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     }