AxolotlService.java

   1package eu.siacs.conversations.crypto.axolotl;
   2
   3import android.os.Bundle;
   4import android.security.KeyChain;
   5import android.support.annotation.NonNull;
   6import android.support.annotation.Nullable;
   7import android.util.Log;
   8import android.util.Pair;
   9
  10import org.bouncycastle.jce.provider.BouncyCastleProvider;
  11import org.whispersystems.libsignal.SignalProtocolAddress;
  12import org.whispersystems.libsignal.IdentityKey;
  13import org.whispersystems.libsignal.IdentityKeyPair;
  14import org.whispersystems.libsignal.InvalidKeyException;
  15import org.whispersystems.libsignal.InvalidKeyIdException;
  16import org.whispersystems.libsignal.SessionBuilder;
  17import org.whispersystems.libsignal.UntrustedIdentityException;
  18import org.whispersystems.libsignal.ecc.ECPublicKey;
  19import org.whispersystems.libsignal.state.PreKeyBundle;
  20import org.whispersystems.libsignal.state.PreKeyRecord;
  21import org.whispersystems.libsignal.state.SignedPreKeyRecord;
  22import org.whispersystems.libsignal.util.KeyHelper;
  23
  24import java.security.PrivateKey;
  25import java.security.Security;
  26import java.security.Signature;
  27import java.security.cert.X509Certificate;
  28import java.util.ArrayList;
  29import java.util.Arrays;
  30import java.util.Collection;
  31import java.util.Collections;
  32import java.util.HashMap;
  33import java.util.HashSet;
  34import java.util.Iterator;
  35import java.util.List;
  36import java.util.Map;
  37import java.util.Random;
  38import java.util.Set;
  39import java.util.concurrent.atomic.AtomicBoolean;
  40
  41import eu.siacs.conversations.Config;
  42import eu.siacs.conversations.entities.Account;
  43import eu.siacs.conversations.entities.Contact;
  44import eu.siacs.conversations.entities.Conversation;
  45import eu.siacs.conversations.entities.Message;
  46import eu.siacs.conversations.parser.IqParser;
  47import eu.siacs.conversations.services.XmppConnectionService;
  48import eu.siacs.conversations.utils.CryptoHelper;
  49import eu.siacs.conversations.utils.SerialSingleThreadExecutor;
  50import eu.siacs.conversations.xml.Element;
  51import eu.siacs.conversations.xml.Namespace;
  52import eu.siacs.conversations.xmpp.OnAdvancedStreamFeaturesLoaded;
  53import eu.siacs.conversations.xmpp.OnIqPacketReceived;
  54import eu.siacs.conversations.xmpp.jid.InvalidJidException;
  55import eu.siacs.conversations.xmpp.jid.Jid;
  56import eu.siacs.conversations.xmpp.pep.PublishOptions;
  57import eu.siacs.conversations.xmpp.stanzas.IqPacket;
  58
  59public class AxolotlService implements OnAdvancedStreamFeaturesLoaded {
  60
  61	public static final String PEP_PREFIX = "eu.siacs.conversations.axolotl";
  62	public static final String PEP_DEVICE_LIST = PEP_PREFIX + ".devicelist";
  63	public static final String PEP_DEVICE_LIST_NOTIFY = PEP_DEVICE_LIST + "+notify";
  64	public static final String PEP_BUNDLES = PEP_PREFIX + ".bundles";
  65	public static final String PEP_VERIFICATION = PEP_PREFIX + ".verification";
  66
  67	public static final String LOGPREFIX = "AxolotlService";
  68
  69	public static final int NUM_KEYS_TO_PUBLISH = 100;
  70	public static final int publishTriesThreshold = 3;
  71
  72	private final Account account;
  73	private final XmppConnectionService mXmppConnectionService;
  74	private final SQLiteAxolotlStore axolotlStore;
  75	private final SessionMap sessions;
  76	private final Map<Jid, Set<Integer>> deviceIds;
  77	private final Map<String, XmppAxolotlMessage> messageCache;
  78	private final FetchStatusMap fetchStatusMap;
  79	private final HashMap<Jid,List<OnDeviceIdsFetched>> fetchDeviceIdsMap = new HashMap<>();
  80	private final SerialSingleThreadExecutor executor;
  81	private int numPublishTriesOnEmptyPep = 0;
  82	private boolean pepBroken = false;
  83	private int lastDeviceListNotificationHash = 0;
  84
  85	private AtomicBoolean changeAccessMode = new AtomicBoolean(false);
  86
  87	@Override
  88	public void onAdvancedStreamFeaturesAvailable(Account account) {
  89		if (Config.supportOmemo()
  90				&& account.getXmppConnection() != null
  91				&& account.getXmppConnection().getFeatures().pep()) {
  92			publishBundlesIfNeeded(true, false);
  93		} else {
  94			Log.d(Config.LOGTAG,account.getJid().toBareJid()+": skipping OMEMO initialization");
  95		}
  96	}
  97
  98	public boolean fetchMapHasErrors(List<Jid> jids) {
  99		for(Jid jid : jids) {
 100			if (deviceIds.get(jid) != null) {
 101				for (Integer foreignId : this.deviceIds.get(jid)) {
 102					SignalProtocolAddress address = new SignalProtocolAddress(jid.toPreppedString(), foreignId);
 103					if (fetchStatusMap.getAll(address.getName()).containsValue(FetchStatus.ERROR)) {
 104						return true;
 105					}
 106				}
 107			}
 108		}
 109		return false;
 110	}
 111
 112	public void preVerifyFingerprint(Contact contact, String fingerprint) {
 113		axolotlStore.preVerifyFingerprint(contact.getAccount(), contact.getJid().toBareJid().toPreppedString(), fingerprint);
 114	}
 115
 116	public void preVerifyFingerprint(Account account, String fingerprint) {
 117		axolotlStore.preVerifyFingerprint(account, account.getJid().toBareJid().toPreppedString(), fingerprint);
 118	}
 119
 120	public boolean hasVerifiedKeys(String name) {
 121		for(XmppAxolotlSession session : this.sessions.getAll(name).values()) {
 122			if (session.getTrust().isVerified()) {
 123				return true;
 124			}
 125		}
 126		return false;
 127	}
 128
 129	private static class AxolotlAddressMap<T> {
 130		protected Map<String, Map<Integer, T>> map;
 131		protected final Object MAP_LOCK = new Object();
 132
 133		public AxolotlAddressMap() {
 134			this.map = new HashMap<>();
 135		}
 136
 137		public void put(SignalProtocolAddress address, T value) {
 138			synchronized (MAP_LOCK) {
 139				Map<Integer, T> devices = map.get(address.getName());
 140				if (devices == null) {
 141					devices = new HashMap<>();
 142					map.put(address.getName(), devices);
 143				}
 144				devices.put(address.getDeviceId(), value);
 145			}
 146		}
 147
 148		public T get(SignalProtocolAddress address) {
 149			synchronized (MAP_LOCK) {
 150				Map<Integer, T> devices = map.get(address.getName());
 151				if (devices == null) {
 152					return null;
 153				}
 154				return devices.get(address.getDeviceId());
 155			}
 156		}
 157
 158		public Map<Integer, T> getAll(String name) {
 159			synchronized (MAP_LOCK) {
 160				Map<Integer, T> devices = map.get(name);
 161				if (devices == null) {
 162					return new HashMap<>();
 163				}
 164				return devices;
 165			}
 166		}
 167
 168		public boolean hasAny(SignalProtocolAddress address) {
 169			synchronized (MAP_LOCK) {
 170				Map<Integer, T> devices = map.get(address.getName());
 171				return devices != null && !devices.isEmpty();
 172			}
 173		}
 174
 175		public void clear() {
 176			map.clear();
 177		}
 178
 179	}
 180
 181	private static class SessionMap extends AxolotlAddressMap<XmppAxolotlSession> {
 182		private final XmppConnectionService xmppConnectionService;
 183		private final Account account;
 184
 185		public SessionMap(XmppConnectionService service, SQLiteAxolotlStore store, Account account) {
 186			super();
 187			this.xmppConnectionService = service;
 188			this.account = account;
 189			this.fillMap(store);
 190		}
 191
 192		private void putDevicesForJid(String bareJid, List<Integer> deviceIds, SQLiteAxolotlStore store) {
 193			for (Integer deviceId : deviceIds) {
 194				SignalProtocolAddress axolotlAddress = new SignalProtocolAddress(bareJid, deviceId);
 195				IdentityKey identityKey = store.loadSession(axolotlAddress).getSessionState().getRemoteIdentityKey();
 196				if(Config.X509_VERIFICATION) {
 197					X509Certificate certificate = store.getFingerprintCertificate(CryptoHelper.bytesToHex(identityKey.getPublicKey().serialize()));
 198					if (certificate != null) {
 199						Bundle information = CryptoHelper.extractCertificateInformation(certificate);
 200						try {
 201							final String cn = information.getString("subject_cn");
 202							final Jid jid = Jid.fromString(bareJid);
 203							Log.d(Config.LOGTAG,"setting common name for "+jid+" to "+cn);
 204							account.getRoster().getContact(jid).setCommonName(cn);
 205						} catch (final InvalidJidException ignored) {
 206							//ignored
 207						}
 208					}
 209				}
 210				this.put(axolotlAddress, new XmppAxolotlSession(account, store, axolotlAddress, identityKey));
 211			}
 212		}
 213
 214		private void fillMap(SQLiteAxolotlStore store) {
 215			List<Integer> deviceIds = store.getSubDeviceSessions(account.getJid().toBareJid().toPreppedString());
 216			putDevicesForJid(account.getJid().toBareJid().toPreppedString(), deviceIds, store);
 217			for (String  address : store.getKnownAddresses()) {
 218				deviceIds = store.getSubDeviceSessions(address);
 219				putDevicesForJid(address, deviceIds, store);
 220			}
 221		}
 222
 223		@Override
 224		public void put(SignalProtocolAddress address, XmppAxolotlSession value) {
 225			super.put(address, value);
 226			value.setNotFresh();
 227		}
 228
 229		public void put(XmppAxolotlSession session) {
 230			this.put(session.getRemoteAddress(), session);
 231		}
 232	}
 233
 234	public enum FetchStatus {
 235		PENDING,
 236		SUCCESS,
 237		SUCCESS_VERIFIED,
 238		TIMEOUT,
 239		SUCCESS_TRUSTED,
 240		ERROR
 241	}
 242
 243	private static class FetchStatusMap extends AxolotlAddressMap<FetchStatus> {
 244
 245		public void clearErrorFor(Jid jid) {
 246			synchronized (MAP_LOCK) {
 247				Map<Integer, FetchStatus> devices = this.map.get(jid.toBareJid().toPreppedString());
 248				if (devices == null) {
 249					return;
 250				}
 251				for(Map.Entry<Integer, FetchStatus> entry : devices.entrySet()) {
 252					if (entry.getValue() == FetchStatus.ERROR) {
 253						Log.d(Config.LOGTAG,"resetting error for "+jid.toBareJid()+"("+entry.getKey()+")");
 254						entry.setValue(FetchStatus.TIMEOUT);
 255					}
 256				}
 257			}
 258		}
 259	}
 260
 261	public static String getLogprefix(Account account) {
 262		return LOGPREFIX + " (" + account.getJid().toBareJid().toString() + "): ";
 263	}
 264
 265	public AxolotlService(Account account, XmppConnectionService connectionService) {
 266		if (account == null || connectionService == null) {
 267			throw new IllegalArgumentException("account and service cannot be null");
 268		}
 269		if (Security.getProvider("BC") == null) {
 270			Security.addProvider(new BouncyCastleProvider());
 271		}
 272		this.mXmppConnectionService = connectionService;
 273		this.account = account;
 274		this.axolotlStore = new SQLiteAxolotlStore(this.account, this.mXmppConnectionService);
 275		this.deviceIds = new HashMap<>();
 276		this.messageCache = new HashMap<>();
 277		this.sessions = new SessionMap(mXmppConnectionService, axolotlStore, account);
 278		this.fetchStatusMap = new FetchStatusMap();
 279		this.executor = new SerialSingleThreadExecutor("Axolotl");
 280	}
 281
 282	public String getOwnFingerprint() {
 283		return CryptoHelper.bytesToHex(axolotlStore.getIdentityKeyPair().getPublicKey().serialize());
 284	}
 285
 286	public Set<IdentityKey> getKeysWithTrust(FingerprintStatus status) {
 287		return axolotlStore.getContactKeysWithTrust(account.getJid().toBareJid().toPreppedString(), status);
 288	}
 289
 290	public Set<IdentityKey> getKeysWithTrust(FingerprintStatus status, Jid jid) {
 291		return axolotlStore.getContactKeysWithTrust(jid.toBareJid().toPreppedString(), status);
 292	}
 293
 294	public Set<IdentityKey> getKeysWithTrust(FingerprintStatus status, List<Jid> jids) {
 295		Set<IdentityKey> keys = new HashSet<>();
 296		for(Jid jid : jids) {
 297			keys.addAll(axolotlStore.getContactKeysWithTrust(jid.toPreppedString(), status));
 298		}
 299		return keys;
 300	}
 301
 302	public long getNumTrustedKeys(Jid jid) {
 303		return axolotlStore.getContactNumTrustedKeys(jid.toBareJid().toPreppedString());
 304	}
 305
 306	public boolean anyTargetHasNoTrustedKeys(List<Jid> jids) {
 307		for(Jid jid : jids) {
 308			if (axolotlStore.getContactNumTrustedKeys(jid.toBareJid().toPreppedString()) == 0) {
 309				return true;
 310			}
 311		}
 312		return false;
 313	}
 314
 315	private SignalProtocolAddress getAddressForJid(Jid jid) {
 316		return new SignalProtocolAddress(jid.toPreppedString(), 0);
 317	}
 318
 319	public Collection<XmppAxolotlSession> findOwnSessions() {
 320		SignalProtocolAddress ownAddress = getAddressForJid(account.getJid().toBareJid());
 321		ArrayList<XmppAxolotlSession> s = new ArrayList<>(this.sessions.getAll(ownAddress.getName()).values());
 322		Collections.sort(s);
 323		return s;
 324	}
 325
 326
 327
 328	public Collection<XmppAxolotlSession> findSessionsForContact(Contact contact) {
 329		SignalProtocolAddress contactAddress = getAddressForJid(contact.getJid());
 330		ArrayList<XmppAxolotlSession> s = new ArrayList<>(this.sessions.getAll(contactAddress.getName()).values());
 331		Collections.sort(s);
 332		return s;
 333	}
 334
 335	private Set<XmppAxolotlSession> findSessionsForConversation(Conversation conversation) {
 336		HashSet<XmppAxolotlSession> sessions = new HashSet<>();
 337		for(Jid jid : conversation.getAcceptedCryptoTargets()) {
 338			sessions.addAll(this.sessions.getAll(getAddressForJid(jid).getName()).values());
 339		}
 340		return sessions;
 341	}
 342
 343	private boolean hasAny(Jid jid) {
 344		return sessions.hasAny(getAddressForJid(jid));
 345	}
 346
 347	public boolean isPepBroken() {
 348		return this.pepBroken;
 349	}
 350
 351	public void resetBrokenness() {
 352		this.pepBroken = false;
 353		this.numPublishTriesOnEmptyPep = 0;
 354		this.lastDeviceListNotificationHash = 0;
 355	}
 356
 357	public void clearErrorsInFetchStatusMap(Jid jid) {
 358		fetchStatusMap.clearErrorFor(jid);
 359	}
 360
 361	public void regenerateKeys(boolean wipeOther) {
 362		axolotlStore.regenerate();
 363		sessions.clear();
 364		fetchStatusMap.clear();
 365		fetchDeviceIdsMap.clear();
 366		publishBundlesIfNeeded(true, wipeOther);
 367	}
 368
 369	public void destroy() {
 370		Log.d(Config.LOGTAG,account.getJid().toBareJid()+": destroying old axolotl service. no longer in use");
 371		mXmppConnectionService.databaseBackend.wipeAxolotlDb(account);
 372	}
 373
 374	public AxolotlService makeNew() {
 375		Log.d(Config.LOGTAG,account.getJid().toBareJid()+": make new axolotl service");
 376		return new AxolotlService(this.account,this.mXmppConnectionService);
 377	}
 378
 379	public int getOwnDeviceId() {
 380		return axolotlStore.getLocalRegistrationId();
 381	}
 382
 383	public SignalProtocolAddress getOwnAxolotlAddress() {
 384		return new SignalProtocolAddress(account.getJid().toBareJid().toPreppedString(),getOwnDeviceId());
 385	}
 386
 387	public Set<Integer> getOwnDeviceIds() {
 388		return this.deviceIds.get(account.getJid().toBareJid());
 389	}
 390
 391	public void registerDevices(final Jid jid, @NonNull final Set<Integer> deviceIds) {
 392		final int hash = deviceIds.hashCode();
 393		final boolean me = jid.toBareJid().equals(account.getJid().toBareJid());
 394		if (me && hash == this.lastDeviceListNotificationHash) {
 395			Log.d(Config.LOGTAG,account.getJid().toBareJid()+": ignoring duplicate own device id list");
 396			return;
 397		}
 398		this.lastDeviceListNotificationHash = hash;
 399		boolean needsPublishing = me && !deviceIds.contains(getOwnDeviceId());
 400		if (me) {
 401			deviceIds.remove(getOwnDeviceId());
 402		}
 403		Set<Integer> expiredDevices = new HashSet<>(axolotlStore.getSubDeviceSessions(jid.toBareJid().toPreppedString()));
 404		expiredDevices.removeAll(deviceIds);
 405		for (Integer deviceId : expiredDevices) {
 406			SignalProtocolAddress address = new SignalProtocolAddress(jid.toBareJid().toPreppedString(), deviceId);
 407			XmppAxolotlSession session = sessions.get(address);
 408			if (session != null && session.getFingerprint() != null) {
 409				if (session.getTrust().isActive()) {
 410					session.setTrust(session.getTrust().toInactive());
 411				}
 412			}
 413		}
 414		Set<Integer> newDevices = new HashSet<>(deviceIds);
 415		for (Integer deviceId : newDevices) {
 416			SignalProtocolAddress address = new SignalProtocolAddress(jid.toBareJid().toPreppedString(), deviceId);
 417			XmppAxolotlSession session = sessions.get(address);
 418			if (session != null && session.getFingerprint() != null) {
 419				if (!session.getTrust().isActive()) {
 420					Log.d(Config.LOGTAG,"reactivating device with fingerprint "+session.getFingerprint());
 421					session.setTrust(session.getTrust().toActive());
 422				}
 423			}
 424		}
 425		if (me) {
 426			if (Config.OMEMO_AUTO_EXPIRY != 0) {
 427				needsPublishing |= deviceIds.removeAll(getExpiredDevices());
 428			}
 429			needsPublishing |= this.changeAccessMode.get();
 430			for (Integer deviceId : deviceIds) {
 431				SignalProtocolAddress ownDeviceAddress = new SignalProtocolAddress(jid.toBareJid().toPreppedString(), deviceId);
 432				if (sessions.get(ownDeviceAddress) == null) {
 433					FetchStatus status = fetchStatusMap.get(ownDeviceAddress);
 434					if (status == null || status == FetchStatus.TIMEOUT) {
 435						fetchStatusMap.put(ownDeviceAddress, FetchStatus.PENDING);
 436						this.buildSessionFromPEP(ownDeviceAddress);
 437					}
 438				}
 439			}
 440			if (needsPublishing) {
 441				publishOwnDeviceId(deviceIds);
 442			}
 443		}
 444		this.deviceIds.put(jid, deviceIds);
 445		mXmppConnectionService.updateConversationUi(); //update the lock icon
 446		mXmppConnectionService.keyStatusUpdated(null);
 447	}
 448
 449	public void wipeOtherPepDevices() {
 450		if (pepBroken) {
 451			Log.d(Config.LOGTAG, getLogprefix(account) + "wipeOtherPepDevices called, but PEP is broken. Ignoring... ");
 452			return;
 453		}
 454		Set<Integer> deviceIds = new HashSet<>();
 455		deviceIds.add(getOwnDeviceId());
 456		publishDeviceIdsAndRefineAccessModel(deviceIds);
 457	}
 458
 459	public void distrustFingerprint(final String fingerprint) {
 460		final String fp = fingerprint.replaceAll("\\s", "");
 461		final FingerprintStatus fingerprintStatus = axolotlStore.getFingerprintStatus(fp);
 462		axolotlStore.setFingerprintStatus(fp,fingerprintStatus.toUntrusted());
 463	}
 464
 465	public void publishOwnDeviceIdIfNeeded() {
 466		if (pepBroken) {
 467			Log.d(Config.LOGTAG, getLogprefix(account) + "publishOwnDeviceIdIfNeeded called, but PEP is broken. Ignoring... ");
 468			return;
 469		}
 470		IqPacket packet = mXmppConnectionService.getIqGenerator().retrieveDeviceIds(account.getJid().toBareJid());
 471		mXmppConnectionService.sendIqPacket(account, packet, new OnIqPacketReceived() {
 472			@Override
 473			public void onIqPacketReceived(Account account, IqPacket packet) {
 474				if (packet.getType() == IqPacket.TYPE.TIMEOUT) {
 475					Log.d(Config.LOGTAG, getLogprefix(account) + "Timeout received while retrieving own Device Ids.");
 476				} else {
 477					Element item = mXmppConnectionService.getIqParser().getItem(packet);
 478					Set<Integer> deviceIds = mXmppConnectionService.getIqParser().deviceIds(item);
 479					Log.d(Config.LOGTAG,account.getJid().toBareJid()+": retrieved own device list: "+deviceIds);
 480					registerDevices(account.getJid().toBareJid(),deviceIds);
 481				}
 482			}
 483		});
 484	}
 485
 486	private Set<Integer> getExpiredDevices() {
 487		Set<Integer> devices = new HashSet<>();
 488		for(XmppAxolotlSession session : findOwnSessions()) {
 489			if (session.getTrust().isActive()) {
 490				long diff = System.currentTimeMillis() - session.getTrust().getLastActivation();
 491				if (diff > Config.OMEMO_AUTO_EXPIRY) {
 492					long lastMessageDiff = System.currentTimeMillis() - mXmppConnectionService.databaseBackend.getLastTimeFingerprintUsed(account,session.getFingerprint());
 493					long hours = Math.round(lastMessageDiff/(1000*60.0*60.0));
 494					if (lastMessageDiff > Config.OMEMO_AUTO_EXPIRY) {
 495						devices.add(session.getRemoteAddress().getDeviceId());
 496						session.setTrust(session.getTrust().toInactive());
 497						Log.d(Config.LOGTAG,account.getJid().toBareJid()+": added own device " + session.getFingerprint() + " to list of expired devices. Last message received "+hours+" hours ago");
 498					} else {
 499						Log.d(Config.LOGTAG,account.getJid().toBareJid()+": own device "+session.getFingerprint()+" was active "+hours+" hours ago");
 500					}
 501				}
 502			}
 503		}
 504		return devices;
 505	}
 506
 507	public void publishOwnDeviceId(Set<Integer> deviceIds) {
 508		Set<Integer> deviceIdsCopy = new HashSet<>(deviceIds);
 509		Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "publishing own device ids");
 510		if (deviceIdsCopy.isEmpty()) {
 511			if (numPublishTriesOnEmptyPep >= publishTriesThreshold) {
 512				Log.w(Config.LOGTAG, getLogprefix(account) + "Own device publish attempt threshold exceeded, aborting...");
 513				pepBroken = true;
 514				return;
 515			} else {
 516				numPublishTriesOnEmptyPep++;
 517				Log.w(Config.LOGTAG, getLogprefix(account) + "Own device list empty, attempting to publish (try " + numPublishTriesOnEmptyPep + ")");
 518			}
 519		} else {
 520			numPublishTriesOnEmptyPep = 0;
 521		}
 522		deviceIdsCopy.add(getOwnDeviceId());
 523		publishDeviceIdsAndRefineAccessModel(deviceIdsCopy);
 524	}
 525
 526	private void publishDeviceIdsAndRefineAccessModel(Set<Integer> ids) {
 527		publishDeviceIdsAndRefineAccessModel(ids,true);
 528	}
 529
 530	private void publishDeviceIdsAndRefineAccessModel(final Set<Integer> ids, final boolean firstAttempt) {
 531		final Bundle publishOptions = account.getXmppConnection().getFeatures().pepPublishOptions() ? PublishOptions.openAccess() : null;
 532		IqPacket publish = mXmppConnectionService.getIqGenerator().publishDeviceIds(ids, publishOptions);
 533		mXmppConnectionService.sendIqPacket(account, publish, new OnIqPacketReceived() {
 534			@Override
 535			public void onIqPacketReceived(Account account, IqPacket packet) {
 536				Element error = packet.getType() == IqPacket.TYPE.ERROR ? packet.findChild("error") : null;
 537				if (firstAttempt && error != null && error.hasChild("precondition-not-met",Namespace.PUBSUB_ERROR)) {
 538					Log.d(Config.LOGTAG,account.getJid().toBareJid()+": precondition wasn't met for device list. pushing node configuration");
 539					mXmppConnectionService.pushNodeConfiguration(account, AxolotlService.PEP_DEVICE_LIST, publishOptions, new XmppConnectionService.OnConfigurationPushed() {
 540						@Override
 541						public void onPushSucceeded() {
 542							publishDeviceIdsAndRefineAccessModel(ids, false);
 543						}
 544
 545						@Override
 546						public void onPushFailed() {
 547							publishDeviceIdsAndRefineAccessModel(ids, false);
 548						}
 549					});
 550				} else {
 551					if (AxolotlService.this.changeAccessMode.compareAndSet(true,false)) {
 552						Log.d(Config.LOGTAG,account.getJid().toBareJid()+": done changing access mode");
 553						account.setOption(Account.OPTION_REQUIRES_ACCESS_MODE_CHANGE,false);
 554						mXmppConnectionService.databaseBackend.updateAccount(account);
 555					}
 556					if (packet.getType() == IqPacket.TYPE.ERROR) {
 557						pepBroken = true;
 558						Log.d(Config.LOGTAG, getLogprefix(account) + "Error received while publishing own device id" + packet.findChild("error"));
 559					}
 560				}
 561			}
 562		});
 563	}
 564
 565	public void publishDeviceVerificationAndBundle(final SignedPreKeyRecord signedPreKeyRecord,
 566												   final Set<PreKeyRecord> preKeyRecords,
 567												   final boolean announceAfter,
 568												   final boolean wipe) {
 569		try {
 570			IdentityKey axolotlPublicKey = axolotlStore.getIdentityKeyPair().getPublicKey();
 571			PrivateKey x509PrivateKey = KeyChain.getPrivateKey(mXmppConnectionService, account.getPrivateKeyAlias());
 572			X509Certificate[] chain = KeyChain.getCertificateChain(mXmppConnectionService, account.getPrivateKeyAlias());
 573			Signature verifier = Signature.getInstance("sha256WithRSA");
 574			verifier.initSign(x509PrivateKey,mXmppConnectionService.getRNG());
 575			verifier.update(axolotlPublicKey.serialize());
 576			byte[] signature = verifier.sign();
 577			IqPacket packet = mXmppConnectionService.getIqGenerator().publishVerification(signature, chain, getOwnDeviceId());
 578			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + ": publish verification for device "+getOwnDeviceId());
 579			mXmppConnectionService.sendIqPacket(account, packet, new OnIqPacketReceived() {
 580				@Override
 581				public void onIqPacketReceived(final Account account, IqPacket packet) {
 582					String node = AxolotlService.PEP_VERIFICATION+":"+getOwnDeviceId();
 583					mXmppConnectionService.pushNodeConfiguration(account, node, PublishOptions.openAccess(), new XmppConnectionService.OnConfigurationPushed() {
 584						@Override
 585						public void onPushSucceeded() {
 586							Log.d(Config.LOGTAG,getLogprefix(account) + "configured verification node to be world readable");
 587							publishDeviceBundle(signedPreKeyRecord, preKeyRecords, announceAfter, wipe);
 588						}
 589
 590						@Override
 591						public void onPushFailed() {
 592							Log.d(Config.LOGTAG,getLogprefix(account) + "unable to set access model on verification node");
 593							publishDeviceBundle(signedPreKeyRecord, preKeyRecords, announceAfter, wipe);
 594						}
 595					});
 596				}
 597			});
 598		} catch (Exception  e) {
 599			e.printStackTrace();
 600		}
 601	}
 602
 603	public void publishBundlesIfNeeded(final boolean announce, final boolean wipe) {
 604		if (pepBroken) {
 605			Log.d(Config.LOGTAG, getLogprefix(account) + "publishBundlesIfNeeded called, but PEP is broken. Ignoring... ");
 606			return;
 607		}
 608
 609		if (account.getXmppConnection().getFeatures().pepPublishOptions()) {
 610			this.changeAccessMode.set(account.isOptionSet(Account.OPTION_REQUIRES_ACCESS_MODE_CHANGE));
 611		} else {
 612			if (account.setOption(Account.OPTION_REQUIRES_ACCESS_MODE_CHANGE,true)) {
 613				Log.d(Config.LOGTAG, account.getJid().toBareJid() + ": server doesn’t support publish-options. setting for later access mode change");
 614				mXmppConnectionService.databaseBackend.updateAccount(account);
 615			}
 616		}
 617		if (this.changeAccessMode.get()) {
 618			Log.d(Config.LOGTAG, account.getJid().toBareJid() + ": server gained publish-options capabilities. changing access model");
 619		}
 620		IqPacket packet = mXmppConnectionService.getIqGenerator().retrieveBundlesForDevice(account.getJid().toBareJid(), getOwnDeviceId());
 621		mXmppConnectionService.sendIqPacket(account, packet, new OnIqPacketReceived() {
 622			@Override
 623			public void onIqPacketReceived(Account account, IqPacket packet) {
 624
 625				if (packet.getType() == IqPacket.TYPE.TIMEOUT) {
 626					return; //ignore timeout. do nothing
 627				}
 628
 629				if (packet.getType() == IqPacket.TYPE.ERROR) {
 630					Element error = packet.findChild("error");
 631					if (error == null || !error.hasChild("item-not-found")) {
 632						pepBroken = true;
 633						Log.w(Config.LOGTAG, AxolotlService.getLogprefix(account) + "request for device bundles came back with something other than item-not-found" + packet);
 634						return;
 635					}
 636				}
 637
 638				PreKeyBundle bundle = mXmppConnectionService.getIqParser().bundle(packet);
 639				Map<Integer, ECPublicKey> keys = mXmppConnectionService.getIqParser().preKeyPublics(packet);
 640				boolean flush = false;
 641				if (bundle == null) {
 642					Log.w(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Received invalid bundle:" + packet);
 643					bundle = new PreKeyBundle(-1, -1, -1, null, -1, null, null, null);
 644					flush = true;
 645				}
 646				if (keys == null) {
 647					Log.w(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Received invalid prekeys:" + packet);
 648				}
 649				try {
 650					boolean changed = false;
 651					// Validate IdentityKey
 652					IdentityKeyPair identityKeyPair = axolotlStore.getIdentityKeyPair();
 653					if (flush || !identityKeyPair.getPublicKey().equals(bundle.getIdentityKey())) {
 654						Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Adding own IdentityKey " + identityKeyPair.getPublicKey() + " to PEP.");
 655						changed = true;
 656					}
 657
 658					// Validate signedPreKeyRecord + ID
 659					SignedPreKeyRecord signedPreKeyRecord;
 660					int numSignedPreKeys = axolotlStore.getSignedPreKeysCount();
 661					try {
 662						signedPreKeyRecord = axolotlStore.loadSignedPreKey(bundle.getSignedPreKeyId());
 663						if (flush
 664								|| !bundle.getSignedPreKey().equals(signedPreKeyRecord.getKeyPair().getPublicKey())
 665								|| !Arrays.equals(bundle.getSignedPreKeySignature(), signedPreKeyRecord.getSignature())) {
 666							Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Adding new signedPreKey with ID " + (numSignedPreKeys + 1) + " to PEP.");
 667							signedPreKeyRecord = KeyHelper.generateSignedPreKey(identityKeyPair, numSignedPreKeys + 1);
 668							axolotlStore.storeSignedPreKey(signedPreKeyRecord.getId(), signedPreKeyRecord);
 669							changed = true;
 670						}
 671					} catch (InvalidKeyIdException e) {
 672						Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Adding new signedPreKey with ID " + (numSignedPreKeys + 1) + " to PEP.");
 673						signedPreKeyRecord = KeyHelper.generateSignedPreKey(identityKeyPair, numSignedPreKeys + 1);
 674						axolotlStore.storeSignedPreKey(signedPreKeyRecord.getId(), signedPreKeyRecord);
 675						changed = true;
 676					}
 677
 678					// Validate PreKeys
 679					Set<PreKeyRecord> preKeyRecords = new HashSet<>();
 680					if (keys != null) {
 681						for (Integer id : keys.keySet()) {
 682							try {
 683								PreKeyRecord preKeyRecord = axolotlStore.loadPreKey(id);
 684								if (preKeyRecord.getKeyPair().getPublicKey().equals(keys.get(id))) {
 685									preKeyRecords.add(preKeyRecord);
 686								}
 687							} catch (InvalidKeyIdException ignored) {
 688							}
 689						}
 690					}
 691					int newKeys = NUM_KEYS_TO_PUBLISH - preKeyRecords.size();
 692					if (newKeys > 0) {
 693						List<PreKeyRecord> newRecords = KeyHelper.generatePreKeys(
 694								axolotlStore.getCurrentPreKeyId() + 1, newKeys);
 695						preKeyRecords.addAll(newRecords);
 696						for (PreKeyRecord record : newRecords) {
 697							axolotlStore.storePreKey(record.getId(), record);
 698						}
 699						changed = true;
 700						Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Adding " + newKeys + " new preKeys to PEP.");
 701					}
 702
 703
 704					if (changed || changeAccessMode.get()) {
 705						if (account.getPrivateKeyAlias() != null && Config.X509_VERIFICATION) {
 706							mXmppConnectionService.publishDisplayName(account);
 707							publishDeviceVerificationAndBundle(signedPreKeyRecord, preKeyRecords, announce, wipe);
 708						} else {
 709							publishDeviceBundle(signedPreKeyRecord, preKeyRecords, announce, wipe);
 710						}
 711					} else {
 712						Log.d(Config.LOGTAG, getLogprefix(account) + "Bundle " + getOwnDeviceId() + " in PEP was current");
 713						if (wipe) {
 714							wipeOtherPepDevices();
 715						} else if (announce) {
 716							Log.d(Config.LOGTAG, getLogprefix(account) + "Announcing device " + getOwnDeviceId());
 717							publishOwnDeviceIdIfNeeded();
 718						}
 719					}
 720				} catch (InvalidKeyException e) {
 721					Log.e(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Failed to publish bundle " + getOwnDeviceId() + ", reason: " + e.getMessage());
 722				}
 723			}
 724		});
 725	}
 726
 727	private void publishDeviceBundle(SignedPreKeyRecord signedPreKeyRecord,
 728									 Set<PreKeyRecord> preKeyRecords,
 729									 final boolean announceAfter,
 730									 final boolean wipe) {
 731		publishDeviceBundle(signedPreKeyRecord,preKeyRecords,announceAfter,wipe,true);
 732	}
 733
 734	private void publishDeviceBundle(final SignedPreKeyRecord signedPreKeyRecord,
 735									 final Set<PreKeyRecord> preKeyRecords,
 736									 final boolean announceAfter,
 737									 final boolean wipe,
 738									 final boolean firstAttempt) {
 739		final Bundle publishOptions = account.getXmppConnection().getFeatures().pepPublishOptions() ? PublishOptions.openAccess() : null;
 740		IqPacket publish = mXmppConnectionService.getIqGenerator().publishBundles(
 741				signedPreKeyRecord, axolotlStore.getIdentityKeyPair().getPublicKey(),
 742				preKeyRecords, getOwnDeviceId(),publishOptions);
 743		Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + ": Bundle " + getOwnDeviceId() + " in PEP not current. Publishing...");
 744		mXmppConnectionService.sendIqPacket(account, publish, new OnIqPacketReceived() {
 745			@Override
 746			public void onIqPacketReceived(final Account account, IqPacket packet) {
 747				Element error = packet.getType() == IqPacket.TYPE.ERROR ? packet.findChild("error") : null;
 748				if (firstAttempt && error != null && error.hasChild("precondition-not-met", Namespace.PUBSUB_ERROR)) {
 749					Log.d(Config.LOGTAG,account.getJid().toBareJid()+": precondition wasn't met for bundle. pushing node configuration");
 750					final String node = AxolotlService.PEP_BUNDLES + ":" + getOwnDeviceId();
 751					mXmppConnectionService.pushNodeConfiguration(account, node, publishOptions, new XmppConnectionService.OnConfigurationPushed() {
 752						@Override
 753						public void onPushSucceeded() {
 754							publishDeviceBundle(signedPreKeyRecord,preKeyRecords, announceAfter, wipe, false);
 755						}
 756
 757						@Override
 758						public void onPushFailed() {
 759							publishDeviceBundle(signedPreKeyRecord,preKeyRecords, announceAfter, wipe, false);
 760						}
 761					});
 762				} else if (packet.getType() == IqPacket.TYPE.RESULT) {
 763					Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Successfully published bundle. ");
 764					if (wipe) {
 765						wipeOtherPepDevices();
 766					} else if (announceAfter) {
 767						Log.d(Config.LOGTAG, getLogprefix(account) + "Announcing device " + getOwnDeviceId());
 768						publishOwnDeviceIdIfNeeded();
 769					}
 770				} else if (packet.getType() == IqPacket.TYPE.ERROR) {
 771					pepBroken = true;
 772					Log.d(Config.LOGTAG, getLogprefix(account) + "Error received while publishing bundle: " + packet.findChild("error"));
 773				}
 774			}
 775		});
 776	}
 777
 778	public enum AxolotlCapability {
 779		FULL,
 780		MISSING_PRESENCE,
 781		MISSING_KEYS,
 782		WRONG_CONFIGURATION,
 783		NO_MEMBERS
 784	}
 785
 786	public boolean isConversationAxolotlCapable(Conversation conversation) {
 787		return conversation.getMode() == Conversation.MODE_SINGLE || (conversation.getMucOptions().nonanonymous() && conversation.getMucOptions().membersOnly());
 788	}
 789
 790	public Pair<AxolotlCapability,Jid> isConversationAxolotlCapableDetailed(Conversation conversation) {
 791		if (conversation.getMode() == Conversation.MODE_SINGLE
 792				|| (conversation.getMucOptions().membersOnly() && conversation.getMucOptions().nonanonymous())) {
 793			final List<Jid> jids = getCryptoTargets(conversation);
 794			for(Jid jid : jids) {
 795				if (!hasAny(jid) && (!deviceIds.containsKey(jid) || deviceIds.get(jid).isEmpty())) {
 796					if (conversation.getAccount().getRoster().getContact(jid).mutualPresenceSubscription()) {
 797						return new Pair<>(AxolotlCapability.MISSING_KEYS,jid);
 798					} else {
 799						return new Pair<>(AxolotlCapability.MISSING_PRESENCE,jid);
 800					}
 801				}
 802			}
 803			if (jids.size() > 0) {
 804				return new Pair<>(AxolotlCapability.FULL, null);
 805			} else {
 806				return new Pair<>(AxolotlCapability.NO_MEMBERS, null);
 807			}
 808		} else {
 809			return new Pair<>(AxolotlCapability.WRONG_CONFIGURATION, null);
 810		}
 811	}
 812
 813	public List<Jid> getCryptoTargets(Conversation conversation) {
 814		final List<Jid> jids;
 815		if (conversation.getMode() == Conversation.MODE_SINGLE) {
 816			jids = new ArrayList<>();
 817			jids.add(conversation.getJid().toBareJid());
 818		} else {
 819			jids = conversation.getMucOptions().getMembers();
 820		}
 821		return jids;
 822	}
 823
 824	public FingerprintStatus getFingerprintTrust(String fingerprint) {
 825		return axolotlStore.getFingerprintStatus(fingerprint);
 826	}
 827
 828	public X509Certificate getFingerprintCertificate(String fingerprint) {
 829		return axolotlStore.getFingerprintCertificate(fingerprint);
 830	}
 831
 832	public void setFingerprintTrust(String fingerprint, FingerprintStatus status) {
 833		axolotlStore.setFingerprintStatus(fingerprint, status);
 834	}
 835
 836	private void verifySessionWithPEP(final XmppAxolotlSession session) {
 837		Log.d(Config.LOGTAG, "trying to verify fresh session (" + session.getRemoteAddress().getName() + ") with pep");
 838		final SignalProtocolAddress address = session.getRemoteAddress();
 839		final IdentityKey identityKey = session.getIdentityKey();
 840		try {
 841			IqPacket packet = mXmppConnectionService.getIqGenerator().retrieveVerificationForDevice(Jid.fromString(address.getName()), address.getDeviceId());
 842			mXmppConnectionService.sendIqPacket(account, packet, new OnIqPacketReceived() {
 843				@Override
 844				public void onIqPacketReceived(Account account, IqPacket packet) {
 845					Pair<X509Certificate[],byte[]> verification = mXmppConnectionService.getIqParser().verification(packet);
 846					if (verification != null) {
 847						try {
 848							Signature verifier = Signature.getInstance("sha256WithRSA");
 849							verifier.initVerify(verification.first[0]);
 850							verifier.update(identityKey.serialize());
 851							if (verifier.verify(verification.second)) {
 852								try {
 853									mXmppConnectionService.getMemorizingTrustManager().getNonInteractive().checkClientTrusted(verification.first, "RSA");
 854									String fingerprint = session.getFingerprint();
 855									Log.d(Config.LOGTAG, "verified session with x.509 signature. fingerprint was: "+fingerprint);
 856									setFingerprintTrust(fingerprint, FingerprintStatus.createActiveVerified(true));
 857									axolotlStore.setFingerprintCertificate(fingerprint, verification.first[0]);
 858									fetchStatusMap.put(address, FetchStatus.SUCCESS_VERIFIED);
 859									Bundle information = CryptoHelper.extractCertificateInformation(verification.first[0]);
 860									try {
 861										final String cn = information.getString("subject_cn");
 862										final Jid jid = Jid.fromString(address.getName());
 863										Log.d(Config.LOGTAG,"setting common name for "+jid+" to "+cn);
 864										account.getRoster().getContact(jid).setCommonName(cn);
 865									} catch (final InvalidJidException ignored) {
 866										//ignored
 867									}
 868									finishBuildingSessionsFromPEP(address);
 869									return;
 870								} catch (Exception e) {
 871									Log.d(Config.LOGTAG,"could not verify certificate");
 872								}
 873							}
 874						} catch (Exception e) {
 875							Log.d(Config.LOGTAG, "error during verification " + e.getMessage());
 876						}
 877					} else {
 878						Log.d(Config.LOGTAG,"no verification found");
 879					}
 880					fetchStatusMap.put(address, FetchStatus.SUCCESS);
 881					finishBuildingSessionsFromPEP(address);
 882				}
 883			});
 884		} catch (InvalidJidException e) {
 885			fetchStatusMap.put(address, FetchStatus.SUCCESS);
 886			finishBuildingSessionsFromPEP(address);
 887		}
 888	}
 889
 890	private final Set<Integer> PREVIOUSLY_REMOVED_FROM_ANNOUNCEMENT = new HashSet<>();
 891
 892	private void finishBuildingSessionsFromPEP(final SignalProtocolAddress address) {
 893		SignalProtocolAddress ownAddress = new SignalProtocolAddress(account.getJid().toBareJid().toPreppedString(), 0);
 894		Map<Integer, FetchStatus> own = fetchStatusMap.getAll(ownAddress.getName());
 895		Map<Integer, FetchStatus> remote = fetchStatusMap.getAll(address.getName());
 896		if (!own.containsValue(FetchStatus.PENDING) && !remote.containsValue(FetchStatus.PENDING)) {
 897			FetchStatus report = null;
 898			if (own.containsValue(FetchStatus.SUCCESS) || remote.containsValue(FetchStatus.SUCCESS)) {
 899				report = FetchStatus.SUCCESS;
 900			} else if (own.containsValue(FetchStatus.SUCCESS_VERIFIED) || remote.containsValue(FetchStatus.SUCCESS_VERIFIED)) {
 901				report = FetchStatus.SUCCESS_VERIFIED;
 902			} else if (own.containsValue(FetchStatus.SUCCESS_TRUSTED) || remote.containsValue(FetchStatus.SUCCESS_TRUSTED)) {
 903				report = FetchStatus.SUCCESS_TRUSTED;
 904			} else if (own.containsValue(FetchStatus.ERROR) || remote.containsValue(FetchStatus.ERROR)) {
 905				report = FetchStatus.ERROR;
 906			}
 907			mXmppConnectionService.keyStatusUpdated(report);
 908		}
 909		if (Config.REMOVE_BROKEN_DEVICES) {
 910			Set<Integer> ownDeviceIds = new HashSet<>(getOwnDeviceIds());
 911			boolean publish = false;
 912			for (Map.Entry<Integer, FetchStatus> entry : own.entrySet()) {
 913				int id = entry.getKey();
 914				if (entry.getValue() == FetchStatus.ERROR && PREVIOUSLY_REMOVED_FROM_ANNOUNCEMENT.add(id) && ownDeviceIds.remove(id)) {
 915					publish = true;
 916					Log.d(Config.LOGTAG, account.getJid().toBareJid() + ": error fetching own device with id " + id + ". removing from announcement");
 917				}
 918			}
 919			if (publish) {
 920				publishOwnDeviceId(ownDeviceIds);
 921			}
 922		}
 923	}
 924
 925	public boolean hasEmptyDeviceList(Jid jid) {
 926		return !hasAny(jid) && (!deviceIds.containsKey(jid) || deviceIds.get(jid).isEmpty());
 927	}
 928
 929	public interface OnDeviceIdsFetched {
 930		void fetched(Jid jid, Set<Integer> deviceIds);
 931	}
 932
 933	public interface OnMultipleDeviceIdFetched {
 934		void fetched();
 935	}
 936
 937	public void fetchDeviceIds(final Jid jid) {
 938		fetchDeviceIds(jid,null);
 939	}
 940
 941	public void fetchDeviceIds(final Jid jid, OnDeviceIdsFetched callback) {
 942		synchronized (this.fetchDeviceIdsMap) {
 943			List<OnDeviceIdsFetched> callbacks = this.fetchDeviceIdsMap.get(jid);
 944			if (callbacks != null) {
 945				if (callback != null) {
 946					callbacks.add(callback);
 947				}
 948				Log.d(Config.LOGTAG,account.getJid().toBareJid()+": fetching device ids for "+jid+" already running. adding callback");
 949			} else {
 950				callbacks = new ArrayList<>();
 951				if (callback != null) {
 952					callbacks.add(callback);
 953				}
 954				this.fetchDeviceIdsMap.put(jid,callbacks);
 955				Log.d(Config.LOGTAG,account.getJid().toBareJid()+": fetching device ids for " + jid);
 956				IqPacket packet = mXmppConnectionService.getIqGenerator().retrieveDeviceIds(jid);
 957				mXmppConnectionService.sendIqPacket(account, packet, new OnIqPacketReceived() {
 958					@Override
 959					public void onIqPacketReceived(Account account, IqPacket packet) {
 960						synchronized (fetchDeviceIdsMap) {
 961							List<OnDeviceIdsFetched> callbacks = fetchDeviceIdsMap.remove(jid);
 962							if (packet.getType() == IqPacket.TYPE.RESULT) {
 963								Element item = mXmppConnectionService.getIqParser().getItem(packet);
 964								Set<Integer> deviceIds = mXmppConnectionService.getIqParser().deviceIds(item);
 965								registerDevices(jid, deviceIds);
 966								if (callbacks != null) {
 967									for(OnDeviceIdsFetched callback : callbacks) {
 968										callback.fetched(jid, deviceIds);
 969									}
 970								}
 971							} else {
 972								Log.d(Config.LOGTAG, packet.toString());
 973								if (callbacks != null) {
 974									for(OnDeviceIdsFetched callback : callbacks) {
 975										callback.fetched(jid, null);
 976									}
 977								}
 978							}
 979						}
 980					}
 981				});
 982			}
 983		}
 984	}
 985
 986	private void fetchDeviceIds(List<Jid> jids, final OnMultipleDeviceIdFetched callback) {
 987		final ArrayList<Jid> unfinishedJids = new ArrayList<>(jids);
 988		synchronized (unfinishedJids) {
 989			for (Jid jid : unfinishedJids) {
 990				fetchDeviceIds(jid, new OnDeviceIdsFetched() {
 991					@Override
 992					public void fetched(Jid jid, Set<Integer> deviceIds) {
 993						synchronized (unfinishedJids) {
 994							unfinishedJids.remove(jid);
 995							if (unfinishedJids.size() == 0 && callback != null) {
 996								callback.fetched();
 997							}
 998						}
 999					}
1000				});
1001			}
1002		}
1003	}
1004
1005	private void buildSessionFromPEP(final SignalProtocolAddress address) {
1006		Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Building new session for " + address.toString());
1007		if (address.equals(getOwnAxolotlAddress())) {
1008			throw new AssertionError("We should NEVER build a session with ourselves. What happened here?!");
1009		}
1010
1011		try {
1012			IqPacket bundlesPacket = mXmppConnectionService.getIqGenerator().retrieveBundlesForDevice(
1013					Jid.fromString(address.getName()), address.getDeviceId());
1014			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Retrieving bundle: " + bundlesPacket);
1015			mXmppConnectionService.sendIqPacket(account, bundlesPacket, new OnIqPacketReceived() {
1016
1017				@Override
1018				public void onIqPacketReceived(Account account, IqPacket packet) {
1019					if (packet.getType() == IqPacket.TYPE.TIMEOUT) {
1020						fetchStatusMap.put(address, FetchStatus.TIMEOUT);
1021					} else if (packet.getType() == IqPacket.TYPE.RESULT) {
1022						Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Received preKey IQ packet, processing...");
1023						final IqParser parser = mXmppConnectionService.getIqParser();
1024						final List<PreKeyBundle> preKeyBundleList = parser.preKeys(packet);
1025						final PreKeyBundle bundle = parser.bundle(packet);
1026						if (preKeyBundleList.isEmpty() || bundle == null) {
1027							Log.e(Config.LOGTAG, AxolotlService.getLogprefix(account) + "preKey IQ packet invalid: " + packet);
1028							fetchStatusMap.put(address, FetchStatus.ERROR);
1029							finishBuildingSessionsFromPEP(address);
1030							return;
1031						}
1032						Random random = new Random();
1033						final PreKeyBundle preKey = preKeyBundleList.get(random.nextInt(preKeyBundleList.size()));
1034						if (preKey == null) {
1035							//should never happen
1036							fetchStatusMap.put(address, FetchStatus.ERROR);
1037							finishBuildingSessionsFromPEP(address);
1038							return;
1039						}
1040
1041						final PreKeyBundle preKeyBundle = new PreKeyBundle(0, address.getDeviceId(),
1042								preKey.getPreKeyId(), preKey.getPreKey(),
1043								bundle.getSignedPreKeyId(), bundle.getSignedPreKey(),
1044								bundle.getSignedPreKeySignature(), bundle.getIdentityKey());
1045
1046						try {
1047							SessionBuilder builder = new SessionBuilder(axolotlStore, address);
1048							builder.process(preKeyBundle);
1049							XmppAxolotlSession session = new XmppAxolotlSession(account, axolotlStore, address, bundle.getIdentityKey());
1050							sessions.put(address, session);
1051							if (Config.X509_VERIFICATION) {
1052								verifySessionWithPEP(session);
1053							} else {
1054								FingerprintStatus status = getFingerprintTrust(CryptoHelper.bytesToHex(bundle.getIdentityKey().getPublicKey().serialize()));
1055								FetchStatus fetchStatus;
1056								if (status != null && status.isVerified()) {
1057									fetchStatus = FetchStatus.SUCCESS_VERIFIED;
1058								} else if (status != null && status.isTrusted()) {
1059									fetchStatus = FetchStatus.SUCCESS_TRUSTED;
1060								} else {
1061									fetchStatus = FetchStatus.SUCCESS;
1062								}
1063								fetchStatusMap.put(address, fetchStatus);
1064								finishBuildingSessionsFromPEP(address);
1065							}
1066						} catch (UntrustedIdentityException | InvalidKeyException e) {
1067							Log.e(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Error building session for " + address + ": "
1068									+ e.getClass().getName() + ", " + e.getMessage());
1069							fetchStatusMap.put(address, FetchStatus.ERROR);
1070							finishBuildingSessionsFromPEP(address);
1071						}
1072					} else {
1073						fetchStatusMap.put(address, FetchStatus.ERROR);
1074						Log.d(Config.LOGTAG, getLogprefix(account) + "Error received while building session:" + packet.findChild("error"));
1075						finishBuildingSessionsFromPEP(address);
1076					}
1077				}
1078			});
1079		} catch (InvalidJidException e) {
1080			Log.e(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Got address with invalid jid: " + address.getName());
1081		}
1082	}
1083
1084	public Set<SignalProtocolAddress> findDevicesWithoutSession(final Conversation conversation) {
1085		Set<SignalProtocolAddress> addresses = new HashSet<>();
1086		for(Jid jid : getCryptoTargets(conversation)) {
1087			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Finding devices without session for " + jid);
1088			if (deviceIds.get(jid) != null) {
1089				for (Integer foreignId : this.deviceIds.get(jid)) {
1090					SignalProtocolAddress address = new SignalProtocolAddress(jid.toPreppedString(), foreignId);
1091					if (sessions.get(address) == null) {
1092						IdentityKey identityKey = axolotlStore.loadSession(address).getSessionState().getRemoteIdentityKey();
1093						if (identityKey != null) {
1094							Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Already have session for " + address.toString() + ", adding to cache...");
1095							XmppAxolotlSession session = new XmppAxolotlSession(account, axolotlStore, address, identityKey);
1096							sessions.put(address, session);
1097						} else {
1098							Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Found device " + jid + ":" + foreignId);
1099							if (fetchStatusMap.get(address) != FetchStatus.ERROR) {
1100								addresses.add(address);
1101							} else {
1102								Log.d(Config.LOGTAG, getLogprefix(account) + "skipping over " + address + " because it's broken");
1103							}
1104						}
1105					}
1106				}
1107			} else {
1108				mXmppConnectionService.keyStatusUpdated(FetchStatus.ERROR);
1109				Log.w(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Have no target devices in PEP!");
1110			}
1111		}
1112		if (deviceIds.get(account.getJid().toBareJid()) != null) {
1113			for (Integer ownId : this.deviceIds.get(account.getJid().toBareJid())) {
1114				SignalProtocolAddress address = new SignalProtocolAddress(account.getJid().toBareJid().toPreppedString(), ownId);
1115				if (sessions.get(address) == null) {
1116					IdentityKey identityKey = axolotlStore.loadSession(address).getSessionState().getRemoteIdentityKey();
1117					if (identityKey != null) {
1118						Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Already have session for " + address.toString() + ", adding to cache...");
1119						XmppAxolotlSession session = new XmppAxolotlSession(account, axolotlStore, address, identityKey);
1120						sessions.put(address, session);
1121					} else {
1122						Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Found device " + account.getJid().toBareJid() + ":" + ownId);
1123						if (fetchStatusMap.get(address) != FetchStatus.ERROR) {
1124							addresses.add(address);
1125						} else {
1126							Log.d(Config.LOGTAG,getLogprefix(account)+"skipping over "+address+" because it's broken");
1127						}
1128					}
1129				}
1130			}
1131		}
1132
1133		return addresses;
1134	}
1135
1136	public boolean createSessionsIfNeeded(final Conversation conversation) {
1137		final List<Jid> jidsWithEmptyDeviceList = getCryptoTargets(conversation);
1138		for(Iterator<Jid> iterator = jidsWithEmptyDeviceList.iterator(); iterator.hasNext();) {
1139			final Jid jid = iterator.next();
1140			if (!hasEmptyDeviceList(jid)) {
1141				iterator.remove();
1142			}
1143		}
1144		Log.d(Config.LOGTAG,account.getJid().toBareJid()+": createSessionsIfNeeded() - jids with empty device list: "+jidsWithEmptyDeviceList);
1145		if (jidsWithEmptyDeviceList.size() > 0) {
1146			fetchDeviceIds(jidsWithEmptyDeviceList, new OnMultipleDeviceIdFetched() {
1147				@Override
1148				public void fetched() {
1149					createSessionsIfNeededActual(conversation);
1150				}
1151			});
1152			return true;
1153		} else {
1154			return createSessionsIfNeededActual(conversation);
1155		}
1156	}
1157
1158	private boolean createSessionsIfNeededActual(final Conversation conversation) {
1159		Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Creating axolotl sessions if needed...");
1160		boolean newSessions = false;
1161		Set<SignalProtocolAddress> addresses = findDevicesWithoutSession(conversation);
1162		for (SignalProtocolAddress address : addresses) {
1163			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Processing device: " + address.toString());
1164			FetchStatus status = fetchStatusMap.get(address);
1165			if (status == null || status == FetchStatus.TIMEOUT) {
1166				fetchStatusMap.put(address, FetchStatus.PENDING);
1167				this.buildSessionFromPEP(address);
1168				newSessions = true;
1169			} else if (status == FetchStatus.PENDING) {
1170				newSessions = true;
1171			} else {
1172				Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Already fetching bundle for " + address.toString());
1173			}
1174		}
1175
1176		return newSessions;
1177	}
1178
1179	public boolean trustedSessionVerified(final Conversation conversation) {
1180		Set<XmppAxolotlSession> sessions = findSessionsForConversation(conversation);
1181		sessions.addAll(findOwnSessions());
1182		boolean verified = false;
1183		for(XmppAxolotlSession session : sessions) {
1184			if (session.getTrust().isTrustedAndActive()) {
1185				if (session.getTrust().getTrust() == FingerprintStatus.Trust.VERIFIED_X509) {
1186					verified = true;
1187				} else {
1188					return false;
1189				}
1190			}
1191		}
1192		return verified;
1193	}
1194
1195	public boolean hasPendingKeyFetches(Account account, List<Jid> jids) {
1196		SignalProtocolAddress ownAddress = new SignalProtocolAddress(account.getJid().toBareJid().toPreppedString(), 0);
1197		if (fetchStatusMap.getAll(ownAddress.getName()).containsValue(FetchStatus.PENDING)) {
1198			return true;
1199		}
1200		synchronized (this.fetchDeviceIdsMap) {
1201			for (Jid jid : jids) {
1202				SignalProtocolAddress foreignAddress = new SignalProtocolAddress(jid.toBareJid().toPreppedString(), 0);
1203				if (fetchStatusMap.getAll(foreignAddress.getName()).containsValue(FetchStatus.PENDING) || this.fetchDeviceIdsMap.containsKey(jid)) {
1204					return true;
1205				}
1206			}
1207		}
1208		return false;
1209	}
1210
1211	@Nullable
1212	private boolean buildHeader(XmppAxolotlMessage axolotlMessage, Conversation conversation) {
1213		Set<XmppAxolotlSession> remoteSessions = findSessionsForConversation(conversation);
1214		Collection<XmppAxolotlSession> ownSessions = findOwnSessions();
1215		if (remoteSessions.isEmpty()) {
1216			return false;
1217		}
1218		for (XmppAxolotlSession session : remoteSessions) {
1219			axolotlMessage.addDevice(session);
1220		}
1221		for (XmppAxolotlSession session : ownSessions) {
1222			axolotlMessage.addDevice(session);
1223		}
1224
1225		return true;
1226	}
1227
1228	@Nullable
1229	public XmppAxolotlMessage encrypt(Message message) {
1230		final XmppAxolotlMessage axolotlMessage = new XmppAxolotlMessage(account.getJid().toBareJid(), getOwnDeviceId());
1231		final String content;
1232		if (message.hasFileOnRemoteHost()) {
1233			content = message.getFileParams().url.toString();
1234		} else {
1235			content = message.getBody();
1236		}
1237		try {
1238			axolotlMessage.encrypt(content);
1239		} catch (CryptoFailedException e) {
1240			Log.w(Config.LOGTAG, getLogprefix(account) + "Failed to encrypt message: " + e.getMessage());
1241			return null;
1242		}
1243		if (!buildHeader(axolotlMessage,message.getConversation())) {
1244			return null;
1245		}
1246
1247		return axolotlMessage;
1248	}
1249
1250	public void preparePayloadMessage(final Message message, final boolean delay) {
1251		executor.execute(new Runnable() {
1252			@Override
1253			public void run() {
1254				XmppAxolotlMessage axolotlMessage = encrypt(message);
1255				if (axolotlMessage == null) {
1256					mXmppConnectionService.markMessage(message, Message.STATUS_SEND_FAILED);
1257					//mXmppConnectionService.updateConversationUi();
1258				} else {
1259					Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Generated message, caching: " + message.getUuid());
1260					messageCache.put(message.getUuid(), axolotlMessage);
1261					mXmppConnectionService.resendMessage(message, delay);
1262				}
1263			}
1264		});
1265	}
1266
1267	public void prepareKeyTransportMessage(final Conversation conversation, final OnMessageCreatedCallback onMessageCreatedCallback) {
1268		executor.execute(new Runnable() {
1269			@Override
1270			public void run() {
1271				final XmppAxolotlMessage axolotlMessage = new XmppAxolotlMessage(account.getJid().toBareJid(), getOwnDeviceId());
1272				if (buildHeader(axolotlMessage,conversation)) {
1273					onMessageCreatedCallback.run(axolotlMessage);
1274				} else {
1275					onMessageCreatedCallback.run(null);
1276				}
1277			}
1278		});
1279	}
1280
1281	public XmppAxolotlMessage fetchAxolotlMessageFromCache(Message message) {
1282		XmppAxolotlMessage axolotlMessage = messageCache.get(message.getUuid());
1283		if (axolotlMessage != null) {
1284			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Cache hit: " + message.getUuid());
1285			messageCache.remove(message.getUuid());
1286		} else {
1287			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Cache miss: " + message.getUuid());
1288		}
1289		return axolotlMessage;
1290	}
1291
1292	private XmppAxolotlSession recreateUncachedSession(SignalProtocolAddress address) {
1293		IdentityKey identityKey = axolotlStore.loadSession(address).getSessionState().getRemoteIdentityKey();
1294		return (identityKey != null)
1295				? new XmppAxolotlSession(account, axolotlStore, address, identityKey)
1296				: null;
1297	}
1298
1299	private XmppAxolotlSession getReceivingSession(XmppAxolotlMessage message) {
1300		SignalProtocolAddress senderAddress = new SignalProtocolAddress(message.getFrom().toPreppedString(),
1301				message.getSenderDeviceId());
1302		XmppAxolotlSession session = sessions.get(senderAddress);
1303		if (session == null) {
1304			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Account: " + account.getJid() + " No axolotl session found while parsing received message " + message);
1305			session = recreateUncachedSession(senderAddress);
1306			if (session == null) {
1307				session = new XmppAxolotlSession(account, axolotlStore, senderAddress);
1308			}
1309		}
1310		return session;
1311	}
1312
1313	public XmppAxolotlMessage.XmppAxolotlPlaintextMessage processReceivingPayloadMessage(XmppAxolotlMessage message) {
1314		XmppAxolotlMessage.XmppAxolotlPlaintextMessage plaintextMessage = null;
1315
1316		XmppAxolotlSession session = getReceivingSession(message);
1317		try {
1318			plaintextMessage = message.decrypt(session, getOwnDeviceId());
1319			Integer preKeyId = session.getPreKeyId();
1320			if (preKeyId != null) {
1321				publishBundlesIfNeeded(false, false);
1322				session.resetPreKeyId();
1323			}
1324		} catch (CryptoFailedException e) {
1325			Log.w(Config.LOGTAG, getLogprefix(account) + "Failed to decrypt message from "+message.getFrom()+": " + e.getMessage());
1326		}
1327
1328		if (session.isFresh() && plaintextMessage != null) {
1329			putFreshSession(session);
1330		}
1331
1332		return plaintextMessage;
1333	}
1334
1335	public XmppAxolotlMessage.XmppAxolotlKeyTransportMessage processReceivingKeyTransportMessage(XmppAxolotlMessage message) {
1336		XmppAxolotlMessage.XmppAxolotlKeyTransportMessage keyTransportMessage;
1337
1338		XmppAxolotlSession session = getReceivingSession(message);
1339		try {
1340			keyTransportMessage = message.getParameters(session, getOwnDeviceId());
1341		} catch (CryptoFailedException e) {
1342			Log.d(Config.LOGTAG,"could not decrypt keyTransport message "+e.getMessage());
1343			keyTransportMessage = null;
1344		}
1345
1346		if (session.isFresh() && keyTransportMessage != null) {
1347			putFreshSession(session);
1348		}
1349
1350		return keyTransportMessage;
1351	}
1352
1353	private void putFreshSession(XmppAxolotlSession session) {
1354		Log.d(Config.LOGTAG,"put fresh session");
1355		sessions.put(session);
1356		if (Config.X509_VERIFICATION) {
1357			if (session.getIdentityKey() != null) {
1358				verifySessionWithPEP(session);
1359			} else {
1360				Log.e(Config.LOGTAG,account.getJid().toBareJid()+": identity key was empty after reloading for x509 verification");
1361			}
1362		}
1363	}
1364}