CipherInputStream挂起 [英] CipherInputStream hangs
问题描述
我正在尝试使用加密来使用Java通过套接字进行通信.我已经成功地与未加密的套接字通信，但是当我尝试进行加密时，程序将冻结.
I am attempting to use encryption to communicate over sockets using java. I've successfully communicated with sockets without encryption, but when I try with encryption the program freezes.
这是父 Connection 类，它可以正常工作:
Here is the parent Connection class that works just fine:
public class Connection implements Runnable
{
protected Socket socket;
protected ObjectInputStream objectInputStream;
protected ObjectOutputStream objectOutputStream;
protected Thread listeningThread;
protected Thread dispatchThread;
protected boolean listen;
protected ArrayBlockingQueue<Object> readingQueue;
protected ConnectionListener connectionListener;
public Connection()
{
listen = true;
readingQueue = new ArrayBlockingQueue<Object>(10);
}
public Connection(Socket socket, ConnectionListener listener)
{
listen = true;
connectionListener = listener;
readingQueue = new ArrayBlockingQueue<Object>(10);
this.socket = socket;
try
{
objectOutputStream = new ObjectOutputStream(socket.getOutputStream());
objectInputStream = new ObjectInputStream(socket.getInputStream());
}
catch (IOException e)
{
e.printStackTrace();
}
startConnection();
}
这是使用加密的子类:
public class EncryptedConnection extends Connection
{
private Key key;
private Cipher cipherEncryption;
private Cipher cipherDecryption;
public EncryptedConnection(Socket socket, ConnectionListener listener, byte[] keydata)
{
super();
super.socket = socket;
super.connectionListener = listener;
try
{
key = new SecretKeySpec(keydata, "AES");
cipherEncryption = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipherDecryption = Cipher.getInstance("AES/CBC/PKCS5Padding");
byte[] iv = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
IvParameterSpec ivspec = new IvParameterSpec(iv);
cipherEncryption.init(Cipher.ENCRYPT_MODE, key, ivspec);
cipherDecryption.init(Cipher.DECRYPT_MODE, key, ivspec);
objectOutputStream = new ObjectOutputStream(new CipherOutputStream(socket.getOutputStream(),cipherEncryption));
objectInputStream = new ObjectInputStream(new CipherInputStream(socket.getInputStream(),cipherDecryption));
//The hanging or freezing occurs on the above line of code
}
catch(Exception e)
{
}
这是创建套接字的服务器代码:
Here is the Server code that creates the socket:
@Override
public void run()
{
try
{
while(true)
{
Socket s = serverSocket.accept();
byte[] key = new byte[16];
for(int i=0;i<key.length;i++)
key[i] = 0x01;
EncryptedConnection c = new EncryptedConnection(s,connectionListener,key);
connections.add(c);
System.out.println("New Connection Established From"+s.getInetAddress().toString());
}
}
catch(java.net.SocketException e)
{
System.out.println("Listening thread terminated with exception.");
}
catch(IOException e)
{
e.printStackTrace();
}
}
这是创建套接字的客户端代码:
And here is the Client code that creates the socket:
@Override
public void actionPerformed(ActionEvent e)
{
if(e.getSource() == connect)
{
try
{
Socket s = new Socket(ipBox.getText(), Integer.parseInt(portBox.getText()));
byte[] key = new byte[16];
for(int i=0;i<key.length;i++)
key[i] = 0x01;
EncryptedConnection c = new EncryptedConnection(s,parent,key);
parent.connectionSuccessful(c);
}
catch (NumberFormatException e1)
{
JOptionPane.showMessageDialog(this, "Error! Port number must be a number", "Error", JOptionPane.ERROR_MESSAGE);
}
catch (UnknownHostException e1)
{
JOptionPane.showMessageDialog(this, "Error! Unable to find that host", "Error", JOptionPane.ERROR_MESSAGE);
}
catch (IOException e1)
{
e1.printStackTrace();
}
}
}
我已经查看了这篇文章，但没有帮助. CipherInputStream冻结，挂起的ObjectInputStream 我还尝试了使用不同的AES加密模式(启用和禁用填充)，但得到的结果相同.
I have viewed this post, but did not find it helpful. ObjectInputStream with CipherInputStream freezing, hanging I've also tried different AES encryption modes with padding on and off but I get the same result.
这是可以正常工作的示例代码.我本质上是在做同样的事情，但是使用套接字而不是文件.
Here is sample code that works just fine. I am essentially doing the same thing but instead of files, using sockets.
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.security.Key;
import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
public class IOTest
{
public static void main(String[] args)
{
FileOutputStream fos = null;
FileInputStream fis = null;
CipherInputStream cis = null;
CipherOutputStream cos = null;
ObjectOutputStream oos = null;
ObjectInputStream ois = null;
Key key = null;
Cipher cipherD = null;
Cipher cipherE = null;
byte[] keydata = new byte[16];
byte[] iv = new byte[16];
IvParameterSpec ivspect = new IvParameterSpec(iv);
try
{
key = new SecretKeySpec(keydata,"AES");
cipherE = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipherD = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipherE.init(Cipher.ENCRYPT_MODE, key,ivspect);
cipherD.init(Cipher.DECRYPT_MODE, key, ivspect);
fos = new FileOutputStream("hello.data");
cos = new CipherOutputStream(fos,cipherE);
oos = new ObjectOutputStream(cos);
oos.writeObject(new String("H"));
oos.flush();
oos.close();
fis = new FileInputStream("hello.data");
cis = new CipherInputStream(fis, cipherD);
ois = new ObjectInputStream(cis);
String s = ois.readObject().toString();
System.out.println(s);
ois.close();
}
catch(Exception e)
{
}
}
}
推荐答案
由于 AES 是块密码(块大小为128位)，因此它以16字节的块为单位处理数据.如果没有足够的数据用于完整的加密块，则数据将仅位于输入缓冲区中，等待出现更多数据.在接收端，您将被卡住.
As AES is a block cipher (block size of 128 bit), it processes data in blocks of 16 bytes .. if there is not enough data for a full encryption block, the data will just sit in an input buffer waiting for more data to be present. In the receiving end you would just be stuck.
仅当有足够的数据来显示整个数据块或关闭蒸汽时，才会处理滞留的数据.在关闭流的情况下，最终数据将根据使用的填充说明(例如PKCS5Padding)被修补为完整的块大小.
Only when enough data is present for a full block or if the steams is closed, will the stuck data be processed. In the case of closing the stream, the final data is patched up to a full block size according to the padding scheam used (eg. PKCS5Padding).
这篇关于CipherInputStream挂起的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
