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<Jid, Info> 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("unhandled exception in DNS resolver");
 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			this.attempt--; //don't count attempt when reconnecting instantly anyway
 233		} finally {
 234			if (wakeLock.isHeld()) {
 235				try {
 236					wakeLock.release();
 237				} catch (final RuntimeException ignored) {
 238				}
 239			}
 240		}
 241	}
 242
 243	@Override
 244	public void run() {
 245		try {
 246			if (socket != null) {
 247				socket.close();
 248			}
 249		} catch (final IOException ignored) {
 250
 251		}
 252		connect();
 253	}
 254
 255	private void processStream(final Tag currentTag) throws XmlPullParserException,
 256					IOException, NoSuchAlgorithmException {
 257						Tag nextTag = tagReader.readTag();
 258
 259						while ((nextTag != null) && (!nextTag.isEnd("stream"))) {
 260							if (nextTag.isStart("error")) {
 261								processStreamError(nextTag);
 262							} else if (nextTag.isStart("features")) {
 263								processStreamFeatures(nextTag);
 264							} else if (nextTag.isStart("proceed")) {
 265								switchOverToTls(nextTag);
 266							} else if (nextTag.isStart("success")) {
 267								final String challenge = tagReader.readElement(nextTag).getContent();
 268								try {
 269									saslMechanism.getResponse(challenge);
 270								} catch (final SaslMechanism.AuthenticationException e) {
 271									disconnect(true);
 272									Log.e(Config.LOGTAG, String.valueOf(e));
 273								}
 274								Log.d(Config.LOGTAG, account.getJid().toBareJid().toString() + ": logged in");
 275								account.setKey(Account.PINNED_MECHANISM_KEY,
 276										String.valueOf(saslMechanism.getPriority()));
 277								tagReader.reset();
 278								sendStartStream();
 279								processStream(tagReader.readTag());
 280								break;
 281							} else if (nextTag.isStart("failure")) {
 282								tagReader.readElement(nextTag);
 283								changeStatus(Account.State.UNAUTHORIZED);
 284							} else if (nextTag.isStart("challenge")) {
 285								final String challenge = tagReader.readElement(nextTag).getContent();
 286								final Element response = new Element("response");
 287								response.setAttribute("xmlns",
 288										"urn:ietf:params:xml:ns:xmpp-sasl");
 289								try {
 290									response.setContent(saslMechanism.getResponse(challenge));
 291								} catch (final SaslMechanism.AuthenticationException e) {
 292									// TODO: Send auth abort tag.
 293									Log.e(Config.LOGTAG, e.toString());
 294								}
 295								tagWriter.writeElement(response);
 296							} else if (nextTag.isStart("enabled")) {
 297								final Element enabled = tagReader.readElement(nextTag);
 298								if ("true".equals(enabled.getAttribute("resume"))) {
 299									this.streamId = enabled.getAttribute("id");
 300									Log.d(Config.LOGTAG, account.getJid().toBareJid().toString()
 301											+ ": stream managment(" + smVersion
 302											+ ") enabled (resumable)");
 303								} else {
 304									Log.d(Config.LOGTAG, account.getJid().toBareJid().toString()
 305											+ ": stream managment(" + smVersion + ") enabled");
 306								}
 307								this.lastSessionStarted = SystemClock.elapsedRealtime();
 308								this.stanzasReceived = 0;
 309								final RequestPacket r = new RequestPacket(smVersion);
 310								tagWriter.writeStanzaAsync(r);
 311							} else if (nextTag.isStart("resumed")) {
 312								lastPacketReceived = SystemClock.elapsedRealtime();
 313								final Element resumed = tagReader.readElement(nextTag);
 314								final String h = resumed.getAttribute("h");
 315								try {
 316									final int serverCount = Integer.parseInt(h);
 317									if (serverCount != stanzasSent) {
 318										Log.d(Config.LOGTAG, account.getJid().toBareJid().toString()
 319												+ ": session resumed with lost packages");
 320										stanzasSent = serverCount;
 321									} else {
 322										Log.d(Config.LOGTAG, account.getJid().toBareJid().toString()
 323												+ ": session resumed");
 324									}
 325									if (acknowledgedListener != null) {
 326										for (int i = 0; i < messageReceipts.size(); ++i) {
 327											if (serverCount >= messageReceipts.keyAt(i)) {
 328												acknowledgedListener.onMessageAcknowledged(
 329														account, messageReceipts.valueAt(i));
 330											}
 331										}
 332									}
 333									messageReceipts.clear();
 334								} catch (final NumberFormatException ignored) {
 335								}
 336								sendServiceDiscoveryInfo(account.getServer());
 337								sendServiceDiscoveryInfo(account.getJid().toBareJid());
 338								sendServiceDiscoveryItems(account.getServer());
 339								sendInitialPing();
 340							} else if (nextTag.isStart("r")) {
 341								tagReader.readElement(nextTag);
 342								if (Config.EXTENDED_SM_LOGGING) {
 343									Log.d(Config.LOGTAG, account.getJid().toBareJid() + ": acknowledging stanza #" + this.stanzasReceived);
 344								}
 345								final AckPacket ack = new AckPacket(this.stanzasReceived, smVersion);
 346								tagWriter.writeStanzaAsync(ack);
 347							} else if (nextTag.isStart("a")) {
 348								final Element ack = tagReader.readElement(nextTag);
 349								lastPacketReceived = SystemClock.elapsedRealtime();
 350								final int serverSequence = Integer.parseInt(ack.getAttribute("h"));
 351								if (Config.EXTENDED_SM_LOGGING) {
 352									Log.d(Config.LOGTAG, account.getJid().toBareJid() + ": server acknowledged stanza #" + serverSequence);
 353								}
 354								final String msgId = this.messageReceipts.get(serverSequence);
 355								if (msgId != null) {
 356									if (this.acknowledgedListener != null) {
 357										this.acknowledgedListener.onMessageAcknowledged(
 358												account, msgId);
 359									}
 360									this.messageReceipts.remove(serverSequence);
 361								}
 362							} else if (nextTag.isStart("failed")) {
 363								tagReader.readElement(nextTag);
 364								Log.d(Config.LOGTAG, account.getJid().toBareJid().toString() + ": resumption failed");
 365								streamId = null;
 366								if (account.getStatus() != Account.State.ONLINE) {
 367									sendBindRequest();
 368								}
 369							} else if (nextTag.isStart("iq")) {
 370								processIq(nextTag);
 371							} else if (nextTag.isStart("message")) {
 372								processMessage(nextTag);
 373							} else if (nextTag.isStart("presence")) {
 374								processPresence(nextTag);
 375							}
 376							nextTag = tagReader.readTag();
 377						}
 378						if (account.getStatus() == Account.State.ONLINE) {
 379							account. setStatus(Account.State.OFFLINE);
 380							if (statusListener != null) {
 381								statusListener.onStatusChanged(account);
 382							}
 383						}
 384	}
 385
 386	private void sendInitialPing() {
 387		Log.d(Config.LOGTAG, account.getJid().toBareJid().toString() + ": sending intial ping");
 388		final IqPacket iq = new IqPacket(IqPacket.TYPE.GET);
 389		iq.setFrom(account.getJid());
 390		iq.addChild("ping", "urn:xmpp:ping");
 391		this.sendIqPacket(iq, new OnIqPacketReceived() {
 392			@Override
 393			public void onIqPacketReceived(final Account account, final IqPacket packet) {
 394				Log.d(Config.LOGTAG, account.getJid().toBareJid().toString()
 395						+ ": online with resource " + account.getResource());
 396				changeStatus(Account.State.ONLINE);
 397			}
 398		});
 399	}
 400
 401	private Element processPacket(final Tag currentTag, final int packetType)
 402		throws XmlPullParserException, IOException {
 403		Element element;
 404		switch (packetType) {
 405			case PACKET_IQ:
 406				element = new IqPacket();
 407				break;
 408			case PACKET_MESSAGE:
 409				element = new MessagePacket();
 410				break;
 411			case PACKET_PRESENCE:
 412				element = new PresencePacket();
 413				break;
 414			default:
 415				return null;
 416		}
 417		element.setAttributes(currentTag.getAttributes());
 418		Tag nextTag = tagReader.readTag();
 419		if (nextTag == null) {
 420			throw new IOException("interrupted mid tag");
 421		}
 422		while (!nextTag.isEnd(element.getName())) {
 423			if (!nextTag.isNo()) {
 424				final Element child = tagReader.readElement(nextTag);
 425				final String type = currentTag.getAttribute("type");
 426				if (packetType == PACKET_IQ
 427						&& "jingle".equals(child.getName())
 428						&& ("set".equalsIgnoreCase(type) || "get"
 429							.equalsIgnoreCase(type))) {
 430					element = new JinglePacket();
 431					element.setAttributes(currentTag.getAttributes());
 432							}
 433				element.addChild(child);
 434			}
 435			nextTag = tagReader.readTag();
 436			if (nextTag == null) {
 437				throw new IOException("interrupted mid tag");
 438			}
 439		}
 440		++stanzasReceived;
 441		lastPacketReceived = SystemClock.elapsedRealtime();
 442		return element;
 443	}
 444
 445	private void processIq(final Tag currentTag) throws XmlPullParserException, IOException {
 446		final IqPacket packet = (IqPacket) processPacket(currentTag, PACKET_IQ);
 447
 448		if (packet.getId() == null) {
 449			return; // an iq packet without id is definitely invalid
 450		}
 451
 452		if (packet instanceof JinglePacket) {
 453			if (this.jingleListener != null) {
 454				this.jingleListener.onJinglePacketReceived(account,(JinglePacket) packet);
 455			}
 456		} else {
 457			if (packetCallbacks.containsKey(packet.getId())) {
 458				final Pair<IqPacket, OnIqPacketReceived> packetCallbackDuple = packetCallbacks.get(packet.getId());
 459				// Packets to the server should have responses from the server
 460				if (packetCallbackDuple.first.toServer(account)) {
 461					if (packet.fromServer(account)) {
 462						packetCallbackDuple.second.onIqPacketReceived(account, packet);
 463						packetCallbacks.remove(packet.getId());
 464					} else {
 465						Log.e(Config.LOGTAG,account.getJid().toBareJid().toString()+": ignoring spoofed iq packet");
 466					}
 467				} else {
 468					if (packet.getFrom().equals(packetCallbackDuple.first.getTo())) {
 469						packetCallbackDuple.second.onIqPacketReceived(account, packet);
 470						packetCallbacks.remove(packet.getId());
 471					} else {
 472						Log.e(Config.LOGTAG,account.getJid().toBareJid().toString()+": ignoring spoofed iq packet");
 473					}
 474				}
 475			} else if (packet.getType() == IqPacket.TYPE.GET|| packet.getType() == IqPacket.TYPE.SET) {
 476				this.unregisteredIqListener.onIqPacketReceived(account, packet);
 477			}
 478		}
 479	}
 480
 481	private void processMessage(final Tag currentTag) throws XmlPullParserException, IOException {
 482		final MessagePacket packet = (MessagePacket) processPacket(currentTag,PACKET_MESSAGE);
 483		this.messageListener.onMessagePacketReceived(account, packet);
 484	}
 485
 486	private void processPresence(final Tag currentTag) throws XmlPullParserException, IOException {
 487		PresencePacket packet = (PresencePacket) processPacket(currentTag, PACKET_PRESENCE);
 488		this.presenceListener.onPresencePacketReceived(account, packet);
 489	}
 490
 491	private void sendStartTLS() throws IOException {
 492		final Tag startTLS = Tag.empty("starttls");
 493		startTLS.setAttribute("xmlns", "urn:ietf:params:xml:ns:xmpp-tls");
 494		tagWriter.writeTag(startTLS);
 495	}
 496
 497	private SharedPreferences getPreferences() {
 498		return PreferenceManager.getDefaultSharedPreferences(applicationContext);
 499	}
 500
 501	private boolean enableLegacySSL() {
 502		return getPreferences().getBoolean("enable_legacy_ssl", false);
 503	}
 504
 505	private void switchOverToTls(final Tag currentTag) throws XmlPullParserException, IOException {
 506		tagReader.readTag();
 507		try {
 508			final SSLContext sc = SSLContext.getInstance("TLS");
 509			sc.init(null,new X509TrustManager[]{this.mXmppConnectionService.getMemorizingTrustManager()},mXmppConnectionService.getRNG());
 510			final SSLSocketFactory factory = sc.getSocketFactory();
 511			final HostnameVerifier verifier = this.mXmppConnectionService.getMemorizingTrustManager().wrapHostnameVerifier(new StrictHostnameVerifier());
 512			final InetAddress address = socket == null ? null : socket.getInetAddress();
 513
 514			if (factory == null || address == null || verifier == null) {
 515				throw new IOException("could not setup ssl");
 516			}
 517
 518			final SSLSocket sslSocket = (SSLSocket) factory.createSocket(socket,address.getHostAddress(), socket.getPort(),true);
 519
 520			if (sslSocket == null) {
 521				throw new IOException("could not initialize ssl socket");
 522			}
 523
 524			final String[] supportProtocols;
 525			final Collection<String> supportedProtocols = new LinkedList<>(
 526					Arrays.asList(sslSocket.getSupportedProtocols()));
 527			supportedProtocols.remove("SSLv3");
 528			supportProtocols = supportedProtocols.toArray(new String[supportedProtocols.size()]);
 529
 530			sslSocket.setEnabledProtocols(supportProtocols);
 531
 532			final String[] cipherSuites = CryptoHelper.getOrderedCipherSuites(
 533					sslSocket.getSupportedCipherSuites());
 534			//Log.d(Config.LOGTAG, "Using ciphers: " + Arrays.toString(cipherSuites));
 535			if (cipherSuites.length > 0) {
 536				sslSocket.setEnabledCipherSuites(cipherSuites);
 537			}
 538
 539			if (!verifier.verify(account.getServer().getDomainpart(),sslSocket.getSession())) {
 540				Log.d(Config.LOGTAG,account.getJid().toBareJid()+": TLS certificate verification failed");
 541				disconnect(true);
 542				changeStatus(Account.State.SECURITY_ERROR);
 543			}
 544			tagReader.setInputStream(sslSocket.getInputStream());
 545			tagWriter.setOutputStream(sslSocket.getOutputStream());
 546			sendStartStream();
 547			Log.d(Config.LOGTAG, account.getJid().toBareJid()+ ": TLS connection established");
 548			features.encryptionEnabled = true;
 549			processStream(tagReader.readTag());
 550			sslSocket.close();
 551		} catch (final NoSuchAlgorithmException | KeyManagementException e1) {
 552			Log.d(Config.LOGTAG,account.getJid().toBareJid()+": TLS certificate verification failed");
 553			disconnect(true);
 554			changeStatus(Account.State.SECURITY_ERROR);
 555		}
 556	}
 557
 558	private void processStreamFeatures(final Tag currentTag)
 559		throws XmlPullParserException, IOException {
 560		this.streamFeatures = tagReader.readElement(currentTag);
 561		if (this.streamFeatures.hasChild("starttls") && !features.encryptionEnabled) {
 562			sendStartTLS();
 563		} else if (this.streamFeatures.hasChild("register")
 564				&& account.isOptionSet(Account.OPTION_REGISTER)
 565				&& features.encryptionEnabled) {
 566			sendRegistryRequest();
 567		} else if (!this.streamFeatures.hasChild("register")
 568				&& account.isOptionSet(Account.OPTION_REGISTER)) {
 569			changeStatus(Account.State.REGISTRATION_NOT_SUPPORTED);
 570			disconnect(true);
 571		} else if (this.streamFeatures.hasChild("mechanisms")
 572				&& shouldAuthenticate && features.encryptionEnabled) {
 573			final List<String> mechanisms = extractMechanisms(streamFeatures
 574					.findChild("mechanisms"));
 575			final Element auth = new Element("auth");
 576			auth.setAttribute("xmlns", "urn:ietf:params:xml:ns:xmpp-sasl");
 577			if (mechanisms.contains("SCRAM-SHA-1")) {
 578				saslMechanism = new ScramSha1(tagWriter, account, mXmppConnectionService.getRNG());
 579			} else if (mechanisms.contains("PLAIN")) {
 580				saslMechanism = new Plain(tagWriter, account);
 581			} else if (mechanisms.contains("DIGEST-MD5")) {
 582				saslMechanism = new DigestMd5(tagWriter, account, mXmppConnectionService.getRNG());
 583			}
 584			if (saslMechanism != null) {
 585				final JSONObject keys = account.getKeys();
 586				try {
 587					if (keys.has(Account.PINNED_MECHANISM_KEY) &&
 588							keys.getInt(Account.PINNED_MECHANISM_KEY) > saslMechanism.getPriority()) {
 589						Log.e(Config.LOGTAG, "Auth failed. Authentication mechanism " + saslMechanism.getMechanism() +
 590								" has lower priority (" + String.valueOf(saslMechanism.getPriority()) +
 591								") than pinned priority (" + keys.getInt(Account.PINNED_MECHANISM_KEY) +
 592								"). Possible downgrade attack?");
 593						disconnect(true);
 594						changeStatus(Account.State.SECURITY_ERROR);
 595					}
 596				} catch (final JSONException e) {
 597					Log.d(Config.LOGTAG, "Parse error while checking pinned auth mechanism");
 598				}
 599				Log.d(Config.LOGTAG, account.getJid().toString() + ": Authenticating with " + saslMechanism.getMechanism());
 600				auth.setAttribute("mechanism", saslMechanism.getMechanism());
 601				if (!saslMechanism.getClientFirstMessage().isEmpty()) {
 602					auth.setContent(saslMechanism.getClientFirstMessage());
 603				}
 604				tagWriter.writeElement(auth);
 605			} else {
 606				disconnect(true);
 607				changeStatus(Account.State.INCOMPATIBLE_SERVER);
 608			}
 609		} else if (this.streamFeatures.hasChild("sm", "urn:xmpp:sm:"
 610					+ smVersion)
 611				&& streamId != null) {
 612			if (Config.EXTENDED_SM_LOGGING) {
 613				Log.d(Config.LOGTAG,account.getJid().toBareJid()+": resuming after stanza #"+stanzasReceived);
 614			}
 615			final ResumePacket resume = new ResumePacket(this.streamId, stanzasReceived, smVersion);
 616			this.tagWriter.writeStanzaAsync(resume);
 617		} else if (this.streamFeatures.hasChild("bind") && shouldBind) {
 618			sendBindRequest();
 619		} else {
 620			disconnect(true);
 621			changeStatus(Account.State.INCOMPATIBLE_SERVER);
 622		}
 623	}
 624
 625	private List<String> extractMechanisms(final Element stream) {
 626		final ArrayList<String> mechanisms = new ArrayList<>(stream
 627				.getChildren().size());
 628		for (final Element child : stream.getChildren()) {
 629			mechanisms.add(child.getContent());
 630		}
 631		return mechanisms;
 632	}
 633
 634	private void sendRegistryRequest() {
 635		final IqPacket register = new IqPacket(IqPacket.TYPE.GET);
 636		register.query("jabber:iq:register");
 637		register.setTo(account.getServer());
 638		sendIqPacket(register, new OnIqPacketReceived() {
 639
 640			@Override
 641			public void onIqPacketReceived(final Account account, final IqPacket packet) {
 642				final Element instructions = packet.query().findChild("instructions");
 643				if (packet.query().hasChild("username")
 644						&& (packet.query().hasChild("password"))) {
 645					final IqPacket register = new IqPacket(IqPacket.TYPE.SET);
 646					final Element username = new Element("username")
 647						.setContent(account.getUsername());
 648					final Element password = new Element("password")
 649						.setContent(account.getPassword());
 650					register.query("jabber:iq:register").addChild(username);
 651					register.query().addChild(password);
 652					sendIqPacket(register, new OnIqPacketReceived() {
 653
 654						@Override
 655						public void onIqPacketReceived(final Account account, final IqPacket packet) {
 656							if (packet.getType() == IqPacket.TYPE.RESULT) {
 657								account.setOption(Account.OPTION_REGISTER,
 658										false);
 659								changeStatus(Account.State.REGISTRATION_SUCCESSFUL);
 660							} else if (packet.hasChild("error")
 661									&& (packet.findChild("error")
 662										.hasChild("conflict"))) {
 663								changeStatus(Account.State.REGISTRATION_CONFLICT);
 664							} else {
 665								changeStatus(Account.State.REGISTRATION_FAILED);
 666								Log.d(Config.LOGTAG, packet.toString());
 667							}
 668							disconnect(true);
 669						}
 670					});
 671				} else {
 672					changeStatus(Account.State.REGISTRATION_FAILED);
 673					disconnect(true);
 674					Log.d(Config.LOGTAG, account.getJid().toBareJid()
 675							+ ": could not register. instructions are"
 676							+ instructions.getContent());
 677				}
 678			}
 679		});
 680	}
 681
 682	private void sendBindRequest() {
 683		while(!mXmppConnectionService.areMessagesInitialized()) {
 684			try {
 685				Thread.sleep(500);
 686			} catch (final InterruptedException ignored) {
 687			}
 688		}
 689		final IqPacket iq = new IqPacket(IqPacket.TYPE.SET);
 690		iq.addChild("bind", "urn:ietf:params:xml:ns:xmpp-bind")
 691			.addChild("resource").setContent(account.getResource());
 692		this.sendUnmodifiedIqPacket(iq, new OnIqPacketReceived() {
 693			@Override
 694			public void onIqPacketReceived(final Account account, final IqPacket packet) {
 695				final Element bind = packet.findChild("bind");
 696				if (bind != null) {
 697					final Element jid = bind.findChild("jid");
 698					if (jid != null && jid.getContent() != null) {
 699						try {
 700							account.setResource(Jid.fromString(jid.getContent()).getResourcepart());
 701						} catch (final InvalidJidException e) {
 702							// TODO: Handle the case where an external JID is technically invalid?
 703						}
 704						if (streamFeatures.hasChild("session")) {
 705							sendStartSession();
 706						} else {
 707							sendPostBindInitialization();
 708						}
 709					} else {
 710						disconnect(true);
 711					}
 712				} else {
 713					disconnect(true);
 714				}
 715			}
 716		});
 717	}
 718
 719	private void sendStartSession() {
 720		final IqPacket startSession = new IqPacket(IqPacket.TYPE.SET);
 721		startSession.addChild("session","urn:ietf:params:xml:ns:xmpp-session");
 722		this.sendUnmodifiedIqPacket(startSession, new OnIqPacketReceived() {
 723			@Override
 724			public void onIqPacketReceived(Account account, IqPacket packet) {
 725				if (packet.getType() == IqPacket.TYPE.RESULT) {
 726					sendPostBindInitialization();
 727				} else {
 728					disconnect(true);
 729				}
 730			}
 731		});
 732	}
 733
 734	private void sendPostBindInitialization() {
 735		smVersion = 0;
 736		if (streamFeatures.hasChild("sm", "urn:xmpp:sm:3")) {
 737			smVersion = 3;
 738		} else if (streamFeatures.hasChild("sm", "urn:xmpp:sm:2")) {
 739			smVersion = 2;
 740		}
 741		if (smVersion != 0) {
 742			final EnablePacket enable = new EnablePacket(smVersion);
 743			tagWriter.writeStanzaAsync(enable);
 744			stanzasSent = 0;
 745			messageReceipts.clear();
 746		}
 747		features.carbonsEnabled = false;
 748		features.blockListRequested = false;
 749		disco.clear();
 750		sendServiceDiscoveryInfo(account.getServer());
 751		sendServiceDiscoveryInfo(account.getJid().toBareJid());
 752		sendServiceDiscoveryItems(account.getServer());
 753		if (bindListener != null) {
 754			bindListener.onBind(account);
 755		}
 756		sendInitialPing();
 757	}
 758
 759	private void sendServiceDiscoveryInfo(final Jid jid) {
 760		if (disco.containsKey(jid)) {
 761			if (account.getServer().equals(jid)) {
 762				enableAdvancedStreamFeatures();
 763			}
 764		} else {
 765			final IqPacket iq = new IqPacket(IqPacket.TYPE.GET);
 766			iq.setTo(jid);
 767			iq.query("http://jabber.org/protocol/disco#info");
 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					final Info info = new Info();
 774					for (final Element element : elements) {
 775						if (element.getName().equals("identity")) {
 776							String type = element.getAttribute("type");
 777							String category = element.getAttribute("category");
 778							if (type != null && category != null) {
 779								info.identities.add(new Pair<>(category,type));
 780							}
 781						} else if (element.getName().equals("feature")) {
 782							info.features.add(element.getAttribute("var"));
 783						}
 784					}
 785					disco.put(jid, info);
 786
 787					if (account.getServer().equals(jid)) {
 788						enableAdvancedStreamFeatures();
 789						for (final OnAdvancedStreamFeaturesLoaded listener : advancedStreamFeaturesLoadedListeners) {
 790							listener.onAdvancedStreamFeaturesAvailable(account);
 791						}
 792					}
 793				}
 794			});
 795		}
 796	}
 797
 798	private void enableAdvancedStreamFeatures() {
 799		if (getFeatures().carbons() && !features.carbonsEnabled) {
 800			sendEnableCarbons();
 801		}
 802		if (getFeatures().blocking() && !features.blockListRequested) {
 803			Log.d(Config.LOGTAG,account.getJid().toBareJid()+": Requesting block list");
 804			this.sendIqPacket(getIqGenerator().generateGetBlockList(), mXmppConnectionService.getIqParser());
 805		}
 806	}
 807
 808	private void sendServiceDiscoveryItems(final Jid server) {
 809		final IqPacket iq = new IqPacket(IqPacket.TYPE.GET);
 810		iq.setTo(server.toDomainJid());
 811		iq.query("http://jabber.org/protocol/disco#items");
 812		this.sendIqPacket(iq, new OnIqPacketReceived() {
 813
 814			@Override
 815			public void onIqPacketReceived(final Account account, final IqPacket packet) {
 816				final List<Element> elements = packet.query().getChildren();
 817				for (final Element element : elements) {
 818					if (element.getName().equals("item")) {
 819						final Jid jid = element.getAttributeAsJid("jid");
 820						if (jid != null && !jid.equals(account.getServer())) {
 821							sendServiceDiscoveryInfo(jid);
 822						}
 823					}
 824				}
 825			}
 826		});
 827	}
 828
 829	private void sendEnableCarbons() {
 830		final IqPacket iq = new IqPacket(IqPacket.TYPE.SET);
 831		iq.addChild("enable", "urn:xmpp:carbons:2");
 832		this.sendIqPacket(iq, new OnIqPacketReceived() {
 833
 834			@Override
 835			public void onIqPacketReceived(final Account account, final IqPacket packet) {
 836				if (!packet.hasChild("error")) {
 837					Log.d(Config.LOGTAG, account.getJid().toBareJid()
 838							+ ": successfully enabled carbons");
 839					features.carbonsEnabled = true;
 840				} else {
 841					Log.d(Config.LOGTAG, account.getJid().toBareJid()
 842							+ ": error enableing carbons " + packet.toString());
 843				}
 844			}
 845		});
 846	}
 847
 848	private void processStreamError(final Tag currentTag)
 849		throws XmlPullParserException, IOException {
 850		final Element streamError = tagReader.readElement(currentTag);
 851		if (streamError != null && streamError.hasChild("conflict")) {
 852			final String resource = account.getResource().split("\\.")[0];
 853			account.setResource(resource + "." + nextRandomId());
 854			Log.d(Config.LOGTAG,
 855					account.getJid().toBareJid() + ": switching resource due to conflict ("
 856					+ account.getResource() + ")");
 857		}
 858	}
 859
 860	private void sendStartStream() throws IOException {
 861		final Tag stream = Tag.start("stream:stream");
 862		stream.setAttribute("from", account.getJid().toBareJid().toString());
 863		stream.setAttribute("to", account.getServer().toString());
 864		stream.setAttribute("version", "1.0");
 865		stream.setAttribute("xml:lang", "en");
 866		stream.setAttribute("xmlns", "jabber:client");
 867		stream.setAttribute("xmlns:stream", "http://etherx.jabber.org/streams");
 868		tagWriter.writeTag(stream);
 869	}
 870
 871	private String nextRandomId() {
 872		return new BigInteger(50, mXmppConnectionService.getRNG()).toString(32);
 873	}
 874
 875	public void sendIqPacket(final IqPacket packet, final OnIqPacketReceived callback) {
 876		packet.setFrom(account.getJid());
 877		this.sendUnmodifiedIqPacket(packet,callback);
 878
 879	}
 880
 881	private synchronized void sendUnmodifiedIqPacket(final IqPacket packet, final OnIqPacketReceived callback) {
 882		if (packet.getId() == null) {
 883			final String id = nextRandomId();
 884			packet.setAttribute("id", id);
 885		}
 886		if (callback != null) {
 887			if (packet.getId() == null) {
 888				packet.setId(nextRandomId());
 889			}
 890			packetCallbacks.put(packet.getId(), new Pair<>(packet, callback));
 891		}
 892		this.sendPacket(packet);
 893	}
 894
 895	public void sendMessagePacket(final MessagePacket packet) {
 896		this.sendPacket(packet);
 897	}
 898
 899	public void sendPresencePacket(final PresencePacket packet) {
 900		this.sendPacket(packet);
 901	}
 902
 903	private synchronized void sendPacket(final AbstractStanza packet) {
 904		final String name = packet.getName();
 905		if (name.equals("iq") || name.equals("message") || name.equals("presence")) {
 906			++stanzasSent;
 907		}
 908		tagWriter.writeStanzaAsync(packet);
 909		if (packet instanceof MessagePacket && packet.getId() != null && this.streamId != null) {
 910			if (Config.EXTENDED_SM_LOGGING) {
 911				Log.d(Config.LOGTAG, account.getJid().toBareJid() + ": requesting ack for message stanza #" + stanzasSent);
 912			}
 913			this.messageReceipts.put(stanzasSent, packet.getId());
 914			tagWriter.writeStanzaAsync(new RequestPacket(this.smVersion));
 915		}
 916	}
 917
 918	public void sendPing() {
 919		if (streamFeatures.hasChild("sm")) {
 920			tagWriter.writeStanzaAsync(new RequestPacket(smVersion));
 921		} else {
 922			final IqPacket iq = new IqPacket(IqPacket.TYPE.GET);
 923			iq.setFrom(account.getJid());
 924			iq.addChild("ping", "urn:xmpp:ping");
 925			this.sendIqPacket(iq, null);
 926		}
 927		this.lastPingSent = SystemClock.elapsedRealtime();
 928	}
 929
 930	public void setOnMessagePacketReceivedListener(
 931			final OnMessagePacketReceived listener) {
 932		this.messageListener = listener;
 933			}
 934
 935	public void setOnUnregisteredIqPacketReceivedListener(
 936			final OnIqPacketReceived listener) {
 937		this.unregisteredIqListener = listener;
 938			}
 939
 940	public void setOnPresencePacketReceivedListener(
 941			final OnPresencePacketReceived listener) {
 942		this.presenceListener = listener;
 943			}
 944
 945	public void setOnJinglePacketReceivedListener(
 946			final OnJinglePacketReceived listener) {
 947		this.jingleListener = listener;
 948			}
 949
 950	public void setOnStatusChangedListener(final OnStatusChanged listener) {
 951		this.statusListener = listener;
 952	}
 953
 954	public void setOnBindListener(final OnBindListener listener) {
 955		this.bindListener = listener;
 956	}
 957
 958	public void setOnMessageAcknowledgeListener(final OnMessageAcknowledged listener) {
 959		this.acknowledgedListener = listener;
 960	}
 961
 962	public void addOnAdvancedStreamFeaturesAvailableListener(final OnAdvancedStreamFeaturesLoaded listener) {
 963		if (!this.advancedStreamFeaturesLoadedListeners.contains(listener)) {
 964			this.advancedStreamFeaturesLoadedListeners.add(listener);
 965		}
 966	}
 967
 968	public void disconnect(final boolean force) {
 969		Log.d(Config.LOGTAG, account.getJid().toBareJid() + ": disconnecting");
 970		try {
 971			if (force) {
 972				socket.close();
 973				return;
 974			}
 975			new Thread(new Runnable() {
 976
 977				@Override
 978				public void run() {
 979					if (tagWriter.isActive()) {
 980						tagWriter.finish();
 981						try {
 982							while (!tagWriter.finished()) {
 983								Log.d(Config.LOGTAG, "not yet finished");
 984								Thread.sleep(100);
 985							}
 986							tagWriter.writeTag(Tag.end("stream:stream"));
 987							socket.close();
 988						} catch (final IOException e) {
 989							Log.d(Config.LOGTAG,
 990									"io exception during disconnect");
 991						} catch (final InterruptedException e) {
 992							Log.d(Config.LOGTAG, "interrupted");
 993						}
 994					}
 995				}
 996			}).start();
 997		} catch (final IOException e) {
 998			Log.d(Config.LOGTAG, "io exception during disconnect");
 999		}
1000	}
1001
1002	public void resetStreamId() {
1003		this.streamId = null;
1004	}
1005
1006	public List<String> findDiscoItemsByFeature(final String feature) {
1007		final List<String> items = new ArrayList<>();
1008		for (final Entry<Jid, Info> cursor : disco.entrySet()) {
1009			if (cursor.getValue().features.contains(feature)) {
1010				items.add(cursor.getKey().toString());
1011			}
1012		}
1013		return items;
1014	}
1015
1016	public String findDiscoItemByFeature(final String feature) {
1017		final List<String> items = findDiscoItemsByFeature(feature);
1018		if (items.size() >= 1) {
1019			return items.get(0);
1020		}
1021		return null;
1022	}
1023
1024	public void r() {
1025		this.tagWriter.writeStanzaAsync(new RequestPacket(smVersion));
1026	}
1027
1028	public String getMucServer() {
1029		for (final Entry<Jid, Info> cursor : disco.entrySet()) {
1030			final Info value = cursor.getValue();
1031			if (value.features.contains("http://jabber.org/protocol/muc")
1032					&& !value.features.contains("jabber:iq:gateway")
1033					&& !value.identities.contains(new Pair<>("conference","irc"))) {
1034				return cursor.getKey().toString();
1035			}
1036		}
1037		return null;
1038	}
1039
1040	public int getTimeToNextAttempt() {
1041		final int interval = (int) (25 * Math.pow(1.5, attempt));
1042		final int secondsSinceLast = (int) ((SystemClock.elapsedRealtime() - this.lastConnect) / 1000);
1043		return interval - secondsSinceLast;
1044	}
1045
1046	public int getAttempt() {
1047		return this.attempt;
1048	}
1049
1050	public Features getFeatures() {
1051		return this.features;
1052	}
1053
1054	public long getLastSessionEstablished() {
1055		final long diff;
1056		if (this.lastSessionStarted == 0) {
1057			diff = SystemClock.elapsedRealtime() - this.lastConnect;
1058		} else {
1059			diff = SystemClock.elapsedRealtime() - this.lastSessionStarted;
1060		}
1061		return System.currentTimeMillis() - diff;
1062	}
1063
1064	public long getLastConnect() {
1065		return this.lastConnect;
1066	}
1067
1068	public long getLastPingSent() {
1069		return this.lastPingSent;
1070	}
1071
1072	public long getLastPacketReceived() {
1073		return this.lastPacketReceived;
1074	}
1075
1076	public void sendActive() {
1077		this.sendPacket(new ActivePacket());
1078	}
1079
1080	public void sendInactive() {
1081		this.sendPacket(new InactivePacket());
1082	}
1083
1084	public void resetAttemptCount() {
1085		this.attempt = 0;
1086		this.lastConnect = 0;
1087	}
1088
1089	private class Info {
1090		public final ArrayList<String> features = new ArrayList<>();
1091		public final ArrayList<Pair<String,String>> identities = new ArrayList<>();
1092	}
1093
1094	public class Features {
1095		XmppConnection connection;
1096		private boolean carbonsEnabled = false;
1097		private boolean encryptionEnabled = false;
1098		private boolean blockListRequested = false;
1099
1100		public Features(final XmppConnection connection) {
1101			this.connection = connection;
1102		}
1103
1104		private boolean hasDiscoFeature(final Jid server, final String feature) {
1105			return connection.disco.containsKey(server) &&
1106				connection.disco.get(server).features.contains(feature);
1107		}
1108
1109		public boolean carbons() {
1110			return hasDiscoFeature(account.getServer(), "urn:xmpp:carbons:2");
1111		}
1112
1113		public boolean blocking() {
1114			return hasDiscoFeature(account.getServer(), Xmlns.BLOCKING);
1115		}
1116
1117		public boolean register() {
1118			return hasDiscoFeature(account.getServer(), Xmlns.REGISTER);
1119		}
1120
1121		public boolean sm() {
1122			return streamId != null
1123					|| (connection.streamFeatures != null && connection.streamFeatures.hasChild("sm"));
1124		}
1125
1126		public boolean csi() {
1127			return connection.streamFeatures != null && connection.streamFeatures.hasChild("csi", "urn:xmpp:csi:0");
1128		}
1129
1130		public boolean pep() {
1131			final Pair<String,String> needle = new Pair<>("pubsub","pep");
1132			Info info = disco.get(account.getServer());
1133			if (info != null && info.identities.contains(needle)) {
1134				return true;
1135			} else {
1136				info = disco.get(account.getJid().toBareJid());
1137				return info != null && info.identities.contains(needle);
1138			}
1139		}
1140
1141		public boolean mam() {
1142			if (hasDiscoFeature(account.getJid().toBareJid(), "urn:xmpp:mam:0")) {
1143				return true;
1144			} else {
1145				return hasDiscoFeature(account.getServer(), "urn:xmpp:mam:0");
1146			}
1147		}
1148
1149		public boolean advancedStreamFeaturesLoaded() {
1150			return disco.containsKey(account.getServer());
1151		}
1152
1153		public boolean rosterVersioning() {
1154			return connection.streamFeatures != null && connection.streamFeatures.hasChild("ver");
1155		}
1156
1157		public void setBlockListRequested(boolean value) {
1158			this.blockListRequested = value;
1159		}
1160	}
1161
1162	private IqGenerator getIqGenerator() {
1163		return mXmppConnectionService.getIqGenerator();
1164	}
1165}