~singpolyma/cheogram-android

681ce91ab8c5d6591cbba50c2bff2c96289e3189 — Daniel Gultsch 5 years ago 6121217
do not run through connection loop after thread was interrupted and resolver returned 0 results
M src/main/java/eu/siacs/conversations/utils/Resolver.java => src/main/java/eu/siacs/conversations/utils/Resolver.java +1 -3
@@ 123,9 123,7 @@ public class Resolver {
            for(Thread thread : threads) {
                thread.interrupt();
            }
            synchronized (results) {
                return new ArrayList<>(results);
            }
            return Collections.emptyList();
        }
    }


M src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java => src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java +1782 -1780
@@ 81,10 81,10 @@ import eu.siacs.conversations.utils.Resolver;
import eu.siacs.conversations.utils.SSLSocketHelper;
import eu.siacs.conversations.utils.SocksSocketFactory;
import eu.siacs.conversations.xml.Element;
import eu.siacs.conversations.xml.Namespace;
import eu.siacs.conversations.xml.Tag;
import eu.siacs.conversations.xml.TagWriter;
import eu.siacs.conversations.xml.XmlReader;
import eu.siacs.conversations.xml.Namespace;
import eu.siacs.conversations.xmpp.forms.Data;
import eu.siacs.conversations.xmpp.forms.Field;
import eu.siacs.conversations.xmpp.jingle.OnJinglePacketReceived;


@@ 104,1783 104,1785 @@ import rocks.xmpp.addr.Jid;

public class XmppConnection implements Runnable {

	private static final int PACKET_IQ = 0;
	private static final int PACKET_MESSAGE = 1;
	private static final int PACKET_PRESENCE = 2;
	public final OnIqPacketReceived registrationResponseListener = new OnIqPacketReceived() {
		@Override
		public void onIqPacketReceived(Account account, IqPacket packet) {
			if (packet.getType() == IqPacket.TYPE.RESULT) {
				account.setOption(Account.OPTION_REGISTER, false);
				throw new StateChangingError(Account.State.REGISTRATION_SUCCESSFUL);
			} else {
				final List<String> PASSWORD_TOO_WEAK_MSGS = Arrays.asList(
						"The password is too weak",
						"Please use a longer password.");
				Element error = packet.findChild("error");
				Account.State state = Account.State.REGISTRATION_FAILED;
				if (error != null) {
					if (error.hasChild("conflict")) {
						state = Account.State.REGISTRATION_CONFLICT;
					} else if (error.hasChild("resource-constraint")
							&& "wait".equals(error.getAttribute("type"))) {
						state = Account.State.REGISTRATION_PLEASE_WAIT;
					} else if (error.hasChild("not-acceptable")
							&& PASSWORD_TOO_WEAK_MSGS.contains(error.findChildContent("text"))) {
						state = Account.State.REGISTRATION_PASSWORD_TOO_WEAK;
					}
				}
				throw new StateChangingError(state);
			}
		}
	};
	protected final Account account;
	private final Features features = new Features(this);
	private final HashMap<Jid, ServiceDiscoveryResult> disco = new HashMap<>();
	private final SparseArray<AbstractAcknowledgeableStanza> mStanzaQueue = new SparseArray<>();
	private final Hashtable<String, Pair<IqPacket, OnIqPacketReceived>> packetCallbacks = new Hashtable<>();
	private final Set<OnAdvancedStreamFeaturesLoaded> advancedStreamFeaturesLoadedListeners = new HashSet<>();
	private final XmppConnectionService mXmppConnectionService;
	private Socket socket;
	private XmlReader tagReader;
	private TagWriter tagWriter = new TagWriter();
	private boolean shouldAuthenticate = true;
	private boolean inSmacksSession = false;
	private boolean isBound = false;
	private Element streamFeatures;
	private String streamId = null;
	private int smVersion = 3;
	private int stanzasReceived = 0;
	private int stanzasSent = 0;
	private long lastPacketReceived = 0;
	private long lastPingSent = 0;
	private long lastConnect = 0;
	private long lastSessionStarted = 0;
	private long lastDiscoStarted = 0;
	private AtomicInteger mPendingServiceDiscoveries = new AtomicInteger(0);
	private AtomicBoolean mWaitForDisco = new AtomicBoolean(true);
	private AtomicBoolean mWaitingForSmCatchup = new AtomicBoolean(false);
	private AtomicInteger mSmCatchupMessageCounter = new AtomicInteger(0);
	private boolean mInteractive = false;
	private int attempt = 0;
	private OnPresencePacketReceived presenceListener = null;
	private OnJinglePacketReceived jingleListener = null;
	private OnIqPacketReceived unregisteredIqListener = null;
	private OnMessagePacketReceived messageListener = null;
	private OnStatusChanged statusListener = null;
	private OnBindListener bindListener = null;
	private OnMessageAcknowledged acknowledgedListener = null;
	private SaslMechanism saslMechanism;
	private URL redirectionUrl = null;
	private String verifiedHostname = null;
	private volatile Thread mThread;
	private CountDownLatch mStreamCountDownLatch;



	public XmppConnection(final Account account, final XmppConnectionService service) {
		this.account = account;
		this.mXmppConnectionService = service;
	}

	private static void fixResource(Context context, Account account) {
		String resource = account.getResource();
		int fixedPartLength = context.getString(R.string.app_name).length() + 1; //include the trailing dot
		int randomPartLength = 4; // 3 bytes
		if (resource != null && resource.length() > fixedPartLength + randomPartLength) {
			if (validBase64(resource.substring(fixedPartLength, fixedPartLength + randomPartLength))) {
				account.setResource(resource.substring(0, fixedPartLength + randomPartLength));
			}
		}
	}

	private static boolean validBase64(String input) {
		try {
			return Base64.decode(input, Base64.URL_SAFE).length == 3;
		} catch (Throwable throwable) {
			return false;
		}
	}

	protected void changeStatus(final Account.State nextStatus) {
		synchronized (this) {
			if (Thread.currentThread().isInterrupted()) {
				Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": not changing status to " + nextStatus + " because thread was interrupted");
				return;
			}
			if (account.getStatus() != nextStatus) {
				if ((nextStatus == Account.State.OFFLINE)
						&& (account.getStatus() != Account.State.CONNECTING)
						&& (account.getStatus() != Account.State.ONLINE)
						&& (account.getStatus() != Account.State.DISABLED)) {
					return;
				}
				if (nextStatus == Account.State.ONLINE) {
					this.attempt = 0;
				}
				account.setStatus(nextStatus);
			} else {
				return;
			}
		}
		if (statusListener != null) {
			statusListener.onStatusChanged(account);
		}
	}

	public void prepareNewConnection() {
		this.lastConnect = SystemClock.elapsedRealtime();
		this.lastPingSent = SystemClock.elapsedRealtime();
		this.lastDiscoStarted = Long.MAX_VALUE;
		this.mWaitingForSmCatchup.set(false);
		this.changeStatus(Account.State.CONNECTING);
	}

	public boolean isWaitingForSmCatchup() {
		return mWaitingForSmCatchup.get();
	}

	public void incrementSmCatchupMessageCounter() {
		this.mSmCatchupMessageCounter.incrementAndGet();
	}

	protected void connect() {
		if (mXmppConnectionService.areMessagesInitialized()) {
			mXmppConnectionService.resetSendingToWaiting(account);
		}
		Log.d(Config.LOGTAG, account.getJid().asBareJid().toString() + ": connecting");
		features.encryptionEnabled = false;
		inSmacksSession = false;
		isBound = false;
		this.attempt++;
		this.verifiedHostname = null; //will be set if user entered hostname is being used or hostname was verified with dnssec
		try {
			Socket localSocket;
			shouldAuthenticate = !account.isOptionSet(Account.OPTION_REGISTER);
			this.changeStatus(Account.State.CONNECTING);
			final boolean useTor = mXmppConnectionService.useTorToConnect() || account.isOnion();
			final boolean extended = mXmppConnectionService.showExtendedConnectionOptions();
			if (useTor) {
				String destination;
				if (account.getHostname().isEmpty()) {
					destination = account.getServer();
				} else {
					destination = account.getHostname();
					this.verifiedHostname = destination;
				}
				Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": connect to " + destination + " via Tor");
				localSocket = SocksSocketFactory.createSocketOverTor(destination, account.getPort());
				try {
					startXmpp(localSocket);
				} catch (InterruptedException e) {
					Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": thread was interrupted before beginning stream");
					return;
				} catch (Exception e) {
					throw new IOException(e.getMessage());
				}
			} else if (extended && !account.getHostname().isEmpty()) {

				this.verifiedHostname = account.getHostname();

				try {
					InetSocketAddress address = new InetSocketAddress(this.verifiedHostname, account.getPort());
					features.encryptionEnabled = address.getPort() == 5223;
					if (features.encryptionEnabled) {
						try {
							final TlsFactoryVerifier tlsFactoryVerifier = getTlsFactoryVerifier();
							localSocket = tlsFactoryVerifier.factory.createSocket();
							localSocket.connect(address, Config.SOCKET_TIMEOUT * 1000);
							final SSLSession session = ((SSLSocket) localSocket).getSession();
							final String domain = account.getJid().getDomain();
							if (!tlsFactoryVerifier.verifier.verify(domain, this.verifiedHostname, session)) {
								Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": TLS certificate verification failed");
								throw new StateChangingException(Account.State.TLS_ERROR);
							}
						} catch (KeyManagementException e) {
							throw new StateChangingException(Account.State.TLS_ERROR);
						}
					} else {
						localSocket = new Socket();
						localSocket.connect(address, Config.SOCKET_TIMEOUT * 1000);
					}
				} catch (IOException | IllegalArgumentException e) {
					throw new UnknownHostException();
				}
				try {
					startXmpp(localSocket);
				} catch (InterruptedException e) {
					Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": thread was interrupted before beginning stream");
					return;
				} catch (Exception e) {
					throw new IOException(e.getMessage());
				}
			} else if (IP.matches(account.getServer())) {
				localSocket = new Socket();
				try {
					localSocket.connect(new InetSocketAddress(account.getServer(), 5222), Config.SOCKET_TIMEOUT * 1000);
				} catch (IOException e) {
					throw new UnknownHostException();
				}
				try {
					startXmpp(localSocket);
				} catch (InterruptedException e) {
					Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": thread was interrupted before beginning stream");
					return;
				} catch (Exception e) {
					throw new IOException(e.getMessage());
				}
			} else {
				final String domain = account.getJid().getDomain();
				List<Resolver.Result> results = Resolver.resolve(account.getJid().getDomain());
				Resolver.Result storedBackupResult;
				if (!Thread.currentThread().isInterrupted()) {
					storedBackupResult = mXmppConnectionService.databaseBackend.findResolverResult(domain);
					if (storedBackupResult != null && !results.contains(storedBackupResult)) {
						results.add(storedBackupResult);
						Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": loaded backup resolver result from db: " + storedBackupResult);
					}
				} else {
					storedBackupResult = null;
				}
				for (Iterator<Resolver.Result> iterator = results.iterator(); iterator.hasNext(); ) {
					final Resolver.Result result = iterator.next();
					if (Thread.currentThread().isInterrupted()) {
						Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": Thread was interrupted");
						return;
					}
					try {
						// if tls is true, encryption is implied and must not be started
						features.encryptionEnabled = result.isDirectTls();
						verifiedHostname = result.isAuthenticated() ? result.getHostname().toString() : null;
						final InetSocketAddress addr;
						if (result.getIp() != null) {
							addr = new InetSocketAddress(result.getIp(), result.getPort());
							Log.d(Config.LOGTAG, account.getJid().asBareJid().toString()
									+ ": using values from dns " + result.getHostname().toString()
									+ "/" + result.getIp().getHostAddress() + ":" + result.getPort() + " tls: " + features.encryptionEnabled);
						} else {
							addr = new InetSocketAddress(IDN.toASCII(result.getHostname().toString()), result.getPort());
							Log.d(Config.LOGTAG, account.getJid().asBareJid().toString()
									+ ": using values from dns "
									+ result.getHostname().toString() + ":" + result.getPort() + " tls: " + features.encryptionEnabled);
						}

						if (!features.encryptionEnabled) {
							localSocket = new Socket();
							localSocket.connect(addr, Config.SOCKET_TIMEOUT * 1000);
						} else {
							final TlsFactoryVerifier tlsFactoryVerifier = getTlsFactoryVerifier();
							localSocket = tlsFactoryVerifier.factory.createSocket();

							if (localSocket == null) {
								throw new IOException("could not initialize ssl socket");
							}

							SSLSocketHelper.setSecurity((SSLSocket) localSocket);
							SSLSocketHelper.setHostname((SSLSocket) localSocket, account.getServer());
							SSLSocketHelper.setApplicationProtocol((SSLSocket) localSocket, "xmpp-client");

							localSocket.connect(addr, Config.SOCKET_TIMEOUT * 1000);

							if (!tlsFactoryVerifier.verifier.verify(account.getServer(), verifiedHostname, ((SSLSocket) localSocket).getSession())) {
								Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": TLS certificate verification failed");
								if (!iterator.hasNext()) {
									throw new StateChangingException(Account.State.TLS_ERROR);
								}
							}
						}
						if (startXmpp(localSocket)) {
							if (!result.equals(storedBackupResult)) {
								mXmppConnectionService.databaseBackend.saveResolverResult(domain, result);
							}
							break; // successfully connected to server that speaks xmpp
						} else {
							localSocket.close();
						}
					} catch (final StateChangingException e) {
						throw e;
					} catch (InterruptedException e) {
						Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": thread was interrupted before beginning stream");
						return;
					} catch (final Throwable e) {
						Log.d(Config.LOGTAG, account.getJid().asBareJid().toString() + ": " + e.getMessage() + "(" + e.getClass().getName() + ")");
						if (!iterator.hasNext()) {
							throw new UnknownHostException();
						}
					}
				}
			}
			processStream();
		} catch (final SecurityException e) {
			this.changeStatus(Account.State.MISSING_INTERNET_PERMISSION);
		} catch (final StateChangingException e) {
			this.changeStatus(e.state);
		} catch (final UnknownHostException | ConnectException e) {
			this.changeStatus(Account.State.SERVER_NOT_FOUND);
		} catch (final SocksSocketFactory.SocksProxyNotFoundException e) {
			this.changeStatus(Account.State.TOR_NOT_AVAILABLE);
		} catch (final IOException | XmlPullParserException | NoSuchAlgorithmException e) {
			Log.d(Config.LOGTAG, account.getJid().asBareJid().toString() + ": " + e.getMessage());
			this.changeStatus(Account.State.OFFLINE);
			this.attempt = Math.max(0, this.attempt - 1);
		} finally {
			if (!Thread.currentThread().isInterrupted()) {
				forceCloseSocket();
			} else {
				Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": not force closing socket because thread was interrupted");
			}
		}
	}

	/**
	 * Starts xmpp protocol, call after connecting to socket
	 *
	 * @return true if server returns with valid xmpp, false otherwise
	 */
	private boolean startXmpp(Socket socket) throws Exception {
		if (Thread.currentThread().isInterrupted()) {
			throw new InterruptedException();
		}
		this.socket = socket;
		tagReader = new XmlReader();
		if (tagWriter != null) {
			tagWriter.forceClose();
		}
		tagWriter = new TagWriter();
		tagWriter.setOutputStream(socket.getOutputStream());
		tagReader.setInputStream(socket.getInputStream());
		tagWriter.beginDocument();
		sendStartStream();
		final Tag tag = tagReader.readTag();
		if (Thread.currentThread().isInterrupted()) {
			throw new InterruptedException();
		}
		if (socket instanceof SSLSocket) {
			SSLSocketHelper.log(account, (SSLSocket) socket);
		}
		return tag != null && tag.isStart("stream");
	}

	private TlsFactoryVerifier getTlsFactoryVerifier() throws NoSuchAlgorithmException, KeyManagementException, IOException {
		final SSLContext sc = SSLSocketHelper.getSSLContext();
		MemorizingTrustManager trustManager = this.mXmppConnectionService.getMemorizingTrustManager();
		KeyManager[] keyManager;
		if (account.getPrivateKeyAlias() != null && account.getPassword().isEmpty()) {
			keyManager = new KeyManager[]{new MyKeyManager()};
		} else {
			keyManager = null;
		}
		String domain = account.getJid().getDomain();
		sc.init(keyManager, new X509TrustManager[]{mInteractive ? trustManager.getInteractive(domain) : trustManager.getNonInteractive(domain)}, mXmppConnectionService.getRNG());
		final SSLSocketFactory factory = sc.getSocketFactory();
		final DomainHostnameVerifier verifier = trustManager.wrapHostnameVerifier(new XmppDomainVerifier(), mInteractive);
		return new TlsFactoryVerifier(factory, verifier);
	}

	@Override
	public void run() {
		synchronized (this) {
			this.mThread = Thread.currentThread();
			if (this.mThread.isInterrupted()) {
				Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": aborting connect because thread was interrupted");
				return;
			}
			forceCloseSocket();
		}
		connect();
	}

	private void processStream() throws XmlPullParserException, IOException {
		final CountDownLatch streamCountDownLatch = new CountDownLatch(1);
		this.mStreamCountDownLatch = streamCountDownLatch;
		Tag nextTag = tagReader.readTag();
		while (nextTag != null && !nextTag.isEnd("stream")) {
			if (nextTag.isStart("error")) {
				processStreamError(nextTag);
			} else if (nextTag.isStart("features")) {
				processStreamFeatures(nextTag);
			} else if (nextTag.isStart("proceed")) {
				switchOverToTls(nextTag);
			} else if (nextTag.isStart("success")) {
				final String challenge = tagReader.readElement(nextTag).getContent();
				try {
					saslMechanism.getResponse(challenge);
				} catch (final SaslMechanism.AuthenticationException e) {
					Log.e(Config.LOGTAG, String.valueOf(e));
					throw new StateChangingException(Account.State.UNAUTHORIZED);
				}
				Log.d(Config.LOGTAG, account.getJid().asBareJid().toString() + ": logged in");
				account.setKey(Account.PINNED_MECHANISM_KEY,
						String.valueOf(saslMechanism.getPriority()));
				tagReader.reset();
				sendStartStream();
				final Tag tag = tagReader.readTag();
				if (tag != null && tag.isStart("stream")) {
					processStream();
				} else {
					throw new IOException("server didn't restart stream after successful auth");
				}
				break;
			} else if (nextTag.isStart("failure")) {
				final Element failure = tagReader.readElement(nextTag);
				if (Namespace.SASL.equals(failure.getNamespace())) {
					final String text = failure.findChildContent("text");
					if (failure.hasChild("account-disabled") && text != null) {
						Matcher matcher = Patterns.AUTOLINK_WEB_URL.matcher(text);
						if (matcher.find()) {
							try {
								URL url = new URL(text.substring(matcher.start(), matcher.end()));
								if (url.getProtocol().equals("https")) {
									this.redirectionUrl = url;
									throw new StateChangingException(Account.State.PAYMENT_REQUIRED);
								}
							} catch (MalformedURLException e) {
								throw new StateChangingException(Account.State.UNAUTHORIZED);
							}
						}
					}
					throw new StateChangingException(Account.State.UNAUTHORIZED);
				} else if (Namespace.TLS.equals(failure.getNamespace())) {
					throw new StateChangingException(Account.State.TLS_ERROR);
				} else {
					throw new StateChangingException(Account.State.INCOMPATIBLE_SERVER);
				}
			} else if (nextTag.isStart("challenge")) {
				final String challenge = tagReader.readElement(nextTag).getContent();
				final Element response = new Element("response", Namespace.SASL);
				try {
					response.setContent(saslMechanism.getResponse(challenge));
				} catch (final SaslMechanism.AuthenticationException e) {
					// TODO: Send auth abort tag.
					Log.e(Config.LOGTAG, e.toString());
				}
				tagWriter.writeElement(response);
			} else if (nextTag.isStart("enabled")) {
				final Element enabled = tagReader.readElement(nextTag);
				if ("true".equals(enabled.getAttribute("resume"))) {
					this.streamId = enabled.getAttribute("id");
					Log.d(Config.LOGTAG, account.getJid().asBareJid().toString()
							+ ": stream management(" + smVersion
							+ ") enabled (resumable)");
				} else {
					Log.d(Config.LOGTAG, account.getJid().asBareJid().toString()
							+ ": stream management(" + smVersion + ") enabled");
				}
				this.stanzasReceived = 0;
				this.inSmacksSession = true;
				final RequestPacket r = new RequestPacket(smVersion);
				tagWriter.writeStanzaAsync(r);
			} else if (nextTag.isStart("resumed")) {
				this.inSmacksSession = true;
				this.isBound = true;
				this.tagWriter.writeStanzaAsync(new RequestPacket(smVersion));
				lastPacketReceived = SystemClock.elapsedRealtime();
				final Element resumed = tagReader.readElement(nextTag);
				final String h = resumed.getAttribute("h");
				try {
					ArrayList<AbstractAcknowledgeableStanza> failedStanzas = new ArrayList<>();
					final boolean acknowledgedMessages;
					synchronized (this.mStanzaQueue) {
						final int serverCount = Integer.parseInt(h);
						if (serverCount < stanzasSent) {
							Log.d(Config.LOGTAG, account.getJid().asBareJid().toString()
									+ ": session resumed with lost packages");
							stanzasSent = serverCount;
						} else {
							Log.d(Config.LOGTAG, account.getJid().asBareJid().toString() + ": session resumed");
						}
						acknowledgedMessages = acknowledgeStanzaUpTo(serverCount);
						for (int i = 0; i < this.mStanzaQueue.size(); ++i) {
							failedStanzas.add(mStanzaQueue.valueAt(i));
						}
						mStanzaQueue.clear();
					}
					if (acknowledgedMessages) {
						mXmppConnectionService.updateConversationUi();
					}
					Log.d(Config.LOGTAG, "resending " + failedStanzas.size() + " stanzas");
					for (AbstractAcknowledgeableStanza packet : failedStanzas) {
						if (packet instanceof MessagePacket) {
							MessagePacket message = (MessagePacket) packet;
							mXmppConnectionService.markMessage(account,
									message.getTo().asBareJid(),
									message.getId(),
									Message.STATUS_UNSEND);
						}
						sendPacket(packet);
					}
				} catch (final NumberFormatException ignored) {
				}
				Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": online with resource " + account.getResource());
				changeStatus(Account.State.ONLINE);
			} else if (nextTag.isStart("r")) {
				tagReader.readElement(nextTag);
				if (Config.EXTENDED_SM_LOGGING) {
					Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": acknowledging stanza #" + this.stanzasReceived);
				}
				final AckPacket ack = new AckPacket(this.stanzasReceived, smVersion);
				tagWriter.writeStanzaAsync(ack);
			} else if (nextTag.isStart("a")) {
				boolean accountUiNeedsRefresh = false;
				synchronized (NotificationService.CATCHUP_LOCK) {
					if (mWaitingForSmCatchup.compareAndSet(true, false)) {
						int count = mSmCatchupMessageCounter.get();
						Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": SM catchup complete (" + count + ")");
						accountUiNeedsRefresh = true;
						if (count > 0) {
							mXmppConnectionService.getNotificationService().finishBacklog(true, account);
						}
					}
				}
				if (accountUiNeedsRefresh) {
					mXmppConnectionService.updateAccountUi();
				}
				final Element ack = tagReader.readElement(nextTag);
				lastPacketReceived = SystemClock.elapsedRealtime();
				try {
					final boolean acknowledgedMessages;
					synchronized (this.mStanzaQueue) {
						final int serverSequence = Integer.parseInt(ack.getAttribute("h"));
						acknowledgedMessages = acknowledgeStanzaUpTo(serverSequence);
					}
					if (acknowledgedMessages) {
						mXmppConnectionService.updateConversationUi();
					}
				} catch (NumberFormatException | NullPointerException e) {
					Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": server send ack without sequence number");
				}
			} else if (nextTag.isStart("failed")) {
				Element failed = tagReader.readElement(nextTag);
				try {
					final int serverCount = Integer.parseInt(failed.getAttribute("h"));
					Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": resumption failed but server acknowledged stanza #" + serverCount);
					final boolean acknowledgedMessages;
					synchronized (this.mStanzaQueue) {
						acknowledgedMessages = acknowledgeStanzaUpTo(serverCount);
					}
					if (acknowledgedMessages) {
						mXmppConnectionService.updateConversationUi();
					}
				} catch (NumberFormatException | NullPointerException e) {
					Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": resumption failed");
				}
				resetStreamId();
				sendBindRequest();
			} else if (nextTag.isStart("iq")) {
				processIq(nextTag);
			} else if (nextTag.isStart("message")) {
				processMessage(nextTag);
			} else if (nextTag.isStart("presence")) {
				processPresence(nextTag);
			}
			nextTag = tagReader.readTag();
		}
		if (nextTag != null && nextTag.isEnd("stream")) {
			streamCountDownLatch.countDown();
		}
	}

	private boolean acknowledgeStanzaUpTo(int serverCount) {
		if (serverCount > stanzasSent) {
			Log.e(Config.LOGTAG, "server acknowledged more stanzas than we sent. serverCount=" + serverCount + ", ourCount=" + stanzasSent);
		}
		boolean acknowledgedMessages = false;
		for (int i = 0; i < mStanzaQueue.size(); ++i) {
			if (serverCount >= mStanzaQueue.keyAt(i)) {
				if (Config.EXTENDED_SM_LOGGING) {
					Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": server acknowledged stanza #" + mStanzaQueue.keyAt(i));
				}
				AbstractAcknowledgeableStanza stanza = mStanzaQueue.valueAt(i);
				if (stanza instanceof MessagePacket && acknowledgedListener != null) {
					MessagePacket packet = (MessagePacket) stanza;
					acknowledgedMessages |= acknowledgedListener.onMessageAcknowledged(account, packet.getId());
				}
				mStanzaQueue.removeAt(i);
				i--;
			}
		}
		return acknowledgedMessages;
	}

	private @NonNull
	Element processPacket(final Tag currentTag, final int packetType) throws XmlPullParserException, IOException {
		Element element;
		switch (packetType) {
			case PACKET_IQ:
				element = new IqPacket();
				break;
			case PACKET_MESSAGE:
				element = new MessagePacket();
				break;
			case PACKET_PRESENCE:
				element = new PresencePacket();
				break;
			default:
				throw new AssertionError("Should never encounter invalid type");
		}
		element.setAttributes(currentTag.getAttributes());
		Tag nextTag = tagReader.readTag();
		if (nextTag == null) {
			throw new IOException("interrupted mid tag");
		}
		while (!nextTag.isEnd(element.getName())) {
			if (!nextTag.isNo()) {
				final Element child = tagReader.readElement(nextTag);
				final String type = currentTag.getAttribute("type");
				if (packetType == PACKET_IQ
						&& "jingle".equals(child.getName())
						&& ("set".equalsIgnoreCase(type) || "get"
						.equalsIgnoreCase(type))) {
					element = new JinglePacket();
					element.setAttributes(currentTag.getAttributes());
				}
				element.addChild(child);
			}
			nextTag = tagReader.readTag();
			if (nextTag == null) {
				throw new IOException("interrupted mid tag");
			}
		}
		if (stanzasReceived == Integer.MAX_VALUE) {
			resetStreamId();
			throw new IOException("time to restart the session. cant handle >2 billion pcks");
		}
		if (inSmacksSession) {
			++stanzasReceived;
		} else if (features.sm()) {
			Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": not counting stanza(" + element.getClass().getSimpleName() + "). Not in smacks session.");
		}
		lastPacketReceived = SystemClock.elapsedRealtime();
		if (Config.BACKGROUND_STANZA_LOGGING && mXmppConnectionService.checkListeners()) {
			Log.d(Config.LOGTAG, "[background stanza] " + element);
		}
		return element;
	}

	private void processIq(final Tag currentTag) throws XmlPullParserException, IOException {
		final IqPacket packet = (IqPacket) processPacket(currentTag, PACKET_IQ);
		if (!packet.valid()) {
			Log.e(Config.LOGTAG, "encountered invalid iq from='" + packet.getFrom() + "' to='" + packet.getTo() + "'");
			return;
		}
		if (packet instanceof JinglePacket) {
			if (this.jingleListener != null) {
				this.jingleListener.onJinglePacketReceived(account, (JinglePacket) packet);
			}
		} else {
			OnIqPacketReceived callback = null;
			synchronized (this.packetCallbacks) {
				if (packetCallbacks.containsKey(packet.getId())) {
					final Pair<IqPacket, OnIqPacketReceived> packetCallbackDuple = packetCallbacks.get(packet.getId());
					// Packets to the server should have responses from the server
					if (packetCallbackDuple.first.toServer(account)) {
						if (packet.fromServer(account)) {
							callback = packetCallbackDuple.second;
							packetCallbacks.remove(packet.getId());
						} else {
							Log.e(Config.LOGTAG, account.getJid().asBareJid().toString() + ": ignoring spoofed iq packet");
						}
					} else {
						if (packet.getFrom() != null && packet.getFrom().equals(packetCallbackDuple.first.getTo())) {
							callback = packetCallbackDuple.second;
							packetCallbacks.remove(packet.getId());
						} else {
							Log.e(Config.LOGTAG, account.getJid().asBareJid().toString() + ": ignoring spoofed iq packet");
						}
					}
				} else if (packet.getType() == IqPacket.TYPE.GET || packet.getType() == IqPacket.TYPE.SET) {
					callback = this.unregisteredIqListener;
				}
			}
			if (callback != null) {
				try {
					callback.onIqPacketReceived(account, packet);
				} catch (StateChangingError error) {
					throw new StateChangingException(error.state);
				}
			}
		}
	}

	private void processMessage(final Tag currentTag) throws XmlPullParserException, IOException {
		final MessagePacket packet = (MessagePacket) processPacket(currentTag, PACKET_MESSAGE);
		if (!packet.valid()) {
			Log.e(Config.LOGTAG, "encountered invalid message from='" + packet.getFrom() + "' to='" + packet.getTo() + "'");
			return;
		}
		this.messageListener.onMessagePacketReceived(account, packet);
	}

	private void processPresence(final Tag currentTag) throws XmlPullParserException, IOException {
		PresencePacket packet = (PresencePacket) processPacket(currentTag, PACKET_PRESENCE);
		if (!packet.valid()) {
			Log.e(Config.LOGTAG, "encountered invalid presence from='" + packet.getFrom() + "' to='" + packet.getTo() + "'");
			return;
		}
		this.presenceListener.onPresencePacketReceived(account, packet);
	}

	private void sendStartTLS() throws IOException {
		final Tag startTLS = Tag.empty("starttls");
		startTLS.setAttribute("xmlns", Namespace.TLS);
		tagWriter.writeTag(startTLS);
	}

	private void switchOverToTls(final Tag currentTag) throws XmlPullParserException, IOException {
		tagReader.readTag();
		try {
			final TlsFactoryVerifier tlsFactoryVerifier = getTlsFactoryVerifier();
			final InetAddress address = socket == null ? null : socket.getInetAddress();

			if (address == null) {
				throw new IOException("could not setup ssl");
			}

			final SSLSocket sslSocket = (SSLSocket) tlsFactoryVerifier.factory.createSocket(socket, address.getHostAddress(), socket.getPort(), true);

			if (sslSocket == null) {
				throw new IOException("could not initialize ssl socket");
			}

			SSLSocketHelper.setSecurity(sslSocket);

			if (!tlsFactoryVerifier.verifier.verify(account.getServer(), this.verifiedHostname, sslSocket.getSession())) {
				Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": TLS certificate verification failed");
				throw new StateChangingException(Account.State.TLS_ERROR);
			}
			tagReader.setInputStream(sslSocket.getInputStream());
			tagWriter.setOutputStream(sslSocket.getOutputStream());
			sendStartStream();
			Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": TLS connection established");
			features.encryptionEnabled = true;
			final Tag tag = tagReader.readTag();
			if (tag != null && tag.isStart("stream")) {
				SSLSocketHelper.log(account, sslSocket);
				processStream();
			} else {
				throw new IOException("server didn't restart stream after STARTTLS");
			}
			sslSocket.close();
		} catch (final NoSuchAlgorithmException | KeyManagementException e1) {
			Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": TLS certificate verification failed");
			throw new StateChangingException(Account.State.TLS_ERROR);
		}
	}

	private void processStreamFeatures(final Tag currentTag) throws XmlPullParserException, IOException {
		this.streamFeatures = tagReader.readElement(currentTag);
		final boolean isSecure = features.encryptionEnabled || Config.ALLOW_NON_TLS_CONNECTIONS;
		final boolean needsBinding = !isBound && !account.isOptionSet(Account.OPTION_REGISTER);
		if (this.streamFeatures.hasChild("starttls") && !features.encryptionEnabled) {
			sendStartTLS();
		} else if (this.streamFeatures.hasChild("register") && account.isOptionSet(Account.OPTION_REGISTER)) {
			if (isSecure) {
				sendRegistryRequest();
			} else {
				throw new StateChangingException(Account.State.INCOMPATIBLE_SERVER);
			}
		} else if (!this.streamFeatures.hasChild("register") && account.isOptionSet(Account.OPTION_REGISTER)) {
			throw new StateChangingException(Account.State.REGISTRATION_NOT_SUPPORTED);
		} else if (this.streamFeatures.hasChild("mechanisms") && shouldAuthenticate && isSecure) {
			authenticate();
		} else if (this.streamFeatures.hasChild("sm", "urn:xmpp:sm:" + smVersion) && streamId != null) {
			if (Config.EXTENDED_SM_LOGGING) {
				Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": resuming after stanza #" + stanzasReceived);
			}
			final ResumePacket resume = new ResumePacket(this.streamId, stanzasReceived, smVersion);
			this.mSmCatchupMessageCounter.set(0);
			this.mWaitingForSmCatchup.set(true);
			this.tagWriter.writeStanzaAsync(resume);
		} else if (needsBinding) {
			if (this.streamFeatures.hasChild("bind") && isSecure) {
				sendBindRequest();
			} else {
				throw new StateChangingException(Account.State.INCOMPATIBLE_SERVER);
			}
		}
	}

	private void authenticate() throws IOException {
		final List<String> mechanisms = extractMechanisms(streamFeatures
				.findChild("mechanisms"));
		final Element auth = new Element("auth", Namespace.SASL);
		if (mechanisms.contains("EXTERNAL") && account.getPrivateKeyAlias() != null) {
			saslMechanism = new External(tagWriter, account, mXmppConnectionService.getRNG());
		} else if (mechanisms.contains("SCRAM-SHA-256")) {
			saslMechanism = new ScramSha256(tagWriter, account, mXmppConnectionService.getRNG());
		} else if (mechanisms.contains("SCRAM-SHA-1")) {
			saslMechanism = new ScramSha1(tagWriter, account, mXmppConnectionService.getRNG());
		} else if (mechanisms.contains("PLAIN") && !account.getJid().getDomain().equals("nimbuzz.com")) {
			saslMechanism = new Plain(tagWriter, account);
		} else if (mechanisms.contains("DIGEST-MD5")) {
			saslMechanism = new DigestMd5(tagWriter, account, mXmppConnectionService.getRNG());
		} else if (mechanisms.contains("ANONYMOUS")) {
			saslMechanism = new Anonymous(tagWriter, account, mXmppConnectionService.getRNG());
		}
		if (saslMechanism != null) {
			final int pinnedMechanism = account.getKeyAsInt(Account.PINNED_MECHANISM_KEY, -1);
			if (pinnedMechanism > saslMechanism.getPriority()) {
				Log.e(Config.LOGTAG, "Auth failed. Authentication mechanism " + saslMechanism.getMechanism() +
						" has lower priority (" + String.valueOf(saslMechanism.getPriority()) +
						") than pinned priority (" + pinnedMechanism +
						"). Possible downgrade attack?");
				throw new StateChangingException(Account.State.DOWNGRADE_ATTACK);
			}
			Log.d(Config.LOGTAG, account.getJid().toString() + ": Authenticating with " + saslMechanism.getMechanism());
			auth.setAttribute("mechanism", saslMechanism.getMechanism());
			if (!saslMechanism.getClientFirstMessage().isEmpty()) {
				auth.setContent(saslMechanism.getClientFirstMessage());
			}
			tagWriter.writeElement(auth);
		} else {
			throw new StateChangingException(Account.State.INCOMPATIBLE_SERVER);
		}
	}

	private List<String> extractMechanisms(final Element stream) {
		final ArrayList<String> mechanisms = new ArrayList<>(stream
				.getChildren().size());
		for (final Element child : stream.getChildren()) {
			mechanisms.add(child.getContent());
		}
		return mechanisms;
	}

	private void sendRegistryRequest() {
		final IqPacket register = new IqPacket(IqPacket.TYPE.GET);
		register.query("jabber:iq:register");
		register.setTo(Jid.of(account.getServer()));
		sendUnmodifiedIqPacket(register, (account, packet) -> {
			if (packet.getType() == IqPacket.TYPE.TIMEOUT) {
				return;
			}
			if (packet.getType() == IqPacket.TYPE.ERROR) {
				throw new StateChangingError(Account.State.REGISTRATION_FAILED);
			}
			final Element query = packet.query("jabber:iq:register");
			if (query.hasChild("username") && (query.hasChild("password"))) {
				final IqPacket register1 = new IqPacket(IqPacket.TYPE.SET);
				final Element username = new Element("username").setContent(account.getUsername());
				final Element password = new Element("password").setContent(account.getPassword());
				register1.query("jabber:iq:register").addChild(username);
				register1.query().addChild(password);
				register1.setFrom(account.getJid().asBareJid());
				sendUnmodifiedIqPacket(register1, registrationResponseListener, true);
			} else if (query.hasChild("x", Namespace.DATA)) {
				final Data data = Data.parse(query.findChild("x", Namespace.DATA));
				final Element blob = query.findChild("data", "urn:xmpp:bob");
				final String id = packet.getId();
				InputStream is;
				if (blob != null) {
					try {
						final String base64Blob = blob.getContent();
						final byte[] strBlob = Base64.decode(base64Blob, Base64.DEFAULT);
						is = new ByteArrayInputStream(strBlob);
					} catch (Exception e) {
						is = null;
					}
				} else {
					try {
						Field field = data.getFieldByName("url");
						URL url = field != null && field.getValue() != null ? new URL(field.getValue()) : null;
						is = url != null ? url.openStream() : null;
					} catch (IOException e) {
						is = null;
					}
				}

				if (is != null) {
					Bitmap captcha = BitmapFactory.decodeStream(is);
					try {
						if (mXmppConnectionService.displayCaptchaRequest(account, id, data, captcha)) {
							return;
						}
					} catch (Exception e) {
						throw new StateChangingError(Account.State.REGISTRATION_FAILED);
					}
				}
				throw new StateChangingError(Account.State.REGISTRATION_FAILED);
			} else if (query.hasChild("instructions") || query.hasChild("x", Namespace.OOB)) {
				final String instructions = query.findChildContent("instructions");
				final Element oob = query.findChild("x", Namespace.OOB);
				final String url = oob == null ? null : oob.findChildContent("url");
				if (url != null) {
					setAccountCreationFailed(url);
				} else if (instructions != null) {
					Matcher matcher = Patterns.AUTOLINK_WEB_URL.matcher(instructions);
					if (matcher.find()) {
						setAccountCreationFailed(instructions.substring(matcher.start(), matcher.end()));
					}
				}
				throw new StateChangingError(Account.State.REGISTRATION_FAILED);
			}
		}, true);
	}

	private void setAccountCreationFailed(String url) {
		if (url != null) {
			try {
				this.redirectionUrl = new URL(url);
				if (this.redirectionUrl.getProtocol().equals("https")) {
					throw new StateChangingError(Account.State.REGISTRATION_WEB);
				}
			} catch (MalformedURLException e) {
				//fall through
			}
		}
		throw new StateChangingError(Account.State.REGISTRATION_FAILED);
	}

	public URL getRedirectionUrl() {
		return this.redirectionUrl;
	}

	public void resetEverything() {
		resetAttemptCount(true);
		resetStreamId();
		clearIqCallbacks();
		this.stanzasSent = 0;
		mStanzaQueue.clear();
		this.redirectionUrl = null;
		synchronized (this.disco) {
			disco.clear();
		}
	}

	private void sendBindRequest() {
		try {
			mXmppConnectionService.restoredFromDatabaseLatch.await();
		} catch (InterruptedException e) {
			Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": interrupted while waiting for DB restore during bind");
			return;
		}
		clearIqCallbacks();
		if (account.getJid().isBareJid()) {
			account.setResource(this.createNewResource());
		} else {
			fixResource(mXmppConnectionService, account);
		}
		final IqPacket iq = new IqPacket(IqPacket.TYPE.SET);
		final String resource = Config.USE_RANDOM_RESOURCE_ON_EVERY_BIND ? nextRandomId() : account.getResource();
		iq.addChild("bind", Namespace.BIND).addChild("resource").setContent(resource);
		this.sendUnmodifiedIqPacket(iq, (account, packet) -> {
			if (packet.getType() == IqPacket.TYPE.TIMEOUT) {
				return;
			}
			final Element bind = packet.findChild("bind");
			if (bind != null && packet.getType() == IqPacket.TYPE.RESULT) {
				isBound = true;
				final Element jid = bind.findChild("jid");
				if (jid != null && jid.getContent() != null) {
					try {
						Jid assignedJid = Jid.ofEscaped(jid.getContent());
						if (!account.getJid().getDomain().equals(assignedJid.getDomain())) {
							Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": server tried to re-assign domain to " + assignedJid.getDomain());
							throw new StateChangingError(Account.State.BIND_FAILURE);
						}
						if (account.setJid(assignedJid)) {
							Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": jid changed during bind. updating database");
							mXmppConnectionService.databaseBackend.updateAccount(account);
						}
						if (streamFeatures.hasChild("session")
								&& !streamFeatures.findChild("session").hasChild("optional")) {
							sendStartSession();
						} else {
							sendPostBindInitialization();
						}
						return;
					} catch (final IllegalArgumentException e) {
						Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": server reported invalid jid (" + jid.getContent() + ") on bind");
					}
				} else {
					Log.d(Config.LOGTAG, account.getJid() + ": disconnecting because of bind failure. (no jid)");
				}
			} else {
				Log.d(Config.LOGTAG, account.getJid() + ": disconnecting because of bind failure (" + packet.toString());
			}
			final Element error = packet.findChild("error");
			if (packet.getType() == IqPacket.TYPE.ERROR && error != null && error.hasChild("conflict")) {
				account.setResource(createNewResource());
			}
			throw new StateChangingError(Account.State.BIND_FAILURE);
		}, true);
	}

	private void clearIqCallbacks() {
		final IqPacket failurePacket = new IqPacket(IqPacket.TYPE.TIMEOUT);
		final ArrayList<OnIqPacketReceived> callbacks = new ArrayList<>();
		synchronized (this.packetCallbacks) {
			if (this.packetCallbacks.size() == 0) {
				return;
			}
			Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": clearing " + this.packetCallbacks.size() + " iq callbacks");
			final Iterator<Pair<IqPacket, OnIqPacketReceived>> iterator = this.packetCallbacks.values().iterator();
			while (iterator.hasNext()) {
				Pair<IqPacket, OnIqPacketReceived> entry = iterator.next();
				callbacks.add(entry.second);
				iterator.remove();
			}
		}
		for (OnIqPacketReceived callback : callbacks) {
			try {
				callback.onIqPacketReceived(account, failurePacket);
			} catch (StateChangingError error) {
				Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": caught StateChangingError(" + error.state.toString() + ") while clearing callbacks");
				//ignore
			}
		}
		Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": done clearing iq callbacks. " + this.packetCallbacks.size() + " left");
	}

	public void sendDiscoTimeout() {
		if (mWaitForDisco.compareAndSet(true, false)) {
			Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": finalizing bind after disco timeout");
			finalizeBind();
		}
	}

	private void sendStartSession() {
		Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": sending legacy session to outdated server");
		final IqPacket startSession = new IqPacket(IqPacket.TYPE.SET);
		startSession.addChild("session", "urn:ietf:params:xml:ns:xmpp-session");
		this.sendUnmodifiedIqPacket(startSession, (account, packet) -> {
			if (packet.getType() == IqPacket.TYPE.RESULT) {
				sendPostBindInitialization();
			} else if (packet.getType() != IqPacket.TYPE.TIMEOUT) {
				throw new StateChangingError(Account.State.SESSION_FAILURE);
			}
		}, true);
	}

	private void sendPostBindInitialization() {
		smVersion = 0;
		if (streamFeatures.hasChild("sm", "urn:xmpp:sm:3")) {
			smVersion = 3;
		} else if (streamFeatures.hasChild("sm", "urn:xmpp:sm:2")) {
			smVersion = 2;
		}
		if (smVersion != 0) {
			synchronized (this.mStanzaQueue) {
				final EnablePacket enable = new EnablePacket(smVersion);
				tagWriter.writeStanzaAsync(enable);
				stanzasSent = 0;
				mStanzaQueue.clear();
			}
		}
		features.carbonsEnabled = false;
		features.blockListRequested = false;
		synchronized (this.disco) {
			this.disco.clear();
		}
		Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": starting service discovery");
		mPendingServiceDiscoveries.set(0);
		if (smVersion == 0 || Patches.DISCO_EXCEPTIONS.contains(account.getJid().getDomain())) {
			Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": do not wait for service discovery");
			mWaitForDisco.set(false);
		} else {
			mWaitForDisco.set(true);
		}
		lastDiscoStarted = SystemClock.elapsedRealtime();
		mXmppConnectionService.scheduleWakeUpCall(Config.CONNECT_DISCO_TIMEOUT, account.getUuid().hashCode());
		Element caps = streamFeatures.findChild("c");
		final String hash = caps == null ? null : caps.getAttribute("hash");
		final String ver = caps == null ? null : caps.getAttribute("ver");
		ServiceDiscoveryResult discoveryResult = null;
		if (hash != null && ver != null) {
			discoveryResult = mXmppConnectionService.getCachedServiceDiscoveryResult(new Pair<>(hash, ver));
		}
		final boolean requestDiscoItemsFirst = !account.isOptionSet(Account.OPTION_LOGGED_IN_SUCCESSFULLY);
		if (requestDiscoItemsFirst) {
			sendServiceDiscoveryItems(Jid.of(account.getServer()));
		}
		if (discoveryResult == null) {
			sendServiceDiscoveryInfo(Jid.of(account.getServer()));
		} else {
			Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": server caps came from cache");
			disco.put(Jid.of(account.getServer()), discoveryResult);
		}
		sendServiceDiscoveryInfo(account.getJid().asBareJid());
		if (!requestDiscoItemsFirst) {
			sendServiceDiscoveryItems(Jid.of(account.getServer()));
		}

		if (!mWaitForDisco.get()) {
			finalizeBind();
		}
		this.lastSessionStarted = SystemClock.elapsedRealtime();
	}

	private void sendServiceDiscoveryInfo(final Jid jid) {
		mPendingServiceDiscoveries.incrementAndGet();
		final IqPacket iq = new IqPacket(IqPacket.TYPE.GET);
		iq.setTo(jid);
		iq.query("http://jabber.org/protocol/disco#info");
		this.sendIqPacket(iq, (account, packet) -> {
			if (packet.getType() == IqPacket.TYPE.RESULT) {
				boolean advancedStreamFeaturesLoaded;
				synchronized (XmppConnection.this.disco) {
					ServiceDiscoveryResult result = new ServiceDiscoveryResult(packet);
					if (jid.equals(Jid.of(account.getServer()))) {
						mXmppConnectionService.databaseBackend.insertDiscoveryResult(result);
					}
					disco.put(jid, result);
					advancedStreamFeaturesLoaded = disco.containsKey(Jid.of(account.getServer()))
							&& disco.containsKey(account.getJid().asBareJid());
				}
				if (advancedStreamFeaturesLoaded && (jid.equals(Jid.of(account.getServer())) || jid.equals(account.getJid().asBareJid()))) {
					enableAdvancedStreamFeatures();
				}
			} else {
				Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": could not query disco info for " + jid.toString());
			}
			if (packet.getType() != IqPacket.TYPE.TIMEOUT) {
				if (mPendingServiceDiscoveries.decrementAndGet() == 0
						&& mWaitForDisco.compareAndSet(true, false)) {
					finalizeBind();
				}
			}
		});
	}

	private void finalizeBind() {
		Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": online with resource " + account.getResource());
		if (bindListener != null) {
			bindListener.onBind(account);
		}
		changeStatus(Account.State.ONLINE);
	}

	private void enableAdvancedStreamFeatures() {
		if (getFeatures().carbons() && !features.carbonsEnabled) {
			sendEnableCarbons();
		}
		if (getFeatures().blocking() && !features.blockListRequested) {
			Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": Requesting block list");
			this.sendIqPacket(getIqGenerator().generateGetBlockList(), mXmppConnectionService.getIqParser());
		}
		for (final OnAdvancedStreamFeaturesLoaded listener : advancedStreamFeaturesLoadedListeners) {
			listener.onAdvancedStreamFeaturesAvailable(account);
		}
	}

	private void sendServiceDiscoveryItems(final Jid server) {
		mPendingServiceDiscoveries.incrementAndGet();
		final IqPacket iq = new IqPacket(IqPacket.TYPE.GET);
		iq.setTo(Jid.ofDomain(server.getDomain()));
		iq.query("http://jabber.org/protocol/disco#items");
		this.sendIqPacket(iq, (account, packet) -> {
			if (packet.getType() == IqPacket.TYPE.RESULT) {
				HashSet<Jid> items = new HashSet<Jid>();
				final List<Element> elements = packet.query().getChildren();
				for (final Element element : elements) {
					if (element.getName().equals("item")) {
						final Jid jid = InvalidJid.getNullForInvalid(element.getAttributeAsJid("jid"));
						if (jid != null && !jid.equals(Jid.of(account.getServer()))) {
							items.add(jid);
						}
					}
				}
				for (Jid jid : items) {
					sendServiceDiscoveryInfo(jid);
				}
			} else {
				Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": could not query disco items of " + server);
			}
			if (packet.getType() != IqPacket.TYPE.TIMEOUT) {
				if (mPendingServiceDiscoveries.decrementAndGet() == 0
						&& mWaitForDisco.compareAndSet(true, false)) {
					finalizeBind();
				}
			}
		});
	}

	private void sendEnableCarbons() {
		final IqPacket iq = new IqPacket(IqPacket.TYPE.SET);
		iq.addChild("enable", "urn:xmpp:carbons:2");
		this.sendIqPacket(iq, new OnIqPacketReceived() {

			@Override
			public void onIqPacketReceived(final Account account, final IqPacket packet) {
				if (!packet.hasChild("error")) {
					Log.d(Config.LOGTAG, account.getJid().asBareJid()
							+ ": successfully enabled carbons");
					features.carbonsEnabled = true;
				} else {
					Log.d(Config.LOGTAG, account.getJid().asBareJid()
							+ ": error enableing carbons " + packet.toString());
				}
			}
		});
	}

	private void processStreamError(final Tag currentTag) throws XmlPullParserException, IOException {
		final Element streamError = tagReader.readElement(currentTag);
		if (streamError == null) {
			return;
		}
		if (streamError.hasChild("conflict")) {
			account.setResource(createNewResource());
			Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": switching resource due to conflict (" + account.getResource() + ")");
			throw new IOException();
		} else if (streamError.hasChild("host-unknown")) {
			throw new StateChangingException(Account.State.HOST_UNKNOWN);
		} else if (streamError.hasChild("policy-violation")) {
			throw new StateChangingException(Account.State.POLICY_VIOLATION);
		} else {
			Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": stream error " + streamError.toString());
			throw new StateChangingException(Account.State.STREAM_ERROR);
		}
	}

	private void sendStartStream() throws IOException {
		final Tag stream = Tag.start("stream:stream");
		stream.setAttribute("to", account.getServer());
		stream.setAttribute("version", "1.0");
		stream.setAttribute("xml:lang", "en");
		stream.setAttribute("xmlns", "jabber:client");
		stream.setAttribute("xmlns:stream", "http://etherx.jabber.org/streams");
		tagWriter.writeTag(stream);
	}

	private String createNewResource() {
		return mXmppConnectionService.getString(R.string.app_name) + '.' + nextRandomId(true);
	}

	private String nextRandomId() {
		return nextRandomId(false);
	}

	private String nextRandomId(boolean s) {
		return CryptoHelper.random(s ? 3 : 9, mXmppConnectionService.getRNG());
	}

	public String sendIqPacket(final IqPacket packet, final OnIqPacketReceived callback) {
		packet.setFrom(account.getJid());
		return this.sendUnmodifiedIqPacket(packet, callback, false);
	}

	public synchronized String sendUnmodifiedIqPacket(final IqPacket packet, final OnIqPacketReceived callback, boolean force) {
		if (packet.getId() == null) {
			packet.setAttribute("id", nextRandomId());
		}
		if (callback != null) {
			synchronized (this.packetCallbacks) {
				packetCallbacks.put(packet.getId(), new Pair<>(packet, callback));
			}
		}
		this.sendPacket(packet, force);
		return packet.getId();
	}

	public void sendMessagePacket(final MessagePacket packet) {
		this.sendPacket(packet);
	}

	public void sendPresencePacket(final PresencePacket packet) {
		this.sendPacket(packet);
	}

	private synchronized void sendPacket(final AbstractStanza packet) {
		sendPacket(packet, false);
	}

	private synchronized void sendPacket(final AbstractStanza packet, final boolean force) {
		if (stanzasSent == Integer.MAX_VALUE) {
			resetStreamId();
			disconnect(true);
			return;
		}
		synchronized (this.mStanzaQueue) {
			if (force || isBound) {
				tagWriter.writeStanzaAsync(packet);
			} else {
				Log.d(Config.LOGTAG, account.getJid().asBareJid() + " do not write stanza to unbound stream " + packet.toString());
			}
			if (packet instanceof AbstractAcknowledgeableStanza) {
				AbstractAcknowledgeableStanza stanza = (AbstractAcknowledgeableStanza) packet;

				if (this.mStanzaQueue.size() != 0) {
					int currentHighestKey = this.mStanzaQueue.keyAt(this.mStanzaQueue.size() - 1);
					if (currentHighestKey != stanzasSent) {
						throw new AssertionError("Stanza count messed up");
					}
				}

				++stanzasSent;
				this.mStanzaQueue.append(stanzasSent, stanza);
				if (stanza instanceof MessagePacket && stanza.getId() != null && inSmacksSession) {
					if (Config.EXTENDED_SM_LOGGING) {
						Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": requesting ack for message stanza #" + stanzasSent);
					}
					tagWriter.writeStanzaAsync(new RequestPacket(this.smVersion));
				}
			}
		}
	}

	public void sendPing() {
		if (!r()) {
			final IqPacket iq = new IqPacket(IqPacket.TYPE.GET);
			iq.setFrom(account.getJid());
			iq.addChild("ping", "urn:xmpp:ping");
			this.sendIqPacket(iq, null);
		}
		this.lastPingSent = SystemClock.elapsedRealtime();
	}

	public void setOnMessagePacketReceivedListener(
			final OnMessagePacketReceived listener) {
		this.messageListener = listener;
	}

	public void setOnUnregisteredIqPacketReceivedListener(
			final OnIqPacketReceived listener) {
		this.unregisteredIqListener = listener;
	}

	public void setOnPresencePacketReceivedListener(
			final OnPresencePacketReceived listener) {
		this.presenceListener = listener;
	}

	public void setOnJinglePacketReceivedListener(
			final OnJinglePacketReceived listener) {
		this.jingleListener = listener;
	}

	public void setOnStatusChangedListener(final OnStatusChanged listener) {
		this.statusListener = listener;
	}

	public void setOnBindListener(final OnBindListener listener) {
		this.bindListener = listener;
	}

	public void setOnMessageAcknowledgeListener(final OnMessageAcknowledged listener) {
		this.acknowledgedListener = listener;
	}

	public void addOnAdvancedStreamFeaturesAvailableListener(final OnAdvancedStreamFeaturesLoaded listener) {
		this.advancedStreamFeaturesLoadedListeners.add(listener);
	}

	private void forceCloseSocket() {
		if (socket != null) {
			try {
				socket.close();
			} catch (IOException e) {
				Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": io exception " + e.getMessage() + " during force close");
			}
		} else {
			Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": socket was null during force close");
		}
	}

	public void interrupt() {
		if (this.mThread != null) {
			this.mThread.interrupt();
		}
	}

	public void disconnect(final boolean force) {
		interrupt();
		Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": disconnecting force=" + Boolean.toString(force));
		if (force) {
			forceCloseSocket();
		} else {
			final TagWriter currentTagWriter = this.tagWriter;
			if (currentTagWriter.isActive()) {
				currentTagWriter.finish();
				final Socket currentSocket = this.socket;
				final CountDownLatch streamCountDownLatch = this.mStreamCountDownLatch;
				try {
					currentTagWriter.await(1, TimeUnit.SECONDS);
					Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": closing stream");
					currentTagWriter.writeTag(Tag.end("stream:stream"));
					if (streamCountDownLatch != null) {
						if (streamCountDownLatch.await(1, TimeUnit.SECONDS)) {
							Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": remote ended stream");
						} else {
							Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": remote has not closed socket. force closing");
						}
					}
				} catch (InterruptedException e) {
					Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": interrupted while gracefully closing stream");
				} catch (final IOException e) {
					Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": io exception during disconnect (" + e.getMessage() + ")");
				} finally {
					FileBackend.close(currentSocket);
				}
			} else {
				forceCloseSocket();
			}
		}
	}

	private void resetStreamId() {
		this.streamId = null;
	}

	private List<Entry<Jid, ServiceDiscoveryResult>> findDiscoItemsByFeature(final String feature) {
		synchronized (this.disco) {
			final List<Entry<Jid, ServiceDiscoveryResult>> items = new ArrayList<>();
			for (final Entry<Jid, ServiceDiscoveryResult> cursor : this.disco.entrySet()) {
				if (cursor.getValue().getFeatures().contains(feature)) {
					items.add(cursor);
				}
			}
			return items;
		}
	}

	public Jid findDiscoItemByFeature(final String feature) {
		final List<Entry<Jid, ServiceDiscoveryResult>> items = findDiscoItemsByFeature(feature);
		if (items.size() >= 1) {
			return items.get(0).getKey();
		}
		return null;
	}

	public boolean r() {
		if (getFeatures().sm()) {
			this.tagWriter.writeStanzaAsync(new RequestPacket(smVersion));
			return true;
		} else {
			return false;
		}
	}

	public List<String> getMucServersWithholdAccount() {
		List<String> servers = getMucServers();
		servers.remove(account.getServer());
		return servers;
	}

	public List<String> getMucServers() {
		List<String> servers = new ArrayList<>();
		synchronized (this.disco) {
			for (final Entry<Jid, ServiceDiscoveryResult> cursor : disco.entrySet()) {
				final ServiceDiscoveryResult value = cursor.getValue();
				if (value.getFeatures().contains("http://jabber.org/protocol/muc")
						&& value.hasIdentity("conference", "text")
						&& !value.getFeatures().contains("jabber:iq:gateway")
						&& !value.hasIdentity("conference", "irc")) {
					servers.add(cursor.getKey().toString());
				}
			}
		}
		return servers;
	}

	public String getMucServer() {
		List<String> servers = getMucServers();
		return servers.size() > 0 ? servers.get(0) : null;
	}

	public int getTimeToNextAttempt() {
		final int interval = Math.min((int) (25 * Math.pow(1.3, attempt)), 300);
		final int secondsSinceLast = (int) ((SystemClock.elapsedRealtime() - this.lastConnect) / 1000);
		return interval - secondsSinceLast;
	}

	public int getAttempt() {
		return this.attempt;
	}

	public Features getFeatures() {
		return this.features;
	}

	public long getLastSessionEstablished() {
		final long diff = SystemClock.elapsedRealtime() - this.lastSessionStarted;
		return System.currentTimeMillis() - diff;
	}

	public long getLastConnect() {
		return this.lastConnect;
	}

	public long getLastPingSent() {
		return this.lastPingSent;
	}

	public long getLastDiscoStarted() {
		return this.lastDiscoStarted;
	}

	public long getLastPacketReceived() {
		return this.lastPacketReceived;
	}

	public void sendActive() {
		this.sendPacket(new ActivePacket());
	}

	public void sendInactive() {
		this.sendPacket(new InactivePacket());
	}

	public void resetAttemptCount(boolean resetConnectTime) {
		this.attempt = 0;
		if (resetConnectTime) {
			this.lastConnect = 0;
		}
	}

	public void setInteractive(boolean interactive) {
		this.mInteractive = interactive;
	}

	public Identity getServerIdentity() {
		synchronized (this.disco) {
			ServiceDiscoveryResult result = disco.get(Jid.ofDomain(account.getJid().getDomain()));
			if (result == null) {
				return Identity.UNKNOWN;
			}
			for (final ServiceDiscoveryResult.Identity id : result.getIdentities()) {
				if (id.getType().equals("im") && id.getCategory().equals("server") && id.getName() != null) {
					switch (id.getName()) {
						case "Prosody":
							return Identity.PROSODY;
						case "ejabberd":
							return Identity.EJABBERD;
						case "Slack-XMPP":
							return Identity.SLACK;
					}
				}
			}
		}
		return Identity.UNKNOWN;
	}

	private IqGenerator getIqGenerator() {
		return mXmppConnectionService.getIqGenerator();
	}

	public enum Identity {
		FACEBOOK,
		SLACK,
		EJABBERD,
		PROSODY,
		NIMBUZZ,
		UNKNOWN
	}

	private static class TlsFactoryVerifier {
		private final SSLSocketFactory factory;
		private final DomainHostnameVerifier verifier;

		TlsFactoryVerifier(final SSLSocketFactory factory, final DomainHostnameVerifier verifier) throws IOException {
			this.factory = factory;
			this.verifier = verifier;
			if (factory == null || verifier == null) {
				throw new IOException("could not setup ssl");
			}
		}
	}

	private class MyKeyManager implements X509KeyManager {
		@Override
		public String chooseClientAlias(String[] strings, Principal[] principals, Socket socket) {
			return account.getPrivateKeyAlias();
		}

		@Override
		public String chooseServerAlias(String s, Principal[] principals, Socket socket) {
			return null;
		}

		@Override
		public X509Certificate[] getCertificateChain(String alias) {
			Log.d(Config.LOGTAG, "getting certificate chain");
			try {
				return KeyChain.getCertificateChain(mXmppConnectionService, alias);
			} catch (Exception e) {
				Log.d(Config.LOGTAG, e.getMessage());
				return new X509Certificate[0];
			}
		}

		@Override
		public String[] getClientAliases(String s, Principal[] principals) {
			final String alias = account.getPrivateKeyAlias();
			return alias != null ? new String[]{alias} : new String[0];
		}

		@Override
		public String[] getServerAliases(String s, Principal[] principals) {
			return new String[0];
		}

		@Override
		public PrivateKey getPrivateKey(String alias) {
			try {
				return KeyChain.getPrivateKey(mXmppConnectionService, alias);
			} catch (Exception e) {
				return null;
			}
		}
	}

	private class StateChangingError extends Error {
		private final Account.State state;

		public StateChangingError(Account.State state) {
			this.state = state;
		}
	}

	private class StateChangingException extends IOException {
		private final Account.State state;

		public StateChangingException(Account.State state) {
			this.state = state;
		}
	}

	public class Features {
		XmppConnection connection;
		private boolean carbonsEnabled = false;
		private boolean encryptionEnabled = false;
		private boolean blockListRequested = false;

		public Features(final XmppConnection connection) {
			this.connection = connection;
		}

		private boolean hasDiscoFeature(final Jid server, final String feature) {
			synchronized (XmppConnection.this.disco) {
				return connection.disco.containsKey(server) &&
						connection.disco.get(server).getFeatures().contains(feature);
			}
		}

		public boolean carbons() {
			return hasDiscoFeature(Jid.of(account.getServer()), "urn:xmpp:carbons:2");
		}

		public boolean bookmarksConversion() {
			return hasDiscoFeature(account.getJid().asBareJid(),Namespace.BOOKMARKS_CONVERSION) && pepPublishOptions();
		}

		public boolean blocking() {
			return hasDiscoFeature(Jid.of(account.getServer()), Namespace.BLOCKING);
		}

		public boolean spamReporting() {
			return hasDiscoFeature(Jid.of(account.getServer()), "urn:xmpp:reporting:reason:spam:0");
		}

		public boolean flexibleOfflineMessageRetrieval() {
			return hasDiscoFeature(Jid.of(account.getServer()), Namespace.FLEXIBLE_OFFLINE_MESSAGE_RETRIEVAL);
		}

		public boolean register() {
			return hasDiscoFeature(Jid.of(account.getServer()), Namespace.REGISTER);
		}

		public boolean sm() {
			return streamId != null
					|| (connection.streamFeatures != null && connection.streamFeatures.hasChild("sm"));
		}

		public boolean csi() {
			return connection.streamFeatures != null && connection.streamFeatures.hasChild("csi", "urn:xmpp:csi:0");
		}

		public boolean pep() {
			synchronized (XmppConnection.this.disco) {
				ServiceDiscoveryResult info = disco.get(account.getJid().asBareJid());
				return info != null && info.hasIdentity("pubsub", "pep");
			}
		}

		public boolean pepPersistent() {
			synchronized (XmppConnection.this.disco) {
				ServiceDiscoveryResult info = disco.get(account.getJid().asBareJid());
				return info != null && info.getFeatures().contains("http://jabber.org/protocol/pubsub#persistent-items");
			}
		}

		public boolean pepPublishOptions() {
			return hasDiscoFeature(account.getJid().asBareJid(), Namespace.PUBSUB_PUBLISH_OPTIONS);
		}

		public boolean pepOmemoWhitelisted() {
			return hasDiscoFeature(account.getJid().asBareJid(), AxolotlService.PEP_OMEMO_WHITELISTED);
		}

		public boolean mam() {
			return MessageArchiveService.Version.has(getAccountFeatures());
		}

		public List<String> getAccountFeatures() {
			ServiceDiscoveryResult result = connection.disco.get(account.getJid().asBareJid());
			return result == null ? Collections.emptyList() : result.getFeatures();
		}

		public boolean push() {
			return hasDiscoFeature(account.getJid().asBareJid(), "urn:xmpp:push:0")
					|| hasDiscoFeature(Jid.of(account.getServer()), "urn:xmpp:push:0");
		}

		public boolean rosterVersioning() {
			return connection.streamFeatures != null && connection.streamFeatures.hasChild("ver");
		}

		public void setBlockListRequested(boolean value) {
			this.blockListRequested = value;
		}

		public boolean p1S3FileTransfer() {
			return hasDiscoFeature(Jid.of(account.getServer()),Namespace.P1_S3_FILE_TRANSFER);
		}

		public boolean httpUpload(long filesize) {
			if (Config.DISABLE_HTTP_UPLOAD) {
				return false;
			} else {
				for(String namespace : new String[]{Namespace.HTTP_UPLOAD, Namespace.HTTP_UPLOAD_LEGACY}) {
					List<Entry<Jid, ServiceDiscoveryResult>> items = findDiscoItemsByFeature(namespace);
					if (items.size() > 0) {
						try {
							long maxsize = Long.parseLong(items.get(0).getValue().getExtendedDiscoInformation(namespace, "max-file-size"));
							if (filesize <= maxsize) {
								return true;
							} else {
								Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": http upload is not available for files with size " + filesize + " (max is " + maxsize + ")");
								return false;
							}
						} catch (Exception e) {
							return true;
						}
					}
				}
				return false;
			}
		}

		public boolean useLegacyHttpUpload() {
			return findDiscoItemByFeature(Namespace.HTTP_UPLOAD) == null && findDiscoItemByFeature(Namespace.HTTP_UPLOAD_LEGACY) != null;
		}

		public long getMaxHttpUploadSize() {
			for(String namespace : new String[]{Namespace.HTTP_UPLOAD, Namespace.HTTP_UPLOAD_LEGACY}) {
				List<Entry<Jid, ServiceDiscoveryResult>> items = findDiscoItemsByFeature(namespace);
				if (items.size() > 0) {
					try {
						return Long.parseLong(items.get(0).getValue().getExtendedDiscoInformation(namespace, "max-file-size"));
					} catch (Exception e) {
						//ignored
					}
				}
			}
			return -1;
		}

		public boolean stanzaIds() {
			return hasDiscoFeature(account.getJid().asBareJid(), Namespace.STANZA_IDS);
		}
	}
    private static final int PACKET_IQ = 0;
    private static final int PACKET_MESSAGE = 1;
    private static final int PACKET_PRESENCE = 2;
    public final OnIqPacketReceived registrationResponseListener = new OnIqPacketReceived() {
        @Override
        public void onIqPacketReceived(Account account, IqPacket packet) {
            if (packet.getType() == IqPacket.TYPE.RESULT) {
                account.setOption(Account.OPTION_REGISTER, false);
                throw new StateChangingError(Account.State.REGISTRATION_SUCCESSFUL);
            } else {
                final List<String> PASSWORD_TOO_WEAK_MSGS = Arrays.asList(
                        "The password is too weak",
                        "Please use a longer password.");
                Element error = packet.findChild("error");
                Account.State state = Account.State.REGISTRATION_FAILED;
                if (error != null) {
                    if (error.hasChild("conflict")) {
                        state = Account.State.REGISTRATION_CONFLICT;
                    } else if (error.hasChild("resource-constraint")
                            && "wait".equals(error.getAttribute("type"))) {
                        state = Account.State.REGISTRATION_PLEASE_WAIT;
                    } else if (error.hasChild("not-acceptable")
                            && PASSWORD_TOO_WEAK_MSGS.contains(error.findChildContent("text"))) {
                        state = Account.State.REGISTRATION_PASSWORD_TOO_WEAK;
                    }
                }
                throw new StateChangingError(state);
            }
        }
    };
    protected final Account account;
    private final Features features = new Features(this);
    private final HashMap<Jid, ServiceDiscoveryResult> disco = new HashMap<>();
    private final SparseArray<AbstractAcknowledgeableStanza> mStanzaQueue = new SparseArray<>();
    private final Hashtable<String, Pair<IqPacket, OnIqPacketReceived>> packetCallbacks = new Hashtable<>();
    private final Set<OnAdvancedStreamFeaturesLoaded> advancedStreamFeaturesLoadedListeners = new HashSet<>();
    private final XmppConnectionService mXmppConnectionService;
    private Socket socket;
    private XmlReader tagReader;
    private TagWriter tagWriter = new TagWriter();
    private boolean shouldAuthenticate = true;
    private boolean inSmacksSession = false;
    private boolean isBound = false;
    private Element streamFeatures;
    private String streamId = null;
    private int smVersion = 3;
    private int stanzasReceived = 0;
    private int stanzasSent = 0;
    private long lastPacketReceived = 0;
    private long lastPingSent = 0;
    private long lastConnect = 0;
    private long lastSessionStarted = 0;
    private long lastDiscoStarted = 0;
    private AtomicInteger mPendingServiceDiscoveries = new AtomicInteger(0);
    private AtomicBoolean mWaitForDisco = new AtomicBoolean(true);
    private AtomicBoolean mWaitingForSmCatchup = new AtomicBoolean(false);
    private AtomicInteger mSmCatchupMessageCounter = new AtomicInteger(0);
    private boolean mInteractive = false;
    private int attempt = 0;
    private OnPresencePacketReceived presenceListener = null;
    private OnJinglePacketReceived jingleListener = null;
    private OnIqPacketReceived unregisteredIqListener = null;
    private OnMessagePacketReceived messageListener = null;
    private OnStatusChanged statusListener = null;
    private OnBindListener bindListener = null;
    private OnMessageAcknowledged acknowledgedListener = null;
    private SaslMechanism saslMechanism;
    private URL redirectionUrl = null;
    private String verifiedHostname = null;
    private volatile Thread mThread;
    private CountDownLatch mStreamCountDownLatch;


    public XmppConnection(final Account account, final XmppConnectionService service) {
        this.account = account;
        this.mXmppConnectionService = service;
    }

    private static void fixResource(Context context, Account account) {
        String resource = account.getResource();
        int fixedPartLength = context.getString(R.string.app_name).length() + 1; //include the trailing dot
        int randomPartLength = 4; // 3 bytes
        if (resource != null && resource.length() > fixedPartLength + randomPartLength) {
            if (validBase64(resource.substring(fixedPartLength, fixedPartLength + randomPartLength))) {
                account.setResource(resource.substring(0, fixedPartLength + randomPartLength));
            }
        }
    }

    private static boolean validBase64(String input) {
        try {
            return Base64.decode(input, Base64.URL_SAFE).length == 3;
        } catch (Throwable throwable) {
            return false;
        }
    }

    protected void changeStatus(final Account.State nextStatus) {
        synchronized (this) {
            if (Thread.currentThread().isInterrupted()) {
                Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": not changing status to " + nextStatus + " because thread was interrupted");
                return;
            }
            if (account.getStatus() != nextStatus) {
                if ((nextStatus == Account.State.OFFLINE)
                        && (account.getStatus() != Account.State.CONNECTING)
                        && (account.getStatus() != Account.State.ONLINE)
                        && (account.getStatus() != Account.State.DISABLED)) {
                    return;
                }
                if (nextStatus == Account.State.ONLINE) {
                    this.attempt = 0;
                }
                account.setStatus(nextStatus);
            } else {
                return;
            }
        }
        if (statusListener != null) {
            statusListener.onStatusChanged(account);
        }
    }

    public void prepareNewConnection() {
        this.lastConnect = SystemClock.elapsedRealtime();
        this.lastPingSent = SystemClock.elapsedRealtime();
        this.lastDiscoStarted = Long.MAX_VALUE;
        this.mWaitingForSmCatchup.set(false);
        this.changeStatus(Account.State.CONNECTING);
    }

    public boolean isWaitingForSmCatchup() {
        return mWaitingForSmCatchup.get();
    }

    public void incrementSmCatchupMessageCounter() {
        this.mSmCatchupMessageCounter.incrementAndGet();
    }

    protected void connect() {
        if (mXmppConnectionService.areMessagesInitialized()) {
            mXmppConnectionService.resetSendingToWaiting(account);
        }
        Log.d(Config.LOGTAG, account.getJid().asBareJid().toString() + ": connecting");
        features.encryptionEnabled = false;
        inSmacksSession = false;
        isBound = false;
        this.attempt++;
        this.verifiedHostname = null; //will be set if user entered hostname is being used or hostname was verified with dnssec
        try {
            Socket localSocket;
            shouldAuthenticate = !account.isOptionSet(Account.OPTION_REGISTER);
            this.changeStatus(Account.State.CONNECTING);
            final boolean useTor = mXmppConnectionService.useTorToConnect() || account.isOnion();
            final boolean extended = mXmppConnectionService.showExtendedConnectionOptions();
            if (useTor) {
                String destination;
                if (account.getHostname().isEmpty()) {
                    destination = account.getServer();
                } else {
                    destination = account.getHostname();
                    this.verifiedHostname = destination;
                }
                Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": connect to " + destination + " via Tor");
                localSocket = SocksSocketFactory.createSocketOverTor(destination, account.getPort());
                try {
                    startXmpp(localSocket);
                } catch (InterruptedException e) {
                    Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": thread was interrupted before beginning stream");
                    return;
                } catch (Exception e) {
                    throw new IOException(e.getMessage());
                }
            } else if (extended && !account.getHostname().isEmpty()) {

                this.verifiedHostname = account.getHostname();

                try {
                    InetSocketAddress address = new InetSocketAddress(this.verifiedHostname, account.getPort());
                    features.encryptionEnabled = address.getPort() == 5223;
                    if (features.encryptionEnabled) {
                        try {
                            final TlsFactoryVerifier tlsFactoryVerifier = getTlsFactoryVerifier();
                            localSocket = tlsFactoryVerifier.factory.createSocket();
                            localSocket.connect(address, Config.SOCKET_TIMEOUT * 1000);
                            final SSLSession session = ((SSLSocket) localSocket).getSession();
                            final String domain = account.getJid().getDomain();
                            if (!tlsFactoryVerifier.verifier.verify(domain, this.verifiedHostname, session)) {
                                Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": TLS certificate verification failed");
                                throw new StateChangingException(Account.State.TLS_ERROR);
                            }
                        } catch (KeyManagementException e) {
                            throw new StateChangingException(Account.State.TLS_ERROR);
                        }
                    } else {
                        localSocket = new Socket();
                        localSocket.connect(address, Config.SOCKET_TIMEOUT * 1000);
                    }
                } catch (IOException | IllegalArgumentException e) {
                    throw new UnknownHostException();
                }
                try {
                    startXmpp(localSocket);
                } catch (InterruptedException e) {
                    Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": thread was interrupted before beginning stream");
                    return;
                } catch (Exception e) {
                    throw new IOException(e.getMessage());
                }
            } else if (IP.matches(account.getServer())) {
                localSocket = new Socket();
                try {
                    localSocket.connect(new InetSocketAddress(account.getServer(), 5222), Config.SOCKET_TIMEOUT * 1000);
                } catch (IOException e) {
                    throw new UnknownHostException();
                }
                try {
                    startXmpp(localSocket);
                } catch (InterruptedException e) {
                    Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": thread was interrupted before beginning stream");
                    return;
                } catch (Exception e) {
                    throw new IOException(e.getMessage());
                }
            } else {
                final String domain = account.getJid().getDomain();
                final List<Resolver.Result> results = Resolver.resolve(account.getJid().getDomain());
                if (Thread.currentThread().isInterrupted()) {
                    Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": Thread was interrupted");
                    return;
                }
                if (results.size() == 0) {
                    Log.e(Config.LOGTAG,account.getJid().asBareJid()+": Resolver results were empty");
                    return;
                }
                final Resolver.Result storedBackupResult = mXmppConnectionService.databaseBackend.findResolverResult(domain);
                if (storedBackupResult != null && !results.contains(storedBackupResult)) {
                    results.add(storedBackupResult);
                    Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": loaded backup resolver result from db: " + storedBackupResult);
                }
                for (Iterator<Resolver.Result> iterator = results.iterator(); iterator.hasNext(); ) {
                    final Resolver.Result result = iterator.next();
                    if (Thread.currentThread().isInterrupted()) {
                        Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": Thread was interrupted");
                        return;
                    }
                    try {
                        // if tls is true, encryption is implied and must not be started
                        features.encryptionEnabled = result.isDirectTls();
                        verifiedHostname = result.isAuthenticated() ? result.getHostname().toString() : null;
                        final InetSocketAddress addr;
                        if (result.getIp() != null) {
                            addr = new InetSocketAddress(result.getIp(), result.getPort());
                            Log.d(Config.LOGTAG, account.getJid().asBareJid().toString()
                                    + ": using values from dns " + result.getHostname().toString()
                                    + "/" + result.getIp().getHostAddress() + ":" + result.getPort() + " tls: " + features.encryptionEnabled);
                        } else {
                            addr = new InetSocketAddress(IDN.toASCII(result.getHostname().toString()), result.getPort());
                            Log.d(Config.LOGTAG, account.getJid().asBareJid().toString()
                                    + ": using values from dns "
                                    + result.getHostname().toString() + ":" + result.getPort() + " tls: " + features.encryptionEnabled);
                        }

                        if (!features.encryptionEnabled) {
                            localSocket = new Socket();
                            localSocket.connect(addr, Config.SOCKET_TIMEOUT * 1000);
                        } else {
                            final TlsFactoryVerifier tlsFactoryVerifier = getTlsFactoryVerifier();
                            localSocket = tlsFactoryVerifier.factory.createSocket();

                            if (localSocket == null) {
                                throw new IOException("could not initialize ssl socket");
                            }

                            SSLSocketHelper.setSecurity((SSLSocket) localSocket);
                            SSLSocketHelper.setHostname((SSLSocket) localSocket, account.getServer());
                            SSLSocketHelper.setApplicationProtocol((SSLSocket) localSocket, "xmpp-client");

                            localSocket.connect(addr, Config.SOCKET_TIMEOUT * 1000);

                            if (!tlsFactoryVerifier.verifier.verify(account.getServer(), verifiedHostname, ((SSLSocket) localSocket).getSession())) {
                                Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": TLS certificate verification failed");
                                if (!iterator.hasNext()) {
                                    throw new StateChangingException(Account.State.TLS_ERROR);
                                }
                            }
                        }
                        if (startXmpp(localSocket)) {
                            if (!result.equals(storedBackupResult)) {
                                mXmppConnectionService.databaseBackend.saveResolverResult(domain, result);
                            }
                            break; // successfully connected to server that speaks xmpp
                        } else {
                            localSocket.close();
                        }
                    } catch (final StateChangingException e) {
                        throw e;
                    } catch (InterruptedException e) {
                        Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": thread was interrupted before beginning stream");
                        return;
                    } catch (final Throwable e) {
                        Log.d(Config.LOGTAG, account.getJid().asBareJid().toString() + ": " + e.getMessage() + "(" + e.getClass().getName() + ")");
                        if (!iterator.hasNext()) {
                            throw new UnknownHostException();
                        }
                    }
                }
            }
            processStream();
        } catch (final SecurityException e) {
            this.changeStatus(Account.State.MISSING_INTERNET_PERMISSION);
        } catch (final StateChangingException e) {
            this.changeStatus(e.state);
        } catch (final UnknownHostException | ConnectException e) {
            this.changeStatus(Account.State.SERVER_NOT_FOUND);
        } catch (final SocksSocketFactory.SocksProxyNotFoundException e) {
            this.changeStatus(Account.State.TOR_NOT_AVAILABLE);
        } catch (final IOException | XmlPullParserException | NoSuchAlgorithmException e) {
            Log.d(Config.LOGTAG, account.getJid().asBareJid().toString() + ": " + e.getMessage());
            this.changeStatus(Account.State.OFFLINE);
            this.attempt = Math.max(0, this.attempt - 1);
        } finally {
            if (!Thread.currentThread().isInterrupted()) {
                forceCloseSocket();
            } else {
                Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": not force closing socket because thread was interrupted");
            }
        }
    }

    /**
     * Starts xmpp protocol, call after connecting to socket
     *
     * @return true if server returns with valid xmpp, false otherwise
     */
    private boolean startXmpp(Socket socket) throws Exception {
        if (Thread.currentThread().isInterrupted()) {
            throw new InterruptedException();
        }
        this.socket = socket;
        tagReader = new XmlReader();
        if (tagWriter != null) {
            tagWriter.forceClose();
        }
        tagWriter = new TagWriter();
        tagWriter.setOutputStream(socket.getOutputStream());
        tagReader.setInputStream(socket.getInputStream());
        tagWriter.beginDocument();
        sendStartStream();
        final Tag tag = tagReader.readTag();
        if (Thread.currentThread().isInterrupted()) {
            throw new InterruptedException();
        }
        if (socket instanceof SSLSocket) {
            SSLSocketHelper.log(account, (SSLSocket) socket);
        }
        return tag != null && tag.isStart("stream");
    }

    private TlsFactoryVerifier getTlsFactoryVerifier() throws NoSuchAlgorithmException, KeyManagementException, IOException {
        final SSLContext sc = SSLSocketHelper.getSSLContext();
        MemorizingTrustManager trustManager = this.mXmppConnectionService.getMemorizingTrustManager();
        KeyManager[] keyManager;
        if (account.getPrivateKeyAlias() != null && account.getPassword().isEmpty()) {
            keyManager = new KeyManager[]{new MyKeyManager()};
        } else {
            keyManager = null;
        }
        String domain = account.getJid().getDomain();
        sc.init(keyManager, new X509TrustManager[]{mInteractive ? trustManager.getInteractive(domain) : trustManager.getNonInteractive(domain)}, mXmppConnectionService.getRNG());
        final SSLSocketFactory factory = sc.getSocketFactory();
        final DomainHostnameVerifier verifier = trustManager.wrapHostnameVerifier(new XmppDomainVerifier(), mInteractive);
        return new TlsFactoryVerifier(factory, verifier);
    }

    @Override
    public void run() {
        synchronized (this) {
            this.mThread = Thread.currentThread();
            if (this.mThread.isInterrupted()) {
                Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": aborting connect because thread was interrupted");
                return;
            }
            forceCloseSocket();
        }
        connect();
    }

    private void processStream() throws XmlPullParserException, IOException {
        final CountDownLatch streamCountDownLatch = new CountDownLatch(1);
        this.mStreamCountDownLatch = streamCountDownLatch;
        Tag nextTag = tagReader.readTag();
        while (nextTag != null && !nextTag.isEnd("stream")) {
            if (nextTag.isStart("error")) {
                processStreamError(nextTag);
            } else if (nextTag.isStart("features")) {
                processStreamFeatures(nextTag);
            } else if (nextTag.isStart("proceed")) {
                switchOverToTls(nextTag);
            } else if (nextTag.isStart("success")) {
                final String challenge = tagReader.readElement(nextTag).getContent();
                try {
                    saslMechanism.getResponse(challenge);
                } catch (final SaslMechanism.AuthenticationException e) {
                    Log.e(Config.LOGTAG, String.valueOf(e));
                    throw new StateChangingException(Account.State.UNAUTHORIZED);
                }
                Log.d(Config.LOGTAG, account.getJid().asBareJid().toString() + ": logged in");
                account.setKey(Account.PINNED_MECHANISM_KEY,
                        String.valueOf(saslMechanism.getPriority()));
                tagReader.reset();
                sendStartStream();
                final Tag tag = tagReader.readTag();
                if (tag != null && tag.isStart("stream")) {
                    processStream();
                } else {
                    throw new IOException("server didn't restart stream after successful auth");
                }
                break;
            } else if (nextTag.isStart("failure")) {
                final Element failure = tagReader.readElement(nextTag);
                if (Namespace.SASL.equals(failure.getNamespace())) {
                    final String text = failure.findChildContent("text");
                    if (failure.hasChild("account-disabled") && text != null) {
                        Matcher matcher = Patterns.AUTOLINK_WEB_URL.matcher(text);
                        if (matcher.find()) {
                            try {
                                URL url = new URL(text.substring(matcher.start(), matcher.end()));
                                if (url.getProtocol().equals("https")) {
                                    this.redirectionUrl = url;
                                    throw new StateChangingException(Account.State.PAYMENT_REQUIRED);
                                }
                            } catch (MalformedURLException e) {
                                throw new StateChangingException(Account.State.UNAUTHORIZED);
                            }
                        }
                    }
                    throw new StateChangingException(Account.State.UNAUTHORIZED);
                } else if (Namespace.TLS.equals(failure.getNamespace())) {
                    throw new StateChangingException(Account.State.TLS_ERROR);
                } else {
                    throw new StateChangingException(Account.State.INCOMPATIBLE_SERVER);
                }
            } else if (nextTag.isStart("challenge")) {
                final String challenge = tagReader.readElement(nextTag).getContent();
                final Element response = new Element("response", Namespace.SASL);
                try {
                    response.setContent(saslMechanism.getResponse(challenge));
                } catch (final SaslMechanism.AuthenticationException e) {
                    // TODO: Send auth abort tag.
                    Log.e(Config.LOGTAG, e.toString());
                }
                tagWriter.writeElement(response);
            } else if (nextTag.isStart("enabled")) {
                final Element enabled = tagReader.readElement(nextTag);
                if ("true".equals(enabled.getAttribute("resume"))) {
                    this.streamId = enabled.getAttribute("id");
                    Log.d(Config.LOGTAG, account.getJid().asBareJid().toString()
                            + ": stream management(" + smVersion
                            + ") enabled (resumable)");
                } else {
                    Log.d(Config.LOGTAG, account.getJid().asBareJid().toString()
                            + ": stream management(" + smVersion + ") enabled");
                }
                this.stanzasReceived = 0;
                this.inSmacksSession = true;
                final RequestPacket r = new RequestPacket(smVersion);
                tagWriter.writeStanzaAsync(r);
            } else if (nextTag.isStart("resumed")) {
                this.inSmacksSession = true;
                this.isBound = true;
                this.tagWriter.writeStanzaAsync(new RequestPacket(smVersion));
                lastPacketReceived = SystemClock.elapsedRealtime();
                final Element resumed = tagReader.readElement(nextTag);
                final String h = resumed.getAttribute("h");
                try {
                    ArrayList<AbstractAcknowledgeableStanza> failedStanzas = new ArrayList<>();
                    final boolean acknowledgedMessages;
                    synchronized (this.mStanzaQueue) {
                        final int serverCount = Integer.parseInt(h);
                        if (serverCount < stanzasSent) {
                            Log.d(Config.LOGTAG, account.getJid().asBareJid().toString()
                                    + ": session resumed with lost packages");
                            stanzasSent = serverCount;
                        } else {
                            Log.d(Config.LOGTAG, account.getJid().asBareJid().toString() + ": session resumed");
                        }
                        acknowledgedMessages = acknowledgeStanzaUpTo(serverCount);
                        for (int i = 0; i < this.mStanzaQueue.size(); ++i) {
                            failedStanzas.add(mStanzaQueue.valueAt(i));
                        }
                        mStanzaQueue.clear();
                    }
                    if (acknowledgedMessages) {
                        mXmppConnectionService.updateConversationUi();
                    }
                    Log.d(Config.LOGTAG, "resending " + failedStanzas.size() + " stanzas");
                    for (AbstractAcknowledgeableStanza packet : failedStanzas) {
                        if (packet instanceof MessagePacket) {
                            MessagePacket message = (MessagePacket) packet;
                            mXmppConnectionService.markMessage(account,
                                    message.getTo().asBareJid(),
                                    message.getId(),
                                    Message.STATUS_UNSEND);
                        }
                        sendPacket(packet);
                    }
                } catch (final NumberFormatException ignored) {
                }
                Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": online with resource " + account.getResource());
                changeStatus(Account.State.ONLINE);
            } else if (nextTag.isStart("r")) {
                tagReader.readElement(nextTag);
                if (Config.EXTENDED_SM_LOGGING) {
                    Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": acknowledging stanza #" + this.stanzasReceived);
                }
                final AckPacket ack = new AckPacket(this.stanzasReceived, smVersion);
                tagWriter.writeStanzaAsync(ack);
            } else if (nextTag.isStart("a")) {
                boolean accountUiNeedsRefresh = false;
                synchronized (NotificationService.CATCHUP_LOCK) {
                    if (mWaitingForSmCatchup.compareAndSet(true, false)) {
                        int count = mSmCatchupMessageCounter.get();
                        Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": SM catchup complete (" + count + ")");
                        accountUiNeedsRefresh = true;
                        if (count > 0) {
                            mXmppConnectionService.getNotificationService().finishBacklog(true, account);
                        }
                    }
                }
                if (accountUiNeedsRefresh) {
                    mXmppConnectionService.updateAccountUi();
                }
                final Element ack = tagReader.readElement(nextTag);
                lastPacketReceived = SystemClock.elapsedRealtime();
                try {
                    final boolean acknowledgedMessages;
                    synchronized (this.mStanzaQueue) {
                        final int serverSequence = Integer.parseInt(ack.getAttribute("h"));
                        acknowledgedMessages = acknowledgeStanzaUpTo(serverSequence);
                    }
                    if (acknowledgedMessages) {
                        mXmppConnectionService.updateConversationUi();
                    }
                } catch (NumberFormatException | NullPointerException e) {
                    Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": server send ack without sequence number");
                }
            } else if (nextTag.isStart("failed")) {
                Element failed = tagReader.readElement(nextTag);
                try {
                    final int serverCount = Integer.parseInt(failed.getAttribute("h"));
                    Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": resumption failed but server acknowledged stanza #" + serverCount);
                    final boolean acknowledgedMessages;
                    synchronized (this.mStanzaQueue) {
                        acknowledgedMessages = acknowledgeStanzaUpTo(serverCount);
                    }
                    if (acknowledgedMessages) {
                        mXmppConnectionService.updateConversationUi();
                    }
                } catch (NumberFormatException | NullPointerException e) {
                    Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": resumption failed");
                }
                resetStreamId();
                sendBindRequest();
            } else if (nextTag.isStart("iq")) {
                processIq(nextTag);
            } else if (nextTag.isStart("message")) {
                processMessage(nextTag);
            } else if (nextTag.isStart("presence")) {
                processPresence(nextTag);
            }
            nextTag = tagReader.readTag();
        }
        if (nextTag != null && nextTag.isEnd("stream")) {
            streamCountDownLatch.countDown();
        }
    }

    private boolean acknowledgeStanzaUpTo(int serverCount) {
        if (serverCount > stanzasSent) {
            Log.e(Config.LOGTAG, "server acknowledged more stanzas than we sent. serverCount=" + serverCount + ", ourCount=" + stanzasSent);
        }
        boolean acknowledgedMessages = false;
        for (int i = 0; i < mStanzaQueue.size(); ++i) {
            if (serverCount >= mStanzaQueue.keyAt(i)) {
                if (Config.EXTENDED_SM_LOGGING) {
                    Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": server acknowledged stanza #" + mStanzaQueue.keyAt(i));
                }
                AbstractAcknowledgeableStanza stanza = mStanzaQueue.valueAt(i);
                if (stanza instanceof MessagePacket && acknowledgedListener != null) {
                    MessagePacket packet = (MessagePacket) stanza;
                    acknowledgedMessages |= acknowledgedListener.onMessageAcknowledged(account, packet.getId());
                }
                mStanzaQueue.removeAt(i);
                i--;
            }
        }
        return acknowledgedMessages;
    }

    private @NonNull
    Element processPacket(final Tag currentTag, final int packetType) throws XmlPullParserException, IOException {
        Element element;
        switch (packetType) {
            case PACKET_IQ:
                element = new IqPacket();
                break;
            case PACKET_MESSAGE:
                element = new MessagePacket();
                break;
            case PACKET_PRESENCE:
                element = new PresencePacket();
                break;
            default:
                throw new AssertionError("Should never encounter invalid type");
        }
        element.setAttributes(currentTag.getAttributes());
        Tag nextTag = tagReader.readTag();
        if (nextTag == null) {
            throw new IOException("interrupted mid tag");
        }
        while (!nextTag.isEnd(element.getName())) {
            if (!nextTag.isNo()) {
                final Element child = tagReader.readElement(nextTag);
                final String type = currentTag.getAttribute("type");
                if (packetType == PACKET_IQ
                        && "jingle".equals(child.getName())
                        && ("set".equalsIgnoreCase(type) || "get"
                        .equalsIgnoreCase(type))) {
                    element = new JinglePacket();
                    element.setAttributes(currentTag.getAttributes());
                }
                element.addChild(child);
            }
            nextTag = tagReader.readTag();
            if (nextTag == null) {
                throw new IOException("interrupted mid tag");
            }
        }
        if (stanzasReceived == Integer.MAX_VALUE) {
            resetStreamId();
            throw new IOException("time to restart the session. cant handle >2 billion pcks");
        }
        if (inSmacksSession) {
            ++stanzasReceived;
        } else if (features.sm()) {
            Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": not counting stanza(" + element.getClass().getSimpleName() + "). Not in smacks session.");
        }
        lastPacketReceived = SystemClock.elapsedRealtime();
        if (Config.BACKGROUND_STANZA_LOGGING && mXmppConnectionService.checkListeners()) {
            Log.d(Config.LOGTAG, "[background stanza] " + element);
        }
        return element;
    }

    private void processIq(final Tag currentTag) throws XmlPullParserException, IOException {
        final IqPacket packet = (IqPacket) processPacket(currentTag, PACKET_IQ);
        if (!packet.valid()) {
            Log.e(Config.LOGTAG, "encountered invalid iq from='" + packet.getFrom() + "' to='" + packet.getTo() + "'");
            return;
        }
        if (packet instanceof JinglePacket) {
            if (this.jingleListener != null) {
                this.jingleListener.onJinglePacketReceived(account, (JinglePacket) packet);
            }
        } else {
            OnIqPacketReceived callback = null;
            synchronized (this.packetCallbacks) {
                if (packetCallbacks.containsKey(packet.getId())) {
                    final Pair<IqPacket, OnIqPacketReceived> packetCallbackDuple = packetCallbacks.get(packet.getId());
                    // Packets to the server should have responses from the server
                    if (packetCallbackDuple.first.toServer(account)) {
                        if (packet.fromServer(account)) {
                            callback = packetCallbackDuple.second;
                            packetCallbacks.remove(packet.getId());
                        } else {
                            Log.e(Config.LOGTAG, account.getJid().asBareJid().toString() + ": ignoring spoofed iq packet");
                        }
                    } else {
                        if (packet.getFrom() != null && packet.getFrom().equals(packetCallbackDuple.first.getTo())) {
                            callback = packetCallbackDuple.second;
                            packetCallbacks.remove(packet.getId());
                        } else {
                            Log.e(Config.LOGTAG, account.getJid().asBareJid().toString() + ": ignoring spoofed iq packet");
                        }
                    }
                } else if (packet.getType() == IqPacket.TYPE.GET || packet.getType() == IqPacket.TYPE.SET) {
                    callback = this.unregisteredIqListener;
                }
            }
            if (callback != null) {
                try {
                    callback.onIqPacketReceived(account, packet);
                } catch (StateChangingError error) {
                    throw new StateChangingException(error.state);
                }
            }
        }
    }

    private void processMessage(final Tag currentTag) throws XmlPullParserException, IOException {
        final MessagePacket packet = (MessagePacket) processPacket(currentTag, PACKET_MESSAGE);
        if (!packet.valid()) {
            Log.e(Config.LOGTAG, "encountered invalid message from='" + packet.getFrom() + "' to='" + packet.getTo() + "'");
            return;
        }
        this.messageListener.onMessagePacketReceived(account, packet);
    }

    private void processPresence(final Tag currentTag) throws XmlPullParserException, IOException {
        PresencePacket packet = (PresencePacket) processPacket(currentTag, PACKET_PRESENCE);
        if (!packet.valid()) {
            Log.e(Config.LOGTAG, "encountered invalid presence from='" + packet.getFrom() + "' to='" + packet.getTo() + "'");
            return;
        }
        this.presenceListener.onPresencePacketReceived(account, packet);
    }

    private void sendStartTLS() throws IOException {
        final Tag startTLS = Tag.empty("starttls");
        startTLS.setAttribute("xmlns", Namespace.TLS);
        tagWriter.writeTag(startTLS);
    }

    private void switchOverToTls(final Tag currentTag) throws XmlPullParserException, IOException {
        tagReader.readTag();
        try {
            final TlsFactoryVerifier tlsFactoryVerifier = getTlsFactoryVerifier();
            final InetAddress address = socket == null ? null : socket.getInetAddress();

            if (address == null) {
                throw new IOException("could not setup ssl");
            }

            final SSLSocket sslSocket = (SSLSocket) tlsFactoryVerifier.factory.createSocket(socket, address.getHostAddress(), socket.getPort(), true);

            if (sslSocket == null) {
                throw new IOException("could not initialize ssl socket");
            }

            SSLSocketHelper.setSecurity(sslSocket);

            if (!tlsFactoryVerifier.verifier.verify(account.getServer(), this.verifiedHostname, sslSocket.getSession())) {
                Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": TLS certificate verification failed");
                throw new StateChangingException(Account.State.TLS_ERROR);
            }
            tagReader.setInputStream(sslSocket.getInputStream());
            tagWriter.setOutputStream(sslSocket.getOutputStream());
            sendStartStream();
            Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": TLS connection established");
            features.encryptionEnabled = true;
            final Tag tag = tagReader.readTag();
            if (tag != null && tag.isStart("stream")) {
                SSLSocketHelper.log(account, sslSocket);
                processStream();
            } else {
                throw new IOException("server didn't restart stream after STARTTLS");
            }
            sslSocket.close();
        } catch (final NoSuchAlgorithmException | KeyManagementException e1) {
            Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": TLS certificate verification failed");
            throw new StateChangingException(Account.State.TLS_ERROR);
        }
    }

    private void processStreamFeatures(final Tag currentTag) throws XmlPullParserException, IOException {
        this.streamFeatures = tagReader.readElement(currentTag);
        final boolean isSecure = features.encryptionEnabled || Config.ALLOW_NON_TLS_CONNECTIONS;
        final boolean needsBinding = !isBound && !account.isOptionSet(Account.OPTION_REGISTER);
        if (this.streamFeatures.hasChild("starttls") && !features.encryptionEnabled) {
            sendStartTLS();
        } else if (this.streamFeatures.hasChild("register") && account.isOptionSet(Account.OPTION_REGISTER)) {
            if (isSecure) {
                sendRegistryRequest();
            } else {
                throw new StateChangingException(Account.State.INCOMPATIBLE_SERVER);
            }
        } else if (!this.streamFeatures.hasChild("register") && account.isOptionSet(Account.OPTION_REGISTER)) {
            throw new StateChangingException(Account.State.REGISTRATION_NOT_SUPPORTED);
        } else if (this.streamFeatures.hasChild("mechanisms") && shouldAuthenticate && isSecure) {
            authenticate();
        } else if (this.streamFeatures.hasChild("sm", "urn:xmpp:sm:" + smVersion) && streamId != null) {
            if (Config.EXTENDED_SM_LOGGING) {
                Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": resuming after stanza #" + stanzasReceived);
            }
            final ResumePacket resume = new ResumePacket(this.streamId, stanzasReceived, smVersion);
            this.mSmCatchupMessageCounter.set(0);
            this.mWaitingForSmCatchup.set(true);
            this.tagWriter.writeStanzaAsync(resume);
        } else if (needsBinding) {
            if (this.streamFeatures.hasChild("bind") && isSecure) {
                sendBindRequest();
            } else {
                throw new StateChangingException(Account.State.INCOMPATIBLE_SERVER);
            }
        }
    }

    private void authenticate() throws IOException {
        final List<String> mechanisms = extractMechanisms(streamFeatures
                .findChild("mechanisms"));
        final Element auth = new Element("auth", Namespace.SASL);
        if (mechanisms.contains("EXTERNAL") && account.getPrivateKeyAlias() != null) {
            saslMechanism = new External(tagWriter, account, mXmppConnectionService.getRNG());
        } else if (mechanisms.contains("SCRAM-SHA-256")) {
            saslMechanism = new ScramSha256(tagWriter, account, mXmppConnectionService.getRNG());
        } else if (mechanisms.contains("SCRAM-SHA-1")) {
            saslMechanism = new ScramSha1(tagWriter, account, mXmppConnectionService.getRNG());
        } else if (mechanisms.contains("PLAIN") && !account.getJid().getDomain().equals("nimbuzz.com")) {
            saslMechanism = new Plain(tagWriter, account);
        } else if (mechanisms.contains("DIGEST-MD5")) {
            saslMechanism = new DigestMd5(tagWriter, account, mXmppConnectionService.getRNG());
        } else if (mechanisms.contains("ANONYMOUS")) {
            saslMechanism = new Anonymous(tagWriter, account, mXmppConnectionService.getRNG());
        }
        if (saslMechanism != null) {
            final int pinnedMechanism = account.getKeyAsInt(Account.PINNED_MECHANISM_KEY, -1);
            if (pinnedMechanism > saslMechanism.getPriority()) {
                Log.e(Config.LOGTAG, "Auth failed. Authentication mechanism " + saslMechanism.getMechanism() +
                        " has lower priority (" + String.valueOf(saslMechanism.getPriority()) +
                        ") than pinned priority (" + pinnedMechanism +
                        "). Possible downgrade attack?");
                throw new StateChangingException(Account.State.DOWNGRADE_ATTACK);
            }
            Log.d(Config.LOGTAG, account.getJid().toString() + ": Authenticating with " + saslMechanism.getMechanism());
            auth.setAttribute("mechanism", saslMechanism.getMechanism());
            if (!saslMechanism.getClientFirstMessage().isEmpty()) {
                auth.setContent(saslMechanism.getClientFirstMessage());
            }
            tagWriter.writeElement(auth);
        } else {
            throw new StateChangingException(Account.State.INCOMPATIBLE_SERVER);
        }
    }

    private List<String> extractMechanisms(final Element stream) {
        final ArrayList<String> mechanisms = new ArrayList<>(stream
                .getChildren().size());
        for (final Element child : stream.getChildren()) {
            mechanisms.add(child.getContent());
        }
        return mechanisms;
    }

    private void sendRegistryRequest() {
        final IqPacket register = new IqPacket(IqPacket.TYPE.GET);
        register.query("jabber:iq:register");
        register.setTo(Jid.of(account.getServer()));
        sendUnmodifiedIqPacket(register, (account, packet) -> {
            if (packet.getType() == IqPacket.TYPE.TIMEOUT) {
                return;
            }
            if (packet.getType() == IqPacket.TYPE.ERROR) {
                throw new StateChangingError(Account.State.REGISTRATION_FAILED);
            }
            final Element query = packet.query("jabber:iq:register");
            if (query.hasChild("username") && (query.hasChild("password"))) {
                final IqPacket register1 = new IqPacket(IqPacket.TYPE.SET);
                final Element username = new Element("username").setContent(account.getUsername());
                final Element password = new Element("password").setContent(account.getPassword());
                register1.query("jabber:iq:register").addChild(username);
                register1.query().addChild(password);
                register1.setFrom(account.getJid().asBareJid());
                sendUnmodifiedIqPacket(register1, registrationResponseListener, true);
            } else if (query.hasChild("x", Namespace.DATA)) {
                final Data data = Data.parse(query.findChild("x", Namespace.DATA));
                final Element blob = query.findChild("data", "urn:xmpp:bob");
                final String id = packet.getId();
                InputStream is;
                if (blob != null) {
                    try {
                        final String base64Blob = blob.getContent();
                        final byte[] strBlob = Base64.decode(base64Blob, Base64.DEFAULT);
                        is = new ByteArrayInputStream(strBlob);
                    } catch (Exception e) {
                        is = null;
                    }
                } else {
                    try {
                        Field field = data.getFieldByName("url");
                        URL url = field != null && field.getValue() != null ? new URL(field.getValue()) : null;
                        is = url != null ? url.openStream() : null;
                    } catch (IOException e) {
                        is = null;
                    }
                }

                if (is != null) {
                    Bitmap captcha = BitmapFactory.decodeStream(is);
                    try {
                        if (mXmppConnectionService.displayCaptchaRequest(account, id, data, captcha)) {
                            return;
                        }
                    } catch (Exception e) {
                        throw new StateChangingError(Account.State.REGISTRATION_FAILED);
                    }
                }
                throw new StateChangingError(Account.State.REGISTRATION_FAILED);
            } else if (query.hasChild("instructions") || query.hasChild("x", Namespace.OOB)) {
                final String instructions = query.findChildContent("instructions");
                final Element oob = query.findChild("x", Namespace.OOB);
                final String url = oob == null ? null : oob.findChildContent("url");
                if (url != null) {
                    setAccountCreationFailed(url);
                } else if (instructions != null) {
                    Matcher matcher = Patterns.AUTOLINK_WEB_URL.matcher(instructions);
                    if (matcher.find()) {
                        setAccountCreationFailed(instructions.substring(matcher.start(), matcher.end()));
                    }
                }
                throw new StateChangingError(Account.State.REGISTRATION_FAILED);
            }
        }, true);
    }

    private void setAccountCreationFailed(String url) {
        if (url != null) {
            try {
                this.redirectionUrl = new URL(url);
                if (this.redirectionUrl.getProtocol().equals("https")) {
                    throw new StateChangingError(Account.State.REGISTRATION_WEB);
                }
            } catch (MalformedURLException e) {
                //fall through
            }
        }
        throw new StateChangingError(Account.State.REGISTRATION_FAILED);
    }

    public URL getRedirectionUrl() {
        return this.redirectionUrl;
    }

    public void resetEverything() {
        resetAttemptCount(true);
        resetStreamId();
        clearIqCallbacks();
        this.stanzasSent = 0;
        mStanzaQueue.clear();
        this.redirectionUrl = null;
        synchronized (this.disco) {
            disco.clear();
        }
    }

    private void sendBindRequest() {
        try {
            mXmppConnectionService.restoredFromDatabaseLatch.await();
        } catch (InterruptedException e) {
            Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": interrupted while waiting for DB restore during bind");
            return;
        }
        clearIqCallbacks();
        if (account.getJid().isBareJid()) {
            account.setResource(this.createNewResource());
        } else {
            fixResource(mXmppConnectionService, account);
        }
        final IqPacket iq = new IqPacket(IqPacket.TYPE.SET);
        final String resource = Config.USE_RANDOM_RESOURCE_ON_EVERY_BIND ? nextRandomId() : account.getResource();
        iq.addChild("bind", Namespace.BIND).addChild("resource").setContent(resource);
        this.sendUnmodifiedIqPacket(iq, (account, packet) -> {
            if (packet.getType() == IqPacket.TYPE.TIMEOUT) {
                return;
            }
            final Element bind = packet.findChild("bind");
            if (bind != null && packet.getType() == IqPacket.TYPE.RESULT) {
                isBound = true;
                final Element jid = bind.findChild("jid");
                if (jid != null && jid.getContent() != null) {
                    try {
                        Jid assignedJid = Jid.ofEscaped(jid.getContent());
                        if (!account.getJid().getDomain().equals(assignedJid.getDomain())) {
                            Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": server tried to re-assign domain to " + assignedJid.getDomain());
                            throw new StateChangingError(Account.State.BIND_FAILURE);
                        }
                        if (account.setJid(assignedJid)) {
                            Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": jid changed during bind. updating database");
                            mXmppConnectionService.databaseBackend.updateAccount(account);
                        }
                        if (streamFeatures.hasChild("session")
                                && !streamFeatures.findChild("session").hasChild("optional")) {
                            sendStartSession();
                        } else {
                            sendPostBindInitialization();
                        }
                        return;
                    } catch (final IllegalArgumentException e) {
                        Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": server reported invalid jid (" + jid.getContent() + ") on bind");
                    }
                } else {
                    Log.d(Config.LOGTAG, account.getJid() + ": disconnecting because of bind failure. (no jid)");
                }
            } else {
                Log.d(Config.LOGTAG, account.getJid() + ": disconnecting because of bind failure (" + packet.toString());
            }
            final Element error = packet.findChild("error");
            if (packet.getType() == IqPacket.TYPE.ERROR && error != null && error.hasChild("conflict")) {
                account.setResource(createNewResource());
            }
            throw new StateChangingError(Account.State.BIND_FAILURE);
        }, true);
    }

    private void clearIqCallbacks() {
        final IqPacket failurePacket = new IqPacket(IqPacket.TYPE.TIMEOUT);
        final ArrayList<OnIqPacketReceived> callbacks = new ArrayList<>();
        synchronized (this.packetCallbacks) {
            if (this.packetCallbacks.size() == 0) {
                return;
            }
            Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": clearing " + this.packetCallbacks.size() + " iq callbacks");
            final Iterator<Pair<IqPacket, OnIqPacketReceived>> iterator = this.packetCallbacks.values().iterator();
            while (iterator.hasNext()) {
                Pair<IqPacket, OnIqPacketReceived> entry = iterator.next();
                callbacks.add(entry.second);
                iterator.remove();
            }
        }
        for (OnIqPacketReceived callback : callbacks) {
            try {
                callback.onIqPacketReceived(account, failurePacket);
            } catch (StateChangingError error) {
                Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": caught StateChangingError(" + error.state.toString() + ") while clearing callbacks");
                //ignore
            }
        }
        Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": done clearing iq callbacks. " + this.packetCallbacks.size() + " left");
    }

    public void sendDiscoTimeout() {
        if (mWaitForDisco.compareAndSet(true, false)) {
            Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": finalizing bind after disco timeout");
            finalizeBind();
        }
    }

    private void sendStartSession() {
        Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": sending legacy session to outdated server");
        final IqPacket startSession = new IqPacket(IqPacket.TYPE.SET);
        startSession.addChild("session", "urn:ietf:params:xml:ns:xmpp-session");
        this.sendUnmodifiedIqPacket(startSession, (account, packet) -> {
            if (packet.getType() == IqPacket.TYPE.RESULT) {
                sendPostBindInitialization();
            } else if (packet.getType() != IqPacket.TYPE.TIMEOUT) {
                throw new StateChangingError(Account.State.SESSION_FAILURE);
            }
        }, true);
    }

    private void sendPostBindInitialization() {
        smVersion = 0;
        if (streamFeatures.hasChild("sm", "urn:xmpp:sm:3")) {
            smVersion = 3;
        } else if (streamFeatures.hasChild("sm", "urn:xmpp:sm:2")) {
            smVersion = 2;
        }
        if (smVersion != 0) {
            synchronized (this.mStanzaQueue) {
                final EnablePacket enable = new EnablePacket(smVersion);
                tagWriter.writeStanzaAsync(enable);
                stanzasSent = 0;
                mStanzaQueue.clear();
            }
        }
        features.carbonsEnabled = false;
        features.blockListRequested = false;
        synchronized (this.disco) {
            this.disco.clear();
        }
        Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": starting service discovery");
        mPendingServiceDiscoveries.set(0);
        if (smVersion == 0 || Patches.DISCO_EXCEPTIONS.contains(account.getJid().getDomain())) {
            Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": do not wait for service discovery");
            mWaitForDisco.set(false);
        } else {
            mWaitForDisco.set(true);
        }
        lastDiscoStarted = SystemClock.elapsedRealtime();
        mXmppConnectionService.scheduleWakeUpCall(Config.CONNECT_DISCO_TIMEOUT, account.getUuid().hashCode());
        Element caps = streamFeatures.findChild("c");
        final String hash = caps == null ? null : caps.getAttribute("hash");
        final String ver = caps == null ? null : caps.getAttribute("ver");
        ServiceDiscoveryResult discoveryResult = null;
        if (hash != null && ver != null) {
            discoveryResult = mXmppConnectionService.getCachedServiceDiscoveryResult(new Pair<>(hash, ver));
        }
        final boolean requestDiscoItemsFirst = !account.isOptionSet(Account.OPTION_LOGGED_IN_SUCCESSFULLY);
        if (requestDiscoItemsFirst) {
            sendServiceDiscoveryItems(Jid.of(account.getServer()));
        }
        if (discoveryResult == null) {
            sendServiceDiscoveryInfo(Jid.of(account.getServer()));
        } else {
            Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": server caps came from cache");
            disco.put(Jid.of(account.getServer()), discoveryResult);
        }
        sendServiceDiscoveryInfo(account.getJid().asBareJid());
        if (!requestDiscoItemsFirst) {
            sendServiceDiscoveryItems(Jid.of(account.getServer()));
        }

        if (!mWaitForDisco.get()) {
            finalizeBind();
        }
        this.lastSessionStarted = SystemClock.elapsedRealtime();
    }

    private void sendServiceDiscoveryInfo(final Jid jid) {
        mPendingServiceDiscoveries.incrementAndGet();
        final IqPacket iq = new IqPacket(IqPacket.TYPE.GET);
        iq.setTo(jid);
        iq.query("http://jabber.org/protocol/disco#info");
        this.sendIqPacket(iq, (account, packet) -> {
            if (packet.getType() == IqPacket.TYPE.RESULT) {
                boolean advancedStreamFeaturesLoaded;
                synchronized (XmppConnection.this.disco) {
                    ServiceDiscoveryResult result = new ServiceDiscoveryResult(packet);
                    if (jid.equals(Jid.of(account.getServer()))) {
                        mXmppConnectionService.databaseBackend.insertDiscoveryResult(result);
                    }
                    disco.put(jid, result);
                    advancedStreamFeaturesLoaded = disco.containsKey(Jid.of(account.getServer()))
                            && disco.containsKey(account.getJid().asBareJid());
                }
                if (advancedStreamFeaturesLoaded && (jid.equals(Jid.of(account.getServer())) || jid.equals(account.getJid().asBareJid()))) {
                    enableAdvancedStreamFeatures();
                }
            } else {
                Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": could not query disco info for " + jid.toString());
            }
            if (packet.getType() != IqPacket.TYPE.TIMEOUT) {
                if (mPendingServiceDiscoveries.decrementAndGet() == 0
                        && mWaitForDisco.compareAndSet(true, false)) {
                    finalizeBind();
                }
            }
        });
    }

    private void finalizeBind() {
        Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": online with resource " + account.getResource());
        if (bindListener != null) {
            bindListener.onBind(account);
        }
        changeStatus(Account.State.ONLINE);
    }

    private void enableAdvancedStreamFeatures() {
        if (getFeatures().carbons() && !features.carbonsEnabled) {
            sendEnableCarbons();
        }
        if (getFeatures().blocking() && !features.blockListRequested) {
            Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": Requesting block list");
            this.sendIqPacket(getIqGenerator().generateGetBlockList(), mXmppConnectionService.getIqParser());
        }
        for (final OnAdvancedStreamFeaturesLoaded listener : advancedStreamFeaturesLoadedListeners) {
            listener.onAdvancedStreamFeaturesAvailable(account);
        }
    }

    private void sendServiceDiscoveryItems(final Jid server) {
        mPendingServiceDiscoveries.incrementAndGet();
        final IqPacket iq = new IqPacket(IqPacket.TYPE.GET);
        iq.setTo(Jid.ofDomain(server.getDomain()));
        iq.query("http://jabber.org/protocol/disco#items");
        this.sendIqPacket(iq, (account, packet) -> {
            if (packet.getType() == IqPacket.TYPE.RESULT) {
                HashSet<Jid> items = new HashSet<Jid>();
                final List<Element> elements = packet.query().getChildren();
                for (final Element element : elements) {
                    if (element.getName().equals("item")) {
                        final Jid jid = InvalidJid.getNullForInvalid(element.getAttributeAsJid("jid"));
                        if (jid != null && !jid.equals(Jid.of(account.getServer()))) {
                            items.add(jid);
                        }
                    }
                }
                for (Jid jid : items) {
                    sendServiceDiscoveryInfo(jid);
                }
            } else {
                Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": could not query disco items of " + server);
            }
            if (packet.getType() != IqPacket.TYPE.TIMEOUT) {
                if (mPendingServiceDiscoveries.decrementAndGet() == 0
                        && mWaitForDisco.compareAndSet(true, false)) {
                    finalizeBind();
                }
            }
        });
    }

    private void sendEnableCarbons() {
        final IqPacket iq = new IqPacket(IqPacket.TYPE.SET);
        iq.addChild("enable", "urn:xmpp:carbons:2");
        this.sendIqPacket(iq, new OnIqPacketReceived() {

            @Override
            public void onIqPacketReceived(final Account account, final IqPacket packet) {
                if (!packet.hasChild("error")) {
                    Log.d(Config.LOGTAG, account.getJid().asBareJid()
                            + ": successfully enabled carbons");
                    features.carbonsEnabled = true;
                } else {
                    Log.d(Config.LOGTAG, account.getJid().asBareJid()
                            + ": error enableing carbons " + packet.toString());
                }
            }
        });
    }

    private void processStreamError(final Tag currentTag) throws XmlPullParserException, IOException {
        final Element streamError = tagReader.readElement(currentTag);
        if (streamError == null) {
            return;
        }
        if (streamError.hasChild("conflict")) {
            account.setResource(createNewResource());
            Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": switching resource due to conflict (" + account.getResource() + ")");
            throw new IOException();
        } else if (streamError.hasChild("host-unknown")) {
            throw new StateChangingException(Account.State.HOST_UNKNOWN);
        } else if (streamError.hasChild("policy-violation")) {
            throw new StateChangingException(Account.State.POLICY_VIOLATION);
        } else {
            Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": stream error " + streamError.toString());
            throw new StateChangingException(Account.State.STREAM_ERROR);
        }
    }

    private void sendStartStream() throws IOException {
        final Tag stream = Tag.start("stream:stream");
        stream.setAttribute("to", account.getServer());
        stream.setAttribute("version", "1.0");
        stream.setAttribute("xml:lang", "en");
        stream.setAttribute("xmlns", "jabber:client");
        stream.setAttribute("xmlns:stream", "http://etherx.jabber.org/streams");
        tagWriter.writeTag(stream);
    }

    private String createNewResource() {
        return mXmppConnectionService.getString(R.string.app_name) + '.' + nextRandomId(true);
    }

    private String nextRandomId() {
        return nextRandomId(false);
    }

    private String nextRandomId(boolean s) {
        return CryptoHelper.random(s ? 3 : 9, mXmppConnectionService.getRNG());
    }

    public String sendIqPacket(final IqPacket packet, final OnIqPacketReceived callback) {
        packet.setFrom(account.getJid());
        return this.sendUnmodifiedIqPacket(packet, callback, false);
    }

    public synchronized String sendUnmodifiedIqPacket(final IqPacket packet, final OnIqPacketReceived callback, boolean force) {
        if (packet.getId() == null) {
            packet.setAttribute("id", nextRandomId());
        }
        if (callback != null) {
            synchronized (this.packetCallbacks) {
                packetCallbacks.put(packet.getId(), new Pair<>(packet, callback));
            }
        }
        this.sendPacket(packet, force);
        return packet.getId();
    }

    public void sendMessagePacket(final MessagePacket packet) {
        this.sendPacket(packet);
    }

    public void sendPresencePacket(final PresencePacket packet) {
        this.sendPacket(packet);
    }

    private synchronized void sendPacket(final AbstractStanza packet) {
        sendPacket(packet, false);
    }

    private synchronized void sendPacket(final AbstractStanza packet, final boolean force) {
        if (stanzasSent == Integer.MAX_VALUE) {
            resetStreamId();
            disconnect(true);
            return;
        }
        synchronized (this.mStanzaQueue) {
            if (force || isBound) {
                tagWriter.writeStanzaAsync(packet);
            } else {
                Log.d(Config.LOGTAG, account.getJid().asBareJid() + " do not write stanza to unbound stream " + packet.toString());
            }
            if (packet instanceof AbstractAcknowledgeableStanza) {
                AbstractAcknowledgeableStanza stanza = (AbstractAcknowledgeableStanza) packet;

                if (this.mStanzaQueue.size() != 0) {
                    int currentHighestKey = this.mStanzaQueue.keyAt(this.mStanzaQueue.size() - 1);
                    if (currentHighestKey != stanzasSent) {
                        throw new AssertionError("Stanza count messed up");
                    }
                }

                ++stanzasSent;
                this.mStanzaQueue.append(stanzasSent, stanza);
                if (stanza instanceof MessagePacket && stanza.getId() != null && inSmacksSession) {
                    if (Config.EXTENDED_SM_LOGGING) {
                        Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": requesting ack for message stanza #" + stanzasSent);
                    }
                    tagWriter.writeStanzaAsync(new RequestPacket(this.smVersion));
                }
            }
        }
    }

    public void sendPing() {
        if (!r()) {
            final IqPacket iq = new IqPacket(IqPacket.TYPE.GET);
            iq.setFrom(account.getJid());
            iq.addChild("ping", "urn:xmpp:ping");
            this.sendIqPacket(iq, null);
        }
        this.lastPingSent = SystemClock.elapsedRealtime();
    }

    public void setOnMessagePacketReceivedListener(
            final OnMessagePacketReceived listener) {
        this.messageListener = listener;
    }

    public void setOnUnregisteredIqPacketReceivedListener(
            final OnIqPacketReceived listener) {
        this.unregisteredIqListener = listener;
    }

    public void setOnPresencePacketReceivedListener(
            final OnPresencePacketReceived listener) {
        this.presenceListener = listener;
    }

    public void setOnJinglePacketReceivedListener(
            final OnJinglePacketReceived listener) {
        this.jingleListener = listener;
    }

    public void setOnStatusChangedListener(final OnStatusChanged listener) {
        this.statusListener = listener;
    }

    public void setOnBindListener(final OnBindListener listener) {
        this.bindListener = listener;
    }

    public void setOnMessageAcknowledgeListener(final OnMessageAcknowledged listener) {
        this.acknowledgedListener = listener;
    }

    public void addOnAdvancedStreamFeaturesAvailableListener(final OnAdvancedStreamFeaturesLoaded listener) {
        this.advancedStreamFeaturesLoadedListeners.add(listener);
    }

    private void forceCloseSocket() {
        if (socket != null) {
            try {
                socket.close();
            } catch (IOException e) {
                Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": io exception " + e.getMessage() + " during force close");
            }
        } else {
            Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": socket was null during force close");
        }
    }

    public void interrupt() {
        if (this.mThread != null) {
            this.mThread.interrupt();
        }
    }

    public void disconnect(final boolean force) {
        interrupt();
        Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": disconnecting force=" + Boolean.toString(force));
        if (force) {
            forceCloseSocket();
        } else {
            final TagWriter currentTagWriter = this.tagWriter;
            if (currentTagWriter.isActive()) {
                currentTagWriter.finish();
                final Socket currentSocket = this.socket;
                final CountDownLatch streamCountDownLatch = this.mStreamCountDownLatch;
                try {
                    currentTagWriter.await(1, TimeUnit.SECONDS);
                    Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": closing stream");
                    currentTagWriter.writeTag(Tag.end("stream:stream"));
                    if (streamCountDownLatch != null) {
                        if (streamCountDownLatch.await(1, TimeUnit.SECONDS)) {
                            Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": remote ended stream");
                        } else {
                            Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": remote has not closed socket. force closing");
                        }
                    }
                } catch (InterruptedException e) {
                    Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": interrupted while gracefully closing stream");
                } catch (final IOException e) {
                    Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": io exception during disconnect (" + e.getMessage() + ")");
                } finally {
                    FileBackend.close(currentSocket);
                }
            } else {
                forceCloseSocket();
            }
        }
    }

    private void resetStreamId() {
        this.streamId = null;
    }

    private List<Entry<Jid, ServiceDiscoveryResult>> findDiscoItemsByFeature(final String feature) {
        synchronized (this.disco) {
            final List<Entry<Jid, ServiceDiscoveryResult>> items = new ArrayList<>();
            for (final Entry<Jid, ServiceDiscoveryResult> cursor : this.disco.entrySet()) {
                if (cursor.getValue().getFeatures().contains(feature)) {
                    items.add(cursor);
                }
            }
            return items;
        }
    }

    public Jid findDiscoItemByFeature(final String feature) {
        final List<Entry<Jid, ServiceDiscoveryResult>> items = findDiscoItemsByFeature(feature);
        if (items.size() >= 1) {
            return items.get(0).getKey();
        }
        return null;
    }

    public boolean r() {
        if (getFeatures().sm()) {
            this.tagWriter.writeStanzaAsync(new RequestPacket(smVersion));
            return true;
        } else {
            return false;
        }
    }

    public List<String> getMucServersWithholdAccount() {
        List<String> servers = getMucServers();
        servers.remove(account.getServer());
        return servers;
    }

    public List<String> getMucServers() {
        List<String> servers = new ArrayList<>();
        synchronized (this.disco) {
            for (final Entry<Jid, ServiceDiscoveryResult> cursor : disco.entrySet()) {
                final ServiceDiscoveryResult value = cursor.getValue();
                if (value.getFeatures().contains("http://jabber.org/protocol/muc")
                        && value.hasIdentity("conference", "text")
                        && !value.getFeatures().contains("jabber:iq:gateway")
                        && !value.hasIdentity("conference", "irc")) {
                    servers.add(cursor.getKey().toString());
                }
            }
        }
        return servers;
    }

    public String getMucServer() {
        List<String> servers = getMucServers();
        return servers.size() > 0 ? servers.get(0) : null;
    }

    public int getTimeToNextAttempt() {
        final int interval = Math.min((int) (25 * Math.pow(1.3, attempt)), 300);
        final int secondsSinceLast = (int) ((SystemClock.elapsedRealtime() - this.lastConnect) / 1000);
        return interval - secondsSinceLast;
    }

    public int getAttempt() {
        return this.attempt;
    }

    public Features getFeatures() {
        return this.features;
    }

    public long getLastSessionEstablished() {
        final long diff = SystemClock.elapsedRealtime() - this.lastSessionStarted;
        return System.currentTimeMillis() - diff;
    }

    public long getLastConnect() {
        return this.lastConnect;
    }

    public long getLastPingSent() {
        return this.lastPingSent;
    }

    public long getLastDiscoStarted() {
        return this.lastDiscoStarted;
    }

    public long getLastPacketReceived() {
        return this.lastPacketReceived;
    }

    public void sendActive() {
        this.sendPacket(new ActivePacket());
    }

    public void sendInactive() {
        this.sendPacket(new InactivePacket());
    }

    public void resetAttemptCount(boolean resetConnectTime) {
        this.attempt = 0;
        if (resetConnectTime) {
            this.lastConnect = 0;
        }
    }

    public void setInteractive(boolean interactive) {
        this.mInteractive = interactive;
    }

    public Identity getServerIdentity() {
        synchronized (this.disco) {
            ServiceDiscoveryResult result = disco.get(Jid.ofDomain(account.getJid().getDomain()));
            if (result == null) {
                return Identity.UNKNOWN;
            }
            for (final ServiceDiscoveryResult.Identity id : result.getIdentities()) {
                if (id.getType().equals("im") && id.getCategory().equals("server") && id.getName() != null) {
                    switch (id.getName()) {
                        case "Prosody":
                            return Identity.PROSODY;
                        case "ejabberd":
                            return Identity.EJABBERD;
                        case "Slack-XMPP":
                            return Identity.SLACK;
                    }
                }
            }
        }
        return Identity.UNKNOWN;
    }

    private IqGenerator getIqGenerator() {
        return mXmppConnectionService.getIqGenerator();
    }

    public enum Identity {
        FACEBOOK,
        SLACK,
        EJABBERD,
        PROSODY,
        NIMBUZZ,
        UNKNOWN
    }

    private static class TlsFactoryVerifier {
        private final SSLSocketFactory factory;
        private final DomainHostnameVerifier verifier;

        TlsFactoryVerifier(final SSLSocketFactory factory, final DomainHostnameVerifier verifier) throws IOException {
            this.factory = factory;
            this.verifier = verifier;
            if (factory == null || verifier == null) {
                throw new IOException("could not setup ssl");
            }
        }
    }

    private class MyKeyManager implements X509KeyManager {
        @Override
        public String chooseClientAlias(String[] strings, Principal[] principals, Socket socket) {
            return account.getPrivateKeyAlias();
        }

        @Override
        public String chooseServerAlias(String s, Principal[] principals, Socket socket) {
            return null;
        }

        @Override
        public X509Certificate[] getCertificateChain(String alias) {
            Log.d(Config.LOGTAG, "getting certificate chain");
            try {
                return KeyChain.getCertificateChain(mXmppConnectionService, alias);
            } catch (Exception e) {
                Log.d(Config.LOGTAG, e.getMessage());
                return new X509Certificate[0];
            }
        }

        @Override
        public String[] getClientAliases(String s, Principal[] principals) {
            final String alias = account.getPrivateKeyAlias();
            return alias != null ? new String[]{alias} : new String[0];
        }

        @Override
        public String[] getServerAliases(String s, Principal[] principals) {
            return new String[0];
        }

        @Override
        public PrivateKey getPrivateKey(String alias) {
            try {
                return KeyChain.getPrivateKey(mXmppConnectionService, alias);
            } catch (Exception e) {
                return null;
            }
        }
    }

    private class StateChangingError extends Error {
        private final Account.State state;

        public StateChangingError(Account.State state) {
            this.state = state;
        }
    }

    private class StateChangingException extends IOException {
        private final Account.State state;

        public StateChangingException(Account.State state) {
            this.state = state;
        }
    }

    public class Features {
        XmppConnection connection;
        private boolean carbonsEnabled = false;
        private boolean encryptionEnabled = false;
        private boolean blockListRequested = false;

        public Features(final XmppConnection connection) {
            this.connection = connection;
        }

        private boolean hasDiscoFeature(final Jid server, final String feature) {
            synchronized (XmppConnection.this.disco) {
                return connection.disco.containsKey(server) &&
                        connection.disco.get(server).getFeatures().contains(feature);
            }
        }

        public boolean carbons() {
            return hasDiscoFeature(Jid.of(account.getServer()), "urn:xmpp:carbons:2");
        }

        public boolean bookmarksConversion() {
            return hasDiscoFeature(account.getJid().asBareJid(), Namespace.BOOKMARKS_CONVERSION) && pepPublishOptions();
        }

        public boolean blocking() {
            return hasDiscoFeature(Jid.of(account.getServer()), Namespace.BLOCKING);
        }

        public boolean spamReporting() {
            return hasDiscoFeature(Jid.of(account.getServer()), "urn:xmpp:reporting:reason:spam:0");
        }

        public boolean flexibleOfflineMessageRetrieval() {
            return hasDiscoFeature(Jid.of(account.getServer()), Namespace.FLEXIBLE_OFFLINE_MESSAGE_RETRIEVAL);
        }

        public boolean register() {
            return hasDiscoFeature(Jid.of(account.getServer()), Namespace.REGISTER);
        }

        public boolean sm() {
            return streamId != null
                    || (connection.streamFeatures != null && connection.streamFeatures.hasChild("sm"));
        }

        public boolean csi() {
            return connection.streamFeatures != null && connection.streamFeatures.hasChild("csi", "urn:xmpp:csi:0");
        }

        public boolean pep() {
            synchronized (XmppConnection.this.disco) {
                ServiceDiscoveryResult info = disco.get(account.getJid().asBareJid());
                return info != null && info.hasIdentity("pubsub", "pep");
            }
        }

        public boolean pepPersistent() {
            synchronized (XmppConnection.this.disco) {
                ServiceDiscoveryResult info = disco.get(account.getJid().asBareJid());
                return info != null && info.getFeatures().contains("http://jabber.org/protocol/pubsub#persistent-items");
            }
        }

        public boolean pepPublishOptions() {
            return hasDiscoFeature(account.getJid().asBareJid(), Namespace.PUBSUB_PUBLISH_OPTIONS);
        }

        public boolean pepOmemoWhitelisted() {
            return hasDiscoFeature(account.getJid().asBareJid(), AxolotlService.PEP_OMEMO_WHITELISTED);
        }

        public boolean mam() {
            return MessageArchiveService.Version.has(getAccountFeatures());
        }

        public List<String> getAccountFeatures() {
            ServiceDiscoveryResult result = connection.disco.get(account.getJid().asBareJid());
            return result == null ? Collections.emptyList() : result.getFeatures();
        }

        public boolean push() {
            return hasDiscoFeature(account.getJid().asBareJid(), "urn:xmpp:push:0")
                    || hasDiscoFeature(Jid.of(account.getServer()), "urn:xmpp:push:0");
        }

        public boolean rosterVersioning() {
            return connection.streamFeatures != null && connection.streamFeatures.hasChild("ver");
        }

        public void setBlockListRequested(boolean value) {
            this.blockListRequested = value;
        }

        public boolean p1S3FileTransfer() {
            return hasDiscoFeature(Jid.of(account.getServer()), Namespace.P1_S3_FILE_TRANSFER);
        }

        public boolean httpUpload(long filesize) {
            if (Config.DISABLE_HTTP_UPLOAD) {
                return false;
            } else {
                for (String namespace : new String[]{Namespace.HTTP_UPLOAD, Namespace.HTTP_UPLOAD_LEGACY}) {
                    List<Entry<Jid, ServiceDiscoveryResult>> items = findDiscoItemsByFeature(namespace);
                    if (items.size() > 0) {
                        try {
                            long maxsize = Long.parseLong(items.get(0).getValue().getExtendedDiscoInformation(namespace, "max-file-size"));
                            if (filesize <= maxsize) {
                                return true;
                            } else {
                                Log.d(Config.LOGTAG, account.getJid().asBareJid() + ": http upload is not available for files with size " + filesize + " (max is " + maxsize + ")");
                                return f