/** When receive a message, analyze message content and then execute the command: Draw or Clear */
public void receive(Message msg) {
byte[] buf = msg.getRawBuffer();
if (buf == null) {
System.err.println(
"["
+ channel.getAddress()
+ "] received null buffer from "
+ msg.getSrc()
+ ", headers: "
+ msg.printHeaders());
return;
}
try {
DrawCommand comm =
(DrawCommand)
Util.streamableFromByteBuffer(
DrawCommand.class, buf, msg.getOffset(), msg.getLength());
switch (comm.mode) {
case DrawCommand.DRAW:
if (drawPanel != null) drawPanel.drawPoint(comm);
break;
case DrawCommand.CLEAR:
clearPanel();
default:
System.err.println("***** received invalid draw command " + comm.mode);
break;
}
} catch (Exception e) {
e.printStackTrace();
}
}
private void encryptAndSend(Message msg) throws Exception {
EncryptHeader hdr = new EncryptHeader(EncryptHeader.ENCRYPT, getSymVersion());
if (this.encrypt_entire_message) hdr.type |= EncryptHeader.ENCRYPT_ENTIRE_MSG;
if (encrypt_entire_message) {
if (msg.getSrc() == null) msg.setSrc(local_addr);
Buffer serialized_msg = Util.streamableToBuffer(msg);
byte[] encrypted_msg =
code(
serialized_msg.getBuf(),
serialized_msg.getOffset(),
serialized_msg.getLength(),
false);
// exclude existing headers, they will be seen again when we decrypt and unmarshal the msg at
// the receiver
Message tmp = msg.copy(false, false).setBuffer(encrypted_msg).putHeader(this.id, hdr);
down_prot.down(new Event(Event.MSG, tmp));
return;
}
// copy neeeded because same message (object) may be retransmitted -> no double encryption
Message msgEncrypted =
msg.copy(false)
.putHeader(this.id, hdr)
.setBuffer(code(msg.getRawBuffer(), msg.getOffset(), msg.getLength(), false));
down_prot.down(new Event(Event.MSG, msgEncrypted));
}
private Message _decrypt(final Cipher cipher, Message msg, boolean decrypt_entire_msg)
throws Exception {
byte[] decrypted_msg;
if (cipher == null)
decrypted_msg = code(msg.getRawBuffer(), msg.getOffset(), msg.getLength(), true);
else decrypted_msg = cipher.doFinal(msg.getRawBuffer(), msg.getOffset(), msg.getLength());
if (!decrypt_entire_msg) {
msg.setBuffer(decrypted_msg);
return msg;
}
Message ret = Util.streamableFromBuffer(Message.class, decrypted_msg, 0, decrypted_msg.length);
if (ret.getDest() == null) ret.setDest(msg.getDest());
if (ret.getSrc() == null) ret.setSrc(msg.getSrc());
return ret;
}
public Message visit(Message msg, MessageBatch batch) {
EncryptHeader hdr;
if (msg == null
|| (msg.getLength() == 0 && !encrypt_entire_message)
|| ((hdr = (EncryptHeader) msg.getHeader(id)) == null)) return null;
if (hdr.getType() == EncryptHeader.ENCRYPT) {
// if queueing then pass into queue to be dealt with later
if (queue_up) {
queueUpMessage(msg, batch);
return null;
}
// make sure we pass up any queued messages first
if (!suppliedKey) drainUpQueue();
if (lock == null) {
int index = getNextIndex();
lock = decoding_locks[index];
cipher = decoding_ciphers[index];
lock.lock();
}
try {
Message tmpMsg = decryptMessage(cipher, msg.copy()); // need to copy for possible xmits
if (tmpMsg != null) batch.replace(msg, tmpMsg);
} catch (Exception e) {
log.error(
"failed decrypting message from %s (offset=%d, length=%d, buf.length=%d): %s, headers are %s",
msg.getSrc(),
msg.getOffset(),
msg.getLength(),
msg.getRawBuffer().length,
e,
msg.printHeaders());
}
} else {
batch.remove(
msg); // a control message will get handled by ENCRYPT and should not be passed up
handleUpEvent(msg, hdr);
}
return null;
}
