public class DESCrypto

    {

        /// <summary>

        /// 初始化des实例秘钥及向量

        /// </summary>

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

        /// <returns></returns>

        private static DESCryptoServiceProvider InitDESInstance(string key)

        {

            DESCryptoServiceProvider des = new DESCryptoServiceProvider();

            byte[] salt = new byte[] { 0x0A, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0xF1 };

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

            Rfc2898DeriveBytes rfcKey = new Rfc2898DeriveBytes(keyByte, salt, );

            Rfc2898DeriveBytes rfcIv = new Rfc2898DeriveBytes("", salt, );

            des.Key = rfcKey.GetBytes();

            des.IV = rfcIv.GetBytes();

            return des;

        }

        #region 基于Base64的加密解密（不其他格式的加解密方法配合使用）

        /// <summary>

        /// 基于Base64

        /// </summary>

        /// <param name="plaintext"></param>

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

        /// <returns></returns>

        public static string DESEncryptBase64(string plaintext,string key)

        {

            DESCryptoServiceProvider des = InitDESInstance(key);

            byte[] dataByteArray = Encoding.UTF8.GetBytes(plaintext);

            string ciphertext = "";

            using (MemoryStream ms = new MemoryStream())

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

            {

                cs.Write(dataByteArray, , dataByteArray.Length);

                cs.FlushFinalBlock();

                ciphertext = Convert.ToBase64String(ms.ToArray());

            }

            return ciphertext;

        }

        /// <summary>

        /// 基于Base64

        /// </summary>

        /// <param name="encrypt"></param>

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

        /// <returns></returns>

        public static string DESDecryptBase64(string encrypt, string key)

        {

            DESCryptoServiceProvider des = InitDESInstance(key);

            byte[] dataByteArray = Convert.FromBase64String(encrypt);

            using (MemoryStream ms = new MemoryStream())

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

            {

                cs.Write(dataByteArray, , dataByteArray.Length);

                cs.FlushFinalBlock();

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

            }

        }

        #endregion

        #region 基于2位十六进制格式的加密解密（不其他格式的加解密方法配合使用）

        /// <summary>

        /// 加密

        /// </summary>

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

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

        /// <returns></returns>

        public static string DESEncrypt(string plaintext, string key)

        {

            DESCryptoServiceProvider des = InitDESInstance(key);

            StringBuilder sb = new StringBuilder();

            byte[] dataByteArray = Encoding.UTF8.GetBytes(plaintext);

            string ciphertext = "";

            using (MemoryStream ms = new MemoryStream())

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

            {

                cs.Write(dataByteArray, , dataByteArray.Length);

                cs.FlushFinalBlock();

                //输出加密文本

                foreach (byte b in ms.ToArray())

                {

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

                }

                ciphertext = sb.ToString();

            }

            return ciphertext;

        }

        /// <summary>

        /// 解密

        /// </summary>

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

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

        /// <returns></returns>

        public static string DESDecrypt(string ciphertext, string key)

        {

            DESCryptoServiceProvider des = InitDESInstance(key);

            byte[] dataByteArray = new byte[ciphertext.Length / ];

            for (int x = ; x < ciphertext.Length / ; x++)

            {

                int i = (Convert.ToInt32(ciphertext.Substring(x * , ), ));

                dataByteArray[x] = (byte)i;

            }

            using (MemoryStream ms = new MemoryStream())

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

            {

                cs.Write(dataByteArray, , dataByteArray.Length);

                cs.FlushFinalBlock();

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

            }

        }

        #endregion

        #region 文件加密解密（不其他格式的加解密方法配合使用）

        /// <summary>

        /// 加密文件

        /// </summary>

        /// <param name="sourceFile">文件的物理路径</param>

        /// <param name="encryptFile">文件的物理路径</param>

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

        public static void DESEncryptFile(string sourceFile, string encryptFile, string key)

        {

            if (string.IsNullOrEmpty(sourceFile) || string.IsNullOrEmpty(encryptFile)||!File.Exists(sourceFile)) return;

            DESCryptoServiceProvider des = InitDESInstance(key);

            using (FileStream sourceStream = new FileStream(sourceFile, FileMode.Open, FileAccess.Read))

            using (FileStream encryptStream = new FileStream(encryptFile, FileMode.Create, FileAccess.Write))

            {

                byte[] dataByteArray = new byte[sourceStream.Length];

                sourceStream.Read(dataByteArray, , dataByteArray.Length);

                using (CryptoStream cs = new CryptoStream(encryptStream, des.CreateEncryptor(), CryptoStreamMode.Write))

                {

                    cs.Write(dataByteArray, , dataByteArray.Length);

                    cs.FlushFinalBlock();

                }

            }

        }

        /// <summary>

        /// 解密文件

        /// </summary>

        /// <param name="encryptFile">文件的物理路径</param>

        /// <param name="decryptFile">文件的物理路径</param>

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

        public static void DESDecryptFile(string encryptFile, string decryptFile, string key)

        {

            if (string.IsNullOrEmpty(encryptFile) || string.IsNullOrEmpty(decryptFile) || !File.Exists(encryptFile))return;

            DESCryptoServiceProvider des = InitDESInstance(key);

            using (FileStream encryptStream = new FileStream(encryptFile, FileMode.Open, FileAccess.Read))

            using (FileStream decryptStream = new FileStream(decryptFile, FileMode.Create, FileAccess.Write))

            {

                byte[] dataByteArray = new byte[encryptStream.Length];

                encryptStream.Read(dataByteArray, , dataByteArray.Length);

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

                {

                    cs.Write(dataByteArray, , dataByteArray.Length);

                    cs.FlushFinalBlock();

                }

            }

        }

        /// <summary>

        /// 加密文本并输出到文件

        /// </summary>

        /// <param name="plaintext"></param>

        /// <param name="FileName">文件的物理路径</param>

        /// <param name="Key"></param>

        public static void DESEncryptTextToFile(string plaintext, string FileName, string key)

        {

            if (string.IsNullOrEmpty(FileName)) return;

            DESCryptoServiceProvider des = InitDESInstance(key);

            byte[] dataByteArray = Encoding.UTF8.GetBytes(plaintext);

            using (FileStream fStream = File.Open(FileName, FileMode.Create))

            using (CryptoStream cStream = new CryptoStream(fStream, des.CreateEncryptor(), CryptoStreamMode.Write))

            {

                cStream.Write(dataByteArray, , dataByteArray.Length);

                cStream.FlushFinalBlock();

            }

        }

        /// <summary>

        /// 解密文件中的密文并返回

        /// </summary>

        /// <param name="FileName"></param>

        /// <param name="Key"></param>

        /// <returns></returns>

        public static string DESDecryptTextFromFile(string FileName, string key)

        {

            if (string.IsNullOrEmpty(FileName)||!File.Exists(FileName)) return "";

            DESCryptoServiceProvider des = InitDESInstance(key);

            using (FileStream fStream = File.Open(FileName, FileMode.OpenOrCreate))

            using (CryptoStream cStream = new CryptoStream(fStream, des.CreateDecryptor(), CryptoStreamMode.Read))

            using (StreamReader sReader = new StreamReader(cStream))

            {

                string val = sReader.ReadToEnd();

                return val;

            }

        }

        #endregion

    }