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		if (stanzasReceived == Integer.MAX_VALUE) {
 441			resetStreamId();
 442			throw new IOException("time to restart the session. cant handle >2 billion pcks");
 443		}
 444		++stanzasReceived;
 445		lastPacketReceived = SystemClock.elapsedRealtime();
 446		return element;
 447	}
 448
 449	private void processIq(final Tag currentTag) throws XmlPullParserException, IOException {
 450		final IqPacket packet = (IqPacket) processPacket(currentTag, PACKET_IQ);
 451
 452		if (packet.getId() == null) {
 453			return; // an iq packet without id is definitely invalid
 454		}
 455
 456		if (packet instanceof JinglePacket) {
 457			if (this.jingleListener != null) {
 458				this.jingleListener.onJinglePacketReceived(account,(JinglePacket) packet);
 459			}
 460		} else {
 461			if (packetCallbacks.containsKey(packet.getId())) {
 462				final Pair<IqPacket, OnIqPacketReceived> packetCallbackDuple = packetCallbacks.get(packet.getId());
 463				// Packets to the server should have responses from the server
 464				if (packetCallbackDuple.first.toServer(account)) {
 465					if (packet.fromServer(account)) {
 466						packetCallbackDuple.second.onIqPacketReceived(account, packet);
 467						packetCallbacks.remove(packet.getId());
 468					} else {
 469						Log.e(Config.LOGTAG,account.getJid().toBareJid().toString()+": ignoring spoofed iq packet");
 470					}
 471				} else {
 472					if (packet.getFrom().equals(packetCallbackDuple.first.getTo())) {
 473						packetCallbackDuple.second.onIqPacketReceived(account, packet);
 474						packetCallbacks.remove(packet.getId());
 475					} else {
 476						Log.e(Config.LOGTAG,account.getJid().toBareJid().toString()+": ignoring spoofed iq packet");
 477					}
 478				}
 479			} else if (packet.getType() == IqPacket.TYPE.GET|| packet.getType() == IqPacket.TYPE.SET) {
 480				this.unregisteredIqListener.onIqPacketReceived(account, packet);
 481			}
 482		}
 483	}
 484
 485	private void processMessage(final Tag currentTag) throws XmlPullParserException, IOException {
 486		final MessagePacket packet = (MessagePacket) processPacket(currentTag,PACKET_MESSAGE);
 487		this.messageListener.onMessagePacketReceived(account, packet);
 488	}
 489
 490	private void processPresence(final Tag currentTag) throws XmlPullParserException, IOException {
 491		PresencePacket packet = (PresencePacket) processPacket(currentTag, PACKET_PRESENCE);
 492		this.presenceListener.onPresencePacketReceived(account, packet);
 493	}
 494
 495	private void sendStartTLS() throws IOException {
 496		final Tag startTLS = Tag.empty("starttls");
 497		startTLS.setAttribute("xmlns", "urn:ietf:params:xml:ns:xmpp-tls");
 498		tagWriter.writeTag(startTLS);
 499	}
 500
 501	private SharedPreferences getPreferences() {
 502		return PreferenceManager.getDefaultSharedPreferences(applicationContext);
 503	}
 504
 505	private boolean enableLegacySSL() {
 506		return getPreferences().getBoolean("enable_legacy_ssl", false);
 507	}
 508
 509	private void switchOverToTls(final Tag currentTag) throws XmlPullParserException, IOException {
 510		tagReader.readTag();
 511		try {
 512			final SSLContext sc = SSLContext.getInstance("TLS");
 513			sc.init(null,new X509TrustManager[]{this.mXmppConnectionService.getMemorizingTrustManager()},mXmppConnectionService.getRNG());
 514			final SSLSocketFactory factory = sc.getSocketFactory();
 515			final HostnameVerifier verifier = this.mXmppConnectionService.getMemorizingTrustManager().wrapHostnameVerifier(new StrictHostnameVerifier());
 516			final InetAddress address = socket == null ? null : socket.getInetAddress();
 517
 518			if (factory == null || address == null || verifier == null) {
 519				throw new IOException("could not setup ssl");
 520			}
 521
 522			final SSLSocket sslSocket = (SSLSocket) factory.createSocket(socket,address.getHostAddress(), socket.getPort(),true);
 523
 524			if (sslSocket == null) {
 525				throw new IOException("could not initialize ssl socket");
 526			}
 527
 528			final String[] supportProtocols;
 529			final Collection<String> supportedProtocols = new LinkedList<>(
 530					Arrays.asList(sslSocket.getSupportedProtocols()));
 531			supportedProtocols.remove("SSLv3");
 532			supportProtocols = supportedProtocols.toArray(new String[supportedProtocols.size()]);
 533
 534			sslSocket.setEnabledProtocols(supportProtocols);
 535
 536			final String[] cipherSuites = CryptoHelper.getOrderedCipherSuites(
 537					sslSocket.getSupportedCipherSuites());
 538			//Log.d(Config.LOGTAG, "Using ciphers: " + Arrays.toString(cipherSuites));
 539			if (cipherSuites.length > 0) {
 540				sslSocket.setEnabledCipherSuites(cipherSuites);
 541			}
 542
 543			if (!verifier.verify(account.getServer().getDomainpart(),sslSocket.getSession())) {
 544				Log.d(Config.LOGTAG,account.getJid().toBareJid()+": TLS certificate verification failed");
 545				disconnect(true);
 546				changeStatus(Account.State.SECURITY_ERROR);
 547			}
 548			tagReader.setInputStream(sslSocket.getInputStream());
 549			tagWriter.setOutputStream(sslSocket.getOutputStream());
 550			sendStartStream();
 551			Log.d(Config.LOGTAG, account.getJid().toBareJid()+ ": TLS connection established");
 552			features.encryptionEnabled = true;
 553			processStream(tagReader.readTag());
 554			sslSocket.close();
 555		} catch (final NoSuchAlgorithmException | KeyManagementException e1) {
 556			Log.d(Config.LOGTAG,account.getJid().toBareJid()+": TLS certificate verification failed");
 557			disconnect(true);
 558			changeStatus(Account.State.SECURITY_ERROR);
 559		}
 560	}
 561
 562	private void processStreamFeatures(final Tag currentTag)
 563		throws XmlPullParserException, IOException {
 564		this.streamFeatures = tagReader.readElement(currentTag);
 565		if (this.streamFeatures.hasChild("starttls") && !features.encryptionEnabled) {
 566			sendStartTLS();
 567		} else if (this.streamFeatures.hasChild("register")
 568				&& account.isOptionSet(Account.OPTION_REGISTER)
 569				&& features.encryptionEnabled) {
 570			sendRegistryRequest();
 571		} else if (!this.streamFeatures.hasChild("register")
 572				&& account.isOptionSet(Account.OPTION_REGISTER)) {
 573			changeStatus(Account.State.REGISTRATION_NOT_SUPPORTED);
 574			disconnect(true);
 575		} else if (this.streamFeatures.hasChild("mechanisms")
 576				&& shouldAuthenticate && features.encryptionEnabled) {
 577			final List<String> mechanisms = extractMechanisms(streamFeatures
 578					.findChild("mechanisms"));
 579			final Element auth = new Element("auth");
 580			auth.setAttribute("xmlns", "urn:ietf:params:xml:ns:xmpp-sasl");
 581			if (mechanisms.contains("SCRAM-SHA-1")) {
 582				saslMechanism = new ScramSha1(tagWriter, account, mXmppConnectionService.getRNG());
 583			} else if (mechanisms.contains("PLAIN")) {
 584				saslMechanism = new Plain(tagWriter, account);
 585			} else if (mechanisms.contains("DIGEST-MD5")) {
 586				saslMechanism = new DigestMd5(tagWriter, account, mXmppConnectionService.getRNG());
 587			}
 588			if (saslMechanism != null) {
 589				final JSONObject keys = account.getKeys();
 590				try {
 591					if (keys.has(Account.PINNED_MECHANISM_KEY) &&
 592							keys.getInt(Account.PINNED_MECHANISM_KEY) > saslMechanism.getPriority()) {
 593						Log.e(Config.LOGTAG, "Auth failed. Authentication mechanism " + saslMechanism.getMechanism() +
 594								" has lower priority (" + String.valueOf(saslMechanism.getPriority()) +
 595								") than pinned priority (" + keys.getInt(Account.PINNED_MECHANISM_KEY) +
 596								"). Possible downgrade attack?");
 597						disconnect(true);
 598						changeStatus(Account.State.SECURITY_ERROR);
 599					}
 600				} catch (final JSONException e) {
 601					Log.d(Config.LOGTAG, "Parse error while checking pinned auth mechanism");
 602				}
 603				Log.d(Config.LOGTAG, account.getJid().toString() + ": Authenticating with " + saslMechanism.getMechanism());
 604				auth.setAttribute("mechanism", saslMechanism.getMechanism());
 605				if (!saslMechanism.getClientFirstMessage().isEmpty()) {
 606					auth.setContent(saslMechanism.getClientFirstMessage());
 607				}
 608				tagWriter.writeElement(auth);
 609			} else {
 610				disconnect(true);
 611				changeStatus(Account.State.INCOMPATIBLE_SERVER);
 612			}
 613		} else if (this.streamFeatures.hasChild("sm", "urn:xmpp:sm:"
 614					+ smVersion)
 615				&& streamId != null) {
 616			if (Config.EXTENDED_SM_LOGGING) {
 617				Log.d(Config.LOGTAG,account.getJid().toBareJid()+": resuming after stanza #"+stanzasReceived);
 618			}
 619			final ResumePacket resume = new ResumePacket(this.streamId, stanzasReceived, smVersion);
 620			this.tagWriter.writeStanzaAsync(resume);
 621		} else if (this.streamFeatures.hasChild("bind") && shouldBind) {
 622			sendBindRequest();
 623		} else {
 624			disconnect(true);
 625			changeStatus(Account.State.INCOMPATIBLE_SERVER);
 626		}
 627	}
 628
 629	private List<String> extractMechanisms(final Element stream) {
 630		final ArrayList<String> mechanisms = new ArrayList<>(stream
 631				.getChildren().size());
 632		for (final Element child : stream.getChildren()) {
 633			mechanisms.add(child.getContent());
 634		}
 635		return mechanisms;
 636	}
 637
 638	private void sendRegistryRequest() {
 639		final IqPacket register = new IqPacket(IqPacket.TYPE.GET);
 640		register.query("jabber:iq:register");
 641		register.setTo(account.getServer());
 642		sendIqPacket(register, new OnIqPacketReceived() {
 643
 644			@Override
 645			public void onIqPacketReceived(final Account account, final IqPacket packet) {
 646				final Element instructions = packet.query().findChild("instructions");
 647				if (packet.query().hasChild("username")
 648						&& (packet.query().hasChild("password"))) {
 649					final IqPacket register = new IqPacket(IqPacket.TYPE.SET);
 650					final Element username = new Element("username")
 651						.setContent(account.getUsername());
 652					final Element password = new Element("password")
 653						.setContent(account.getPassword());
 654					register.query("jabber:iq:register").addChild(username);
 655					register.query().addChild(password);
 656					sendIqPacket(register, new OnIqPacketReceived() {
 657
 658						@Override
 659						public void onIqPacketReceived(final Account account, final IqPacket packet) {
 660							if (packet.getType() == IqPacket.TYPE.RESULT) {
 661								account.setOption(Account.OPTION_REGISTER,
 662										false);
 663								changeStatus(Account.State.REGISTRATION_SUCCESSFUL);
 664							} else if (packet.hasChild("error")
 665									&& (packet.findChild("error")
 666										.hasChild("conflict"))) {
 667								changeStatus(Account.State.REGISTRATION_CONFLICT);
 668							} else {
 669								changeStatus(Account.State.REGISTRATION_FAILED);
 670								Log.d(Config.LOGTAG, packet.toString());
 671							}
 672							disconnect(true);
 673						}
 674					});
 675				} else {
 676					changeStatus(Account.State.REGISTRATION_FAILED);
 677					disconnect(true);
 678					Log.d(Config.LOGTAG, account.getJid().toBareJid()
 679							+ ": could not register. instructions are"
 680							+ instructions.getContent());
 681				}
 682			}
 683		});
 684	}
 685
 686	private void sendBindRequest() {
 687		while(!mXmppConnectionService.areMessagesInitialized()) {
 688			try {
 689				Thread.sleep(500);
 690			} catch (final InterruptedException ignored) {
 691			}
 692		}
 693		final IqPacket iq = new IqPacket(IqPacket.TYPE.SET);
 694		iq.addChild("bind", "urn:ietf:params:xml:ns:xmpp-bind")
 695			.addChild("resource").setContent(account.getResource());
 696		this.sendUnmodifiedIqPacket(iq, new OnIqPacketReceived() {
 697			@Override
 698			public void onIqPacketReceived(final Account account, final IqPacket packet) {
 699				final Element bind = packet.findChild("bind");
 700				if (bind != null) {
 701					final Element jid = bind.findChild("jid");
 702					if (jid != null && jid.getContent() != null) {
 703						try {
 704							account.setResource(Jid.fromString(jid.getContent()).getResourcepart());
 705						} catch (final InvalidJidException e) {
 706							// TODO: Handle the case where an external JID is technically invalid?
 707						}
 708						if (streamFeatures.hasChild("session")) {
 709							sendStartSession();
 710						} else {
 711							sendPostBindInitialization();
 712						}
 713					} else {
 714						disconnect(true);
 715					}
 716				} else {
 717					disconnect(true);
 718				}
 719			}
 720		});
 721	}
 722
 723	private void sendStartSession() {
 724		final IqPacket startSession = new IqPacket(IqPacket.TYPE.SET);
 725		startSession.addChild("session","urn:ietf:params:xml:ns:xmpp-session");
 726		this.sendUnmodifiedIqPacket(startSession, new OnIqPacketReceived() {
 727			@Override
 728			public void onIqPacketReceived(Account account, IqPacket packet) {
 729				if (packet.getType() == IqPacket.TYPE.RESULT) {
 730					sendPostBindInitialization();
 731				} else {
 732					disconnect(true);
 733				}
 734			}
 735		});
 736	}
 737
 738	private void sendPostBindInitialization() {
 739		smVersion = 0;
 740		if (streamFeatures.hasChild("sm", "urn:xmpp:sm:3")) {
 741			smVersion = 3;
 742		} else if (streamFeatures.hasChild("sm", "urn:xmpp:sm:2")) {
 743			smVersion = 2;
 744		}
 745		if (smVersion != 0) {
 746			final EnablePacket enable = new EnablePacket(smVersion);
 747			tagWriter.writeStanzaAsync(enable);
 748			stanzasSent = 0;
 749			messageReceipts.clear();
 750		}
 751		features.carbonsEnabled = false;
 752		features.blockListRequested = false;
 753		disco.clear();
 754		sendServiceDiscoveryInfo(account.getServer());
 755		sendServiceDiscoveryInfo(account.getJid().toBareJid());
 756		sendServiceDiscoveryItems(account.getServer());
 757		if (bindListener != null) {
 758			bindListener.onBind(account);
 759		}
 760		sendInitialPing();
 761	}
 762
 763	private void sendServiceDiscoveryInfo(final Jid jid) {
 764		if (disco.containsKey(jid)) {
 765			if (account.getServer().equals(jid)) {
 766				enableAdvancedStreamFeatures();
 767			}
 768		} else {
 769			final IqPacket iq = new IqPacket(IqPacket.TYPE.GET);
 770			iq.setTo(jid);
 771			iq.query("http://jabber.org/protocol/disco#info");
 772			this.sendIqPacket(iq, new OnIqPacketReceived() {
 773
 774				@Override
 775				public void onIqPacketReceived(final Account account, final IqPacket packet) {
 776					final List<Element> elements = packet.query().getChildren();
 777					final Info info = new Info();
 778					for (final Element element : elements) {
 779						if (element.getName().equals("identity")) {
 780							String type = element.getAttribute("type");
 781							String category = element.getAttribute("category");
 782							if (type != null && category != null) {
 783								info.identities.add(new Pair<>(category,type));
 784							}
 785						} else if (element.getName().equals("feature")) {
 786							info.features.add(element.getAttribute("var"));
 787						}
 788					}
 789					disco.put(jid, info);
 790
 791					if (account.getServer().equals(jid)) {
 792						enableAdvancedStreamFeatures();
 793						for (final OnAdvancedStreamFeaturesLoaded listener : advancedStreamFeaturesLoadedListeners) {
 794							listener.onAdvancedStreamFeaturesAvailable(account);
 795						}
 796					}
 797				}
 798			});
 799		}
 800	}
 801
 802	private void enableAdvancedStreamFeatures() {
 803		if (getFeatures().carbons() && !features.carbonsEnabled) {
 804			sendEnableCarbons();
 805		}
 806		if (getFeatures().blocking() && !features.blockListRequested) {
 807			Log.d(Config.LOGTAG,account.getJid().toBareJid()+": Requesting block list");
 808			this.sendIqPacket(getIqGenerator().generateGetBlockList(), mXmppConnectionService.getIqParser());
 809		}
 810	}
 811
 812	private void sendServiceDiscoveryItems(final Jid server) {
 813		final IqPacket iq = new IqPacket(IqPacket.TYPE.GET);
 814		iq.setTo(server.toDomainJid());
 815		iq.query("http://jabber.org/protocol/disco#items");
 816		this.sendIqPacket(iq, new OnIqPacketReceived() {
 817
 818			@Override
 819			public void onIqPacketReceived(final Account account, final IqPacket packet) {
 820				final List<Element> elements = packet.query().getChildren();
 821				for (final Element element : elements) {
 822					if (element.getName().equals("item")) {
 823						final Jid jid = element.getAttributeAsJid("jid");
 824						if (jid != null && !jid.equals(account.getServer())) {
 825							sendServiceDiscoveryInfo(jid);
 826						}
 827					}
 828				}
 829			}
 830		});
 831	}
 832
 833	private void sendEnableCarbons() {
 834		final IqPacket iq = new IqPacket(IqPacket.TYPE.SET);
 835		iq.addChild("enable", "urn:xmpp:carbons:2");
 836		this.sendIqPacket(iq, new OnIqPacketReceived() {
 837
 838			@Override
 839			public void onIqPacketReceived(final Account account, final IqPacket packet) {
 840				if (!packet.hasChild("error")) {
 841					Log.d(Config.LOGTAG, account.getJid().toBareJid()
 842							+ ": successfully enabled carbons");
 843					features.carbonsEnabled = true;
 844				} else {
 845					Log.d(Config.LOGTAG, account.getJid().toBareJid()
 846							+ ": error enableing carbons " + packet.toString());
 847				}
 848			}
 849		});
 850	}
 851
 852	private void processStreamError(final Tag currentTag)
 853		throws XmlPullParserException, IOException {
 854		final Element streamError = tagReader.readElement(currentTag);
 855		if (streamError != null && streamError.hasChild("conflict")) {
 856			final String resource = account.getResource().split("\\.")[0];
 857			account.setResource(resource + "." + nextRandomId());
 858			Log.d(Config.LOGTAG,
 859					account.getJid().toBareJid() + ": switching resource due to conflict ("
 860					+ account.getResource() + ")");
 861		}
 862	}
 863
 864	private void sendStartStream() throws IOException {
 865		final Tag stream = Tag.start("stream:stream");
 866		stream.setAttribute("from", account.getJid().toBareJid().toString());
 867		stream.setAttribute("to", account.getServer().toString());
 868		stream.setAttribute("version", "1.0");
 869		stream.setAttribute("xml:lang", "en");
 870		stream.setAttribute("xmlns", "jabber:client");
 871		stream.setAttribute("xmlns:stream", "http://etherx.jabber.org/streams");
 872		tagWriter.writeTag(stream);
 873	}
 874
 875	private String nextRandomId() {
 876		return new BigInteger(50, mXmppConnectionService.getRNG()).toString(32);
 877	}
 878
 879	public void sendIqPacket(final IqPacket packet, final OnIqPacketReceived callback) {
 880		packet.setFrom(account.getJid());
 881		this.sendUnmodifiedIqPacket(packet,callback);
 882
 883	}
 884
 885	private synchronized void sendUnmodifiedIqPacket(final IqPacket packet, final OnIqPacketReceived callback) {
 886		if (packet.getId() == null) {
 887			final String id = nextRandomId();
 888			packet.setAttribute("id", id);
 889		}
 890		if (callback != null) {
 891			if (packet.getId() == null) {
 892				packet.setId(nextRandomId());
 893			}
 894			packetCallbacks.put(packet.getId(), new Pair<>(packet, callback));
 895		}
 896		this.sendPacket(packet);
 897	}
 898
 899	public void sendMessagePacket(final MessagePacket packet) {
 900		this.sendPacket(packet);
 901	}
 902
 903	public void sendPresencePacket(final PresencePacket packet) {
 904		this.sendPacket(packet);
 905	}
 906
 907	private synchronized void sendPacket(final AbstractStanza packet) {
 908		if (stanzasSent == Integer.MAX_VALUE) {
 909			resetStreamId();
 910			disconnect(true);
 911			return;
 912		}
 913		final String name = packet.getName();
 914		if (name.equals("iq") || name.equals("message") || name.equals("presence")) {
 915			++stanzasSent;
 916		}
 917		tagWriter.writeStanzaAsync(packet);
 918		if (packet instanceof MessagePacket && packet.getId() != null && this.streamId != null) {
 919			if (Config.EXTENDED_SM_LOGGING) {
 920				Log.d(Config.LOGTAG, account.getJid().toBareJid() + ": requesting ack for message stanza #" + stanzasSent);
 921			}
 922			this.messageReceipts.put(stanzasSent, packet.getId());
 923			tagWriter.writeStanzaAsync(new RequestPacket(this.smVersion));
 924		}
 925	}
 926
 927	public void sendPing() {
 928		if (streamFeatures.hasChild("sm")) {
 929			tagWriter.writeStanzaAsync(new RequestPacket(smVersion));
 930		} else {
 931			final IqPacket iq = new IqPacket(IqPacket.TYPE.GET);
 932			iq.setFrom(account.getJid());
 933			iq.addChild("ping", "urn:xmpp:ping");
 934			this.sendIqPacket(iq, null);
 935		}
 936		this.lastPingSent = SystemClock.elapsedRealtime();
 937	}
 938
 939	public void setOnMessagePacketReceivedListener(
 940			final OnMessagePacketReceived listener) {
 941		this.messageListener = listener;
 942			}
 943
 944	public void setOnUnregisteredIqPacketReceivedListener(
 945			final OnIqPacketReceived listener) {
 946		this.unregisteredIqListener = listener;
 947			}
 948
 949	public void setOnPresencePacketReceivedListener(
 950			final OnPresencePacketReceived listener) {
 951		this.presenceListener = listener;
 952			}
 953
 954	public void setOnJinglePacketReceivedListener(
 955			final OnJinglePacketReceived listener) {
 956		this.jingleListener = listener;
 957			}
 958
 959	public void setOnStatusChangedListener(final OnStatusChanged listener) {
 960		this.statusListener = listener;
 961	}
 962
 963	public void setOnBindListener(final OnBindListener listener) {
 964		this.bindListener = listener;
 965	}
 966
 967	public void setOnMessageAcknowledgeListener(final OnMessageAcknowledged listener) {
 968		this.acknowledgedListener = listener;
 969	}
 970
 971	public void addOnAdvancedStreamFeaturesAvailableListener(final OnAdvancedStreamFeaturesLoaded listener) {
 972		if (!this.advancedStreamFeaturesLoadedListeners.contains(listener)) {
 973			this.advancedStreamFeaturesLoadedListeners.add(listener);
 974		}
 975	}
 976
 977	public void disconnect(final boolean force) {
 978		Log.d(Config.LOGTAG, account.getJid().toBareJid() + ": disconnecting");
 979		try {
 980			if (force) {
 981				socket.close();
 982				return;
 983			}
 984			new Thread(new Runnable() {
 985
 986				@Override
 987				public void run() {
 988					if (tagWriter.isActive()) {
 989						tagWriter.finish();
 990						try {
 991							while (!tagWriter.finished()) {
 992								Log.d(Config.LOGTAG, "not yet finished");
 993								Thread.sleep(100);
 994							}
 995							tagWriter.writeTag(Tag.end("stream:stream"));
 996							socket.close();
 997						} catch (final IOException e) {
 998							Log.d(Config.LOGTAG,
 999									"io exception during disconnect");
1000						} catch (final InterruptedException e) {
1001							Log.d(Config.LOGTAG, "interrupted");
1002						}
1003					}
1004				}
1005			}).start();
1006		} catch (final IOException e) {
1007			Log.d(Config.LOGTAG, "io exception during disconnect");
1008		}
1009	}
1010
1011	public void resetStreamId() {
1012		this.streamId = null;
1013	}
1014
1015	public List<String> findDiscoItemsByFeature(final String feature) {
1016		final List<String> items = new ArrayList<>();
1017		for (final Entry<Jid, Info> cursor : disco.entrySet()) {
1018			if (cursor.getValue().features.contains(feature)) {
1019				items.add(cursor.getKey().toString());
1020			}
1021		}
1022		return items;
1023	}
1024
1025	public String findDiscoItemByFeature(final String feature) {
1026		final List<String> items = findDiscoItemsByFeature(feature);
1027		if (items.size() >= 1) {
1028			return items.get(0);
1029		}
1030		return null;
1031	}
1032
1033	public void r() {
1034		this.tagWriter.writeStanzaAsync(new RequestPacket(smVersion));
1035	}
1036
1037	public String getMucServer() {
1038		for (final Entry<Jid, Info> cursor : disco.entrySet()) {
1039			final Info value = cursor.getValue();
1040			if (value.features.contains("http://jabber.org/protocol/muc")
1041					&& !value.features.contains("jabber:iq:gateway")
1042					&& !value.identities.contains(new Pair<>("conference","irc"))) {
1043				return cursor.getKey().toString();
1044			}
1045		}
1046		return null;
1047	}
1048
1049	public int getTimeToNextAttempt() {
1050		final int interval = (int) (25 * Math.pow(1.5, attempt));
1051		final int secondsSinceLast = (int) ((SystemClock.elapsedRealtime() - this.lastConnect) / 1000);
1052		return interval - secondsSinceLast;
1053	}
1054
1055	public int getAttempt() {
1056		return this.attempt;
1057	}
1058
1059	public Features getFeatures() {
1060		return this.features;
1061	}
1062
1063	public long getLastSessionEstablished() {
1064		final long diff;
1065		if (this.lastSessionStarted == 0) {
1066			diff = SystemClock.elapsedRealtime() - this.lastConnect;
1067		} else {
1068			diff = SystemClock.elapsedRealtime() - this.lastSessionStarted;
1069		}
1070		return System.currentTimeMillis() - diff;
1071	}
1072
1073	public long getLastConnect() {
1074		return this.lastConnect;
1075	}
1076
1077	public long getLastPingSent() {
1078		return this.lastPingSent;
1079	}
1080
1081	public long getLastPacketReceived() {
1082		return this.lastPacketReceived;
1083	}
1084
1085	public void sendActive() {
1086		this.sendPacket(new ActivePacket());
1087	}
1088
1089	public void sendInactive() {
1090		this.sendPacket(new InactivePacket());
1091	}
1092
1093	public void resetAttemptCount() {
1094		this.attempt = 0;
1095		this.lastConnect = 0;
1096	}
1097
1098	private class Info {
1099		public final ArrayList<String> features = new ArrayList<>();
1100		public final ArrayList<Pair<String,String>> identities = new ArrayList<>();
1101	}
1102
1103	public class Features {
1104		XmppConnection connection;
1105		private boolean carbonsEnabled = false;
1106		private boolean encryptionEnabled = false;
1107		private boolean blockListRequested = false;
1108
1109		public Features(final XmppConnection connection) {
1110			this.connection = connection;
1111		}
1112
1113		private boolean hasDiscoFeature(final Jid server, final String feature) {
1114			return connection.disco.containsKey(server) &&
1115				connection.disco.get(server).features.contains(feature);
1116		}
1117
1118		public boolean carbons() {
1119			return hasDiscoFeature(account.getServer(), "urn:xmpp:carbons:2");
1120		}
1121
1122		public boolean blocking() {
1123			return hasDiscoFeature(account.getServer(), Xmlns.BLOCKING);
1124		}
1125
1126		public boolean register() {
1127			return hasDiscoFeature(account.getServer(), Xmlns.REGISTER);
1128		}
1129
1130		public boolean sm() {
1131			return streamId != null
1132					|| (connection.streamFeatures != null && connection.streamFeatures.hasChild("sm"));
1133		}
1134
1135		public boolean csi() {
1136			return connection.streamFeatures != null && connection.streamFeatures.hasChild("csi", "urn:xmpp:csi:0");
1137		}
1138
1139		public boolean pep() {
1140			final Pair<String,String> needle = new Pair<>("pubsub","pep");
1141			Info info = disco.get(account.getServer());
1142			if (info != null && info.identities.contains(needle)) {
1143				return true;
1144			} else {
1145				info = disco.get(account.getJid().toBareJid());
1146				return info != null && info.identities.contains(needle);
1147			}
1148		}
1149
1150		public boolean mam() {
1151			if (hasDiscoFeature(account.getJid().toBareJid(), "urn:xmpp:mam:0")) {
1152				return true;
1153			} else {
1154				return hasDiscoFeature(account.getServer(), "urn:xmpp:mam:0");
1155			}
1156		}
1157
1158		public boolean advancedStreamFeaturesLoaded() {
1159			return disco.containsKey(account.getServer());
1160		}
1161
1162		public boolean rosterVersioning() {
1163			return connection.streamFeatures != null && connection.streamFeatures.hasChild("ver");
1164		}
1165
1166		public void setBlockListRequested(boolean value) {
1167			this.blockListRequested = value;
1168		}
1169	}
1170
1171	private IqGenerator getIqGenerator() {
1172		return mXmppConnectionService.getIqGenerator();
1173	}
1174}