2016-03-03 51 views
0

我正在与Cipher在底层socketdataoutputstream之间进行连接。现在根据CipherOutputStream的说明文件,为了让最后一个块加密掉,我们需要调用close()。所以在try-with-resource中使用它也会关闭底层的流,我不想因为我需要它们进行进一步的操作。

那么是否有任何方法或实施,这将有助于我在没有dataoutputstreamsocket的情况下关闭cipheroutputstream。我听说FilterOutputStream,但我不知道如何与他们合作。

我的代码:关闭没有DataOutputStream和套接字的CipherOutputStream

public class ClientHandler implements Runnable { 
Socket msock; 
DataInputStream dis; 
DataOutputStream dos; 
String ip; 
private miniClientHandler(Socket msock) { 
      this.msock = msock; 
     } 
@Override 
public void run() { 
    try { 
     dis = new DataInputStream(msock.getInputStream()); 
     dos = new DataOutputStream(msock.getOutputStream()); 

     ip = msock.getInetAddress().getHostAddress(); 

     String msg = dis.readLine(); 
     System.out.println(msg); 

     if (msg.equals("Download")) { 

        String file2dl = dis.readLine(); //2 
        File file = new File(sharedDirectory.toString() + "\\" + file2dl); 
        dos.writeLong(file.length()); //3+ 

        //AES-128 bit key initialization. 
        byte[] keyvalue = "AES128BitPasswd".getBytes(); 
        SecretKey key = new SecretKeySpec(keyvalue, "AES"); 

        //Initialize the Cipher. 
        Cipher encCipher = Cipher.getInstance("AES/CBC/PKCS5Padding"); 
        encCipher.init(Cipher.ENCRYPT_MODE, key); 

        //Get the IV from cipher. 
        IvParameterSpec spec = null; 
        try { 
         spec = encCipher.getParameters().getParameterSpec(IvParameterSpec.class); 
        } catch (InvalidParameterSpecException ex) { 
         Logger.getLogger(PeersController.class.getName()).log(Level.SEVERE, null, ex); 
        } 

        byte[] iv = spec.getIV(); 

        dos.write(iv, 0, iv.length); //4+ 

        //Encryption Mechanism. 
        try (FileInputStream fis = new FileInputStream(file)) { 
         try (CipherOutputStream cos = new CipherOutputStream(dos, encCipher)) { 
          int read; 
          byte[] buffer = new byte[1024 * 1024]; 
          while ((read = fis.read(buffer)) != -1) { 
           cos.write(buffer, 0, read); //5+ due to dos as underlying parameter of cos. 
          } 
         } 
        } 

        String message = dis.readLine(); 
        System.out.println(message); 
        if (message.equals("Fetching Done")) { 
         System.out.println("Fetching Done!"); 
        } else if (message.equals("Fetching Drop")) { 
         System.out.println("Fetching Denied!"); 
        } 
       } 
      } catch (IOException | NoSuchAlgorithmException | NoSuchPaddingException | InvalidKeyException e) { 
       System.out.println(e.getMessage()); 
      } 
     } 

    } 


现在,因为COS被包裹在试穿与资源,当while循环结束,它会关闭流和潜在的dos流已进一步包裹msock导致整个套接字关闭,剩下的代码没用了。

其余代码:

String message = dis.readLine(); 
    System.out.println(message); 
    if (message.equals("Fetching Done")) { 
     System.out.println("Fetching Done!"); 
    } else if (message.equals("Fetching Drop")) { 
       System.out.println("Fetching Denied!"); 
    } 
+0

你必须运行你自己的'Cipher'对象,然后调用'更新()'和'doFinal()'就可以了,而不是使用密码输出流,但你为什么不使用SSL? – EJP

+0

@EJP只是在正常的大学项目上工作。而且,到现在为止,还没有任何关于SSL的经验。无论如何,我会研究它。你能否提供一些片段实施,以便我可以将其标记为最终答案。 – androizer

回答

0

不知何故,我设法解决我的问题,我自己用@EJP推荐的帮助下通过update() & doFinal()创建自己的Cipher对象。

代码:

//Encryption Mechanism. 
    try (FileInputStream fis = new FileInputStream(file)) { 

     byte[] buffer = new byte[1024 * 1024]; 
     byte[] cipherBlock = new byte[encCipher.getOutputSize(buffer.length)]; 
     int cipherBytes; 
     int read; 
     while ((read = fis.read(buffer)) != -1) { 
       cipherBytes = encCipher.update(buffer, 0, read, cipherBlock); 
       dos.write(cipherBlock, 0, cipherBytes); 
     } 
     cipherBytes = encCipher.doFinal(cipherBlock, 0); //let out the last block out of the encryptor. 
     dos.write(cipherBlock, 0, cipherBytes); 
    } catch (ShortBufferException | IllegalBlockSizeException | BadPaddingException ex) { 
       Logger.getLogger(PeersController.class.getName()).log(Level.SEVERE, null, ex); 
     }