DES加密\解密后,文字多了不少!

Question

多谢帮忙!
简单的DES，原始文件：<?xml version=\"1.0\" encoding=\"UTF-8\"?><ChatMember><ID /><Name /><Dept /><Tel/><email>q</email><Password>q</Password><Discription /><AdditionalInfo /><URL /><RejectReason /></ChatMember>加密再解密后变成：<?xml version=\"1.0\" encoding=\"UTF-8\"?><ChatMember><ID /><Name /><Dept /><Tel /><email>q</email><Password>q</Password><Discription /><AdditionalInfo /><URL /><RejectReason /></ChatMember>覰m滣?緑.H??緑.H??緑.H??緑.H??緑.H??緑.H?\0\0\0\0\0\0\0\0
public byte[] EncryptSend(byte[] buf, byte[] desKey, byte[] desIV)
{ MemoryStream fout=new MemoryStream();
try
{
DES des = new DESCryptoServiceProvider();
CryptoStream encStream = new CryptoStream(fout, des.CreateEncryptor(desKey, desIV), CryptoStreamMode.Write);
encStream.Write(buf, 0, buf.Length);
encStream.Close();  
fout.Close();

}
catch(System.Security.Cryptography.CryptographicException)
{
fout.Close();
return null;
}
catch(Exception e)
{
MessageBox.Show("Error\n"+e);
return null;
}
return fout.GetBuffer();;
}public byte[] Decrypt(byte[] buf, byte[] desKey, byte[] desIV)
{

    MemoryStream fout = new MemoryStream();
try
{ DES des = new DESCryptoServiceProvider();
CryptoStream encStream = new CryptoStream(fout, des.CreateDecryptor(desKey, desIV), CryptoStreamMode.Write);
encStream.Write(buf, 0, buf.Length);
fout.Close();

}
catch(System.Security.Cryptography.CryptographicException e)
{
MessageBox.Show(e.Message+e.StackTrace);

fout.Close();
return null;
}
catch(Exception e)
{
MessageBox.Show("Error\n"+e);
return null;
}            
return fout.GetBuffer();
}请问这个该怎么处理好呢？

Answer 1

http://www.loveyuki.com/blogview.asp?logID=167

Answer 2

多谢孟子大哥！
可是我还是不能明白，我按您给的代码加入了FlushFinalBlock：
public byte[] EncryptSend(byte[] buf, byte[] desKey, byte[] desIV)
{ MemoryStream fout=new MemoryStream();
try
{
DES des = new DESCryptoServiceProvider();
CryptoStream encStream = new CryptoStream(fout, des.CreateEncryptor(desKey, desIV), CryptoStreamMode.Write);
encStream.Write(buf, 0, buf.Length);
encStream.FlushFinalBlock();
encStream.Close();  
fout.Close();

}
catch(System.Security.Cryptography.CryptographicException)
{
fout.Close();
return null;
}
catch(Exception e)
{
MessageBox.Show("Error\n"+e);
return null;
}
return fout.GetBuffer();;
}public byte[] Decrypt(byte[] buf, byte[] desKey, byte[] desIV)
{
    MemoryStream fout = new MemoryStream();
try
{
DES des = new DESCryptoServiceProvider();
CryptoStream encStream = new CryptoStream(fout, des.CreateDecryptor(desKey, desIV), CryptoStreamMode.Write);
encStream.Write(buf, 0, buf.Length);
encStream.FlushFinalBlock();
encStream.Close();
fout.Close();
}
catch(System.Security.Cryptography.CryptographicException e)
{
MessageBox.Show(e.Message+e.StackTrace);
fout.Close();
return null;
}
catch(Exception e)
{
MessageBox.Show("Error\n"+e);
return null;
}            
return fout.GetBuffer();
}但是，在解密的时候，一调用FlushFinalBlock，就触发CryptographicException，给出的信息是“不正确的数据”
我给加密端输入的数据是这样生成的：
XmlDocument doc= new XmlDocument();
……
byte[] bb=System.Text.Encoding.Default.GetBytes(doc.OuterXml);