Des与3Des加密解密

    /// <summary>

    /// Des和3Des算法

    /// </summary>

    public class Des

    {

        /// <summary>

        /// Des加密

        /// </summary>

        /// <param name="pToEncrypt">明文</param>

        /// <param name="sKey">密钥</param>

        /// <returns></returns>

        public static string DESEnCode(string pToEncrypt, string sKey)

        {

            pToEncrypt = HttpContext.Current.Server.UrlEncode(pToEncrypt);

            DESCryptoServiceProvider des = new DESCryptoServiceProvider();

            byte[] inputByteArray = Encoding.GetEncoding("UTF-8").GetBytes(pToEncrypt);





            des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);

            des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);

            MemoryStream ms = new MemoryStream();

            CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);



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

            cs.FlushFinalBlock();



            StringBuilder ret = new StringBuilder();

            foreach (byte b in ms.ToArray())

            {

                ret.AppendFormat("{0:X2}", b);

            }

            ret.ToString();

            return ret.ToString();

        }

        /// <summary>

        /// 3Des加密(密钥不能每8位重复，例如：123456781234567812345678，如果这样则算法退化为Des，C#会检测，不能使用)

        /// </summary>

        /// <param name="a_strString">明文</param>

        /// <param name="a_strKey">密钥</param>

        /// <returns></returns>

        public string Decrypt3DES(string a_strString, string a_strKey)

        {

            TripleDESCryptoServiceProvider DES = new TripleDESCryptoServiceProvider();



            DES.Key = ASCIIEncoding.ASCII.GetBytes(a_strKey);

            DES.Mode = CipherMode.ECB;

            DES.Padding = System.Security.Cryptography.PaddingMode.PKCS7;



            ICryptoTransform DESDecrypt = DES.CreateEncryptor();



            string result = "";

            try

            {

                byte[] Buffer = Convert.FromBase64String(a_strString);

                result = ASCIIEncoding.ASCII.GetString(DESDecrypt.TransformFinalBlock(Buffer, 0, Buffer.Length));

            }

            catch (Exception e)

            {



            }

            return result;

        }

        /// <summary>

        /// Des解密

        /// </summary>

        /// <param name="encryptedString">密文</param>

        /// <param name="key">密钥</param>

        /// <returns></returns>

        public string Decrypt(string encryptedString, string key)

        {

            byte[] btKey = Encoding.UTF8.GetBytes(key);



            DESCryptoServiceProvider des = new DESCryptoServiceProvider();

            des.Key = ASCIIEncoding.ASCII.GetBytes(key);

            des.Mode = CipherMode.ECB;

            des.Padding = System.Security.Cryptography.PaddingMode.PKCS7;

            using (MemoryStream ms = new MemoryStream())

            {

                byte[] inData = Convert.FromBase64String(encryptedString);

                try

                {

                    using (CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write))

                    {

                        cs.Write(inData, 0, inData.Length);



                        cs.FlushFinalBlock();

                    }



                    return Encoding.UTF8.GetString(ms.ToArray());

                }

                catch

                {

                    return encryptedString;

                }

            }

        }

        /// <summary>

        /// 3Des解密(密钥不能每8位重复，例如：123456781234567812345678，如果这样则算法退化为Des，C#会检测，不能使用)

        /// </summary>

        /// <param name="a_strString">密文</param>

        /// <param name="a_strKey">密钥</param>

        /// <returns></returns>

        public string Decrypt3DES(string a_strString, string a_strKey)

        {

            TripleDESCryptoServiceProvider DES = new TripleDESCryptoServiceProvider();



            DES.Key = ASCIIEncoding.ASCII.GetBytes(a_strKey);

            DES.Mode = CipherMode.ECB;

            DES.Padding = System.Security.Cryptography.PaddingMode.PKCS7;



            ICryptoTransform DESDecrypt = DES.CreateDecryptor();



            string result = "";

            try

            {

                byte[] Buffer = Convert.FromBase64String(a_strString);

                result = ASCIIEncoding.ASCII.GetString(DESDecrypt.TransformFinalBlock(Buffer, 0, Buffer.Length));

            }

            catch (Exception e)

            {



            }

            return result;

        }

    }