c# winform 文件内容的加密解密

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 1 #region 加密方法
 2 public bool EncryptFile(string filePath,string savePath,string keyStr) 
 3 { 
 4     DESCryptoServiceProvider des = new DESCryptoServiceProvider(); 
 5     if(keyStr=="") 
 6         keyStr=key; 
 7     FileStream fs=File.OpenRead(filePath); 
 8     byte[] inputByteArray =new byte[fs.Length]; 
 9     fs.Read(inputByteArray,0,(int)fs.Length); 
10     fs.Close(); 
11     byte[] keyByteArray=Encoding.Default.GetBytes(keyStr); 
12     SHA1 ha=new SHA1Managed(); 
13     byte[] hb=ha.ComputeHash(keyByteArray); 
14     sKey=new byte[8]; 
15     sIV=new byte[8]; 
16     for(int i=0;i<8;i++) 
17         sKey[i]=hb[i]; 
18     for(int i=8;i<16;i++) 
19         sIV[i-8]=hb[i]; 
20     des.Key=sKey; 
21     des.IV=sIV; 
22     MemoryStream ms = new MemoryStream(); 
23     CryptoStream cs = new CryptoStream(ms,des.CreateEncryptor(),CryptoStreamMode.Write); 
24     cs.Write(inputByteArray, 0, inputByteArray.Length); 
25     cs.FlushFinalBlock(); 
26     fs=File.OpenWrite(savePath); 
27 
28     foreach(byte b in ms.ToArray()) 
29     { 
30         fs.WriteByte(b);             
31     }                    
32     fs.Close(); 
33     cs.Close(); 
34     ms.Close(); 
35     return true; 
36 }
37 #endregion

 解密：

    

#region 解密方法
public bool DecryptFile(string filePath,string savePath,string keyStr) 
{ 
	DESCryptoServiceProvider des = new DESCryptoServiceProvider(); 
	if(keyStr=="") 
		keyStr=key; 
	FileStream fs=File.OpenRead(filePath); 
	byte[] inputByteArray =new byte[fs.Length]; 
	fs.Read(inputByteArray,0,(int)fs.Length); 
	fs.Close(); 
	byte[] keyByteArray=Encoding.Default.GetBytes(keyStr); 
	SHA1 ha=new SHA1Managed(); 
	byte[] hb=ha.ComputeHash(keyByteArray); 
	sKey=new byte[8]; 
	sIV=new byte[8]; 
	for(int i=0;i<8;i++) 
		sKey[i]=hb[i]; 
	for(int i=8;i<16;i++) 
		sIV[i-8]=hb[i]; 
	des.Key=sKey; 
	des.IV=sIV; 
	MemoryStream ms = new MemoryStream(); 
	CryptoStream cs = new CryptoStream(ms,des.CreateDecryptor(),CryptoStreamMode.Write); 
	cs.Write(inputByteArray, 0, inputByteArray.Length); 
	cs.FlushFinalBlock(); 
	fs=File.OpenWrite(savePath); 
	foreach(byte b in ms.ToArray()) 
	{ 
		fs.WriteByte(b); 
	} 
	fs.Close(); 
	cs.Close(); 
	ms.Close(); 
	return true; 
} 
#endregion

 

posted @ 2011-11-16 08:44  Devil_jim  阅读(715)  评论(0)    收藏  举报