XmppConnection.java

   1package eu.siacs.conversations.xmpp;
   2
   3import android.content.Context;
   4import android.content.SharedPreferences;
   5import android.os.Bundle;
   6import android.os.Parcelable;
   7import android.os.PowerManager;
   8import android.os.PowerManager.WakeLock;
   9import android.os.SystemClock;
  10import android.preference.PreferenceManager;
  11import android.util.Log;
  12import android.util.Pair;
  13import android.util.SparseArray;
  14
  15import org.apache.http.conn.ssl.StrictHostnameVerifier;
  16import org.json.JSONException;
  17import org.json.JSONObject;
  18import org.xmlpull.v1.XmlPullParserException;
  19
  20import java.io.IOException;
  21import java.io.InputStream;
  22import java.io.OutputStream;
  23import java.math.BigInteger;
  24import java.net.ConnectException;
  25import java.net.IDN;
  26import java.net.InetAddress;
  27import java.net.InetSocketAddress;
  28import java.net.Socket;
  29import java.net.UnknownHostException;
  30import java.security.KeyManagementException;
  31import java.security.NoSuchAlgorithmException;
  32import java.util.ArrayList;
  33import java.util.Arrays;
  34import java.util.Collection;
  35import java.util.HashMap;
  36import java.util.Hashtable;
  37import java.util.LinkedList;
  38import java.util.List;
  39import java.util.Map;
  40import java.util.Map.Entry;
  41
  42import javax.net.ssl.HostnameVerifier;
  43import javax.net.ssl.SSLContext;
  44import javax.net.ssl.SSLSocket;
  45import javax.net.ssl.SSLSocketFactory;
  46import javax.net.ssl.X509TrustManager;
  47
  48import eu.siacs.conversations.Config;
  49import eu.siacs.conversations.crypto.sasl.DigestMd5;
  50import eu.siacs.conversations.crypto.sasl.Plain;
  51import eu.siacs.conversations.crypto.sasl.SaslMechanism;
  52import eu.siacs.conversations.crypto.sasl.ScramSha1;
  53import eu.siacs.conversations.entities.Account;
  54import eu.siacs.conversations.generator.IqGenerator;
  55import eu.siacs.conversations.services.XmppConnectionService;
  56import eu.siacs.conversations.utils.CryptoHelper;
  57import eu.siacs.conversations.utils.DNSHelper;
  58import eu.siacs.conversations.utils.Xmlns;
  59import eu.siacs.conversations.xml.Element;
  60import eu.siacs.conversations.xml.Tag;
  61import eu.siacs.conversations.xml.TagWriter;
  62import eu.siacs.conversations.xml.XmlReader;
  63import eu.siacs.conversations.xmpp.jid.InvalidJidException;
  64import eu.siacs.conversations.xmpp.jid.Jid;
  65import eu.siacs.conversations.xmpp.jingle.OnJinglePacketReceived;
  66import eu.siacs.conversations.xmpp.jingle.stanzas.JinglePacket;
  67import eu.siacs.conversations.xmpp.stanzas.AbstractStanza;
  68import eu.siacs.conversations.xmpp.stanzas.IqPacket;
  69import eu.siacs.conversations.xmpp.stanzas.MessagePacket;
  70import eu.siacs.conversations.xmpp.stanzas.PresencePacket;
  71import eu.siacs.conversations.xmpp.stanzas.csi.ActivePacket;
  72import eu.siacs.conversations.xmpp.stanzas.csi.InactivePacket;
  73import eu.siacs.conversations.xmpp.stanzas.streammgmt.AckPacket;
  74import eu.siacs.conversations.xmpp.stanzas.streammgmt.EnablePacket;
  75import eu.siacs.conversations.xmpp.stanzas.streammgmt.RequestPacket;
  76import eu.siacs.conversations.xmpp.stanzas.streammgmt.ResumePacket;
  77
  78public class XmppConnection implements Runnable {
  79
  80	private static final int PACKET_IQ = 0;
  81	private static final int PACKET_MESSAGE = 1;
  82	private static final int PACKET_PRESENCE = 2;
  83	private final Context applicationContext;
  84	protected Account account;
  85	private final WakeLock wakeLock;
  86	private Socket socket;
  87	private XmlReader tagReader;
  88	private TagWriter tagWriter;
  89	private final Features features = new Features(this);
  90	private boolean shouldBind = true;
  91	private boolean shouldAuthenticate = true;
  92	private Element streamFeatures;
  93	private final HashMap<String, List<String>> disco = new HashMap<>();
  94
  95	private String streamId = null;
  96	private int smVersion = 3;
  97	private final SparseArray<String> messageReceipts = new SparseArray<>();
  98
  99	private int stanzasReceived = 0;
 100	private int stanzasSent = 0;
 101	private long lastPacketReceived = 0;
 102	private long lastPingSent = 0;
 103	private long lastConnect = 0;
 104	private long lastSessionStarted = 0;
 105	private int attempt = 0;
 106	private final Map<String, Pair<IqPacket, OnIqPacketReceived>> packetCallbacks = new Hashtable<>();
 107	private OnPresencePacketReceived presenceListener = null;
 108	private OnJinglePacketReceived jingleListener = null;
 109	private OnIqPacketReceived unregisteredIqListener = null;
 110	private OnMessagePacketReceived messageListener = null;
 111	private OnStatusChanged statusListener = null;
 112	private OnBindListener bindListener = null;
 113	private final ArrayList<OnAdvancedStreamFeaturesLoaded> advancedStreamFeaturesLoadedListeners = new ArrayList<>();
 114	private OnMessageAcknowledged acknowledgedListener = null;
 115	private XmppConnectionService mXmppConnectionService = null;
 116
 117	private SaslMechanism saslMechanism;
 118
 119	public XmppConnection(final Account account, final XmppConnectionService service) {
 120		this.account = account;
 121		this.wakeLock = service.getPowerManager().newWakeLock(
 122				PowerManager.PARTIAL_WAKE_LOCK, account.getJid().toBareJid().toString());
 123		tagWriter = new TagWriter();
 124		mXmppConnectionService = service;
 125		applicationContext = service.getApplicationContext();
 126	}
 127
 128	protected void changeStatus(final Account.State nextStatus) {
 129		if (account.getStatus() != nextStatus) {
 130			if ((nextStatus == Account.State.OFFLINE)
 131					&& (account.getStatus() != Account.State.CONNECTING)
 132					&& (account.getStatus() != Account.State.ONLINE)
 133					&& (account.getStatus() != Account.State.DISABLED)) {
 134				return;
 135					}
 136			if (nextStatus == Account.State.ONLINE) {
 137				this.attempt = 0;
 138			}
 139			account.setStatus(nextStatus);
 140			if (statusListener != null) {
 141				statusListener.onStatusChanged(account);
 142			}
 143		}
 144	}
 145
 146	protected void connect() {
 147		Log.d(Config.LOGTAG, account.getJid().toBareJid().toString() + ": connecting");
 148		features.encryptionEnabled = false;
 149		lastConnect = SystemClock.elapsedRealtime();
 150		lastPingSent = SystemClock.elapsedRealtime();
 151		this.attempt++;
 152		try {
 153			shouldAuthenticate = shouldBind = !account.isOptionSet(Account.OPTION_REGISTER);
 154			tagReader = new XmlReader(wakeLock);
 155			tagWriter = new TagWriter();
 156			packetCallbacks.clear();
 157			this.changeStatus(Account.State.CONNECTING);
 158			final Bundle result = DNSHelper.getSRVRecord(account.getServer());
 159			final ArrayList<Parcelable> values = result.getParcelableArrayList("values");
 160			if ("timeout".equals(result.getString("error"))) {
 161				throw new IOException("timeout in dns");
 162			} else if (values != null) {
 163				int i = 0;
 164				boolean socketError = true;
 165				while (socketError && values.size() > i) {
 166					final Bundle namePort = (Bundle) values.get(i);
 167					try {
 168						String srvRecordServer;
 169						try {
 170							srvRecordServer=IDN.toASCII(namePort.getString("name"));
 171						} catch (final IllegalArgumentException e) {
 172							// TODO: Handle me?`
 173							srvRecordServer = "";
 174						}
 175						final int srvRecordPort = namePort.getInt("port");
 176						final String srvIpServer = namePort.getString("ip");
 177						final InetSocketAddress addr;
 178						if (srvIpServer != null) {
 179							addr = new InetSocketAddress(srvIpServer, srvRecordPort);
 180							Log.d(Config.LOGTAG, account.getJid().toBareJid().toString()
 181									+ ": using values from dns " + srvRecordServer
 182									+ "[" + srvIpServer + "]:" + srvRecordPort);
 183						} else {
 184							addr = new InetSocketAddress(srvRecordServer, srvRecordPort);
 185							Log.d(Config.LOGTAG, account.getJid().toBareJid().toString()
 186									+ ": using values from dns "
 187									+ srvRecordServer + ":" + srvRecordPort);
 188						}
 189						socket = new Socket();
 190						socket.connect(addr, 20000);
 191						socketError = false;
 192					} catch (final UnknownHostException e) {
 193						Log.d(Config.LOGTAG, account.getJid().toBareJid().toString() + ": " + e.getMessage());
 194						i++;
 195					} catch (final IOException e) {
 196						Log.d(Config.LOGTAG, account.getJid().toBareJid().toString() + ": " + e.getMessage());
 197						i++;
 198					}
 199				}
 200				if (socketError) {
 201					throw new UnknownHostException();
 202				}
 203			} else if (result.containsKey("error")
 204					&& "nosrv".equals(result.getString("error", null))) {
 205				socket = new Socket(account.getServer().getDomainpart(), 5222);
 206			} else {
 207				throw new IOException("timeout in dns");
 208			}
 209			final OutputStream out = socket.getOutputStream();
 210			tagWriter.setOutputStream(out);
 211			final InputStream in = socket.getInputStream();
 212			tagReader.setInputStream(in);
 213			tagWriter.beginDocument();
 214			sendStartStream();
 215			Tag nextTag;
 216			while ((nextTag = tagReader.readTag()) != null) {
 217				if (nextTag.isStart("stream")) {
 218					processStream(nextTag);
 219					break;
 220				} else {
 221					throw new IOException("unknown tag on connect");
 222				}
 223			}
 224			if (socket.isConnected()) {
 225				socket.close();
 226			}
 227		} catch (final UnknownHostException | ConnectException e) {
 228			this.changeStatus(Account.State.SERVER_NOT_FOUND);
 229		} catch (final IOException | XmlPullParserException | NoSuchAlgorithmException e) {
 230			Log.d(Config.LOGTAG, account.getJid().toBareJid().toString() + ": " + e.getMessage());
 231			this.changeStatus(Account.State.OFFLINE);
 232		} finally {
 233			if (wakeLock.isHeld()) {
 234				try {
 235					wakeLock.release();
 236				} catch (final RuntimeException ignored) {
 237				}
 238			}
 239		}
 240	}
 241
 242	@Override
 243	public void run() {
 244		connect();
 245	}
 246
 247	private void processStream(final Tag currentTag) throws XmlPullParserException,
 248					IOException, NoSuchAlgorithmException {
 249						Tag nextTag = tagReader.readTag();
 250
 251						while ((nextTag != null) && (!nextTag.isEnd("stream"))) {
 252							if (nextTag.isStart("error")) {
 253								processStreamError(nextTag);
 254							} else if (nextTag.isStart("features")) {
 255								processStreamFeatures(nextTag);
 256							} else if (nextTag.isStart("proceed")) {
 257								switchOverToTls(nextTag);
 258							} else if (nextTag.isStart("success")) {
 259								final String challenge = tagReader.readElement(nextTag).getContent();
 260								try {
 261									saslMechanism.getResponse(challenge);
 262								} catch (final SaslMechanism.AuthenticationException e) {
 263									disconnect(true);
 264									Log.e(Config.LOGTAG, String.valueOf(e));
 265								}
 266								Log.d(Config.LOGTAG, account.getJid().toBareJid().toString() + ": logged in");
 267								account.setKey(Account.PINNED_MECHANISM_KEY,
 268										String.valueOf(saslMechanism.getPriority()));
 269								tagReader.reset();
 270								sendStartStream();
 271								processStream(tagReader.readTag());
 272								break;
 273							} else if (nextTag.isStart("failure")) {
 274								tagReader.readElement(nextTag);
 275								changeStatus(Account.State.UNAUTHORIZED);
 276							} else if (nextTag.isStart("challenge")) {
 277								final String challenge = tagReader.readElement(nextTag).getContent();
 278								final Element response = new Element("response");
 279								response.setAttribute("xmlns",
 280										"urn:ietf:params:xml:ns:xmpp-sasl");
 281								try {
 282									response.setContent(saslMechanism.getResponse(challenge));
 283								} catch (final SaslMechanism.AuthenticationException e) {
 284									// TODO: Send auth abort tag.
 285									Log.e(Config.LOGTAG, e.toString());
 286								}
 287								tagWriter.writeElement(response);
 288							} else if (nextTag.isStart("enabled")) {
 289								final Element enabled = tagReader.readElement(nextTag);
 290								if ("true".equals(enabled.getAttribute("resume"))) {
 291									this.streamId = enabled.getAttribute("id");
 292									Log.d(Config.LOGTAG, account.getJid().toBareJid().toString()
 293											+ ": stream managment(" + smVersion
 294											+ ") enabled (resumable)");
 295								} else {
 296									Log.d(Config.LOGTAG, account.getJid().toBareJid().toString()
 297											+ ": stream managment(" + smVersion + ") enabled");
 298								}
 299								this.lastSessionStarted = SystemClock.elapsedRealtime();
 300								this.stanzasReceived = 0;
 301								final RequestPacket r = new RequestPacket(smVersion);
 302								tagWriter.writeStanzaAsync(r);
 303							} else if (nextTag.isStart("resumed")) {
 304								lastPacketReceived = SystemClock.elapsedRealtime();
 305								final Element resumed = tagReader.readElement(nextTag);
 306								final String h = resumed.getAttribute("h");
 307								try {
 308									final int serverCount = Integer.parseInt(h);
 309									if (serverCount != stanzasSent) {
 310										Log.d(Config.LOGTAG, account.getJid().toBareJid().toString()
 311												+ ": session resumed with lost packages");
 312										stanzasSent = serverCount;
 313									} else {
 314										Log.d(Config.LOGTAG, account.getJid().toBareJid().toString()
 315												+ ": session resumed");
 316									}
 317									if (acknowledgedListener != null) {
 318										for (int i = 0; i < messageReceipts.size(); ++i) {
 319											if (serverCount >= messageReceipts.keyAt(i)) {
 320												acknowledgedListener.onMessageAcknowledged(
 321														account, messageReceipts.valueAt(i));
 322											}
 323										}
 324									}
 325									messageReceipts.clear();
 326								} catch (final NumberFormatException ignored) {
 327								}
 328								sendServiceDiscoveryInfo(account.getServer());
 329								sendServiceDiscoveryItems(account.getServer());
 330								sendInitialPing();
 331							} else if (nextTag.isStart("r")) {
 332								tagReader.readElement(nextTag);
 333								final AckPacket ack = new AckPacket(this.stanzasReceived, smVersion);
 334								tagWriter.writeStanzaAsync(ack);
 335							} else if (nextTag.isStart("a")) {
 336								final Element ack = tagReader.readElement(nextTag);
 337								lastPacketReceived = SystemClock.elapsedRealtime();
 338								final int serverSequence = Integer.parseInt(ack.getAttribute("h"));
 339								final String msgId = this.messageReceipts.get(serverSequence);
 340								if (msgId != null) {
 341									if (this.acknowledgedListener != null) {
 342										this.acknowledgedListener.onMessageAcknowledged(
 343												account, msgId);
 344									}
 345									this.messageReceipts.remove(serverSequence);
 346								}
 347							} else if (nextTag.isStart("failed")) {
 348								tagReader.readElement(nextTag);
 349								Log.d(Config.LOGTAG, account.getJid().toBareJid().toString() + ": resumption failed");
 350								streamId = null;
 351								if (account.getStatus() != Account.State.ONLINE) {
 352									sendBindRequest();
 353								}
 354							} else if (nextTag.isStart("iq")) {
 355								processIq(nextTag);
 356							} else if (nextTag.isStart("message")) {
 357								processMessage(nextTag);
 358							} else if (nextTag.isStart("presence")) {
 359								processPresence(nextTag);
 360							}
 361							nextTag = tagReader.readTag();
 362						}
 363						if (account.getStatus() == Account.State.ONLINE) {
 364							account. setStatus(Account.State.OFFLINE);
 365							if (statusListener != null) {
 366								statusListener.onStatusChanged(account);
 367							}
 368						}
 369	}
 370
 371	private void sendInitialPing() {
 372		Log.d(Config.LOGTAG, account.getJid().toBareJid().toString() + ": sending intial ping");
 373		final IqPacket iq = new IqPacket(IqPacket.TYPE.GET);
 374		iq.setFrom(account.getJid());
 375		iq.addChild("ping", "urn:xmpp:ping");
 376		this.sendIqPacket(iq, new OnIqPacketReceived() {
 377			@Override
 378			public void onIqPacketReceived(final Account account, final IqPacket packet) {
 379				Log.d(Config.LOGTAG, account.getJid().toBareJid().toString()
 380						+ ": online with resource " + account.getResource());
 381				changeStatus(Account.State.ONLINE);
 382			}
 383		});
 384	}
 385
 386	private Element processPacket(final Tag currentTag, final int packetType)
 387		throws XmlPullParserException, IOException {
 388		Element element;
 389		switch (packetType) {
 390			case PACKET_IQ:
 391				element = new IqPacket();
 392				break;
 393			case PACKET_MESSAGE:
 394				element = new MessagePacket();
 395				break;
 396			case PACKET_PRESENCE:
 397				element = new PresencePacket();
 398				break;
 399			default:
 400				return null;
 401		}
 402		element.setAttributes(currentTag.getAttributes());
 403		Tag nextTag = tagReader.readTag();
 404		if (nextTag == null) {
 405			throw new IOException("interrupted mid tag");
 406		}
 407		while (!nextTag.isEnd(element.getName())) {
 408			if (!nextTag.isNo()) {
 409				final Element child = tagReader.readElement(nextTag);
 410				final String type = currentTag.getAttribute("type");
 411				if (packetType == PACKET_IQ
 412						&& "jingle".equals(child.getName())
 413						&& ("set".equalsIgnoreCase(type) || "get"
 414							.equalsIgnoreCase(type))) {
 415					element = new JinglePacket();
 416					element.setAttributes(currentTag.getAttributes());
 417							}
 418				element.addChild(child);
 419			}
 420			nextTag = tagReader.readTag();
 421			if (nextTag == null) {
 422				throw new IOException("interrupted mid tag");
 423			}
 424		}
 425		++stanzasReceived;
 426		lastPacketReceived = SystemClock.elapsedRealtime();
 427		return element;
 428	}
 429
 430	private void processIq(final Tag currentTag) throws XmlPullParserException, IOException {
 431		final IqPacket packet = (IqPacket) processPacket(currentTag, PACKET_IQ);
 432
 433		if (packet.getId() == null) {
 434			return; // an iq packet without id is definitely invalid
 435		}
 436
 437		if (packet instanceof JinglePacket) {
 438			if (this.jingleListener != null) {
 439				this.jingleListener.onJinglePacketReceived(account,(JinglePacket) packet);
 440			}
 441		} else {
 442			if (packetCallbacks.containsKey(packet.getId())) {
 443				final Pair<IqPacket, OnIqPacketReceived> packetCallbackDuple = packetCallbacks.get(packet.getId());
 444				// Packets to the server should have responses from the server
 445				if (packetCallbackDuple.first.toServer(account)) {
 446					if (packet.fromServer(account)) {
 447						packetCallbackDuple.second.onIqPacketReceived(account, packet);
 448						packetCallbacks.remove(packet.getId());
 449					} else {
 450						Log.e(Config.LOGTAG,account.getJid().toBareJid().toString()+": ignoring spoofed iq packet");
 451					}
 452				} else {
 453					if (packet.getFrom().equals(packetCallbackDuple.first.getTo())) {
 454						packetCallbackDuple.second.onIqPacketReceived(account, packet);
 455						packetCallbacks.remove(packet.getId());
 456					} else {
 457						Log.e(Config.LOGTAG,account.getJid().toBareJid().toString()+": ignoring spoofed iq packet");
 458					}
 459				}
 460			} else if (packet.getType() == IqPacket.TYPE.GET|| packet.getType() == IqPacket.TYPE.SET) {
 461				this.unregisteredIqListener.onIqPacketReceived(account, packet);
 462			}
 463		}
 464	}
 465
 466	private void processMessage(final Tag currentTag) throws XmlPullParserException, IOException {
 467		final MessagePacket packet = (MessagePacket) processPacket(currentTag,PACKET_MESSAGE);
 468		this.messageListener.onMessagePacketReceived(account, packet);
 469	}
 470
 471	private void processPresence(final Tag currentTag) throws XmlPullParserException, IOException {
 472		PresencePacket packet = (PresencePacket) processPacket(currentTag, PACKET_PRESENCE);
 473		this.presenceListener.onPresencePacketReceived(account, packet);
 474	}
 475
 476	private void sendStartTLS() throws IOException {
 477		final Tag startTLS = Tag.empty("starttls");
 478		startTLS.setAttribute("xmlns", "urn:ietf:params:xml:ns:xmpp-tls");
 479		tagWriter.writeTag(startTLS);
 480	}
 481
 482	private SharedPreferences getPreferences() {
 483		return PreferenceManager.getDefaultSharedPreferences(applicationContext);
 484	}
 485
 486	private boolean enableLegacySSL() {
 487		return getPreferences().getBoolean("enable_legacy_ssl", false);
 488	}
 489
 490	private void switchOverToTls(final Tag currentTag) throws XmlPullParserException, IOException {
 491		tagReader.readTag();
 492		try {
 493			final SSLContext sc = SSLContext.getInstance("TLS");
 494			sc.init(null,new X509TrustManager[]{this.mXmppConnectionService.getMemorizingTrustManager()},mXmppConnectionService.getRNG());
 495			final SSLSocketFactory factory = sc.getSocketFactory();
 496			final HostnameVerifier verifier = this.mXmppConnectionService.getMemorizingTrustManager().wrapHostnameVerifier(new StrictHostnameVerifier());
 497			final InetAddress address = socket == null ? null : socket.getInetAddress();
 498
 499			if (factory == null || address == null || verifier == null) {
 500				throw new IOException("could not setup ssl");
 501			}
 502
 503			final SSLSocket sslSocket = (SSLSocket) factory.createSocket(socket,address.getHostAddress(), socket.getPort(),true);
 504
 505			if (sslSocket == null) {
 506				throw new IOException("could not initialize ssl socket");
 507			}
 508
 509			final String[] supportProtocols;
 510			if (enableLegacySSL()) {
 511				supportProtocols = sslSocket.getSupportedProtocols();
 512			} else {
 513				final Collection<String> supportedProtocols = new LinkedList<>(
 514						Arrays.asList(sslSocket.getSupportedProtocols()));
 515				supportedProtocols.remove("SSLv3");
 516				supportProtocols = new String[supportedProtocols.size()];
 517				supportedProtocols.toArray(supportProtocols);
 518
 519				final String[] cipherSuites = CryptoHelper.getSupportedCipherSuites(
 520						sslSocket.getSupportedCipherSuites());
 521				if (cipherSuites.length > 0) {
 522					sslSocket.setEnabledCipherSuites(cipherSuites);
 523				}
 524			}
 525			sslSocket.setEnabledProtocols(supportProtocols);
 526
 527			if (!verifier.verify(account.getServer().getDomainpart(),sslSocket.getSession())) {
 528				Log.d(Config.LOGTAG,account.getJid().toBareJid()+": TLS certificate verification failed");
 529				disconnect(true);
 530				changeStatus(Account.State.SECURITY_ERROR);
 531			}
 532			tagReader.setInputStream(sslSocket.getInputStream());
 533			tagWriter.setOutputStream(sslSocket.getOutputStream());
 534			sendStartStream();
 535			Log.d(Config.LOGTAG, account.getJid().toBareJid()+ ": TLS connection established");
 536			features.encryptionEnabled = true;
 537			processStream(tagReader.readTag());
 538			sslSocket.close();
 539		} catch (final NoSuchAlgorithmException | KeyManagementException e1) {
 540			Log.d(Config.LOGTAG,account.getJid().toBareJid()+": TLS certificate verification failed");
 541			disconnect(true);
 542			changeStatus(Account.State.SECURITY_ERROR);
 543		}
 544	}
 545
 546	private void processStreamFeatures(final Tag currentTag)
 547		throws XmlPullParserException, IOException {
 548		this.streamFeatures = tagReader.readElement(currentTag);
 549		if (this.streamFeatures.hasChild("starttls") && !features.encryptionEnabled) {
 550			sendStartTLS();
 551		} else if (this.streamFeatures.hasChild("register")
 552				&& account.isOptionSet(Account.OPTION_REGISTER)
 553				&& features.encryptionEnabled) {
 554			sendRegistryRequest();
 555		} else if (!this.streamFeatures.hasChild("register")
 556				&& account.isOptionSet(Account.OPTION_REGISTER)) {
 557			changeStatus(Account.State.REGISTRATION_NOT_SUPPORTED);
 558			disconnect(true);
 559		} else if (this.streamFeatures.hasChild("mechanisms")
 560				&& shouldAuthenticate && features.encryptionEnabled) {
 561			final List<String> mechanisms = extractMechanisms(streamFeatures
 562					.findChild("mechanisms"));
 563			final Element auth = new Element("auth");
 564			auth.setAttribute("xmlns", "urn:ietf:params:xml:ns:xmpp-sasl");
 565			if (mechanisms.contains("SCRAM-SHA-1")) {
 566				saslMechanism = new ScramSha1(tagWriter, account, mXmppConnectionService.getRNG());
 567			} else if (mechanisms.contains("PLAIN")) {
 568				saslMechanism = new Plain(tagWriter, account);
 569			} else if (mechanisms.contains("DIGEST-MD5")) {
 570				saslMechanism = new DigestMd5(tagWriter, account, mXmppConnectionService.getRNG());
 571			}
 572			final JSONObject keys = account.getKeys();
 573			try {
 574				if (keys.has(Account.PINNED_MECHANISM_KEY) &&
 575						keys.getInt(Account.PINNED_MECHANISM_KEY) > saslMechanism.getPriority() ) {
 576					Log.e(Config.LOGTAG, "Auth failed. Authentication mechanism " + saslMechanism.getMechanism() +
 577							" has lower priority (" + String.valueOf(saslMechanism.getPriority()) +
 578							") than pinned priority (" + keys.getInt(Account.PINNED_MECHANISM_KEY) +
 579							"). Possible downgrade attack?");
 580					disconnect(true);
 581					changeStatus(Account.State.SECURITY_ERROR);
 582						}
 583			} catch (final JSONException e) {
 584				Log.d(Config.LOGTAG, "Parse error while checking pinned auth mechanism");
 585			}
 586			Log.d(Config.LOGTAG,account.getJid().toString()+": Authenticating with " + saslMechanism.getMechanism());
 587			auth.setAttribute("mechanism", saslMechanism.getMechanism());
 588			if (!saslMechanism.getClientFirstMessage().isEmpty()) {
 589				auth.setContent(saslMechanism.getClientFirstMessage());
 590			}
 591			tagWriter.writeElement(auth);
 592		} else if (this.streamFeatures.hasChild("sm", "urn:xmpp:sm:"
 593					+ smVersion)
 594				&& streamId != null) {
 595			final ResumePacket resume = new ResumePacket(this.streamId,
 596					stanzasReceived, smVersion);
 597			this.tagWriter.writeStanzaAsync(resume);
 598		} else if (this.streamFeatures.hasChild("bind") && shouldBind) {
 599			sendBindRequest();
 600		} else {
 601			disconnect(true);
 602			changeStatus(Account.State.INCOMPATIBLE_SERVER);
 603		}
 604	}
 605
 606	private List<String> extractMechanisms(final Element stream) {
 607		final ArrayList<String> mechanisms = new ArrayList<>(stream
 608				.getChildren().size());
 609		for (final Element child : stream.getChildren()) {
 610			mechanisms.add(child.getContent());
 611		}
 612		return mechanisms;
 613	}
 614
 615	private void sendRegistryRequest() {
 616		final IqPacket register = new IqPacket(IqPacket.TYPE.GET);
 617		register.query("jabber:iq:register");
 618		register.setTo(account.getServer());
 619		sendIqPacket(register, new OnIqPacketReceived() {
 620
 621			@Override
 622			public void onIqPacketReceived(final Account account, final IqPacket packet) {
 623				final Element instructions = packet.query().findChild("instructions");
 624				if (packet.query().hasChild("username")
 625						&& (packet.query().hasChild("password"))) {
 626					final IqPacket register = new IqPacket(IqPacket.TYPE.SET);
 627					final Element username = new Element("username")
 628						.setContent(account.getUsername());
 629					final Element password = new Element("password")
 630						.setContent(account.getPassword());
 631					register.query("jabber:iq:register").addChild(username);
 632					register.query().addChild(password);
 633					sendIqPacket(register, new OnIqPacketReceived() {
 634
 635						@Override
 636						public void onIqPacketReceived(final Account account, final IqPacket packet) {
 637							if (packet.getType() == IqPacket.TYPE.RESULT) {
 638								account.setOption(Account.OPTION_REGISTER,
 639										false);
 640								changeStatus(Account.State.REGISTRATION_SUCCESSFUL);
 641							} else if (packet.hasChild("error")
 642									&& (packet.findChild("error")
 643										.hasChild("conflict"))) {
 644								changeStatus(Account.State.REGISTRATION_CONFLICT);
 645							} else {
 646								changeStatus(Account.State.REGISTRATION_FAILED);
 647								Log.d(Config.LOGTAG, packet.toString());
 648							}
 649							disconnect(true);
 650						}
 651					});
 652				} else {
 653					changeStatus(Account.State.REGISTRATION_FAILED);
 654					disconnect(true);
 655					Log.d(Config.LOGTAG, account.getJid().toBareJid()
 656							+ ": could not register. instructions are"
 657							+ instructions.getContent());
 658				}
 659			}
 660		});
 661	}
 662
 663	private void sendBindRequest() {
 664		final IqPacket iq = new IqPacket(IqPacket.TYPE.SET);
 665		iq.addChild("bind", "urn:ietf:params:xml:ns:xmpp-bind")
 666			.addChild("resource").setContent(account.getResource());
 667		this.sendUnmodifiedIqPacket(iq, new OnIqPacketReceived() {
 668			@Override
 669			public void onIqPacketReceived(final Account account, final IqPacket packet) {
 670				final Element bind = packet.findChild("bind");
 671				if (bind != null) {
 672					final Element jid = bind.findChild("jid");
 673					if (jid != null && jid.getContent() != null) {
 674						try {
 675							account.setResource(Jid.fromString(jid.getContent()).getResourcepart());
 676						} catch (final InvalidJidException e) {
 677							// TODO: Handle the case where an external JID is technically invalid?
 678						}
 679						if (streamFeatures.hasChild("sm", "urn:xmpp:sm:3")) {
 680							smVersion = 3;
 681							final EnablePacket enable = new EnablePacket(smVersion);
 682							tagWriter.writeStanzaAsync(enable);
 683							stanzasSent = 0;
 684							messageReceipts.clear();
 685						} else if (streamFeatures.hasChild("sm", "urn:xmpp:sm:2")) {
 686							smVersion = 2;
 687							final EnablePacket enable = new EnablePacket(smVersion);
 688							tagWriter.writeStanzaAsync(enable);
 689							stanzasSent = 0;
 690							messageReceipts.clear();
 691						}
 692						features.carbonsEnabled = false;
 693						features.blockListRequested = false;
 694						disco.clear();
 695						sendServiceDiscoveryInfo(account.getServer());
 696						sendServiceDiscoveryItems(account.getServer());
 697						if (bindListener != null) {
 698							bindListener.onBind(account);
 699						}
 700						sendInitialPing();
 701					} else {
 702						disconnect(true);
 703					}
 704				} else {
 705					disconnect(true);
 706				}
 707			}
 708		});
 709		if (this.streamFeatures.hasChild("session")) {
 710			Log.d(Config.LOGTAG, account.getJid().toBareJid() + ": sending deprecated session");
 711			final IqPacket startSession = new IqPacket(IqPacket.TYPE.SET);
 712			startSession.addChild("session","urn:ietf:params:xml:ns:xmpp-session");
 713			this.sendUnmodifiedIqPacket(startSession, null);
 714		}
 715	}
 716
 717	private void sendServiceDiscoveryInfo(final Jid server) {
 718		if (disco.containsKey(server.toDomainJid().toString())) {
 719			if (account.getServer().equals(server.toDomainJid())) {
 720				enableAdvancedStreamFeatures();
 721			}
 722		} else {
 723			final IqPacket iq = new IqPacket(IqPacket.TYPE.GET);
 724			iq.setTo(server.toDomainJid());
 725			iq.query("http://jabber.org/protocol/disco#info");
 726			this.sendIqPacket(iq, new OnIqPacketReceived() {
 727
 728				@Override
 729				public void onIqPacketReceived(final Account account, final IqPacket packet) {
 730					final List<Element> elements = packet.query().getChildren();
 731					final List<String> features = new ArrayList<>();
 732					for (final Element element : elements) {
 733						if (element.getName().equals("identity")) {
 734							if ("irc".equals(element.getAttribute("type"))) {
 735								//add fake feature to not confuse irc and real muc
 736								features.add("siacs:no:muc");
 737							}
 738						} else if (element.getName().equals("feature")) {
 739							features.add(element.getAttribute("var"));
 740						}
 741					}
 742					disco.put(server.toDomainJid().toString(), features);
 743
 744					if (account.getServer().equals(server.toDomainJid())) {
 745						enableAdvancedStreamFeatures();
 746						for (final OnAdvancedStreamFeaturesLoaded listener : advancedStreamFeaturesLoadedListeners) {
 747							listener.onAdvancedStreamFeaturesAvailable(account);
 748						}
 749					}
 750				}
 751			});
 752		}
 753	}
 754
 755	private void enableAdvancedStreamFeatures() {
 756		if (getFeatures().carbons() && !features.carbonsEnabled) {
 757			sendEnableCarbons();
 758		}
 759		if (getFeatures().blocking() && !features.blockListRequested) {
 760			Log.d(Config.LOGTAG, "Requesting block list");
 761			this.sendIqPacket(getIqGenerator().generateGetBlockList(), mXmppConnectionService.getIqParser());
 762		}
 763	}
 764
 765	private void sendServiceDiscoveryItems(final Jid server) {
 766		final IqPacket iq = new IqPacket(IqPacket.TYPE.GET);
 767		iq.setTo(server.toDomainJid());
 768		iq.query("http://jabber.org/protocol/disco#items");
 769		this.sendIqPacket(iq, new OnIqPacketReceived() {
 770
 771			@Override
 772			public void onIqPacketReceived(final Account account, final IqPacket packet) {
 773				final List<Element> elements = packet.query().getChildren();
 774				for (final Element element : elements) {
 775					if (element.getName().equals("item")) {
 776						final Jid jid = element.getAttributeAsJid("jid");
 777						if (jid != null && !jid.equals(account.getServer())) {
 778							sendServiceDiscoveryInfo(jid);
 779						}
 780					}
 781				}
 782			}
 783		});
 784	}
 785
 786	private void sendEnableCarbons() {
 787		final IqPacket iq = new IqPacket(IqPacket.TYPE.SET);
 788		iq.addChild("enable", "urn:xmpp:carbons:2");
 789		this.sendIqPacket(iq, new OnIqPacketReceived() {
 790
 791			@Override
 792			public void onIqPacketReceived(final Account account, final IqPacket packet) {
 793				if (!packet.hasChild("error")) {
 794					Log.d(Config.LOGTAG, account.getJid().toBareJid()
 795							+ ": successfully enabled carbons");
 796					features.carbonsEnabled = true;
 797				} else {
 798					Log.d(Config.LOGTAG, account.getJid().toBareJid()
 799							+ ": error enableing carbons " + packet.toString());
 800				}
 801			}
 802		});
 803	}
 804
 805	private void processStreamError(final Tag currentTag)
 806		throws XmlPullParserException, IOException {
 807		final Element streamError = tagReader.readElement(currentTag);
 808		if (streamError != null && streamError.hasChild("conflict")) {
 809			final String resource = account.getResource().split("\\.")[0];
 810			account.setResource(resource + "." + nextRandomId());
 811			Log.d(Config.LOGTAG,
 812					account.getJid().toBareJid() + ": switching resource due to conflict ("
 813					+ account.getResource() + ")");
 814		}
 815	}
 816
 817	private void sendStartStream() throws IOException {
 818		final Tag stream = Tag.start("stream:stream");
 819		stream.setAttribute("from", account.getJid().toBareJid().toString());
 820		stream.setAttribute("to", account.getServer().toString());
 821		stream.setAttribute("version", "1.0");
 822		stream.setAttribute("xml:lang", "en");
 823		stream.setAttribute("xmlns", "jabber:client");
 824		stream.setAttribute("xmlns:stream", "http://etherx.jabber.org/streams");
 825		tagWriter.writeTag(stream);
 826	}
 827
 828	private String nextRandomId() {
 829		return new BigInteger(50, mXmppConnectionService.getRNG()).toString(32);
 830	}
 831
 832	public void sendIqPacket(final IqPacket packet, final OnIqPacketReceived callback) {
 833		packet.setFrom(account.getJid());
 834		this.sendUnmodifiedIqPacket(packet,callback);
 835
 836	}
 837
 838	private synchronized void sendUnmodifiedIqPacket(final IqPacket packet, final OnIqPacketReceived callback) {
 839		if (packet.getId() == null) {
 840			final String id = nextRandomId();
 841			packet.setAttribute("id", id);
 842		}
 843		if (callback != null) {
 844			if (packet.getId() == null) {
 845				packet.setId(nextRandomId());
 846			}
 847			packetCallbacks.put(packet.getId(), new Pair<>(packet, callback));
 848		}
 849		this.sendPacket(packet);
 850	}
 851
 852	public void sendMessagePacket(final MessagePacket packet) {
 853		this.sendPacket(packet);
 854	}
 855
 856	public void sendPresencePacket(final PresencePacket packet) {
 857		this.sendPacket(packet);
 858	}
 859
 860	private synchronized void sendPacket(final AbstractStanza packet) {
 861		final String name = packet.getName();
 862		if (name.equals("iq") || name.equals("message") || name.equals("presence")) {
 863			++stanzasSent;
 864		}
 865		tagWriter.writeStanzaAsync(packet);
 866		if (packet instanceof MessagePacket && packet.getId() != null && this.streamId != null) {
 867			Log.d(Config.LOGTAG, "request delivery report for stanza " + stanzasSent);
 868			this.messageReceipts.put(stanzasSent, packet.getId());
 869			tagWriter.writeStanzaAsync(new RequestPacket(this.smVersion));
 870		}
 871	}
 872
 873	public void sendPing() {
 874		if (streamFeatures.hasChild("sm")) {
 875			tagWriter.writeStanzaAsync(new RequestPacket(smVersion));
 876		} else {
 877			final IqPacket iq = new IqPacket(IqPacket.TYPE.GET);
 878			iq.setFrom(account.getJid());
 879			iq.addChild("ping", "urn:xmpp:ping");
 880			this.sendIqPacket(iq, null);
 881		}
 882		this.lastPingSent = SystemClock.elapsedRealtime();
 883	}
 884
 885	public void setOnMessagePacketReceivedListener(
 886			final OnMessagePacketReceived listener) {
 887		this.messageListener = listener;
 888			}
 889
 890	public void setOnUnregisteredIqPacketReceivedListener(
 891			final OnIqPacketReceived listener) {
 892		this.unregisteredIqListener = listener;
 893			}
 894
 895	public void setOnPresencePacketReceivedListener(
 896			final OnPresencePacketReceived listener) {
 897		this.presenceListener = listener;
 898			}
 899
 900	public void setOnJinglePacketReceivedListener(
 901			final OnJinglePacketReceived listener) {
 902		this.jingleListener = listener;
 903			}
 904
 905	public void setOnStatusChangedListener(final OnStatusChanged listener) {
 906		this.statusListener = listener;
 907	}
 908
 909	public void setOnBindListener(final OnBindListener listener) {
 910		this.bindListener = listener;
 911	}
 912
 913	public void setOnMessageAcknowledgeListener(final OnMessageAcknowledged listener) {
 914		this.acknowledgedListener = listener;
 915	}
 916
 917	public void addOnAdvancedStreamFeaturesAvailableListener(final OnAdvancedStreamFeaturesLoaded listener) {
 918		if (!this.advancedStreamFeaturesLoadedListeners.contains(listener)) {
 919			this.advancedStreamFeaturesLoadedListeners.add(listener);
 920		}
 921	}
 922
 923	public void disconnect(final boolean force) {
 924		Log.d(Config.LOGTAG, account.getJid().toBareJid() + ": disconnecting");
 925		try {
 926			if (force) {
 927				socket.close();
 928				return;
 929			}
 930			new Thread(new Runnable() {
 931
 932				@Override
 933				public void run() {
 934					if (tagWriter.isActive()) {
 935						tagWriter.finish();
 936						try {
 937							while (!tagWriter.finished()) {
 938								Log.d(Config.LOGTAG, "not yet finished");
 939								Thread.sleep(100);
 940							}
 941							tagWriter.writeTag(Tag.end("stream:stream"));
 942							socket.close();
 943						} catch (final IOException e) {
 944							Log.d(Config.LOGTAG,
 945									"io exception during disconnect");
 946						} catch (final InterruptedException e) {
 947							Log.d(Config.LOGTAG, "interrupted");
 948						}
 949					}
 950				}
 951			}).start();
 952		} catch (final IOException e) {
 953			Log.d(Config.LOGTAG, "io exception during disconnect");
 954		}
 955	}
 956
 957	public List<String> findDiscoItemsByFeature(final String feature) {
 958		final List<String> items = new ArrayList<>();
 959		for (final Entry<String, List<String>> cursor : disco.entrySet()) {
 960			if (cursor.getValue().contains(feature)) {
 961				items.add(cursor.getKey());
 962			}
 963		}
 964		return items;
 965	}
 966
 967	public String findDiscoItemByFeature(final String feature) {
 968		final List<String> items = findDiscoItemsByFeature(feature);
 969		if (items.size() >= 1) {
 970			return items.get(0);
 971		}
 972		return null;
 973	}
 974
 975	public void r() {
 976		this.tagWriter.writeStanzaAsync(new RequestPacket(smVersion));
 977	}
 978
 979	public String getMucServer() {
 980		for (final Entry<String, List<String>> cursor : disco.entrySet()) {
 981			final List<String> value = cursor.getValue();
 982			if (value.contains("http://jabber.org/protocol/muc") && !value.contains("jabber:iq:gateway") && !value.contains("siacs:no:muc")) {
 983				return cursor.getKey();
 984			}
 985		}
 986		return null;
 987	}
 988
 989	public int getTimeToNextAttempt() {
 990		final int interval = (int) (25 * Math.pow(1.5, attempt));
 991		final int secondsSinceLast = (int) ((SystemClock.elapsedRealtime() - this.lastConnect) / 1000);
 992		return interval - secondsSinceLast;
 993	}
 994
 995	public int getAttempt() {
 996		return this.attempt;
 997	}
 998
 999	public Features getFeatures() {
1000		return this.features;
1001	}
1002
1003	public long getLastSessionEstablished() {
1004		final long diff;
1005		if (this.lastSessionStarted == 0) {
1006			diff = SystemClock.elapsedRealtime() - this.lastConnect;
1007		} else {
1008			diff = SystemClock.elapsedRealtime() - this.lastSessionStarted;
1009		}
1010		return System.currentTimeMillis() - diff;
1011	}
1012
1013	public long getLastConnect() {
1014		return this.lastConnect;
1015	}
1016
1017	public long getLastPingSent() {
1018		return this.lastPingSent;
1019	}
1020
1021	public long getLastPacketReceived() {
1022		return this.lastPacketReceived;
1023	}
1024
1025	public void sendActive() {
1026		this.sendPacket(new ActivePacket());
1027	}
1028
1029	public void sendInactive() {
1030		this.sendPacket(new InactivePacket());
1031	}
1032
1033	public class Features {
1034		XmppConnection connection;
1035		private boolean carbonsEnabled = false;
1036		private boolean encryptionEnabled = false;
1037		private boolean blockListRequested = false;
1038
1039		public Features(final XmppConnection connection) {
1040			this.connection = connection;
1041		}
1042
1043		private boolean hasDiscoFeature(final Jid server, final String feature) {
1044			return connection.disco.containsKey(server.toDomainJid().toString()) &&
1045				connection.disco.get(server.toDomainJid().toString()).contains(feature);
1046		}
1047
1048		public boolean carbons() {
1049			return hasDiscoFeature(account.getServer(), "urn:xmpp:carbons:2");
1050		}
1051
1052		public boolean blocking() {
1053			return hasDiscoFeature(account.getServer(), Xmlns.BLOCKING);
1054		}
1055
1056		public boolean register() {
1057			return hasDiscoFeature(account.getServer(), Xmlns.REGISTER);
1058		}
1059
1060		public boolean sm() {
1061			return streamId != null;
1062		}
1063
1064		public boolean csi() {
1065			return connection.streamFeatures != null && connection.streamFeatures.hasChild("csi", "urn:xmpp:csi:0");
1066		}
1067
1068		public boolean pubsub() {
1069			return hasDiscoFeature(account.getServer(),
1070					"http://jabber.org/protocol/pubsub#publish");
1071		}
1072
1073		public boolean mam() {
1074			return hasDiscoFeature(account.getServer(), "urn:xmpp:mam:0");
1075		}
1076
1077		public boolean advancedStreamFeaturesLoaded() {
1078			return disco.containsKey(account.getServer().toString());
1079		}
1080
1081		public boolean rosterVersioning() {
1082			return connection.streamFeatures != null && connection.streamFeatures.hasChild("ver");
1083		}
1084
1085		public void setBlockListRequested(boolean value) {
1086			this.blockListRequested = value;
1087		}
1088	}
1089
1090	private IqGenerator getIqGenerator() {
1091		return mXmppConnectionService.getIqGenerator();
1092	}
1093}