asp.net字符串加密与解密

 1 using System;

 2 using System.Data;

 3 using System.Configuration;

 4 using System.Web;

 5 using System.Web.Security;

 6 using System.Web.UI;

 7 using System.Web.UI.WebControls;

 8 using System.Web.UI.WebControls.WebParts;

 9 using System.Web.UI.HtmlControls;

10 using System.Xml ;

11 using System.Data.SqlClient;

12 using System.IO;

13 using System.Net;

14 using System.Text;

15 using System.Text.RegularExpressions;

16 using System.Security.Cryptography;

17 

18 

19 /// <summary>

20     /// 加密

21     /// </summary>

22     /// <param name="pToEncrypt">要加密的字符串</param>

23     /// <param name="sKey">加密密匙 例："abcdefgh"</param>

24     /// <returns></returns>

25     public string Encrypt(string pToEncrypt)

26     {

27         string sKey = "abcdefgh";

28         DESCryptoServiceProvider des = new DESCryptoServiceProvider(); //把字符串放到byte数组中   

29         byte[] inputByteArray = Encoding.Default.GetBytes(pToEncrypt);

30         //byte[] inputByteArray=Encoding.Unicode.GetBytes(pToEncrypt);   

31         des.Key = ASCIIEncoding.ASCII.GetBytes(sKey); //建立加密对象的密钥和偏移量   

32         des.IV = ASCIIEncoding.ASCII.GetBytes(sKey); //原文使用ASCIIEncoding.ASCII方法的GetBytes方法   

33         MemoryStream ms = new MemoryStream(); //使得输入密码必须输入英文文本   

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

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

36         cs.FlushFinalBlock();

37         StringBuilder ret = new StringBuilder();

38         foreach (byte b in ms.ToArray())

39         {

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

41         }

42         ret.ToString();

43         return ret.ToString();

44     }

45     /// <summary>

46     /// 解密

47     /// </summary>

48     /// <param name="pToDecrypt">要解密字符串</param>

49     /// <param name="sKey">解密密匙 例："abcdefgh"</param>

50     /// <returns></returns>

51     public string Decrypt(string pToDecrypt)

52     {

53         string sKey = "abcdefgh";

54         DESCryptoServiceProvider des = new DESCryptoServiceProvider();

55         byte[] inputByteArray = new byte[pToDecrypt.Length / 2];

56         for (int x = 0; x < pToDecrypt.Length / 2; x++)

57         {

58             int i = (Convert.ToInt32(pToDecrypt.Substring(x * 2, 2), 16));

59             inputByteArray[x] = (byte)i;

60         }

61         des.Key = ASCIIEncoding.ASCII.GetBytes(sKey); //建立加密对象的密钥和偏移量，此值重要，不能修改   

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

63         MemoryStream ms = new MemoryStream();

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

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

66         cs.FlushFinalBlock();

67         StringBuilder ret = new StringBuilder(); //建立StringBuild对象，CreateDecrypt使用的是流对象，必须把解密后的文本变成流对象   

68         return System.Text.Encoding.Default.GetString(ms.ToArray());

69     }