = new DESCryptoServiceProvider();

            MemoryStream stream = new MemoryStream(Convert.FromBase64String(str));

            CryptoStream stream2 = new CryptoStream(stream, provider.CreateDecryptor(KEY_64, IV_64), CryptoStreamMode.Read);

            StreamReader reader = new StreamReader(stream2);

            return reader.ReadToEnd();

        }

        /// <summary>

        /// 加密

        /// </summary>

        /// <param name="str"></param>

        /// <returns></returns>

        private static string EncryptCookie(string str)

        {

            if (string.IsNullOrEmpty(str))

            {

                return null;

            }

            byte[] inputByteArray = Encoding.UTF8.GetBytes(str);

            DESCryptoServiceProvider provider = new DESCryptoServiceProvider();

            MemoryStream mStream = new MemoryStream();

            CryptoStream cStream = new CryptoStream(mStream, provider.CreateEncryptor(KEY_64, IV_64), CryptoStreamMode.Write);

            cStream.Write(inputByteArray, 0, inputByteArray.Length);

            cStream.FlushFinalBlock();

            return Convert.ToBase64String(mStream.ToArray());

        }

        /// <summary>

        /// 8字节=64位

        /// </summary>

        private static byte[] IV_64

        {

            get

            {

                return new byte[] { 0x18, 0x56, 0x7e, 0x2e, 0x4c, 0x2c, 0x83, 0x13 };

            }

        }

        private static byte[] KEY_64

        {

            get

            {

                return new byte[] { 0x52, 0xcb, 0x38, 0x38, 0x12, 0x18, 0x63, 0x45 };

            }

        }