c# winform 文件内容的加密解密

主要代码

加密:

#region 加密方法   
public bool EncryptFile(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.CreateEncryptor(),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 

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