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