C# 数据加密解密

 1     public class EncryptProvider
 2     {
 3 
 4         // Hash an input string and return the hash as
 5         // a 32 character hexadecimal string.
 6          public static string GetMd5Hash(string input)
 7         {
 8             MD5CryptoServiceProvider md5Hasher = new MD5CryptoServiceProvider();
 9             byte[] data = md5Hasher.ComputeHash(Encoding.Default.GetBytes(input));
10             StringBuilder sBuilder = new StringBuilder();
11             for (int i = 0; i < data.Length; i++)
12             {
13                 sBuilder.Append(data[i].ToString("x2"));
14             }
15             return sBuilder.ToString();
16         }
17 
18         // Verify a hash against a string.
19         public static bool VerifyMd5Hash(string input, string hash)
20         {
21             string hashOfInput = GetMd5Hash(input);
22             StringComparer comparer = StringComparer.OrdinalIgnoreCase;
23             if (0 == comparer.Compare(hashOfInput, hash))
24             {
25                 return true;
26             }
27             else
28             {
29                 return false;
30             }
31         }
32         //默认密钥向量
33         private static byte[] Keys = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
34         /// <summary>
35         /// DES加密字符串
36         /// </summary>
37         /// <param name="encryptString">待加密的字符串</param>
38         /// <param name="encryptKey">加密密钥,要求为8位</param>
39         /// <returns>加密成功返回加密后的字符串，失败返回源串</returns>
40         public static string EncryptDES(string encryptString, string encryptKey)
41         {
42             try
43             {
44                 byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8));
45                 byte[] rgbIV = Keys;
46                 byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
47                 DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();
48                 MemoryStream mStream = new MemoryStream();
49                 CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
50                 cStream.Write(inputByteArray, 0, inputByteArray.Length);
51                 cStream.FlushFinalBlock();
52                 return Convert.ToBase64String(mStream.ToArray());
53             }
54             catch
55             {
56                 return encryptString;
57             }
58         }
59 
60         /// <summary>
61         /// DES解密字符串
62         /// </summary>
63         /// <param name="decryptString">待解密的字符串</param>
64         /// <param name="decryptKey">解密密钥,要求为8位,和加密密钥相同</param>
65         /// <returns>解密成功返回解密后的字符串，失败返源串</returns>
66         public static string DecryptDES(string decryptString, string decryptKey)
67         {
68             try
69             {
70                 byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey);
71                 byte[] rgbIV = Keys;
72                 byte[] inputByteArray = Convert.FromBase64String(decryptString);
73                 DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();
74                 MemoryStream mStream = new MemoryStream();
75                 CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
76                 cStream.Write(inputByteArray, 0, inputByteArray.Length);
77                 cStream.FlushFinalBlock();
78                 return Encoding.UTF8.GetString(mStream.ToArray());
79             }
80             catch
81             {
82                 return decryptString;
83             }
84         }
85     }
86 
87 
88 
89