1 // 对称加密帮助类
2 public static class CryptoHelper
3 {
4 //详细参考http://www.cnblogs.com/JimmyZhang/archive/2008/10/02/Cryptograph.html
5 private static ICryptoTransform encryptor; // 加密器对象
6 private static ICryptoTransform decryptor; // 解密器对象
7
8 private static SymmetricAlgorithm provider = SymmetricAlgorithm.Create("TripleDES");
9
10 private const int BufferSize = 1024;
11
12
13 /// <summary>
14 /// 加密算法
15 /// </summary>
16 /// <param name="key">为24或16位字符</param>
17 /// <param name="encryptText">被加密的字符串</param>
18 /// <returns></returns>
19 public static string Encrypt(string key, string encryptedText)
20 {
21 provider.IV = new byte[] { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
22 provider.Key = Encoding.UTF8.GetBytes(key);
23
24 encryptor = provider.CreateEncryptor();
25 // 创建明文流
26 byte[] clearBuffer = Encoding.UTF8.GetBytes(encryptedText);
27 MemoryStream clearStream = new MemoryStream(clearBuffer);
28
29 // 创建空的密文流
30 MemoryStream encryptedStream = new MemoryStream();
31
32 CryptoStream cryptoStream =
33 new CryptoStream(encryptedStream, encryptor, CryptoStreamMode.Write);
34
35 // 将明文流写入到buffer中
36 // 将buffer中的数据写入到cryptoStream中
37 int bytesRead = 0;
38 byte[] buffer = new byte[BufferSize];
39 do
40 {
41 bytesRead = clearStream.Read(buffer, 0, BufferSize);
42 cryptoStream.Write(buffer, 0, bytesRead);
43 } while (bytesRead > 0);
44
45 cryptoStream.FlushFinalBlock();
46
47 // 获取加密后的文本
48 buffer = encryptedStream.ToArray();
49 string str = Convert.ToBase64String(buffer);
50 return str;
51 }
52
53 // 解密算法
54 /// <summary>
55 /// </summary>
56 /// <param name="key">为24或16位字符</param>
57 /// <param name="decryptedText">被解密的字符串</param>
58 /// <returns></returns>
59 public static string Decrypt(string key, string decryptedText)
60 {
61 provider.IV = new byte[] { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
62 provider.Key = Encoding.UTF8.GetBytes(key);
63
64 decryptor = provider.CreateDecryptor();
65 byte[] encryptedBuffer = Convert.FromBase64String(decryptedText);
66 Stream encryptedStream = new MemoryStream(encryptedBuffer);
67
68 MemoryStream clearStream = new MemoryStream();
69 CryptoStream cryptoStream =
70 new CryptoStream(encryptedStream, decryptor, CryptoStreamMode.Read);
71
72 int bytesRead = 0;
73 byte[] buffer = new byte[BufferSize];
74
75 do
76 {
77 bytesRead = cryptoStream.Read(buffer, 0, BufferSize);
78 clearStream.Write(buffer, 0, bytesRead);
79 } while (bytesRead > 0);
80
81 buffer = clearStream.GetBuffer();
82 string str =
83 Encoding.UTF8.GetString(buffer, 0, (int)clearStream.Length);
84
85 return str;
86 }
87
88 }
