public static void main(String[] args) throws IOException, NoSuchAlgorithmException {
DataOutputStream output = new DataOutputStream(new BufferedOutputStream(System.out));
LRC lrc = new LRC(output);
DataInputStream input = new DataInputStream(new BufferedInputStream(System.in));
lrc.writeStream(input);
output.flush();
}
public void run() // loop utama, utk nerima user input n kirim ke server&client laen
{
while (thread != null) {
try {
String a = console.readLine();
String b = cryptor.encrypt(a);
streamOut.writeUTF(cryptor.encrypt(a));
streamOut.flush();
} catch (IOException ioe) {
System.out.println("Sending error: " + ioe.getMessage());
stop();
}
}
}
/**
* Compute the hash an IP address. The hash is the first 8 bytes of the SHA digest of the IP
* address.
*/
private static byte[] computeAddressHash() {
/*
* Get the local host's IP address.
*/
byte[] addr =
(byte[])
java.security.AccessController.doPrivileged(
new PrivilegedAction() {
public Object run() {
try {
return InetAddress.getLocalHost().getAddress();
} catch (Exception e) {
}
return new byte[] {0, 0, 0, 0};
}
});
byte[] addrHash;
final int ADDR_HASH_LENGTH = 8;
try {
/*
* Calculate message digest of IP address using SHA.
*/
MessageDigest md = MessageDigest.getInstance("SHA");
ByteArrayOutputStream sink = new ByteArrayOutputStream(64);
DataOutputStream out = new DataOutputStream(new DigestOutputStream(sink, md));
out.write(addr, 0, addr.length);
out.flush();
byte digest[] = md.digest();
int hashlength = Math.min(ADDR_HASH_LENGTH, digest.length);
addrHash = new byte[hashlength];
System.arraycopy(digest, 0, addrHash, 0, hashlength);
} catch (IOException ignore) {
/* can't happen, but be deterministic anyway. */
addrHash = new byte[0];
} catch (NoSuchAlgorithmException complain) {
throw new InternalError(complain.toString());
}
return addrHash;
}
public void actionPerformed(ActionEvent e) {
Object source = e.getSource();
// Client pressed enter in the message entry field-send it
if (source == enterField) {
// Get the message
message = e.getActionCommand();
try {
// Encipher the message
if (message.length() > plaintextBlockSize)
message = message.substring(0, plaintextBlockSize);
byte[] ciphertext =
Ciphers.RSAEncipherWSalt(message.getBytes(), BigIntegerMath.THREE, recipModulus, sr);
// Send to the server
output.write(ciphertext);
output.flush();
// Display same message in client output area
displayArea.append("\n" + message);
enterField.setText("");
} catch (IOException ioe) {
displayArea.append("\nError writing message");
}
} else if (source == connectButton) {
if (connection != null) { // Already connected-button press now means disconnect
try {
// Send final message of 0
byte[] lastMsg = new byte[1];
lastMsg[0] = 0;
output.write(Ciphers.RSAEncipherWSalt(lastMsg, BigIntegerMath.THREE, recipModulus, sr));
output.flush();
// close connection and IO streams, change some components
closeAll();
} catch (IOException ioe) {
displayArea.append("\nError closing connection");
}
} else { // Not connected-connect
// Get name of server to connect to
chatServer = serverField.getText();
displayArea.setText("Attempting connection to " + chatServer);
try {
// Set up the socket
connection = new Socket(chatServer, 55555);
displayArea.append("\nConnected to: " + connection.getInetAddress().getHostName());
// Set up the IO streams
output = new DataOutputStream(connection.getOutputStream());
output.flush();
input = new DataInputStream(connection.getInputStream());
// Exchange public keys with the server-send yours, get theirs
exchangeKeys();
// Change appearance/functionality of some components
serverField.setEditable(false);
connectButton.setLabel("Disconnect from server above");
enterField.setEnabled(true);
// Set up a thread to listen for the connection
listener =
new Thread(
new Runnable() {
public void run() {
go();
}
});
listener.start();
} catch (IOException ioe) {
displayArea.append("\nError connecting to " + chatServer);
}
}
}
}
