1 public class Des

 2     {

 3         public static string Encrypt(string message, string key)

 4         {

 5             DES des = new DESCryptoServiceProvider();

 6             des.Key = Encoding.UTF8.GetBytes(key);

 7             des.IV = Encoding.UTF8.GetBytes(key);

 8             //des.Mode = CipherMode.ECB;

 9

10             byte[] inputByteArray = Encoding.UTF8.GetBytes(message);

11

12             System.IO.MemoryStream ms = new System.IO.MemoryStream();

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

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

15             cs.FlushFinalBlock();

16             ms.Close();

17             StringBuilder ret = new StringBuilder();

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

19             {

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

21             }

22             return ret.ToString();

23

24         }

25

26         //DES解密

27         public static string Decrypt(string content, string key)

28         {

29             try

30             {

31                 DESCryptoServiceProvider provider = new DESCryptoServiceProvider();

32                 // 密钥

33                 provider.Key = Encoding.UTF8.GetBytes(key);

34                 // 偏移量

35                 provider.IV = Encoding.UTF8.GetBytes(key);

36                 byte[] buffer = new byte[content.Length / 2];

37                 for (int i = 0; i < (content.Length / 2); i++)

38                 {

39                     int num2 = Convert.ToInt32(content.Substring(i * 2, 2), 0x10);

40                     buffer[i] = (byte)num2;

41                 }

42                 using(MemoryStream stream = new MemoryStream())

43                 {

44                     CryptoStream stream2 = new CryptoStream(stream, provider.CreateDecryptor(), CryptoStreamMode.Write);

45                     stream2.Write(buffer, 0, buffer.Length);

46                     stream2.FlushFinalBlock();

47                     stream.Close();

48                     return Encoding.UTF8.GetString(stream.ToArray());

49                 }

50             }

51             catch (Exception) { return ""; }

52         }

53     }