【发布时间】:2014-08-24 06:53:01
【问题描述】:
我在使用 Java 的 Cipher 类时遇到了 Socket 和 ObjectInputStream 的问题。 我使用一个客户端 Android,它在 Socket 上编写一个 ObjectOutputStream,以及一个从同一个 Socket 读取这个 ObjectInputStream 的客户端 Java。 这是代码客户端/服务器
客户
[代码]
public static void functionRegistration(String usr, String pwd) throws UnknownHostException, IOException, InvalidKeyException, NoSuchAlgorithmException, NoSuchProviderException, NoSuchPaddingException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException{
Socket socket = new Socket(SERVER_ADDRESS_STRING, PORT_NO);
BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
BufferedReader br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
socket.setSoTimeout(DEFAULT_TIMEOUT);
if(!socket.isConnected()){
System.out.println("[!] [Client] Connection problem!");
socket.close();
return;
}
//Diffie-Hellman
BigInteger shared_key = DiffieHellmanExchangeClient(socket, br, bw);
byte[] hash = ObjectHash.getByteHashCode(shared_key, SECURE_HASH_TYPE.SHA384);
//Extract IV and cipherKey
byte[] IV = new byte[16];
byte[] cipherKey = new byte[32];
int i, limit;
for(i = 0; i < IV.length; i++)
IV[i] = hash[i];
limit = i;
for(; i < hash.length; i++)
cipherKey[i - limit] = hash[i];
//Send username
bw.write(usr);
bw.write("\r\n");
bw.flush();
ObjectOutputStream oos = new ObjectOutputStream(socket.getOutputStream());
//Hash password
String passwordHash = new String(ObjectHash.getByteHashCode(pwd, SECURE_HASH_TYPE.SHA512));
//Cipher password
String encryptedPasswordHash = new String(cipherMessage(passwordHash, cipherKey));
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
IvParameterSpec ivparameters = new IvParameterSpec(IV);
cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(cipherKey, "AES"), ivparameters);
oos.writeObject(new SealedObject(encryptedPasswordHash, cipher));
oos.flush();
if(br.readLine().compareTo("ACK") == 0)
Log.d("ACK", "ACK_RECEIVED");
else
Log.d("ACK","Something was wrong");
br.close();
bw.close();
socket.close();
}
[\代码]
服务器
[代码]
private void getRegistrationUser() throws IOException, InvalidKeyException, InvalidAlgorithmParameterException{
String username = br.readLine();
System.out.println("[+] [Server - Thread " + Thread.currentThread().getId() + "] Username received");
//SHA384 of shared key
byte[] hash = ObjectHash.getByteHashCode(shared_key, SECURE_HASH_TYPE.SHA384);
byte[] IV = new byte[16];
byte[] cipherKey = new byte[32];
int j, limit;
for(j = 0; j < IV.length; j++)
IV[j] = hash[j];
limit = j;
for(; j < hash.length; j++)
cipherKey[j - limit] = hash[j];
try{
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
IvParameterSpec ivparameters = new IvParameterSpec(IV);
cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(cipherKey, "AES"), ivparameters);
ObjectInputStream ois = new ObjectInputStream(client.getInputStream());
String encryptedHashPassword = (String)((SealedObject)ois.readObject()).getObject(cipher);
String decryptedHashPassword = decipherMessage(encryptedHashPassword, cipherKey);
ois.close();
sendACK();
}
catch (IOException e) {
e.printStackTrace();
} catch (InvalidKeyException e) {
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (NoSuchPaddingException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (IllegalBlockSizeException e) {
e.printStackTrace();
} catch (BadPaddingException e) {
e.printStackTrace();
}
}
[\代码]
代码 cipherMessage 和 decipherMessage 中的两个函数使用 Twofish Cipher 分别使用密钥对数据进行加密和解密
问题是:我在调试阶段注意到服务器阻塞了 newObjectInputStream 并且不可能读取客户端写入的对象
我该如何解决我的问题?
【问题讨论】:
-
你的代码在没有加密/解密的情况下能正常工作吗?
-
如果我删除了 Twofish 的操作,客户端的 cipherMessage 和服务器的 decipherMessage,代码不起作用。在调试中,我看到当打开 ObjectInputStream 时服务器被阻止。我不知道为什么。我还在客户端刷新了 ObjectOutputStream
-
服务器代码中的 Diffie-Hellman 在哪里?你是如何调试你的应用程序的?
-
Diffie-Hellman 是正确的。我测试了它。问题是我无法在android和服务器java之间的socket上传输加密信息,但是在客户端java和服务器java之间没有twofish
-
这可能是由于当时的流处理;尝试在缓冲阅读器上使用
ObjectInputStream;它可能会做它应该做的事情并从输入流中读取信息并将其缓冲,将其从ObjectInputStream试图读取的流中删除。
标签: java android security encryption objectinputstream