C#字符串加密

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.Security.Cryptography;

namespace FileCopy
{
    class Program
    {
        //默认密钥向量
        private static byte[] Keys = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
        /****************************************************************************
         *TODO 加密字符串
         *param encryptString 待加密的字符串
         *param encryptKey 加密密钥，要求为8为
         *return 成功 返回加密后的字符串  ； 失败 返回原字符串
         *****************************************************************************/
        public static string EncryptDES(string encryptString, string encryptKey)
        {
            try
            {
                byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8));//转换为字节
                byte[] rgbIV = Keys;
                byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
                DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();//实例化数据加密标准
                MemoryStream mStream = new MemoryStream();//实例化内存流
                //将数据流链接到加密转换的流
                CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
                cStream.Write(inputByteArray, 0, inputByteArray.Length);
                cStream.FlushFinalBlock();
                return Convert.ToBase64String(mStream.ToArray());
            }
            catch
            {
                return encryptString;
            }
        }

        
        /****************************************************************************
         *TODO DES解密字符串
         *param decryptString 待解密的字符串
         *param decryptKey 解密密钥,要求为8位,和加密密钥相同
         *return 成功 返回解密后的字符串  ； 失败 返回原字符串
         *****************************************************************************/
        public static string DecryptDES(string decryptString, string decryptKey)
        {
            try
            {
                byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey);
                byte[] rgbIV = Keys;
                byte[] inputByteArray = Convert.FromBase64String(decryptString);
                DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();
                MemoryStream mStream = new MemoryStream();
                CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
                cStream.Write(inputByteArray, 0, inputByteArray.Length);
                cStream.FlushFinalBlock();
                return Encoding.UTF8.GetString(mStream.ToArray());
            }
            catch
            {
                return decryptString;
            }
        }

        

        static void Main(string[] args)
        {
            //
            string fromName = @"D:\A.txt";
            string toName = @"D:\B.txt";
            StreamReader reader = null;
            StreamWriter writer = null;
            try
            {
                reader = new StreamReader(fromName, System.Text.Encoding.Default);
                writer = new StreamWriter(toName, false, System.Text.Encoding.Default);

                string contentString = reader.ReadLine();
                while (contentString != null)
                {
                    //对字符串进行加密
                    contentString = EncryptDES(contentString, "11111111");
                    Console.WriteLine(contentString);
                    writer.WriteLine(contentString);
                    contentString = reader.ReadLine();
                }
                Console.WriteLine("拷贝成功");
            }
            catch (IOException ex)
            {
                Console.WriteLine("异常" + ex);
            }
            finally 
            {
                reader.Close();
                writer.Close();
            }
                
        }
    }

  
       

        

}