加密解密代码

//---------------------------------------------------------------- // Copyright (C) 2004-2004 Crea.D Soft (www.Crea.com) // All rights reserved. // // Author  : Nick // Create date : 2004-10-22 // Description : DataEncrypt 字符窜加密和解密处理 // Modify date :   By:     Why: //---------------------------------------------------------------- using System; using System.Text; using System.Security.Cryptography ; using System.IO ;

namespace Encrypt {  /// <summary>  /// SwEncrypt 字符窜加密和解密。  /// </summary>  public class DataEncrypt {   private static string KEY_ENCRYPT="c_dc";   /// <summary>   /// 解密字符窜   /// </summary>   /// <param name="pDecryptStr"></param>   /// <returns></returns>   public static string DecryptString(string pDecryptStr) {

   DESCryptoServiceProvider desc = new DESCryptoServiceProvider();    //产生key    PasswordDeriveBytes db = new PasswordDeriveBytes(KEY_ENCRYPT, null);    byte[] key = db.GetBytes(8);    //存储解密后的数据    MemoryStream ms = new MemoryStream();    CryptoStream cs = new CryptoStream(ms,desc.CreateDecryptor(key, key),CryptoStreamMode.Write);    //取到加密后的数据的字节流，如果是保存到文件    try{     byte[] databytes =  Convert.FromBase64String(pDecryptStr);     //解密数据     cs.Write(databytes, 0, databytes.Length);     cs.FlushFinalBlock();     byte[] res = ms.ToArray();     //返回解密后的数据，这里返回的数据应该和参数pwd的值相同。     return  System.Text.Encoding.UTF8.GetString(res);    }    catch{     Console.WriteLine("字符窜" + pDecryptStr + "解密不成功。");       return null;    }   }   /// <summary>   /// 加密字符窜   /// </summary>   /// <param name="pEncryptedStr"></param>   /// <returns></returns>   public static string EncryptString(string pEncryptedStr) {    //des进行加密    DESCryptoServiceProvider desc = new DESCryptoServiceProvider();    //产生key    PasswordDeriveBytes db = new PasswordDeriveBytes(KEY_ENCRYPT, null);    byte[] key = db.GetBytes(8);    //存储加密后的数据    MemoryStream ms = new MemoryStream();    CryptoStream cs = new CryptoStream(ms,desc.CreateEncryptor(key, key),CryptoStreamMode.Write);    //取到密码的字节流    try{     byte[] data = Encoding.UTF8.GetBytes(pEncryptedStr);     //进行加密     cs.Write(data, 0, data.Length);     cs.FlushFinalBlock();     //取加密后的数据     byte[] res = ms.ToArray();     return Convert.ToBase64String(res);    }    catch{     Console.WriteLine("字符窜" + pEncryptedStr + "加密不成功。");       return null;    }

  }  } }