有关MD5的一些代码,转自别人的程序,这里做个记号
from: http://www.cnblogs.com/studyzy/archive/2007/03/30/694179.html
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
1
public class MD5
2
{
3
/// <summary>
4
/// 对给定文件路径的文件加上标签
5
/// </summary>
6
/// <param name="path">要加密的文件的路径</param>
7
/// <returns>标签的值</returns>
8
public static string MD5pdf(string path,string key)
9
{
10![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
11
try
12
{
13
FileStream get_file = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read);
14
byte[] pdfFile = new byte[get_file.Length];
15
get_file.Read(pdfFile, 0, (int)get_file.Length);//将文件流读取到Buffer中
16
get_file.Close();
17![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
18
string result = MD5Buffer(pdfFile, 0, pdfFile.Length );//对Buffer中的字节内容算MD5
19
result = MD5String(result +key);//这儿点的key相当于一个密钥,这样一般人就是知道使用MD5算法,但是若不知道这个字符串还是无法计算出正确的MD5
20![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
21
byte[] md5 = System.Text.Encoding.ASCII.GetBytes(result);//将字符串转换成字节数组以便写人到文件中
22![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
23
FileStream fsWrite = new FileStream(path, FileMode.Open, FileAccess.ReadWrite);
24
fsWrite.Write(pdfFile, 0, pdfFile.Length);//将pdf文件,MD5值 重新写入到文件中。
25
fsWrite.Write(md5, 0, md5.Length);
26
//fsWrite.Write(pdfFile, 10, pdfFile.Length - 10);
27
fsWrite.Close();
28![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
29
return result;
30
}
31
catch (Exception e)
32
{
33
return e.ToString();
34
}
35
}
36
/// <summary>
37
/// 对给定路径的文件进行验证
38
/// </summary>
39
/// <param name="path"></param>
40
/// <returns>是否加了标签或是否标签值与内容值一致</returns>
41
public static bool Check(string path,string key)
42
{
43
try
44
{
45
FileStream get_file = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read);
46![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
47
48
byte[] pdfFile = new byte[get_file.Length];
49
get_file.Read(pdfFile, 0, (int)get_file.Length);
50
get_file.Close();
51
string result = MD5Buffer(pdfFile, 0, pdfFile.Length - 32);//对pdf文件除最后32位以外的字节计算MD5,这个32是因为标签位为32位。
52
result = MD5String(result + key);
53![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
54
string md5 = System.Text.Encoding.ASCII.GetString(pdfFile, pdfFile.Length - 32, 32);//读取pdf文件最后32位,其中保存的就是MD5值
55
return result == md5;
56
}
57
catch
58
{
59![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
60
return false;
61![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
62
}
63
}
64
private static string MD5Buffer(byte[] pdfFile, int index, int count)
65
{
66
System.Security.Cryptography.MD5CryptoServiceProvider get_md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();
67
byte[] hash_byte = get_md5.ComputeHash(pdfFile, index, count);
68![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
69
string result = System.BitConverter.ToString(hash_byte);
70
result = result.Replace("-", "");
71
return result;
72
}
73
private static string MD5String(string str)
74
{
75
byte[] MD5Source = System.Text.Encoding.ASCII.GetBytes(str);
76
return MD5Buffer(MD5Source, 0, MD5Source.Length);
77![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
78
}
79
}
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
1
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
2
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
3
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
4
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
5
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
6
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
7
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
8
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
9
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
10
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
11
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
12
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
13
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
14
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
15
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
16
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
17
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
18
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
19
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
20
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
21
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
22
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
23
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
24
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
25
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
26
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
27
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
28
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
29
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
30
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
31
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
32
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
33
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
34
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
35
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
36
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
37
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
38
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
39
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
40
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
41
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
42
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
43
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
44
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
45
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
46
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
47
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
48
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
49
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
50
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
51
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
52
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
53
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
54
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
55
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
56
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
57
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
58
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
59
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
60
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
61
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
62
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
63
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
64
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
65
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
66
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
67
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
68
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
69
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
70
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
71
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
72
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
73
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
74
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
75
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
76
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
77
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
78
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif)
79
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockEnd.gif)