.NET 雜湊碼計算API使用範例
雜湊碼的應用範圍很廣，舉凡密碼的加密，或是檔案傳輸過程的驗證，或是替一組數據(或一個檔案)產生一個短一點的認證碼，.NET Framework已經提供有現成的類別，支援最常用的MD5跟SHA等演算法，下面程式碼簡單示範叫用的程序。
1 <%@ Page Language="C#" %>
2 <%@ Import Namespace="System.Security.Cryptography" %>
3 <%@ Import Namespace="System.Configuration.Provider" %>
4
5 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
6
7 <script runat="server">
8
9
10 protected string ComputeHash(byte[] data, string hashAlgorithmType)
11 {
12 byte[] result;
13 HashAlgorithm s = HashAlgorithm.Create(hashAlgorithmType);
14 if (s == null)
15 throw new ProviderException("Could not create a hash algorithm");
16 result = s.ComputeHash(data);
17 return Convert.ToBase64String(result);
18 }
19
20 protected void Button1_Click(object sender, EventArgs e)
21 {
22 if (FileUpload1.HasFile)
23 {
24 StringBuilder sb = new StringBuilder();
25 sb.AppendFormat("FileName = {0}<br />", FileUpload1.FileName);
26 sb.AppendFormat("FileSize = {0:#,##0} Bytes<br />", FileUpload1.FileBytes.Length);
27
28 string[] hashAlgorithms = new string[] { "MD5", "SHA1", "SHA256", "SHA512" };
29 for (int i = 0; i < hashAlgorithms.Length; i++)
30 {
31 long startTick = DateTime.Now.Ticks;
32 string smd5 = ComputeHash(FileUpload1.FileBytes, hashAlgorithms[i]);
33 long endTick = DateTime.Now.Ticks;
34 double times = (endTick - startTick) / 10000D;
35 sb.AppendFormat("{0} = {1} ({2}bytes, {3:f4}ms)<br />",hashAlgorithms[i], smd5, smd5.Length, times);
36 }
37 sb.Append("<hr/>");
38
39 laMessage.Text += sb.ToString();
40 }
41 }
42 protected void Button2_Click(object sender, EventArgs e)
43 {
44 laMessage.Text = "";
45 }
46
47 </script>
48
49 <html xmlns="http://www.w3.org/1999/xhtml">
50 <head runat="server">
51 <title>Compute Hash Values</title>
52 </head>
53 <body>
54 <form id="form1" runat="server">
55 <div>
56 <asp:Label ID="Label1" runat="server" Text="Select a file:"></asp:Label>
57 <asp:FileUpload ID="FileUpload1" runat="server" Width="500px" />
58 <br />
59 <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Compute" />
60 <asp:Button ID="Button2" runat="server" OnClick="Button2_Click" Text="Clean" /><br />
61 <br />
62 <asp:Literal ID="laMessage" runat="server"></asp:Literal>
63 </div>
64 </form>
65 </body>
66 </html>
67
2 <%@ Import Namespace="System.Security.Cryptography" %>
3 <%@ Import Namespace="System.Configuration.Provider" %>
4
5 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
6
7 <script runat="server">
8
9
10 protected string ComputeHash(byte[] data, string hashAlgorithmType)
11 {
12 byte[] result;
13 HashAlgorithm s = HashAlgorithm.Create(hashAlgorithmType);
14 if (s == null)
15 throw new ProviderException("Could not create a hash algorithm");
16 result = s.ComputeHash(data);
17 return Convert.ToBase64String(result);
18 }
19
20 protected void Button1_Click(object sender, EventArgs e)
21 {
22 if (FileUpload1.HasFile)
23 {
24 StringBuilder sb = new StringBuilder();
25 sb.AppendFormat("FileName = {0}<br />", FileUpload1.FileName);
26 sb.AppendFormat("FileSize = {0:#,##0} Bytes<br />", FileUpload1.FileBytes.Length);
27
28 string[] hashAlgorithms = new string[] { "MD5", "SHA1", "SHA256", "SHA512" };
29 for (int i = 0; i < hashAlgorithms.Length; i++)
30 {
31 long startTick = DateTime.Now.Ticks;
32 string smd5 = ComputeHash(FileUpload1.FileBytes, hashAlgorithms[i]);
33 long endTick = DateTime.Now.Ticks;
34 double times = (endTick - startTick) / 10000D;
35 sb.AppendFormat("{0} = {1} ({2}bytes, {3:f4}ms)<br />",hashAlgorithms[i], smd5, smd5.Length, times);
36 }
37 sb.Append("<hr/>");
38
39 laMessage.Text += sb.ToString();
40 }
41 }
42 protected void Button2_Click(object sender, EventArgs e)
43 {
44 laMessage.Text = "";
45 }
46
47 </script>
48
49 <html xmlns="http://www.w3.org/1999/xhtml">
50 <head runat="server">
51 <title>Compute Hash Values</title>
52 </head>
53 <body>
54 <form id="form1" runat="server">
55 <div>
56 <asp:Label ID="Label1" runat="server" Text="Select a file:"></asp:Label>
57 <asp:FileUpload ID="FileUpload1" runat="server" Width="500px" />
58 <br />
59 <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Compute" />
60 <asp:Button ID="Button2" runat="server" OnClick="Button2_Click" Text="Clean" /><br />
61 <br />
62 <asp:Literal ID="laMessage" runat="server"></asp:Literal>
63 </div>
64 </form>
65 </body>
66 </html>
67
