@Override
public void fire() {
IoSession session = getSession();
NextFilter nextFilter = getNextFilter();
IoEventType type = getType();
if (DEBUG) {
LOGGER.debug("Firing a {} event for session {}", type, session.getId());
}
switch (type) {
case MESSAGE_RECEIVED:
Object parameter = getParameter();
nextFilter.messageReceived(session, parameter);
break;
case MESSAGE_SENT:
WriteRequest writeRequest = (WriteRequest) getParameter();
nextFilter.messageSent(session, writeRequest);
break;
case WRITE:
writeRequest = (WriteRequest) getParameter();
nextFilter.filterWrite(session, writeRequest);
break;
case CLOSE:
nextFilter.filterClose(session);
break;
case EXCEPTION_CAUGHT:
Throwable throwable = (Throwable) getParameter();
nextFilter.exceptionCaught(session, throwable);
break;
case SESSION_IDLE:
nextFilter.sessionIdle(session, (IdleStatus) getParameter());
break;
case SESSION_OPENED:
nextFilter.sessionOpened(session);
break;
case SESSION_CREATED:
nextFilter.sessionCreated(session);
break;
case SESSION_CLOSED:
nextFilter.sessionClosed(session);
break;
default:
throw new IllegalArgumentException("Unknown event type: " + type);
}
if (DEBUG) {
LOGGER.debug("Event {} has been fired for session {}", type, session.getId());
}
}
public void unwrap(NextFilter nextFilter, IoBuffer buf) {
try {
int len = buf.remaining();
if (len == 0) throw new AuthException("Decryption failed");
byte[] encryptedMsg = new byte[len - 6];
byte[] msgType = new byte[2];
byte[] seqNum = new byte[4];
// Get cipherMsg; msgType; sequenceNum
buf.get(encryptedMsg);
buf.get(msgType);
buf.get(seqNum);
// Decrypt message - CIPHER(Kc, {msg, pad, HMAC(Ki, {SeqNum, msg}[0..9])})
byte[] decryptedMsg;
try {
// Do CBC (chaining) across packets
decryptedMsg = decCipher.update(encryptedMsg);
// update() can return null
if (decryptedMsg == null) throw new IllegalBlockSizeException("" + encryptedMsg.length);
} catch (IllegalBlockSizeException e) {
throw new AuthException("Illegal block sizes used with chosen cipher", e);
}
byte[] msgWithPadding = new byte[decryptedMsg.length - 10];
byte[] mac = new byte[10];
System.arraycopy(decryptedMsg, 0, msgWithPadding, 0, msgWithPadding.length);
System.arraycopy(decryptedMsg, msgWithPadding.length, mac, 0, 10);
int msgLength = msgWithPadding.length;
int blockSize = decCipher.getBlockSize();
if (blockSize > 1) {
// get value of last octet of the byte array
msgLength -= (int) msgWithPadding[msgWithPadding.length - 1];
if (msgLength < 0)
// Discard message and do not increment sequence number
throw new AuthException("Decryption failed");
}
byte[] msg = new byte[msgLength];
System.arraycopy(msgWithPadding, 0, msg, 0, msgLength);
// Re-calculate MAC to ensure integrity
byte[] expectedMac = AuthDigestMD5IoFilter.computeMACBlock(session, msg, true);
byte[] fullMac = new byte[16];
System.arraycopy(mac, 0, fullMac, 0, 10);
System.arraycopy(msgType, 0, fullMac, 10, 2);
System.arraycopy(seqNum, 0, fullMac, 12, 4);
if (isValidMAC(fullMac, expectedMac)) {
IoBuffer out = IoBuffer.allocate(msgLength + LINE_TERMINATOR.length);
out.put(msg);
out.put(LINE_TERMINATOR);
out.flip();
nextFilter.messageReceived(session, out);
}
} catch (Exception ex) {
log.debug(ex.getMessage());
nextFilter.messageReceived(session, "\r\n");
}
if (session instanceof AbstractIoSession)
((AbstractIoSession) session).increaseReadMessages(System.currentTimeMillis());
}
