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.Arrays;
  29import java.util.HashMap;
  30import java.util.HashSet;
  31import java.util.List;
  32import java.util.Map;
  33import java.util.Random;
  34import java.util.Set;
  35
  36import eu.siacs.conversations.Config;
  37import eu.siacs.conversations.entities.Account;
  38import eu.siacs.conversations.entities.Contact;
  39import eu.siacs.conversations.entities.Conversation;
  40import eu.siacs.conversations.entities.Message;
  41import eu.siacs.conversations.parser.IqParser;
  42import eu.siacs.conversations.services.XmppConnectionService;
  43import eu.siacs.conversations.utils.CryptoHelper;
  44import eu.siacs.conversations.utils.SerialSingleThreadExecutor;
  45import eu.siacs.conversations.xml.Element;
  46import eu.siacs.conversations.xmpp.OnAdvancedStreamFeaturesLoaded;
  47import eu.siacs.conversations.xmpp.OnIqPacketReceived;
  48import eu.siacs.conversations.xmpp.jid.InvalidJidException;
  49import eu.siacs.conversations.xmpp.jid.Jid;
  50import eu.siacs.conversations.xmpp.stanzas.IqPacket;
  51
  52public class AxolotlService implements OnAdvancedStreamFeaturesLoaded {
  53
  54	public static final String PEP_PREFIX = "eu.siacs.conversations.axolotl";
  55	public static final String PEP_DEVICE_LIST = PEP_PREFIX + ".devicelist";
  56	public static final String PEP_DEVICE_LIST_NOTIFY = PEP_DEVICE_LIST + "+notify";
  57	public static final String PEP_BUNDLES = PEP_PREFIX + ".bundles";
  58	public static final String PEP_VERIFICATION = PEP_PREFIX + ".verification";
  59
  60	public static final String LOGPREFIX = "AxolotlService";
  61
  62	public static final int NUM_KEYS_TO_PUBLISH = 100;
  63	public static final int publishTriesThreshold = 3;
  64
  65	private final Account account;
  66	private final XmppConnectionService mXmppConnectionService;
  67	private final SQLiteAxolotlStore axolotlStore;
  68	private final SessionMap sessions;
  69	private final Map<Jid, Set<Integer>> deviceIds;
  70	private final Map<String, XmppAxolotlMessage> messageCache;
  71	private final FetchStatusMap fetchStatusMap;
  72	private final SerialSingleThreadExecutor executor;
  73	private int numPublishTriesOnEmptyPep = 0;
  74	private boolean pepBroken = false;
  75
  76	@Override
  77	public void onAdvancedStreamFeaturesAvailable(Account account) {
  78		if (Config.supportOmemo()
  79				&& account.getXmppConnection() != null
  80				&& account.getXmppConnection().getFeatures().pep()) {
  81			publishBundlesIfNeeded(true, false);
  82		} else {
  83			Log.d(Config.LOGTAG,account.getJid().toBareJid()+": skipping OMEMO initialization");
  84		}
  85	}
  86
  87	public boolean fetchMapHasErrors(List<Jid> jids) {
  88		for(Jid jid : jids) {
  89			if (deviceIds.get(jid) != null) {
  90				for (Integer foreignId : this.deviceIds.get(jid)) {
  91					AxolotlAddress address = new AxolotlAddress(jid.toString(), foreignId);
  92					if (fetchStatusMap.getAll(address).containsValue(FetchStatus.ERROR)) {
  93						return true;
  94					}
  95				}
  96			}
  97		}
  98		return false;
  99	}
 100
 101	public void preVerifyFingerprint(Contact contact, String fingerprint) {
 102		axolotlStore.preVerifyFingerprint(contact.getAccount(), contact.getJid().toBareJid().toPreppedString(), fingerprint);
 103	}
 104
 105	public void preVerifyFingerprint(Account account, String fingerprint) {
 106		axolotlStore.preVerifyFingerprint(account, account.getJid().toBareJid().toPreppedString(), fingerprint);
 107	}
 108
 109	private static class AxolotlAddressMap<T> {
 110		protected Map<String, Map<Integer, T>> map;
 111		protected final Object MAP_LOCK = new Object();
 112
 113		public AxolotlAddressMap() {
 114			this.map = new HashMap<>();
 115		}
 116
 117		public void put(AxolotlAddress address, T value) {
 118			synchronized (MAP_LOCK) {
 119				Map<Integer, T> devices = map.get(address.getName());
 120				if (devices == null) {
 121					devices = new HashMap<>();
 122					map.put(address.getName(), devices);
 123				}
 124				devices.put(address.getDeviceId(), value);
 125			}
 126		}
 127
 128		public T get(AxolotlAddress address) {
 129			synchronized (MAP_LOCK) {
 130				Map<Integer, T> devices = map.get(address.getName());
 131				if (devices == null) {
 132					return null;
 133				}
 134				return devices.get(address.getDeviceId());
 135			}
 136		}
 137
 138		public Map<Integer, T> getAll(AxolotlAddress address) {
 139			synchronized (MAP_LOCK) {
 140				Map<Integer, T> devices = map.get(address.getName());
 141				if (devices == null) {
 142					return new HashMap<>();
 143				}
 144				return devices;
 145			}
 146		}
 147
 148		public boolean hasAny(AxolotlAddress address) {
 149			synchronized (MAP_LOCK) {
 150				Map<Integer, T> devices = map.get(address.getName());
 151				return devices != null && !devices.isEmpty();
 152			}
 153		}
 154
 155		public void clear() {
 156			map.clear();
 157		}
 158
 159	}
 160
 161	private static class SessionMap extends AxolotlAddressMap<XmppAxolotlSession> {
 162		private final XmppConnectionService xmppConnectionService;
 163		private final Account account;
 164
 165		public SessionMap(XmppConnectionService service, SQLiteAxolotlStore store, Account account) {
 166			super();
 167			this.xmppConnectionService = service;
 168			this.account = account;
 169			this.fillMap(store);
 170		}
 171
 172		private void putDevicesForJid(String bareJid, List<Integer> deviceIds, SQLiteAxolotlStore store) {
 173			for (Integer deviceId : deviceIds) {
 174				AxolotlAddress axolotlAddress = new AxolotlAddress(bareJid, deviceId);
 175				IdentityKey identityKey = store.loadSession(axolotlAddress).getSessionState().getRemoteIdentityKey();
 176				if(Config.X509_VERIFICATION) {
 177					X509Certificate certificate = store.getFingerprintCertificate(identityKey.getFingerprint().replaceAll("\\s", ""));
 178					if (certificate != null) {
 179						Bundle information = CryptoHelper.extractCertificateInformation(certificate);
 180						try {
 181							final String cn = information.getString("subject_cn");
 182							final Jid jid = Jid.fromString(bareJid);
 183							Log.d(Config.LOGTAG,"setting common name for "+jid+" to "+cn);
 184							account.getRoster().getContact(jid).setCommonName(cn);
 185						} catch (final InvalidJidException ignored) {
 186							//ignored
 187						}
 188					}
 189				}
 190				this.put(axolotlAddress, new XmppAxolotlSession(account, store, axolotlAddress, identityKey));
 191			}
 192		}
 193
 194		private void fillMap(SQLiteAxolotlStore store) {
 195			List<Integer> deviceIds = store.getSubDeviceSessions(account.getJid().toBareJid().toPreppedString());
 196			putDevicesForJid(account.getJid().toBareJid().toPreppedString(), deviceIds, store);
 197			for (Contact contact : account.getRoster().getContacts()) {
 198				Jid bareJid = contact.getJid().toBareJid();
 199				String address = bareJid.toString();
 200				deviceIds = store.getSubDeviceSessions(address);
 201				putDevicesForJid(address, deviceIds, store);
 202			}
 203
 204		}
 205
 206		@Override
 207		public void put(AxolotlAddress address, XmppAxolotlSession value) {
 208			super.put(address, value);
 209			value.setNotFresh();
 210			xmppConnectionService.syncRosterToDisk(account); //TODO why?
 211		}
 212
 213		public void put(XmppAxolotlSession session) {
 214			this.put(session.getRemoteAddress(), session);
 215		}
 216	}
 217
 218	public enum FetchStatus {
 219		PENDING,
 220		SUCCESS,
 221		SUCCESS_VERIFIED,
 222		TIMEOUT,
 223		ERROR
 224	}
 225
 226	private static class FetchStatusMap extends AxolotlAddressMap<FetchStatus> {
 227
 228		public void clearErrorFor(Jid jid) {
 229			synchronized (MAP_LOCK) {
 230				Map<Integer, FetchStatus> devices = this.map.get(jid.toBareJid().toPreppedString());
 231				if (devices == null) {
 232					return;
 233				}
 234				for(Map.Entry<Integer, FetchStatus> entry : devices.entrySet()) {
 235					if (entry.getValue() == FetchStatus.ERROR) {
 236						Log.d(Config.LOGTAG,"resetting error for "+jid.toBareJid()+"("+entry.getKey()+")");
 237						entry.setValue(FetchStatus.TIMEOUT);
 238					}
 239				}
 240			}
 241		}
 242	}
 243
 244	public static String getLogprefix(Account account) {
 245		return LOGPREFIX + " (" + account.getJid().toBareJid().toString() + "): ";
 246	}
 247
 248	public AxolotlService(Account account, XmppConnectionService connectionService) {
 249		if (Security.getProvider("BC") == null) {
 250			Security.addProvider(new BouncyCastleProvider());
 251		}
 252		this.mXmppConnectionService = connectionService;
 253		this.account = account;
 254		this.axolotlStore = new SQLiteAxolotlStore(this.account, this.mXmppConnectionService);
 255		this.deviceIds = new HashMap<>();
 256		this.messageCache = new HashMap<>();
 257		this.sessions = new SessionMap(mXmppConnectionService, axolotlStore, account);
 258		this.fetchStatusMap = new FetchStatusMap();
 259		this.executor = new SerialSingleThreadExecutor();
 260	}
 261
 262	public String getOwnFingerprint() {
 263		return axolotlStore.getIdentityKeyPair().getPublicKey().getFingerprint().replaceAll("\\s", "");
 264	}
 265
 266	public Set<IdentityKey> getKeysWithTrust(FingerprintStatus status) {
 267		return axolotlStore.getContactKeysWithTrust(account.getJid().toBareJid().toPreppedString(), status);
 268	}
 269
 270	public Set<IdentityKey> getKeysWithTrust(FingerprintStatus status, Jid jid) {
 271		return axolotlStore.getContactKeysWithTrust(jid.toBareJid().toPreppedString(), status);
 272	}
 273
 274	public Set<IdentityKey> getKeysWithTrust(FingerprintStatus status, List<Jid> jids) {
 275		Set<IdentityKey> keys = new HashSet<>();
 276		for(Jid jid : jids) {
 277			keys.addAll(axolotlStore.getContactKeysWithTrust(jid.toPreppedString(), status));
 278		}
 279		return keys;
 280	}
 281
 282	public long getNumTrustedKeys(Jid jid) {
 283		return axolotlStore.getContactNumTrustedKeys(jid.toBareJid().toPreppedString());
 284	}
 285
 286	public boolean anyTargetHasNoTrustedKeys(List<Jid> jids) {
 287		for(Jid jid : jids) {
 288			if (axolotlStore.getContactNumTrustedKeys(jid.toBareJid().toPreppedString()) == 0) {
 289				return true;
 290			}
 291		}
 292		return false;
 293	}
 294
 295	private AxolotlAddress getAddressForJid(Jid jid) {
 296		return new AxolotlAddress(jid.toPreppedString(), 0);
 297	}
 298
 299	public Set<XmppAxolotlSession> findOwnSessions() {
 300		AxolotlAddress ownAddress = getAddressForJid(account.getJid().toBareJid());
 301		return new HashSet<>(this.sessions.getAll(ownAddress).values());
 302	}
 303
 304
 305
 306	private Set<XmppAxolotlSession> findSessionsForContact(Contact contact) {
 307		AxolotlAddress contactAddress = getAddressForJid(contact.getJid());
 308		return new HashSet<>(this.sessions.getAll(contactAddress).values());
 309	}
 310
 311	private Set<XmppAxolotlSession> findSessionsForConversation(Conversation conversation) {
 312		HashSet<XmppAxolotlSession> sessions = new HashSet<>();
 313		for(Jid jid : conversation.getAcceptedCryptoTargets()) {
 314			sessions.addAll(this.sessions.getAll(getAddressForJid(jid)).values());
 315		}
 316		return sessions;
 317	}
 318
 319	public Set<String> getFingerprintsForOwnSessions() {
 320		Set<String> fingerprints = new HashSet<>();
 321		for (XmppAxolotlSession session : findOwnSessions()) {
 322			fingerprints.add(session.getFingerprint());
 323		}
 324		return fingerprints;
 325	}
 326
 327	public Set<String> getFingerprintsForContact(final Contact contact) {
 328		Set<String> fingerprints = new HashSet<>();
 329		for (XmppAxolotlSession session : findSessionsForContact(contact)) {
 330			fingerprints.add(session.getFingerprint());
 331		}
 332		return fingerprints;
 333	}
 334
 335	private boolean hasAny(Jid jid) {
 336		return sessions.hasAny(getAddressForJid(jid));
 337	}
 338
 339	public boolean isPepBroken() {
 340		return this.pepBroken;
 341	}
 342
 343	public void resetBrokenness() {
 344		this.pepBroken = false;
 345		numPublishTriesOnEmptyPep = 0;
 346	}
 347
 348	public void clearErrorsInFetchStatusMap(Jid jid) {
 349		fetchStatusMap.clearErrorFor(jid);
 350	}
 351
 352	public void regenerateKeys(boolean wipeOther) {
 353		axolotlStore.regenerate();
 354		sessions.clear();
 355		fetchStatusMap.clear();
 356		publishBundlesIfNeeded(true, wipeOther);
 357	}
 358
 359	public int getOwnDeviceId() {
 360		return axolotlStore.getLocalRegistrationId();
 361	}
 362
 363	public Set<Integer> getOwnDeviceIds() {
 364		return this.deviceIds.get(account.getJid().toBareJid());
 365	}
 366
 367	public void registerDevices(final Jid jid, @NonNull final Set<Integer> deviceIds) {
 368		if (jid.toBareJid().equals(account.getJid().toBareJid())) {
 369			if (!deviceIds.isEmpty()) {
 370				Log.d(Config.LOGTAG, getLogprefix(account) + "Received non-empty own device list. Resetting publish attempts and pepBroken status.");
 371				pepBroken = false;
 372				numPublishTriesOnEmptyPep = 0;
 373			}
 374			if (deviceIds.contains(getOwnDeviceId())) {
 375				deviceIds.remove(getOwnDeviceId());
 376			} else {
 377				publishOwnDeviceId(deviceIds);
 378			}
 379			for (Integer deviceId : deviceIds) {
 380				AxolotlAddress ownDeviceAddress = new AxolotlAddress(jid.toBareJid().toPreppedString(), deviceId);
 381				if (sessions.get(ownDeviceAddress) == null) {
 382					buildSessionFromPEP(ownDeviceAddress);
 383				}
 384			}
 385		}
 386		Set<Integer> expiredDevices = new HashSet<>(axolotlStore.getSubDeviceSessions(jid.toBareJid().toPreppedString()));
 387		expiredDevices.removeAll(deviceIds);
 388		for (Integer deviceId : expiredDevices) {
 389			AxolotlAddress address = new AxolotlAddress(jid.toBareJid().toPreppedString(), deviceId);
 390			XmppAxolotlSession session = sessions.get(address);
 391			if (session != null && session.getFingerprint() != null) {
 392				if (session.getTrust().isActive()) {
 393					session.setTrust(session.getTrust().toInactive());
 394				}
 395			}
 396		}
 397		Set<Integer> newDevices = new HashSet<>(deviceIds);
 398		for (Integer deviceId : newDevices) {
 399			AxolotlAddress address = new AxolotlAddress(jid.toBareJid().toPreppedString(), deviceId);
 400			XmppAxolotlSession session = sessions.get(address);
 401			if (session != null && session.getFingerprint() != null) {
 402				if (!session.getTrust().isActive()) {
 403					session.setTrust(session.getTrust().toActive());
 404				}
 405			}
 406		}
 407		this.deviceIds.put(jid, deviceIds);
 408		mXmppConnectionService.keyStatusUpdated(null);
 409	}
 410
 411	public void wipeOtherPepDevices() {
 412		if (pepBroken) {
 413			Log.d(Config.LOGTAG, getLogprefix(account) + "wipeOtherPepDevices called, but PEP is broken. Ignoring... ");
 414			return;
 415		}
 416		Set<Integer> deviceIds = new HashSet<>();
 417		deviceIds.add(getOwnDeviceId());
 418		IqPacket publish = mXmppConnectionService.getIqGenerator().publishDeviceIds(deviceIds);
 419		Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Wiping all other devices from Pep:" + publish);
 420		mXmppConnectionService.sendIqPacket(account, publish, new OnIqPacketReceived() {
 421			@Override
 422			public void onIqPacketReceived(Account account, IqPacket packet) {
 423				// TODO: implement this!
 424			}
 425		});
 426	}
 427
 428	public void purgeKey(final String fingerprint) {
 429		axolotlStore.setFingerprintStatus(fingerprint.replaceAll("\\s", ""), FingerprintStatus.createCompromised());
 430	}
 431
 432	public void publishOwnDeviceIdIfNeeded() {
 433		if (pepBroken) {
 434			Log.d(Config.LOGTAG, getLogprefix(account) + "publishOwnDeviceIdIfNeeded called, but PEP is broken. Ignoring... ");
 435			return;
 436		}
 437		IqPacket packet = mXmppConnectionService.getIqGenerator().retrieveDeviceIds(account.getJid().toBareJid());
 438		mXmppConnectionService.sendIqPacket(account, packet, new OnIqPacketReceived() {
 439			@Override
 440			public void onIqPacketReceived(Account account, IqPacket packet) {
 441				if (packet.getType() == IqPacket.TYPE.TIMEOUT) {
 442					Log.d(Config.LOGTAG, getLogprefix(account) + "Timeout received while retrieving own Device Ids.");
 443				} else {
 444					Element item = mXmppConnectionService.getIqParser().getItem(packet);
 445					Set<Integer> deviceIds = mXmppConnectionService.getIqParser().deviceIds(item);
 446					if (!deviceIds.contains(getOwnDeviceId())) {
 447						publishOwnDeviceId(deviceIds);
 448					}
 449				}
 450			}
 451		});
 452	}
 453
 454	public void publishOwnDeviceId(Set<Integer> deviceIds) {
 455		Set<Integer> deviceIdsCopy = new HashSet<>(deviceIds);
 456		if (!deviceIdsCopy.contains(getOwnDeviceId())) {
 457			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Own device " + getOwnDeviceId() + " not in PEP devicelist.");
 458			if (deviceIdsCopy.isEmpty()) {
 459				if (numPublishTriesOnEmptyPep >= publishTriesThreshold) {
 460					Log.w(Config.LOGTAG, getLogprefix(account) + "Own device publish attempt threshold exceeded, aborting...");
 461					pepBroken = true;
 462					return;
 463				} else {
 464					numPublishTriesOnEmptyPep++;
 465					Log.w(Config.LOGTAG, getLogprefix(account) + "Own device list empty, attempting to publish (try " + numPublishTriesOnEmptyPep + ")");
 466				}
 467			} else {
 468				numPublishTriesOnEmptyPep = 0;
 469			}
 470			deviceIdsCopy.add(getOwnDeviceId());
 471			IqPacket publish = mXmppConnectionService.getIqGenerator().publishDeviceIds(deviceIdsCopy);
 472			mXmppConnectionService.sendIqPacket(account, publish, new OnIqPacketReceived() {
 473				@Override
 474				public void onIqPacketReceived(Account account, IqPacket packet) {
 475					if (packet.getType() == IqPacket.TYPE.ERROR) {
 476						pepBroken = true;
 477						Log.d(Config.LOGTAG, getLogprefix(account) + "Error received while publishing own device id" + packet.findChild("error"));
 478					}
 479				}
 480			});
 481		}
 482	}
 483
 484	public void publishDeviceVerificationAndBundle(final SignedPreKeyRecord signedPreKeyRecord,
 485												   final Set<PreKeyRecord> preKeyRecords,
 486												   final boolean announceAfter,
 487												   final boolean wipe) {
 488		try {
 489			IdentityKey axolotlPublicKey = axolotlStore.getIdentityKeyPair().getPublicKey();
 490			PrivateKey x509PrivateKey = KeyChain.getPrivateKey(mXmppConnectionService, account.getPrivateKeyAlias());
 491			X509Certificate[] chain = KeyChain.getCertificateChain(mXmppConnectionService, account.getPrivateKeyAlias());
 492			Signature verifier = Signature.getInstance("sha256WithRSA");
 493			verifier.initSign(x509PrivateKey,mXmppConnectionService.getRNG());
 494			verifier.update(axolotlPublicKey.serialize());
 495			byte[] signature = verifier.sign();
 496			IqPacket packet = mXmppConnectionService.getIqGenerator().publishVerification(signature, chain, getOwnDeviceId());
 497			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + ": publish verification for device "+getOwnDeviceId());
 498			mXmppConnectionService.sendIqPacket(account, packet, new OnIqPacketReceived() {
 499				@Override
 500				public void onIqPacketReceived(Account account, IqPacket packet) {
 501					publishDeviceBundle(signedPreKeyRecord, preKeyRecords, announceAfter, wipe);
 502				}
 503			});
 504		} catch (Exception  e) {
 505			e.printStackTrace();
 506		}
 507	}
 508
 509	public void publishBundlesIfNeeded(final boolean announce, final boolean wipe) {
 510		if (pepBroken) {
 511			Log.d(Config.LOGTAG, getLogprefix(account) + "publishBundlesIfNeeded called, but PEP is broken. Ignoring... ");
 512			return;
 513		}
 514		IqPacket packet = mXmppConnectionService.getIqGenerator().retrieveBundlesForDevice(account.getJid().toBareJid(), getOwnDeviceId());
 515		mXmppConnectionService.sendIqPacket(account, packet, new OnIqPacketReceived() {
 516			@Override
 517			public void onIqPacketReceived(Account account, IqPacket packet) {
 518
 519				if (packet.getType() == IqPacket.TYPE.TIMEOUT) {
 520					return; //ignore timeout. do nothing
 521				}
 522
 523				if (packet.getType() == IqPacket.TYPE.ERROR) {
 524					Element error = packet.findChild("error");
 525					if (error == null || !error.hasChild("item-not-found")) {
 526						pepBroken = true;
 527						Log.w(Config.LOGTAG, AxolotlService.getLogprefix(account) + "request for device bundles came back with something other than item-not-found" + packet);
 528						return;
 529					}
 530				}
 531
 532				PreKeyBundle bundle = mXmppConnectionService.getIqParser().bundle(packet);
 533				Map<Integer, ECPublicKey> keys = mXmppConnectionService.getIqParser().preKeyPublics(packet);
 534				boolean flush = false;
 535				if (bundle == null) {
 536					Log.w(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Received invalid bundle:" + packet);
 537					bundle = new PreKeyBundle(-1, -1, -1, null, -1, null, null, null);
 538					flush = true;
 539				}
 540				if (keys == null) {
 541					Log.w(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Received invalid prekeys:" + packet);
 542				}
 543				try {
 544					boolean changed = false;
 545					// Validate IdentityKey
 546					IdentityKeyPair identityKeyPair = axolotlStore.getIdentityKeyPair();
 547					if (flush || !identityKeyPair.getPublicKey().equals(bundle.getIdentityKey())) {
 548						Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Adding own IdentityKey " + identityKeyPair.getPublicKey() + " to PEP.");
 549						changed = true;
 550					}
 551
 552					// Validate signedPreKeyRecord + ID
 553					SignedPreKeyRecord signedPreKeyRecord;
 554					int numSignedPreKeys = axolotlStore.loadSignedPreKeys().size();
 555					try {
 556						signedPreKeyRecord = axolotlStore.loadSignedPreKey(bundle.getSignedPreKeyId());
 557						if (flush
 558								|| !bundle.getSignedPreKey().equals(signedPreKeyRecord.getKeyPair().getPublicKey())
 559								|| !Arrays.equals(bundle.getSignedPreKeySignature(), signedPreKeyRecord.getSignature())) {
 560							Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Adding new signedPreKey with ID " + (numSignedPreKeys + 1) + " to PEP.");
 561							signedPreKeyRecord = KeyHelper.generateSignedPreKey(identityKeyPair, numSignedPreKeys + 1);
 562							axolotlStore.storeSignedPreKey(signedPreKeyRecord.getId(), signedPreKeyRecord);
 563							changed = true;
 564						}
 565					} catch (InvalidKeyIdException e) {
 566						Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Adding new signedPreKey with ID " + (numSignedPreKeys + 1) + " to PEP.");
 567						signedPreKeyRecord = KeyHelper.generateSignedPreKey(identityKeyPair, numSignedPreKeys + 1);
 568						axolotlStore.storeSignedPreKey(signedPreKeyRecord.getId(), signedPreKeyRecord);
 569						changed = true;
 570					}
 571
 572					// Validate PreKeys
 573					Set<PreKeyRecord> preKeyRecords = new HashSet<>();
 574					if (keys != null) {
 575						for (Integer id : keys.keySet()) {
 576							try {
 577								PreKeyRecord preKeyRecord = axolotlStore.loadPreKey(id);
 578								if (preKeyRecord.getKeyPair().getPublicKey().equals(keys.get(id))) {
 579									preKeyRecords.add(preKeyRecord);
 580								}
 581							} catch (InvalidKeyIdException ignored) {
 582							}
 583						}
 584					}
 585					int newKeys = NUM_KEYS_TO_PUBLISH - preKeyRecords.size();
 586					if (newKeys > 0) {
 587						List<PreKeyRecord> newRecords = KeyHelper.generatePreKeys(
 588								axolotlStore.getCurrentPreKeyId() + 1, newKeys);
 589						preKeyRecords.addAll(newRecords);
 590						for (PreKeyRecord record : newRecords) {
 591							axolotlStore.storePreKey(record.getId(), record);
 592						}
 593						changed = true;
 594						Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Adding " + newKeys + " new preKeys to PEP.");
 595					}
 596
 597
 598					if (changed) {
 599						if (account.getPrivateKeyAlias() != null && Config.X509_VERIFICATION) {
 600							mXmppConnectionService.publishDisplayName(account);
 601							publishDeviceVerificationAndBundle(signedPreKeyRecord, preKeyRecords, announce, wipe);
 602						} else {
 603							publishDeviceBundle(signedPreKeyRecord, preKeyRecords, announce, wipe);
 604						}
 605					} else {
 606						Log.d(Config.LOGTAG, getLogprefix(account) + "Bundle " + getOwnDeviceId() + " in PEP was current");
 607						if (wipe) {
 608							wipeOtherPepDevices();
 609						} else if (announce) {
 610							Log.d(Config.LOGTAG, getLogprefix(account) + "Announcing device " + getOwnDeviceId());
 611							publishOwnDeviceIdIfNeeded();
 612						}
 613					}
 614				} catch (InvalidKeyException e) {
 615					Log.e(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Failed to publish bundle " + getOwnDeviceId() + ", reason: " + e.getMessage());
 616				}
 617			}
 618		});
 619	}
 620
 621	private void publishDeviceBundle(SignedPreKeyRecord signedPreKeyRecord,
 622									 Set<PreKeyRecord> preKeyRecords,
 623									 final boolean announceAfter,
 624									 final boolean wipe) {
 625		IqPacket publish = mXmppConnectionService.getIqGenerator().publishBundles(
 626				signedPreKeyRecord, axolotlStore.getIdentityKeyPair().getPublicKey(),
 627				preKeyRecords, getOwnDeviceId());
 628		Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + ": Bundle " + getOwnDeviceId() + " in PEP not current. Publishing: " + publish);
 629		mXmppConnectionService.sendIqPacket(account, publish, new OnIqPacketReceived() {
 630			@Override
 631			public void onIqPacketReceived(Account account, IqPacket packet) {
 632				if (packet.getType() == IqPacket.TYPE.RESULT) {
 633					Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Successfully published bundle. ");
 634					if (wipe) {
 635						wipeOtherPepDevices();
 636					} else if (announceAfter) {
 637						Log.d(Config.LOGTAG, getLogprefix(account) + "Announcing device " + getOwnDeviceId());
 638						publishOwnDeviceIdIfNeeded();
 639					}
 640				} else if (packet.getType() == IqPacket.TYPE.ERROR) {
 641					pepBroken = true;
 642					Log.d(Config.LOGTAG, getLogprefix(account) + "Error received while publishing bundle: " + packet.findChild("error"));
 643				}
 644			}
 645		});
 646	}
 647
 648	public enum AxolotlCapability {
 649		FULL,
 650		MISSING_PRESENCE,
 651		MISSING_KEYS,
 652		WRONG_CONFIGURATION,
 653		NO_MEMBERS
 654	}
 655
 656	public boolean isConversationAxolotlCapable(Conversation conversation) {
 657		return isConversationAxolotlCapableDetailed(conversation).first == AxolotlCapability.FULL;
 658	}
 659
 660	public Pair<AxolotlCapability,Jid> isConversationAxolotlCapableDetailed(Conversation conversation) {
 661		if (conversation.getMode() == Conversation.MODE_SINGLE
 662				|| (conversation.getMucOptions().membersOnly() && conversation.getMucOptions().nonanonymous())) {
 663			final List<Jid> jids = getCryptoTargets(conversation);
 664			for(Jid jid : jids) {
 665				if (!hasAny(jid) && (!deviceIds.containsKey(jid) || deviceIds.get(jid).isEmpty())) {
 666					if (conversation.getAccount().getRoster().getContact(jid).mutualPresenceSubscription()) {
 667						return new Pair<>(AxolotlCapability.MISSING_KEYS,jid);
 668					} else {
 669						return new Pair<>(AxolotlCapability.MISSING_PRESENCE,jid);
 670					}
 671				}
 672			}
 673			if (jids.size() > 0) {
 674				return new Pair<>(AxolotlCapability.FULL, null);
 675			} else {
 676				return new Pair<>(AxolotlCapability.NO_MEMBERS, null);
 677			}
 678		} else {
 679			return new Pair<>(AxolotlCapability.WRONG_CONFIGURATION, null);
 680		}
 681	}
 682
 683	public List<Jid> getCryptoTargets(Conversation conversation) {
 684		final List<Jid> jids;
 685		if (conversation.getMode() == Conversation.MODE_SINGLE) {
 686			jids = Arrays.asList(conversation.getJid().toBareJid());
 687		} else {
 688			jids = conversation.getMucOptions().getMembers();
 689		}
 690		return jids;
 691	}
 692
 693	public FingerprintStatus getFingerprintTrust(String fingerprint) {
 694		return axolotlStore.getFingerprintStatus(fingerprint);
 695	}
 696
 697	public X509Certificate getFingerprintCertificate(String fingerprint) {
 698		return axolotlStore.getFingerprintCertificate(fingerprint);
 699	}
 700
 701	public void setFingerprintTrust(String fingerprint, FingerprintStatus status) {
 702		axolotlStore.setFingerprintStatus(fingerprint, status);
 703	}
 704
 705	private void verifySessionWithPEP(final XmppAxolotlSession session) {
 706		Log.d(Config.LOGTAG, "trying to verify fresh session (" + session.getRemoteAddress().getName() + ") with pep");
 707		final AxolotlAddress address = session.getRemoteAddress();
 708		final IdentityKey identityKey = session.getIdentityKey();
 709		try {
 710			IqPacket packet = mXmppConnectionService.getIqGenerator().retrieveVerificationForDevice(Jid.fromString(address.getName()), address.getDeviceId());
 711			mXmppConnectionService.sendIqPacket(account, packet, new OnIqPacketReceived() {
 712				@Override
 713				public void onIqPacketReceived(Account account, IqPacket packet) {
 714					Pair<X509Certificate[],byte[]> verification = mXmppConnectionService.getIqParser().verification(packet);
 715					if (verification != null) {
 716						try {
 717							Signature verifier = Signature.getInstance("sha256WithRSA");
 718							verifier.initVerify(verification.first[0]);
 719							verifier.update(identityKey.serialize());
 720							if (verifier.verify(verification.second)) {
 721								try {
 722									mXmppConnectionService.getMemorizingTrustManager().getNonInteractive().checkClientTrusted(verification.first, "RSA");
 723									String fingerprint = session.getFingerprint();
 724									Log.d(Config.LOGTAG, "verified session with x.509 signature. fingerprint was: "+fingerprint);
 725									setFingerprintTrust(fingerprint, FingerprintStatus.createActiveVerified(true));
 726									axolotlStore.setFingerprintCertificate(fingerprint, verification.first[0]);
 727									fetchStatusMap.put(address, FetchStatus.SUCCESS_VERIFIED);
 728									Bundle information = CryptoHelper.extractCertificateInformation(verification.first[0]);
 729									try {
 730										final String cn = information.getString("subject_cn");
 731										final Jid jid = Jid.fromString(address.getName());
 732										Log.d(Config.LOGTAG,"setting common name for "+jid+" to "+cn);
 733										account.getRoster().getContact(jid).setCommonName(cn);
 734									} catch (final InvalidJidException ignored) {
 735										//ignored
 736									}
 737									finishBuildingSessionsFromPEP(address);
 738									return;
 739								} catch (Exception e) {
 740									Log.d(Config.LOGTAG,"could not verify certificate");
 741								}
 742							}
 743						} catch (Exception e) {
 744							Log.d(Config.LOGTAG, "error during verification " + e.getMessage());
 745						}
 746					} else {
 747						Log.d(Config.LOGTAG,"no verification found");
 748					}
 749					fetchStatusMap.put(address, FetchStatus.SUCCESS);
 750					finishBuildingSessionsFromPEP(address);
 751				}
 752			});
 753		} catch (InvalidJidException e) {
 754			fetchStatusMap.put(address, FetchStatus.SUCCESS);
 755			finishBuildingSessionsFromPEP(address);
 756		}
 757	}
 758
 759	private void finishBuildingSessionsFromPEP(final AxolotlAddress address) {
 760		AxolotlAddress ownAddress = new AxolotlAddress(account.getJid().toBareJid().toPreppedString(), 0);
 761		Map<Integer, FetchStatus> own = fetchStatusMap.getAll(ownAddress);
 762		Map<Integer, FetchStatus> remote = fetchStatusMap.getAll(address);
 763		if (!own.containsValue(FetchStatus.PENDING) && !remote.containsValue(FetchStatus.PENDING)) {
 764			FetchStatus report = null;
 765			if (own.containsValue(FetchStatus.SUCCESS) || remote.containsValue(FetchStatus.SUCCESS)) {
 766				report = FetchStatus.SUCCESS;
 767			} else if (own.containsValue(FetchStatus.SUCCESS_VERIFIED) || remote.containsValue(FetchStatus.SUCCESS_VERIFIED)) {
 768				report = FetchStatus.SUCCESS_VERIFIED;
 769			} else if (own.containsValue(FetchStatus.ERROR) || remote.containsValue(FetchStatus.ERROR)) {
 770				report = FetchStatus.ERROR;
 771			}
 772			mXmppConnectionService.keyStatusUpdated(report);
 773		}
 774	}
 775
 776	private void buildSessionFromPEP(final AxolotlAddress address) {
 777		Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Building new sesstion for " + address.toString());
 778		if (address.getDeviceId() == getOwnDeviceId()) {
 779			throw new AssertionError("We should NEVER build a session with ourselves. What happened here?!");
 780		}
 781
 782		try {
 783			IqPacket bundlesPacket = mXmppConnectionService.getIqGenerator().retrieveBundlesForDevice(
 784					Jid.fromString(address.getName()), address.getDeviceId());
 785			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Retrieving bundle: " + bundlesPacket);
 786			mXmppConnectionService.sendIqPacket(account, bundlesPacket, new OnIqPacketReceived() {
 787
 788				@Override
 789				public void onIqPacketReceived(Account account, IqPacket packet) {
 790					if (packet.getType() == IqPacket.TYPE.TIMEOUT) {
 791						fetchStatusMap.put(address, FetchStatus.TIMEOUT);
 792					} else if (packet.getType() == IqPacket.TYPE.RESULT) {
 793						Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Received preKey IQ packet, processing...");
 794						final IqParser parser = mXmppConnectionService.getIqParser();
 795						final List<PreKeyBundle> preKeyBundleList = parser.preKeys(packet);
 796						final PreKeyBundle bundle = parser.bundle(packet);
 797						if (preKeyBundleList.isEmpty() || bundle == null) {
 798							Log.e(Config.LOGTAG, AxolotlService.getLogprefix(account) + "preKey IQ packet invalid: " + packet);
 799							fetchStatusMap.put(address, FetchStatus.ERROR);
 800							finishBuildingSessionsFromPEP(address);
 801							return;
 802						}
 803						Random random = new Random();
 804						final PreKeyBundle preKey = preKeyBundleList.get(random.nextInt(preKeyBundleList.size()));
 805						if (preKey == null) {
 806							//should never happen
 807							fetchStatusMap.put(address, FetchStatus.ERROR);
 808							finishBuildingSessionsFromPEP(address);
 809							return;
 810						}
 811
 812						final PreKeyBundle preKeyBundle = new PreKeyBundle(0, address.getDeviceId(),
 813								preKey.getPreKeyId(), preKey.getPreKey(),
 814								bundle.getSignedPreKeyId(), bundle.getSignedPreKey(),
 815								bundle.getSignedPreKeySignature(), bundle.getIdentityKey());
 816
 817						try {
 818							SessionBuilder builder = new SessionBuilder(axolotlStore, address);
 819							builder.process(preKeyBundle);
 820							XmppAxolotlSession session = new XmppAxolotlSession(account, axolotlStore, address, bundle.getIdentityKey());
 821							sessions.put(address, session);
 822							if (Config.X509_VERIFICATION) {
 823								verifySessionWithPEP(session);
 824							} else {
 825								FingerprintStatus status = getFingerprintTrust(bundle.getIdentityKey().getFingerprint().replaceAll("\\s",""));
 826								boolean verified = status != null && status.isVerified();
 827								fetchStatusMap.put(address, verified ? FetchStatus.SUCCESS_VERIFIED : FetchStatus.SUCCESS);
 828								finishBuildingSessionsFromPEP(address);
 829							}
 830						} catch (UntrustedIdentityException | InvalidKeyException e) {
 831							Log.e(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Error building session for " + address + ": "
 832									+ e.getClass().getName() + ", " + e.getMessage());
 833							fetchStatusMap.put(address, FetchStatus.ERROR);
 834							finishBuildingSessionsFromPEP(address);
 835						}
 836					} else {
 837						fetchStatusMap.put(address, FetchStatus.ERROR);
 838						Log.d(Config.LOGTAG, getLogprefix(account) + "Error received while building session:" + packet.findChild("error"));
 839						finishBuildingSessionsFromPEP(address);
 840					}
 841				}
 842			});
 843		} catch (InvalidJidException e) {
 844			Log.e(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Got address with invalid jid: " + address.getName());
 845		}
 846	}
 847
 848	public Set<AxolotlAddress> findDevicesWithoutSession(final Conversation conversation) {
 849		Set<AxolotlAddress> addresses = new HashSet<>();
 850		for(Jid jid : getCryptoTargets(conversation)) {
 851			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Finding devices without session for " + jid);
 852			if (deviceIds.get(jid) != null) {
 853				for (Integer foreignId : this.deviceIds.get(jid)) {
 854					AxolotlAddress address = new AxolotlAddress(jid.toString(), foreignId);
 855					if (sessions.get(address) == null) {
 856						IdentityKey identityKey = axolotlStore.loadSession(address).getSessionState().getRemoteIdentityKey();
 857						if (identityKey != null) {
 858							Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Already have session for " + address.toString() + ", adding to cache...");
 859							XmppAxolotlSession session = new XmppAxolotlSession(account, axolotlStore, address, identityKey);
 860							sessions.put(address, session);
 861						} else {
 862							Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Found device " + jid + ":" + foreignId);
 863							if (fetchStatusMap.get(address) != FetchStatus.ERROR) {
 864								addresses.add(address);
 865							} else {
 866								Log.d(Config.LOGTAG, getLogprefix(account) + "skipping over " + address + " because it's broken");
 867							}
 868						}
 869					}
 870				}
 871			} else {
 872				Log.w(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Have no target devices in PEP!");
 873			}
 874		}
 875		if (deviceIds.get(account.getJid().toBareJid()) != null) {
 876			for (Integer ownId : this.deviceIds.get(account.getJid().toBareJid())) {
 877				AxolotlAddress address = new AxolotlAddress(account.getJid().toBareJid().toPreppedString(), ownId);
 878				if (sessions.get(address) == null) {
 879					IdentityKey identityKey = axolotlStore.loadSession(address).getSessionState().getRemoteIdentityKey();
 880					if (identityKey != null) {
 881						Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Already have session for " + address.toString() + ", adding to cache...");
 882						XmppAxolotlSession session = new XmppAxolotlSession(account, axolotlStore, address, identityKey);
 883						sessions.put(address, session);
 884					} else {
 885						Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Found device " + account.getJid().toBareJid() + ":" + ownId);
 886						if (fetchStatusMap.get(address) != FetchStatus.ERROR) {
 887							addresses.add(address);
 888						} else {
 889							Log.d(Config.LOGTAG,getLogprefix(account)+"skipping over "+address+" because it's broken");
 890						}
 891					}
 892				}
 893			}
 894		}
 895
 896		return addresses;
 897	}
 898
 899	public boolean createSessionsIfNeeded(final Conversation conversation) {
 900		Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Creating axolotl sessions if needed...");
 901		boolean newSessions = false;
 902		Set<AxolotlAddress> addresses = findDevicesWithoutSession(conversation);
 903		for (AxolotlAddress address : addresses) {
 904			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Processing device: " + address.toString());
 905			FetchStatus status = fetchStatusMap.get(address);
 906			if (status == null || status == FetchStatus.TIMEOUT) {
 907				fetchStatusMap.put(address, FetchStatus.PENDING);
 908				this.buildSessionFromPEP(address);
 909				newSessions = true;
 910			} else if (status == FetchStatus.PENDING) {
 911				newSessions = true;
 912			} else {
 913				Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Already fetching bundle for " + address.toString());
 914			}
 915		}
 916
 917		return newSessions;
 918	}
 919
 920	public boolean trustedSessionVerified(final Conversation conversation) {
 921		Set<XmppAxolotlSession> sessions = findSessionsForConversation(conversation);
 922		sessions.addAll(findOwnSessions());
 923		boolean verified = false;
 924		for(XmppAxolotlSession session : sessions) {
 925			if (session.getTrust().isTrustedAndActive()) {
 926				if (session.getTrust().getTrust() == FingerprintStatus.Trust.VERIFIED_X509) {
 927					verified = true;
 928				} else {
 929					return false;
 930				}
 931			}
 932		}
 933		return verified;
 934	}
 935
 936	public boolean hasPendingKeyFetches(Account account, List<Jid> jids) {
 937		AxolotlAddress ownAddress = new AxolotlAddress(account.getJid().toBareJid().toPreppedString(), 0);
 938		if (fetchStatusMap.getAll(ownAddress).containsValue(FetchStatus.PENDING)) {
 939			return true;
 940		}
 941		for(Jid jid : jids) {
 942			AxolotlAddress foreignAddress = new AxolotlAddress(jid.toBareJid().toPreppedString(), 0);
 943			if (fetchStatusMap.getAll(foreignAddress).containsValue(FetchStatus.PENDING)) {
 944				return true;
 945			}
 946		}
 947		return false;
 948	}
 949
 950	@Nullable
 951	private XmppAxolotlMessage buildHeader(Conversation conversation) {
 952		final XmppAxolotlMessage axolotlMessage = new XmppAxolotlMessage(
 953				account.getJid().toBareJid(), getOwnDeviceId());
 954
 955		Set<XmppAxolotlSession> remoteSessions = findSessionsForConversation(conversation);
 956		Set<XmppAxolotlSession> ownSessions = findOwnSessions();
 957		if (remoteSessions.isEmpty()) {
 958			return null;
 959		}
 960		for (XmppAxolotlSession session : remoteSessions) {
 961			axolotlMessage.addDevice(session);
 962		}
 963		for (XmppAxolotlSession session : ownSessions) {
 964			axolotlMessage.addDevice(session);
 965		}
 966
 967		return axolotlMessage;
 968	}
 969
 970	@Nullable
 971	public XmppAxolotlMessage encrypt(Message message) {
 972		XmppAxolotlMessage axolotlMessage = buildHeader(message.getConversation());
 973
 974		if (axolotlMessage != null) {
 975			final String content;
 976			if (message.hasFileOnRemoteHost()) {
 977				content = message.getFileParams().url.toString();
 978			} else {
 979				content = message.getBody();
 980			}
 981			try {
 982				axolotlMessage.encrypt(content);
 983			} catch (CryptoFailedException e) {
 984				Log.w(Config.LOGTAG, getLogprefix(account) + "Failed to encrypt message: " + e.getMessage());
 985				return null;
 986			}
 987		}
 988
 989		return axolotlMessage;
 990	}
 991
 992	public void preparePayloadMessage(final Message message, final boolean delay) {
 993		executor.execute(new Runnable() {
 994			@Override
 995			public void run() {
 996				XmppAxolotlMessage axolotlMessage = encrypt(message);
 997				if (axolotlMessage == null) {
 998					mXmppConnectionService.markMessage(message, Message.STATUS_SEND_FAILED);
 999					//mXmppConnectionService.updateConversationUi();
1000				} else {
1001					Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Generated message, caching: " + message.getUuid());
1002					messageCache.put(message.getUuid(), axolotlMessage);
1003					mXmppConnectionService.resendMessage(message, delay);
1004				}
1005			}
1006		});
1007	}
1008
1009	public void prepareKeyTransportMessage(final Conversation conversation, final OnMessageCreatedCallback onMessageCreatedCallback) {
1010		executor.execute(new Runnable() {
1011			@Override
1012			public void run() {
1013				XmppAxolotlMessage axolotlMessage = buildHeader(conversation);
1014				onMessageCreatedCallback.run(axolotlMessage);
1015			}
1016		});
1017	}
1018
1019	public XmppAxolotlMessage fetchAxolotlMessageFromCache(Message message) {
1020		XmppAxolotlMessage axolotlMessage = messageCache.get(message.getUuid());
1021		if (axolotlMessage != null) {
1022			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Cache hit: " + message.getUuid());
1023			messageCache.remove(message.getUuid());
1024		} else {
1025			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Cache miss: " + message.getUuid());
1026		}
1027		return axolotlMessage;
1028	}
1029
1030	private XmppAxolotlSession recreateUncachedSession(AxolotlAddress address) {
1031		IdentityKey identityKey = axolotlStore.loadSession(address).getSessionState().getRemoteIdentityKey();
1032		return (identityKey != null)
1033				? new XmppAxolotlSession(account, axolotlStore, address, identityKey)
1034				: null;
1035	}
1036
1037	private XmppAxolotlSession getReceivingSession(XmppAxolotlMessage message) {
1038		AxolotlAddress senderAddress = new AxolotlAddress(message.getFrom().toString(),
1039				message.getSenderDeviceId());
1040		XmppAxolotlSession session = sessions.get(senderAddress);
1041		if (session == null) {
1042			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Account: " + account.getJid() + " No axolotl session found while parsing received message " + message);
1043			session = recreateUncachedSession(senderAddress);
1044			if (session == null) {
1045				session = new XmppAxolotlSession(account, axolotlStore, senderAddress);
1046			}
1047		}
1048		return session;
1049	}
1050
1051	public XmppAxolotlMessage.XmppAxolotlPlaintextMessage processReceivingPayloadMessage(XmppAxolotlMessage message) {
1052		XmppAxolotlMessage.XmppAxolotlPlaintextMessage plaintextMessage = null;
1053
1054		XmppAxolotlSession session = getReceivingSession(message);
1055		try {
1056			plaintextMessage = message.decrypt(session, getOwnDeviceId());
1057			Integer preKeyId = session.getPreKeyId();
1058			if (preKeyId != null) {
1059				publishBundlesIfNeeded(false, false);
1060				session.resetPreKeyId();
1061			}
1062		} catch (CryptoFailedException e) {
1063			Log.w(Config.LOGTAG, getLogprefix(account) + "Failed to decrypt message: " + e.getMessage());
1064		}
1065
1066		if (session.isFresh() && plaintextMessage != null) {
1067			putFreshSession(session);
1068		}
1069
1070		return plaintextMessage;
1071	}
1072
1073	public XmppAxolotlMessage.XmppAxolotlKeyTransportMessage processReceivingKeyTransportMessage(XmppAxolotlMessage message) {
1074		XmppAxolotlMessage.XmppAxolotlKeyTransportMessage keyTransportMessage;
1075
1076		XmppAxolotlSession session = getReceivingSession(message);
1077		keyTransportMessage = message.getParameters(session, getOwnDeviceId());
1078
1079		if (session.isFresh() && keyTransportMessage != null) {
1080			putFreshSession(session);
1081		}
1082
1083		return keyTransportMessage;
1084	}
1085
1086	private void putFreshSession(XmppAxolotlSession session) {
1087		Log.d(Config.LOGTAG,"put fresh session");
1088		sessions.put(session);
1089		if (Config.X509_VERIFICATION) {
1090			if (session.getIdentityKey() != null) {
1091				verifySessionWithPEP(session);
1092			} else {
1093				Log.e(Config.LOGTAG,account.getJid().toBareJid()+": identity key was empty after reloading for x509 verification");
1094			}
1095		}
1096	}
1097}