DES加密解密

 

   /// <summary>
        /// 进行DES加密。
        /// </summary>
        /// <param name="pToEncrypt">要加密的字符串。</param>
        /// <param name="sKey">密钥，且必须为8位。</param>
        /// <returns>以Base64格式返回的加密字符串。</returns>
        public static string Encrypt(string pToEncrypt, string sKey)
        {
            using (DESCryptoServiceProvider des = new DESCryptoServiceProvider())
            {
                byte[] inputByteArray = Encoding.UTF8.GetBytes(pToEncrypt);
                des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);
                des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);
                System.IO.MemoryStream ms = new System.IO.MemoryStream();
                using (CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write))
                {
                    cs.Write(inputByteArray, 0, inputByteArray.Length);
                    cs.FlushFinalBlock();
                    cs.Close();
                }
                string str = Convert.ToBase64String(ms.ToArray());
                ms.Close();
                return str;
            }
        }

        /**/
        /// <summary>
        /// 进行DES解密。
        /// </summary>
        /// <param name="pToDecrypt">要解密的以Base64</param>
        /// <param name="sKey">密钥，且必须为8位。</param>
        /// <returns>已解密的字符串。</returns>
        public static string Decrypt(string pToDecrypt, string sKey)
        {
            byte[] inputByteArray = Convert.FromBase64String(pToDecrypt);
            using (DESCryptoServiceProvider des = new DESCryptoServiceProvider())
            {
                des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);
                des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);
                System.IO.MemoryStream ms = new System.IO.MemoryStream();
                using (CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write))
                {
                    cs.Write(inputByteArray, 0, inputByteArray.Length);
                    cs.FlushFinalBlock();
                    cs.Close();
                }
                string str = Encoding.UTF8.GetString(ms.ToArray());
                ms.Close();
                return str;
            }
        }
        /// <summary>
        /// 创建密钥
        /// </summary>
        /// <returns></returns>

        public static string GenerateKey()
        {
            DESCryptoServiceProvider desCrypto = (DESCryptoServiceProvider)DESCryptoServiceProvider.Create();
            return ASCIIEncoding.ASCII.GetString(desCrypto.Key);
        }
    
        /// </summary>
        /// <param name="sInputFilename">待加密的文件绝对路径</param>
        /// <param name="sOutputFilename">加密后的文件保存的绝对路径</param>
        public static void EncryptFile(string sInputFilename, string sOutputFilename, string sKey)
        {

            byte[] btKey = Encoding.Default.GetBytes(sKey);
            byte[] btIV = Encoding.Default.GetBytes(sKey);
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            byte[] btFile = File.ReadAllBytes(sInputFilename);
            using (FileStream fs = new FileStream(sOutputFilename, FileMode.Create, FileAccess.Write))
            {
                try
                {
                    using (CryptoStream cs = new CryptoStream(fs, des.CreateEncryptor(btKey, btIV), CryptoStreamMode.Write))
                    {
                        cs.Write(btFile, 0, btFile.Length);
                        cs.FlushFinalBlock();
                    }
                }
                catch
                {
                    throw;
                }
                finally
                {
                    fs.Close();
                }
            }
        }    

        /// <summary>
        /// 对文件内容进行DES解密
        /// </summary>
        /// <param name="sourceFile">待解密的文件绝对路径</param>
        /// <param name="destFile">解密后的文件保存的绝对路径</param>
        public static void DecryptFile(string sInputFilename, string sOutputFilename, string sKey)
        {

            byte[] btKey = Encoding.Default.GetBytes(sKey);
            byte[] btIV = Encoding.Default.GetBytes(sKey);
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            byte[] btFile = File.ReadAllBytes(sInputFilename);
            using (FileStream fs = new FileStream(sOutputFilename, FileMode.Create, FileAccess.Write))
            {
                try
                {
                    using (CryptoStream cs = new CryptoStream(fs, des.CreateDecryptor(btKey, btIV), CryptoStreamMode.Write))
                    {
                        cs.Write(btFile, 0, btFile.Length);
                        cs.FlushFinalBlock();
                    }
                }
                catch
                {
                    throw;
                }
                finally
                {
                    fs.Close();
                }
            }
        }