ASP.NET上传判断类型，防止黑客上传非法文件
检测文件类型函数类：
1
using System;
2using System.Collections.Generic;
3using System.Web.UI.WebControls;
4using System.IO;
5
6namespace 0x001.Pack
7
{
8
public enum FileExtension
9
{
10 JPG = 255216,
11 GIF = 7173,
12 BMP = 6677,
13 PNG = 13780
14 // 255216 jpg;
15 // 7173 gif;
16 // 6677 bmp,
17 // 13780 png;
18 // 7790 exe dll,
19 // 8297 rar
20 // 6063 xml
21 // 6033 html
22 // 239187 aspx
23 // 117115 cs
24 // 119105 js
25 // 210187 txt
26 //255254 sql
27
}
28
29 public class FileValidation
30 {
31 public static bool IsAllowedExtension(FileUpload fu, FileExtension[] fileEx)
32 {
33 int fileLen = fu.PostedFile.ContentLength;
34 byte[] imgArray = new byte[fileLen];
35 fu.PostedFile.InputStream.Read(imgArray, 0, fileLen);
36 MemoryStream ms = new MemoryStream(imgArray);
37 System.IO.BinaryReader br = new System.IO.BinaryReader(ms);
38 string fileclass = "";
39 byte buffer;
40 try
41 {
42 buffer = br.ReadByte();
43 fileclass = buffer.ToString();
44 buffer = br.ReadByte();
45 fileclass += buffer.ToString();
46 }
47 catch
48 {
49 }
50 br.Close();
51 ms.Close();
52 foreach (FileExtension fe in fileEx)
53 {
54 if (Int32.Parse(fileclass) == (int)fe)
55 return true;
56 }
57 return false;
58 }
59 }
60
}
61
62
using System;2
using System.Collections.Generic;3
using System.Web.UI.WebControls;4
using System.IO; 5
6
namespace 0x001.Pack7
{
8
public enum FileExtension9
{
10
JPG = 255216,11
GIF = 7173,12
BMP = 6677,13
PNG = 1378014
// 255216 jpg;15
// 7173 gif;16
// 6677 bmp,17
// 13780 png;18
// 7790 exe dll,19
// 8297 rar20
// 6063 xml21
// 6033 html22
// 239187 aspx23
// 117115 cs24
// 119105 js25
// 210187 txt26
//255254 sql 27
} 28
29
public class FileValidation30
{31
public static bool IsAllowedExtension(FileUpload fu, FileExtension[] fileEx)32
{33
int fileLen = fu.PostedFile.ContentLength;34
byte[] imgArray = new byte[fileLen];35
fu.PostedFile.InputStream.Read(imgArray, 0, fileLen);36
MemoryStream ms = new MemoryStream(imgArray);37
System.IO.BinaryReader br = new System.IO.BinaryReader(ms);38
string fileclass = "";39
byte buffer;40
try41
{42
buffer = br.ReadByte();43
fileclass = buffer.ToString();44
buffer = br.ReadByte();45
fileclass += buffer.ToString();46
}47
catch48
{49
}50
br.Close();51
ms.Close();52
foreach (FileExtension fe in fileEx)53
{54
if (Int32.Parse(fileclass) == (int)fe)55
return true;56
}57
return false;58
}59
}60
} 61
62
上传事件判断上传类型:
1protected void btnUpload_Click(object sender, EventArgs e)
2{
3 string filename = "";
4 Boolean fileOK = false;
5 if (FileUpload1.HasFile)
6 {
7 String fileExtension = System.IO.Path.GetExtension(FileUpload1.FileName).ToLower();
8 String[] allowedExtensions = { ".gif", ".png", ".jpeg", ".jpg" };
9 for (int i = 0; i < allowedExtensions.Length; i++)
10 {
11 if (fileExtension == allowedExtensions[i])
12 {
13 fileOK = true;
14 }
15 }
16 }
17
18 FileExtension[] fe = { FileExtension.BMP, FileExtension.GIF, FileExtension.JPG, FileExtension.PNG };
19 if (fileOK && FileValidation.IsAllowedExtension(FileUpload1, fe))
20 {
21 string fileExt = System.IO.Path.GetExtension(FileUpload1.FileName).ToLower();
22 filename = "/Images/" + DateTime.Now.ToString("yyyyMMddHHmmss") + fileExt;
23 FileUpload1.PostedFile.SaveAs(Server.MapPath(filename));
24 }
25 else
26 {
27 LTP.Common.MessageBox.Show(this, "只支持以下格式的图片\\rJPG,BMP,GIF,PNG");
28 return;
29 }
30}
31
32
protected void btnUpload_Click(object sender, EventArgs e)2
{3
string filename = "";4
Boolean fileOK = false;5
if (FileUpload1.HasFile)6
{7
String fileExtension = System.IO.Path.GetExtension(FileUpload1.FileName).ToLower();8
String[] allowedExtensions = { ".gif", ".png", ".jpeg", ".jpg" };9
for (int i = 0; i < allowedExtensions.Length; i++)10
{11
if (fileExtension == allowedExtensions[i])12
{13
fileOK = true;14
}15
}16
} 17
18
FileExtension[] fe = { FileExtension.BMP, FileExtension.GIF, FileExtension.JPG, FileExtension.PNG };19
if (fileOK && FileValidation.IsAllowedExtension(FileUpload1, fe))20
{21
string fileExt = System.IO.Path.GetExtension(FileUpload1.FileName).ToLower();22
filename = "/Images/" + DateTime.Now.ToString("yyyyMMddHHmmss") + fileExt;23
FileUpload1.PostedFile.SaveAs(Server.MapPath(filename));24
}25
else26
{27
LTP.Common.MessageBox.Show(this, "只支持以下格式的图片\\rJPG,BMP,GIF,PNG");28
return;29
}30
} 31
32
