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, IOException {
 434		final IqPacket packet = (IqPacket) processPacket(currentTag, PACKET_IQ);
 435
 436		if (packet.getId() == null) {
 437			return; // an iq packet without id is definitely invalid
 438		}
 439
 440		if (packet instanceof JinglePacket) {
 441			if (this.jingleListener != null) {
 442				this.jingleListener.onJinglePacketReceived(account,(JinglePacket) packet);
 443			}
 444		} else {
 445			if (packetCallbacks.containsKey(packet.getId())) {
 446				final Pair<IqPacket, OnIqPacketReceived> packetCallbackDuple = packetCallbacks.get(packet.getId());
 447				// Packets to the server should have responses from the server
 448				if (packetCallbackDuple.first.toServer(account)) {
 449					if (packet.fromServer(account)) {
 450						packetCallbackDuple.second.onIqPacketReceived(account, packet);
 451						packetCallbacks.remove(packet.getId());
 452					} else {
 453						Log.e(Config.LOGTAG,account.getJid().toBareJid().toString()+": ignoring spoofed iq packet");
 454					}
 455				} else {
 456					if (packet.getFrom().equals(packetCallbackDuple.first.getTo())) {
 457						packetCallbackDuple.second.onIqPacketReceived(account, packet);
 458						packetCallbacks.remove(packet.getId());
 459					} else {
 460						Log.e(Config.LOGTAG,account.getJid().toBareJid().toString()+": ignoring spoofed iq packet");
 461					}
 462				}
 463			} else if (packet.getType() == IqPacket.TYPE.GET|| packet.getType() == IqPacket.TYPE.SET) {
 464				this.unregisteredIqListener.onIqPacketReceived(account, packet);
 465			}
 466		}
 467	}
 468
 469	private void processMessage(final Tag currentTag) throws XmlPullParserException, IOException {
 470		final MessagePacket packet = (MessagePacket) processPacket(currentTag,PACKET_MESSAGE);
 471		this.messageListener.onMessagePacketReceived(account, packet);
 472	}
 473
 474	private void processPresence(final Tag currentTag) throws XmlPullParserException, IOException {
 475		PresencePacket packet = (PresencePacket) processPacket(currentTag, PACKET_PRESENCE);
 476		this.presenceListener.onPresencePacketReceived(account, packet);
 477	}
 478
 479	private void sendStartTLS() throws IOException {
 480		final Tag startTLS = Tag.empty("starttls");
 481		startTLS.setAttribute("xmlns", "urn:ietf:params:xml:ns:xmpp-tls");
 482		tagWriter.writeTag(startTLS);
 483	}
 484
 485	private SharedPreferences getPreferences() {
 486		return PreferenceManager.getDefaultSharedPreferences(applicationContext);
 487	}
 488
 489	private boolean enableLegacySSL() {
 490		return getPreferences().getBoolean("enable_legacy_ssl", false);
 491	}
 492
 493	private void switchOverToTls(final Tag currentTag) throws XmlPullParserException, IOException {
 494		tagReader.readTag();
 495		try {
 496			final SSLContext sc = SSLContext.getInstance("TLS");
 497			sc.init(null,new X509TrustManager[]{this.mXmppConnectionService.getMemorizingTrustManager()},mXmppConnectionService.getRNG());
 498			final SSLSocketFactory factory = sc.getSocketFactory();
 499			final HostnameVerifier verifier = this.mXmppConnectionService.getMemorizingTrustManager().wrapHostnameVerifier(new StrictHostnameVerifier());
 500			final InetAddress address = socket == null ? null : socket.getInetAddress();
 501
 502			if (factory == null || address == null || verifier == null) {
 503				throw new IOException("could not setup ssl");
 504			}
 505
 506			final SSLSocket sslSocket = (SSLSocket) factory.createSocket(socket,address.getHostAddress(), socket.getPort(),true);
 507
 508			if (sslSocket == null) {
 509				throw new IOException("could not initialize ssl socket");
 510			}
 511
 512			final String[] supportProtocols;
 513			if (enableLegacySSL()) {
 514				supportProtocols = sslSocket.getSupportedProtocols();
 515			} else {
 516				final Collection<String> supportedProtocols = new LinkedList<>(
 517						Arrays.asList(sslSocket.getSupportedProtocols()));
 518				supportedProtocols.remove("SSLv3");
 519				supportProtocols = new String[supportedProtocols.size()];
 520				supportedProtocols.toArray(supportProtocols);
 521			}
 522			sslSocket.setEnabledProtocols(supportProtocols);
 523
 524			if (!verifier.verify(account.getServer().getDomainpart(),sslSocket.getSession())) {
 525				Log.d(Config.LOGTAG,account.getJid().toBareJid()+": TLS certificate verification failed");
 526				disconnect(true);
 527				changeStatus(Account.State.SECURITY_ERROR);
 528			}
 529			tagReader.setInputStream(sslSocket.getInputStream());
 530			tagWriter.setOutputStream(sslSocket.getOutputStream());
 531			sendStartStream();
 532			Log.d(Config.LOGTAG, account.getJid().toBareJid()+ ": TLS connection established");
 533			enabledEncryption = true;
 534			processStream(tagReader.readTag());
 535			sslSocket.close();
 536		} catch (final NoSuchAlgorithmException | KeyManagementException e1) {
 537			Log.d(Config.LOGTAG,account.getJid().toBareJid()+": TLS certificate verification failed");
 538			disconnect(true);
 539			changeStatus(Account.State.SECURITY_ERROR);
 540		}
 541	}
 542
 543	private void processStreamFeatures(final Tag currentTag)
 544		throws XmlPullParserException, IOException {
 545		this.streamFeatures = tagReader.readElement(currentTag);
 546		if (this.streamFeatures.hasChild("starttls") && !enabledEncryption) {
 547			sendStartTLS();
 548		} else if (this.streamFeatures.hasChild("register")
 549				&& account.isOptionSet(Account.OPTION_REGISTER)
 550				&& enabledEncryption) {
 551			sendRegistryRequest();
 552		} else if (!this.streamFeatures.hasChild("register")
 553				&& account.isOptionSet(Account.OPTION_REGISTER)) {
 554			changeStatus(Account.State.REGISTRATION_NOT_SUPPORTED);
 555			disconnect(true);
 556		} else if (this.streamFeatures.hasChild("mechanisms")
 557				&& shouldAuthenticate && enabledEncryption) {
 558			final List<String> mechanisms = extractMechanisms(streamFeatures
 559					.findChild("mechanisms"));
 560			final Element auth = new Element("auth");
 561			auth.setAttribute("xmlns", "urn:ietf:params:xml:ns:xmpp-sasl");
 562			if (mechanisms.contains("SCRAM-SHA-1")) {
 563				saslMechanism = new ScramSha1(tagWriter, account, mXmppConnectionService.getRNG());
 564			} else if (mechanisms.contains("PLAIN")) {
 565				saslMechanism = new Plain(tagWriter, account);
 566			} else if (mechanisms.contains("DIGEST-MD5")) {
 567				saslMechanism = new DigestMd5(tagWriter, account, mXmppConnectionService.getRNG());
 568			}
 569			final JSONObject keys = account.getKeys();
 570			try {
 571				if (keys.has(Account.PINNED_MECHANISM_KEY) &&
 572						keys.getInt(Account.PINNED_MECHANISM_KEY) > saslMechanism.getPriority() ) {
 573					Log.e(Config.LOGTAG, "Auth failed. Authentication mechanism " + saslMechanism.getMechanism() +
 574							" has lower priority (" + String.valueOf(saslMechanism.getPriority()) +
 575							") than pinned priority (" + keys.getInt(Account.PINNED_MECHANISM_KEY) +
 576							"). Possible downgrade attack?");
 577					disconnect(true);
 578					changeStatus(Account.State.SECURITY_ERROR);
 579						}
 580			} catch (final JSONException e) {
 581				Log.d(Config.LOGTAG, "Parse error while checking pinned auth mechanism");
 582			}
 583			Log.d(Config.LOGTAG,account.getJid().toString()+": Authenticating with " + saslMechanism.getMechanism());
 584			auth.setAttribute("mechanism", saslMechanism.getMechanism());
 585			if (!saslMechanism.getClientFirstMessage().isEmpty()) {
 586				auth.setContent(saslMechanism.getClientFirstMessage());
 587			}
 588			tagWriter.writeElement(auth);
 589		} else if (this.streamFeatures.hasChild("sm", "urn:xmpp:sm:"
 590					+ smVersion)
 591				&& streamId != null) {
 592			final ResumePacket resume = new ResumePacket(this.streamId,
 593					stanzasReceived, smVersion);
 594			this.tagWriter.writeStanzaAsync(resume);
 595		} else if (this.streamFeatures.hasChild("bind") && shouldBind) {
 596			sendBindRequest();
 597		} else {
 598			disconnect(true);
 599			changeStatus(Account.State.INCOMPATIBLE_SERVER);
 600		}
 601	}
 602
 603	private List<String> extractMechanisms(final Element stream) {
 604		final ArrayList<String> mechanisms = new ArrayList<>(stream
 605				.getChildren().size());
 606		for (final Element child : stream.getChildren()) {
 607			mechanisms.add(child.getContent());
 608		}
 609		return mechanisms;
 610	}
 611
 612	private void sendRegistryRequest() {
 613		final IqPacket register = new IqPacket(IqPacket.TYPE.GET);
 614		register.query("jabber:iq:register");
 615		register.setTo(account.getServer());
 616		sendIqPacket(register, new OnIqPacketReceived() {
 617
 618			@Override
 619			public void onIqPacketReceived(final Account account, final IqPacket packet) {
 620				final Element instructions = packet.query().findChild("instructions");
 621				if (packet.query().hasChild("username")
 622						&& (packet.query().hasChild("password"))) {
 623					final IqPacket register = new IqPacket(IqPacket.TYPE.SET);
 624					final Element username = new Element("username")
 625						.setContent(account.getUsername());
 626					final Element password = new Element("password")
 627						.setContent(account.getPassword());
 628					register.query("jabber:iq:register").addChild(username);
 629					register.query().addChild(password);
 630					sendIqPacket(register, new OnIqPacketReceived() {
 631
 632						@Override
 633						public void onIqPacketReceived(final Account account, final IqPacket packet) {
 634							if (packet.getType() == IqPacket.TYPE.RESULT) {
 635								account.setOption(Account.OPTION_REGISTER,
 636										false);
 637								changeStatus(Account.State.REGISTRATION_SUCCESSFUL);
 638							} else if (packet.hasChild("error")
 639									&& (packet.findChild("error")
 640										.hasChild("conflict"))) {
 641								changeStatus(Account.State.REGISTRATION_CONFLICT);
 642							} else {
 643								changeStatus(Account.State.REGISTRATION_FAILED);
 644								Log.d(Config.LOGTAG, packet.toString());
 645							}
 646							disconnect(true);
 647						}
 648					});
 649				} else {
 650					changeStatus(Account.State.REGISTRATION_FAILED);
 651					disconnect(true);
 652					Log.d(Config.LOGTAG, account.getJid().toBareJid()
 653							+ ": could not register. instructions are"
 654							+ instructions.getContent());
 655				}
 656			}
 657		});
 658	}
 659
 660	private void sendBindRequest() {
 661		final IqPacket iq = new IqPacket(IqPacket.TYPE.SET);
 662		iq.addChild("bind", "urn:ietf:params:xml:ns:xmpp-bind")
 663			.addChild("resource").setContent(account.getResource());
 664		this.sendUnmodifiedIqPacket(iq, new OnIqPacketReceived() {
 665			@Override
 666			public void onIqPacketReceived(final Account account, final IqPacket packet) {
 667				final Element bind = packet.findChild("bind");
 668				if (bind != null) {
 669					final Element jid = bind.findChild("jid");
 670					if (jid != null && jid.getContent() != null) {
 671						try {
 672							account.setResource(Jid.fromString(jid.getContent()).getResourcepart());
 673						} catch (final InvalidJidException e) {
 674							// TODO: Handle the case where an external JID is technically invalid?
 675						}
 676						if (streamFeatures.hasChild("sm", "urn:xmpp:sm:3")) {
 677							smVersion = 3;
 678							final EnablePacket enable = new EnablePacket(smVersion);
 679							tagWriter.writeStanzaAsync(enable);
 680							stanzasSent = 0;
 681							messageReceipts.clear();
 682						} else if (streamFeatures.hasChild("sm",
 683									"urn:xmpp:sm:2")) {
 684							smVersion = 2;
 685							final EnablePacket enable = new EnablePacket(smVersion);
 686							tagWriter.writeStanzaAsync(enable);
 687							stanzasSent = 0;
 688							messageReceipts.clear();
 689						}
 690						enabledCarbons = false;
 691						disco.clear();
 692						sendServiceDiscoveryInfo(account.getServer());
 693						sendServiceDiscoveryItems(account.getServer());
 694						if (bindListener != null) {
 695							bindListener.onBind(account);
 696						}
 697						sendInitialPing();
 698					} else {
 699						disconnect(true);
 700					}
 701				} else {
 702					disconnect(true);
 703				}
 704			}
 705		});
 706		if (this.streamFeatures.hasChild("session")) {
 707			Log.d(Config.LOGTAG, account.getJid().toBareJid() + ": sending deprecated session");
 708			final IqPacket startSession = new IqPacket(IqPacket.TYPE.SET);
 709			startSession.addChild("session","urn:ietf:params:xml:ns:xmpp-session");
 710			this.sendUnmodifiedIqPacket(startSession, null);
 711		}
 712	}
 713
 714	private void sendServiceDiscoveryInfo(final Jid server) {
 715		if (disco.containsKey(server.toDomainJid().toString())) {
 716			if (account.getServer().equals(server.toDomainJid())) {
 717				enableAdvancedStreamFeatures();
 718			}
 719		} else {
 720			final IqPacket iq = new IqPacket(IqPacket.TYPE.GET);
 721			iq.setTo(server.toDomainJid());
 722			iq.query("http://jabber.org/protocol/disco#info");
 723			this.sendIqPacket(iq, new OnIqPacketReceived() {
 724
 725				@Override
 726				public void onIqPacketReceived(final Account account, final IqPacket packet) {
 727					final List<Element> elements = packet.query().getChildren();
 728					final List<String> features = new ArrayList<>();
 729					for (final Element element : elements) {
 730						if (element.getName().equals("identity")) {
 731							if ("irc".equals(element.getAttribute("type"))) {
 732								//add fake feature to not confuse irc and real muc
 733								features.add("siacs:no:muc");
 734							}
 735						} else if (element.getName().equals("feature")) {
 736							features.add(element.getAttribute("var"));
 737						}
 738					}
 739					disco.put(server.toDomainJid().toString(), features);
 740
 741					if (account.getServer().equals(server.toDomainJid())) {
 742						enableAdvancedStreamFeatures();
 743						for (final OnAdvancedStreamFeaturesLoaded listener : advancedStreamFeaturesLoadedListeners) {
 744							listener.onAdvancedStreamFeaturesAvailable(account);
 745						}
 746					}
 747				}
 748			});
 749		}
 750	}
 751
 752	private void enableAdvancedStreamFeatures() {
 753		if (getFeatures().carbons()) {
 754			if (!enabledCarbons) {
 755				sendEnableCarbons();
 756			}
 757		}
 758		if (getFeatures().blocking()) {
 759			Log.d(Config.LOGTAG, "Requesting block list");
 760			this.sendIqPacket(getIqGenerator().generateGetBlockList(), mXmppConnectionService.getIqParser());
 761		}
 762	}
 763
 764	private void sendServiceDiscoveryItems(final Jid server) {
 765		final IqPacket iq = new IqPacket(IqPacket.TYPE.GET);
 766		iq.setTo(server.toDomainJid());
 767		iq.query("http://jabber.org/protocol/disco#items");
 768		this.sendIqPacket(iq, new OnIqPacketReceived() {
 769
 770			@Override
 771			public void onIqPacketReceived(final Account account, final IqPacket packet) {
 772				final List<Element> elements = packet.query().getChildren();
 773				for (final Element element : elements) {
 774					if (element.getName().equals("item")) {
 775						final Jid jid = element.getAttributeAsJid("jid");
 776						if (jid != null && !jid.equals(account.getServer())) {
 777							sendServiceDiscoveryInfo(jid);
 778						}
 779					}
 780				}
 781			}
 782		});
 783	}
 784
 785	private void sendEnableCarbons() {
 786		final IqPacket iq = new IqPacket(IqPacket.TYPE.SET);
 787		iq.addChild("enable", "urn:xmpp:carbons:2");
 788		this.sendIqPacket(iq, new OnIqPacketReceived() {
 789
 790			@Override
 791			public void onIqPacketReceived(final Account account, final IqPacket packet) {
 792				if (!packet.hasChild("error")) {
 793					Log.d(Config.LOGTAG, account.getJid().toBareJid()
 794							+ ": successfully enabled carbons");
 795					enabledCarbons = true;
 796				} else {
 797					Log.d(Config.LOGTAG, account.getJid().toBareJid()
 798							+ ": error enableing carbons " + packet.toString());
 799				}
 800			}
 801		});
 802	}
 803
 804	private void processStreamError(final Tag currentTag)
 805		throws XmlPullParserException, IOException {
 806		final Element streamError = tagReader.readElement(currentTag);
 807		if (streamError != null && streamError.hasChild("conflict")) {
 808			final String resource = account.getResource().split("\\.")[0];
 809			account.setResource(resource + "." + nextRandomId());
 810			Log.d(Config.LOGTAG,
 811					account.getJid().toBareJid() + ": switching resource due to conflict ("
 812					+ account.getResource() + ")");
 813		}
 814	}
 815
 816	private void sendStartStream() throws IOException {
 817		final Tag stream = Tag.start("stream:stream");
 818		stream.setAttribute("from", account.getJid().toBareJid().toString());
 819		stream.setAttribute("to", account.getServer().toString());
 820		stream.setAttribute("version", "1.0");
 821		stream.setAttribute("xml:lang", "en");
 822		stream.setAttribute("xmlns", "jabber:client");
 823		stream.setAttribute("xmlns:stream", "http://etherx.jabber.org/streams");
 824		tagWriter.writeTag(stream);
 825	}
 826
 827	private String nextRandomId() {
 828		return new BigInteger(50, mXmppConnectionService.getRNG()).toString(32);
 829	}
 830
 831	public void sendIqPacket(final IqPacket packet, final OnIqPacketReceived callback) {
 832		packet.setFrom(account.getJid());
 833		this.sendUnmodifiedIqPacket(packet,callback);
 834
 835	}
 836
 837	private synchronized void sendUnmodifiedIqPacket(final IqPacket packet, final OnIqPacketReceived callback) {
 838		if (packet.getId() == null) {
 839			final String id = nextRandomId();
 840			packet.setAttribute("id", id);
 841		}
 842		if (callback != null) {
 843			if (packet.getId() == null) {
 844				packet.setId(nextRandomId());
 845			}
 846			packetCallbacks.put(packet.getId(), new Pair<>(packet, callback));
 847		}
 848		this.sendPacket(packet);
 849	}
 850
 851	public void sendMessagePacket(final MessagePacket packet) {
 852		this.sendPacket(packet);
 853	}
 854
 855	public void sendPresencePacket(final PresencePacket packet) {
 856		this.sendPacket(packet);
 857	}
 858
 859	private synchronized void sendPacket(final AbstractStanza packet) {
 860		final String name = packet.getName();
 861		if (name.equals("iq") || name.equals("message") || name.equals("presence")) {
 862			++stanzasSent;
 863		}
 864		tagWriter.writeStanzaAsync(packet);
 865		if (packet instanceof MessagePacket && packet.getId() != null && this.streamId != null) {
 866			Log.d(Config.LOGTAG, "request delivery report for stanza " + stanzasSent);
 867			this.messageReceipts.put(stanzasSent, packet.getId());
 868			tagWriter.writeStanzaAsync(new RequestPacket(this.smVersion));
 869		}
 870	}
 871
 872	public void sendPing() {
 873		if (streamFeatures.hasChild("sm")) {
 874			tagWriter.writeStanzaAsync(new RequestPacket(smVersion));
 875		} else {
 876			final IqPacket iq = new IqPacket(IqPacket.TYPE.GET);
 877			iq.setFrom(account.getJid());
 878			iq.addChild("ping", "urn:xmpp:ping");
 879			this.sendIqPacket(iq, null);
 880		}
 881		this.lastPingSent = SystemClock.elapsedRealtime();
 882	}
 883
 884	public void setOnMessagePacketReceivedListener(
 885			final OnMessagePacketReceived listener) {
 886		this.messageListener = listener;
 887			}
 888
 889	public void setOnUnregisteredIqPacketReceivedListener(
 890			final OnIqPacketReceived listener) {
 891		this.unregisteredIqListener = listener;
 892			}
 893
 894	public void setOnPresencePacketReceivedListener(
 895			final OnPresencePacketReceived listener) {
 896		this.presenceListener = listener;
 897			}
 898
 899	public void setOnJinglePacketReceivedListener(
 900			final OnJinglePacketReceived listener) {
 901		this.jingleListener = listener;
 902			}
 903
 904	public void setOnStatusChangedListener(final OnStatusChanged listener) {
 905		this.statusListener = listener;
 906	}
 907
 908	public void setOnBindListener(final OnBindListener listener) {
 909		this.bindListener = listener;
 910	}
 911
 912	public void setOnMessageAcknowledgeListener(final OnMessageAcknowledged listener) {
 913		this.acknowledgedListener = listener;
 914	}
 915
 916	public void addOnAdvancedStreamFeaturesAvailableListener(final OnAdvancedStreamFeaturesLoaded listener) {
 917		if (!this.advancedStreamFeaturesLoadedListeners.contains(listener)) {
 918			this.advancedStreamFeaturesLoadedListeners.add(listener);
 919		}
 920	}
 921
 922	public void disconnect(final boolean force) {
 923		Log.d(Config.LOGTAG, account.getJid().toBareJid() + ": disconnecting");
 924		try {
 925			if (force) {
 926				socket.close();
 927				return;
 928			}
 929			new Thread(new Runnable() {
 930
 931				@Override
 932				public void run() {
 933					if (tagWriter.isActive()) {
 934						tagWriter.finish();
 935						try {
 936							while (!tagWriter.finished()) {
 937								Log.d(Config.LOGTAG, "not yet finished");
 938								Thread.sleep(100);
 939							}
 940							tagWriter.writeTag(Tag.end("stream:stream"));
 941							socket.close();
 942						} catch (final IOException e) {
 943							Log.d(Config.LOGTAG,
 944									"io exception during disconnect");
 945						} catch (final InterruptedException e) {
 946							Log.d(Config.LOGTAG, "interrupted");
 947						}
 948					}
 949				}
 950			}).start();
 951		} catch (final IOException e) {
 952			Log.d(Config.LOGTAG, "io exception during disconnect");
 953		}
 954	}
 955
 956	public List<String> findDiscoItemsByFeature(final String feature) {
 957		final List<String> items = new ArrayList<>();
 958		for (final Entry<String, List<String>> cursor : disco.entrySet()) {
 959			if (cursor.getValue().contains(feature)) {
 960				items.add(cursor.getKey());
 961			}
 962		}
 963		return items;
 964	}
 965
 966	public String findDiscoItemByFeature(final String feature) {
 967		final List<String> items = findDiscoItemsByFeature(feature);
 968		if (items.size() >= 1) {
 969			return items.get(0);
 970		}
 971		return null;
 972	}
 973
 974	public void r() {
 975		this.tagWriter.writeStanzaAsync(new RequestPacket(smVersion));
 976	}
 977
 978	public String getMucServer() {
 979		for (final Entry<String, List<String>> cursor : disco.entrySet()) {
 980			final List<String> value = cursor.getValue();
 981			if (value.contains("http://jabber.org/protocol/muc") && !value.contains("jabber:iq:gateway") && !value.contains("siacs:no:muc")) {
 982				return cursor.getKey();
 983			}
 984		}
 985		return null;
 986	}
 987
 988	public int getTimeToNextAttempt() {
 989		final int interval = (int) (25 * Math.pow(1.5, attempt));
 990		final int secondsSinceLast = (int) ((SystemClock.elapsedRealtime() - this.lastConnect) / 1000);
 991		return interval - secondsSinceLast;
 992	}
 993
 994	public int getAttempt() {
 995		return this.attempt;
 996	}
 997
 998	public Features getFeatures() {
 999		return this.features;
1000	}
1001
1002	public long getLastSessionEstablished() {
1003		final long diff;
1004		if (this.lastSessionStarted == 0) {
1005			diff = SystemClock.elapsedRealtime() - this.lastConnect;
1006		} else {
1007			diff = SystemClock.elapsedRealtime() - this.lastSessionStarted;
1008		}
1009		return System.currentTimeMillis() - diff;
1010	}
1011
1012	public long getLastConnect() {
1013		return this.lastConnect;
1014	}
1015
1016	public long getLastPingSent() {
1017		return this.lastPingSent;
1018	}
1019
1020	public long getLastPacketReceived() {
1021		return this.lastPaketReceived;
1022	}
1023
1024	public void sendActive() {
1025		this.sendPacket(new ActivePacket());
1026	}
1027
1028	public void sendInactive() {
1029		this.sendPacket(new InactivePacket());
1030	}
1031
1032	public class Features {
1033		XmppConnection connection;
1034
1035		public Features(final XmppConnection connection) {
1036			this.connection = connection;
1037		}
1038
1039		private boolean hasDiscoFeature(final Jid server, final String feature) {
1040			return connection.disco.containsKey(server.toDomainJid().toString()) &&
1041				connection.disco.get(server.toDomainJid().toString()).contains(feature);
1042		}
1043
1044		public boolean carbons() {
1045			return hasDiscoFeature(account.getServer(), "urn:xmpp:carbons:2");
1046		}
1047
1048		public boolean blocking() {
1049			return hasDiscoFeature(account.getServer(), Xmlns.BLOCKING);
1050		}
1051
1052		public boolean register() {
1053			return hasDiscoFeature(account.getServer(), Xmlns.REGISTER);
1054		}
1055
1056		public boolean sm() {
1057			return streamId != null;
1058		}
1059
1060		public boolean csi() {
1061			return connection.streamFeatures != null && connection.streamFeatures.hasChild("csi", "urn:xmpp:csi:0");
1062		}
1063
1064		public boolean pubsub() {
1065			return hasDiscoFeature(account.getServer(),
1066					"http://jabber.org/protocol/pubsub#publish");
1067		}
1068
1069		public boolean mam() {
1070			return hasDiscoFeature(account.getServer(), "urn:xmpp:mam:0");
1071		}
1072
1073		public boolean advancedStreamFeaturesLoaded() {
1074			return disco.containsKey(account.getServer().toString());
1075		}
1076
1077		public boolean rosterVersioning() {
1078			return connection.streamFeatures != null && connection.streamFeatures.hasChild("ver");
1079		}
1080
1081		public boolean streamhost() {
1082			return connection
1083				.findDiscoItemByFeature("http://jabber.org/protocol/bytestreams") != null;
1084		}
1085	}
1086
1087	private IqGenerator getIqGenerator() {
1088		return mXmppConnectionService.getIqGenerator();
1089	}
1090}