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