c#md5與SHA1驗證函數

 1 /// <summary>
 2         /// MD5驗證函數
 3         /// </summary>
 4         /// <param name="fileName">文件的路徑</param>
 5         /// <param name="blockletter">返回的MD5值是否爲大寫</param>
 6         /// <returns></returns>
 7         public static string GetMD5HashFromFile(string fileName,bool blockletter)
 8         {
 9             try
10             {
11                 FileStream file = new FileStream(fileName, FileMode.Open);
12                 System.Security.Cryptography.MD5 md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();
13                 byte[] retVal = md5.ComputeHash(file);
14                 file.Close();
15 
16                 StringBuilder sb = new StringBuilder();
17                 for (int i = 0; i < retVal.Length; i++)
18                 {
19                     if (blockletter)
20                         sb.Append(retVal[i].ToString("X2"));
21                     else 
22                         sb.Append(retVal[i].ToString("x2"));
23                 }
24                 return sb.ToString();
25             }
26             catch (Exception ex)
27             {
28                 return "文件讀取錯誤";
29             }
30         }
31         /// <summary>
32         ///   計算SHA1值
33         /// </summary>
34         /// <param name="fileName">文件地址</param>
35         /// <param name="blockletter">是否輸出大寫</param>
36         /// <returns></returns>
37         public static string GetSHA1HashFromFile(string fileName, bool blockletter)
38         {
39             var tragetFile = new System.IO.FileStream(fileName, System.IO.FileMode.Open);
40             var sha1 = new System.Security.Cryptography.SHA1CryptoServiceProvider();
41             byte[] hashbytes = sha1.ComputeHash(tragetFile);
42             tragetFile.Close();
43 
44             System.Text.StringBuilder sb = new System.Text.StringBuilder();
45             for (int i = 0; i < hashbytes.Length; i++)
46             {
47                 if (blockletter) //判斷輸出大小寫
48                     sb.Append(hashbytes[i].ToString("X2"));
49                 else
50                     sb.Append(hashbytes[i].ToString("x2"));
51             }
52             return sb.ToString();
53         }