C# 实现3Des加密 解密

3Des对每个数据块进行了三次的DES加密算法，是DES的一个更安全的变形。比起最初的DES，3DES更为安全。

都是感觉一目了然的摘过来。

下面是加密解密的源码。ECB模式的。

 1 public class _3DESEncrypt
 2     {
 3 
 4         public static string Encrypt3DES(string a_strString, string a_strKey)
 5         {
 6             TripleDESCryptoServiceProvider DES = new TripleDESCryptoServiceProvider();
 7             DES.Key = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(a_strKey, "md5").Substring(0, 24));
 8             DES.Mode = CipherMode.ECB;
 9             ICryptoTransform DESEncrypt = DES.CreateEncryptor();
10             byte[] Buffer = ASCIIEncoding.ASCII.GetBytes(a_strString);
11             return Convert.ToBase64String(DESEncrypt.TransformFinalBlock(Buffer, 0, Buffer.Length));
12         }
13 
14         public static string Decrypt3DES(string a_strString, string a_strKey)
15         {
16             TripleDESCryptoServiceProvider DES = new TripleDESCryptoServiceProvider();
17             DES.Key = ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(a_strKey, "md5").Substring(0, 24));
18             DES.Mode = CipherMode.ECB;
19             DES.Padding = System.Security.Cryptography.PaddingMode.PKCS7;
20             ICryptoTransform DESDecrypt = DES.CreateDecryptor();
21             string result = "";
22             try
23             {
24                 byte[] Buffer = Convert.FromBase64String(a_strString);
25 
26                 result = ASCIIEncoding.ASCII.GetString(DESDecrypt.TransformFinalBlock(Buffer, 0, Buffer.Length));
27 
28                 //MemoryStream msDecrypt = new MemoryStream(Buffer);
29                 //CryptoStream csDecrypt = new CryptoStream(msDecrypt,
30                 //       DES.CreateDecryptor(DES.Key, DES.IV),
31                 //       CryptoStreamMode.Read);
32 
33                 //// Create buffer to hold the decrypted data.
34                 //byte[] fromEncrypt = new byte[Buffer.Length];
35 
36                 //// Read the decrypted data out of the crypto stream
37                 //// and place it into the temporary buffer.
38                 //csDecrypt.Read(fromEncrypt, 0, fromEncrypt.Length);
39                 //result = System.Text.Encoding.Default.GetString(fromEncrypt);
40             }
41             catch (Exception e)
42             {
43             }
44             return result;
45 
46         }
47     }

里面加解密都是在DES的基础上实现、区别在于3Des的Key值是24位、DES而是8位。
DES的加密解密源码：http://www.cnblogs.com/tainshi/p/3501258.html

对于3DES算法的CBC模式、我是新人存在迷惑、解密出来的数据有乱码现象。大大们有这方面有关的文章、推荐给我喽。

posted @ 2014-01-06 14:08  SummerA  阅读(7734)  评论(4)  编辑  收藏  举报