AxolotlService.java

  1package eu.siacs.conversations.crypto.axolotl;
  2
  3import android.support.annotation.NonNull;
  4import android.support.annotation.Nullable;
  5import android.util.Log;
  6
  7import org.bouncycastle.jce.provider.BouncyCastleProvider;
  8import org.whispersystems.libaxolotl.AxolotlAddress;
  9import org.whispersystems.libaxolotl.IdentityKey;
 10import org.whispersystems.libaxolotl.IdentityKeyPair;
 11import org.whispersystems.libaxolotl.InvalidKeyException;
 12import org.whispersystems.libaxolotl.InvalidKeyIdException;
 13import org.whispersystems.libaxolotl.SessionBuilder;
 14import org.whispersystems.libaxolotl.UntrustedIdentityException;
 15import org.whispersystems.libaxolotl.ecc.ECPublicKey;
 16import org.whispersystems.libaxolotl.state.PreKeyBundle;
 17import org.whispersystems.libaxolotl.state.PreKeyRecord;
 18import org.whispersystems.libaxolotl.state.SignedPreKeyRecord;
 19import org.whispersystems.libaxolotl.util.KeyHelper;
 20
 21import java.security.Security;
 22import java.util.Arrays;
 23import java.util.HashMap;
 24import java.util.HashSet;
 25import java.util.List;
 26import java.util.Map;
 27import java.util.Random;
 28import java.util.Set;
 29
 30import eu.siacs.conversations.Config;
 31import eu.siacs.conversations.entities.Account;
 32import eu.siacs.conversations.entities.Contact;
 33import eu.siacs.conversations.entities.Conversation;
 34import eu.siacs.conversations.entities.Message;
 35import eu.siacs.conversations.parser.IqParser;
 36import eu.siacs.conversations.services.XmppConnectionService;
 37import eu.siacs.conversations.utils.SerialSingleThreadExecutor;
 38import eu.siacs.conversations.xml.Element;
 39import eu.siacs.conversations.xmpp.OnIqPacketReceived;
 40import eu.siacs.conversations.xmpp.jid.InvalidJidException;
 41import eu.siacs.conversations.xmpp.jid.Jid;
 42import eu.siacs.conversations.xmpp.stanzas.IqPacket;
 43
 44public class AxolotlService {
 45
 46	public static final String PEP_PREFIX = "eu.siacs.conversations.axolotl";
 47	public static final String PEP_DEVICE_LIST = PEP_PREFIX + ".devicelist";
 48	public static final String PEP_BUNDLES = PEP_PREFIX + ".bundles";
 49
 50	public static final String LOGPREFIX = "AxolotlService";
 51
 52	public static final int NUM_KEYS_TO_PUBLISH = 100;
 53	public static final int publishTriesThreshold = 3;
 54
 55	private final Account account;
 56	private final XmppConnectionService mXmppConnectionService;
 57	private final SQLiteAxolotlStore axolotlStore;
 58	private final SessionMap sessions;
 59	private final Map<Jid, Set<Integer>> deviceIds;
 60	private final Map<String, XmppAxolotlMessage> messageCache;
 61	private final FetchStatusMap fetchStatusMap;
 62	private final SerialSingleThreadExecutor executor;
 63	private int numPublishTriesOnEmptyPep = 0;
 64	private boolean pepBroken = false;
 65
 66	private static class AxolotlAddressMap<T> {
 67		protected Map<String, Map<Integer, T>> map;
 68		protected final Object MAP_LOCK = new Object();
 69
 70		public AxolotlAddressMap() {
 71			this.map = new HashMap<>();
 72		}
 73
 74		public void put(AxolotlAddress address, T value) {
 75			synchronized (MAP_LOCK) {
 76				Map<Integer, T> devices = map.get(address.getName());
 77				if (devices == null) {
 78					devices = new HashMap<>();
 79					map.put(address.getName(), devices);
 80				}
 81				devices.put(address.getDeviceId(), value);
 82			}
 83		}
 84
 85		public T get(AxolotlAddress address) {
 86			synchronized (MAP_LOCK) {
 87				Map<Integer, T> devices = map.get(address.getName());
 88				if (devices == null) {
 89					return null;
 90				}
 91				return devices.get(address.getDeviceId());
 92			}
 93		}
 94
 95		public Map<Integer, T> getAll(AxolotlAddress address) {
 96			synchronized (MAP_LOCK) {
 97				Map<Integer, T> devices = map.get(address.getName());
 98				if (devices == null) {
 99					return new HashMap<>();
100				}
101				return devices;
102			}
103		}
104
105		public boolean hasAny(AxolotlAddress address) {
106			synchronized (MAP_LOCK) {
107				Map<Integer, T> devices = map.get(address.getName());
108				return devices != null && !devices.isEmpty();
109			}
110		}
111
112		public void clear() {
113			map.clear();
114		}
115
116	}
117
118	private static class SessionMap extends AxolotlAddressMap<XmppAxolotlSession> {
119		private final XmppConnectionService xmppConnectionService;
120		private final Account account;
121
122		public SessionMap(XmppConnectionService service, SQLiteAxolotlStore store, Account account) {
123			super();
124			this.xmppConnectionService = service;
125			this.account = account;
126			this.fillMap(store);
127		}
128
129		private void putDevicesForJid(String bareJid, List<Integer> deviceIds, SQLiteAxolotlStore store) {
130			for (Integer deviceId : deviceIds) {
131				AxolotlAddress axolotlAddress = new AxolotlAddress(bareJid, deviceId);
132				Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Building session for remote address: " + axolotlAddress.toString());
133				String fingerprint = store.loadSession(axolotlAddress).getSessionState().getRemoteIdentityKey().getFingerprint().replaceAll("\\s", "");
134				this.put(axolotlAddress, new XmppAxolotlSession(account, store, axolotlAddress, fingerprint));
135			}
136		}
137
138		private void fillMap(SQLiteAxolotlStore store) {
139			List<Integer> deviceIds = store.getSubDeviceSessions(account.getJid().toBareJid().toString());
140			putDevicesForJid(account.getJid().toBareJid().toString(), deviceIds, store);
141			for (Contact contact : account.getRoster().getContacts()) {
142				Jid bareJid = contact.getJid().toBareJid();
143				if (bareJid == null) {
144					continue; // FIXME: handle this?
145				}
146				String address = bareJid.toString();
147				deviceIds = store.getSubDeviceSessions(address);
148				putDevicesForJid(address, deviceIds, store);
149			}
150
151		}
152
153		@Override
154		public void put(AxolotlAddress address, XmppAxolotlSession value) {
155			super.put(address, value);
156			value.setNotFresh();
157			xmppConnectionService.syncRosterToDisk(account);
158		}
159
160		public void put(XmppAxolotlSession session) {
161			this.put(session.getRemoteAddress(), session);
162		}
163	}
164
165	private static enum FetchStatus {
166		PENDING,
167		SUCCESS,
168		ERROR
169	}
170
171	private static class FetchStatusMap extends AxolotlAddressMap<FetchStatus> {
172
173	}
174
175	public static String getLogprefix(Account account) {
176		return LOGPREFIX + " (" + account.getJid().toBareJid().toString() + "): ";
177	}
178
179	public AxolotlService(Account account, XmppConnectionService connectionService) {
180		if (Security.getProvider("BC") == null) {
181			Security.addProvider(new BouncyCastleProvider());
182		}
183		this.mXmppConnectionService = connectionService;
184		this.account = account;
185		this.axolotlStore = new SQLiteAxolotlStore(this.account, this.mXmppConnectionService);
186		this.deviceIds = new HashMap<>();
187		this.messageCache = new HashMap<>();
188		this.sessions = new SessionMap(mXmppConnectionService, axolotlStore, account);
189		this.fetchStatusMap = new FetchStatusMap();
190		this.executor = new SerialSingleThreadExecutor();
191	}
192
193	public String getOwnFingerprint() {
194		return axolotlStore.getIdentityKeyPair().getPublicKey().getFingerprint().replaceAll("\\s", "");
195	}
196
197	public Set<IdentityKey> getKeysWithTrust(XmppAxolotlSession.Trust trust) {
198		return axolotlStore.getContactKeysWithTrust(account.getJid().toBareJid().toString(), trust);
199	}
200
201	public Set<IdentityKey> getKeysWithTrust(XmppAxolotlSession.Trust trust, Contact contact) {
202		return axolotlStore.getContactKeysWithTrust(contact.getJid().toBareJid().toString(), trust);
203	}
204
205	public long getNumTrustedKeys(Contact contact) {
206		return axolotlStore.getContactNumTrustedKeys(contact.getJid().toBareJid().toString());
207	}
208
209	private AxolotlAddress getAddressForJid(Jid jid) {
210		return new AxolotlAddress(jid.toString(), 0);
211	}
212
213	private Set<XmppAxolotlSession> findOwnSessions() {
214		AxolotlAddress ownAddress = getAddressForJid(account.getJid().toBareJid());
215		Set<XmppAxolotlSession> ownDeviceSessions = new HashSet<>(this.sessions.getAll(ownAddress).values());
216		return ownDeviceSessions;
217	}
218
219	private Set<XmppAxolotlSession> findSessionsforContact(Contact contact) {
220		AxolotlAddress contactAddress = getAddressForJid(contact.getJid());
221		Set<XmppAxolotlSession> sessions = new HashSet<>(this.sessions.getAll(contactAddress).values());
222		return sessions;
223	}
224
225	public Set<String> getFingerprintsForOwnSessions() {
226		Set<String> fingerprints = new HashSet<>();
227		for (XmppAxolotlSession session : findOwnSessions()) {
228			fingerprints.add(session.getFingerprint());
229		}
230		return fingerprints;
231	}
232
233	public Set<String> getFingerprintsForContact(final Contact contact) {
234		Set<String> fingerprints = new HashSet<>();
235		for (XmppAxolotlSession session : findSessionsforContact(contact)) {
236			fingerprints.add(session.getFingerprint());
237		}
238		return fingerprints;
239	}
240
241	private boolean hasAny(Contact contact) {
242		AxolotlAddress contactAddress = getAddressForJid(contact.getJid());
243		return sessions.hasAny(contactAddress);
244	}
245
246	public boolean isPepBroken() {
247		return this.pepBroken;
248	}
249
250	public void regenerateKeys() {
251		axolotlStore.regenerate();
252		sessions.clear();
253		fetchStatusMap.clear();
254		publishBundlesIfNeeded(true);
255	}
256
257	public int getOwnDeviceId() {
258		return axolotlStore.getLocalRegistrationId();
259	}
260
261	public Set<Integer> getOwnDeviceIds() {
262		return this.deviceIds.get(account.getJid().toBareJid());
263	}
264
265	private void setTrustOnSessions(final Jid jid, @NonNull final Set<Integer> deviceIds,
266	                                final XmppAxolotlSession.Trust from,
267	                                final XmppAxolotlSession.Trust to) {
268		for (Integer deviceId : deviceIds) {
269			AxolotlAddress address = new AxolotlAddress(jid.toBareJid().toString(), deviceId);
270			XmppAxolotlSession session = sessions.get(address);
271			if (session != null && session.getFingerprint() != null
272					&& session.getTrust() == from) {
273				session.setTrust(to);
274			}
275		}
276	}
277
278	public void registerDevices(final Jid jid, @NonNull final Set<Integer> deviceIds) {
279		if (jid.toBareJid().equals(account.getJid().toBareJid())) {
280			if (!deviceIds.isEmpty()) {
281				Log.d(Config.LOGTAG, getLogprefix(account) + "Received non-empty own device list. Resetting publish attemps and pepBroken status.");
282				pepBroken = false;
283				numPublishTriesOnEmptyPep = 0;
284			}
285			if (deviceIds.contains(getOwnDeviceId())) {
286				deviceIds.remove(getOwnDeviceId());
287			} else {
288				publishOwnDeviceId(deviceIds);
289			}
290			for (Integer deviceId : deviceIds) {
291				AxolotlAddress ownDeviceAddress = new AxolotlAddress(jid.toBareJid().toString(), deviceId);
292				if (sessions.get(ownDeviceAddress) == null) {
293					buildSessionFromPEP(ownDeviceAddress);
294				}
295			}
296		}
297		Set<Integer> expiredDevices = new HashSet<>(axolotlStore.getSubDeviceSessions(jid.toBareJid().toString()));
298		expiredDevices.removeAll(deviceIds);
299		setTrustOnSessions(jid, expiredDevices, XmppAxolotlSession.Trust.TRUSTED,
300				XmppAxolotlSession.Trust.INACTIVE_TRUSTED);
301		setTrustOnSessions(jid, expiredDevices, XmppAxolotlSession.Trust.UNDECIDED,
302				XmppAxolotlSession.Trust.INACTIVE_UNDECIDED);
303		setTrustOnSessions(jid, expiredDevices, XmppAxolotlSession.Trust.UNTRUSTED,
304				XmppAxolotlSession.Trust.INACTIVE_UNTRUSTED);
305		Set<Integer> newDevices = new HashSet<>(deviceIds);
306		setTrustOnSessions(jid, newDevices, XmppAxolotlSession.Trust.INACTIVE_TRUSTED,
307				XmppAxolotlSession.Trust.TRUSTED);
308		setTrustOnSessions(jid, newDevices, XmppAxolotlSession.Trust.INACTIVE_UNDECIDED,
309				XmppAxolotlSession.Trust.UNDECIDED);
310		setTrustOnSessions(jid, newDevices, XmppAxolotlSession.Trust.INACTIVE_UNTRUSTED,
311				XmppAxolotlSession.Trust.UNTRUSTED);
312		this.deviceIds.put(jid, deviceIds);
313		mXmppConnectionService.keyStatusUpdated();
314	}
315
316	public void wipeOtherPepDevices() {
317		if (pepBroken) {
318			Log.d(Config.LOGTAG, getLogprefix(account) + "wipeOtherPepDevices called, but PEP is broken. Ignoring... ");
319			return;
320		}
321		Set<Integer> deviceIds = new HashSet<>();
322		deviceIds.add(getOwnDeviceId());
323		IqPacket publish = mXmppConnectionService.getIqGenerator().publishDeviceIds(deviceIds);
324		Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Wiping all other devices from Pep:" + publish);
325		mXmppConnectionService.sendIqPacket(account, publish, new OnIqPacketReceived() {
326			@Override
327			public void onIqPacketReceived(Account account, IqPacket packet) {
328				// TODO: implement this!
329			}
330		});
331	}
332
333	public void purgeKey(final String fingerprint) {
334		axolotlStore.setFingerprintTrust(fingerprint.replaceAll("\\s", ""), XmppAxolotlSession.Trust.COMPROMISED);
335	}
336
337	public void publishOwnDeviceIdIfNeeded() {
338		if (pepBroken) {
339			Log.d(Config.LOGTAG, getLogprefix(account) + "publishOwnDeviceIdIfNeeded called, but PEP is broken. Ignoring... ");
340			return;
341		}
342		IqPacket packet = mXmppConnectionService.getIqGenerator().retrieveDeviceIds(account.getJid().toBareJid());
343		mXmppConnectionService.sendIqPacket(account, packet, new OnIqPacketReceived() {
344			@Override
345			public void onIqPacketReceived(Account account, IqPacket packet) {
346				if (packet.getType() == IqPacket.TYPE.TIMEOUT) {
347					Log.d(Config.LOGTAG, getLogprefix(account) + "Timeout received while retrieving own Device Ids.");
348				} else {
349					Element item = mXmppConnectionService.getIqParser().getItem(packet);
350					Set<Integer> deviceIds = mXmppConnectionService.getIqParser().deviceIds(item);
351					if (!deviceIds.contains(getOwnDeviceId())) {
352						publishOwnDeviceId(deviceIds);
353					}
354				}
355			}
356		});
357	}
358
359	public void publishOwnDeviceId(Set<Integer> deviceIds) {
360		Set<Integer> deviceIdsCopy = new HashSet<>(deviceIds);
361		if (!deviceIdsCopy.contains(getOwnDeviceId())) {
362			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Own device " + getOwnDeviceId() + " not in PEP devicelist.");
363			if (deviceIdsCopy.isEmpty()) {
364				if (numPublishTriesOnEmptyPep >= publishTriesThreshold) {
365					Log.w(Config.LOGTAG, getLogprefix(account) + "Own device publish attempt threshold exceeded, aborting...");
366					pepBroken = true;
367					return;
368				} else {
369					numPublishTriesOnEmptyPep++;
370					Log.w(Config.LOGTAG, getLogprefix(account) + "Own device list empty, attempting to publish (try " + numPublishTriesOnEmptyPep + ")");
371				}
372			} else {
373				numPublishTriesOnEmptyPep = 0;
374			}
375			deviceIdsCopy.add(getOwnDeviceId());
376			IqPacket publish = mXmppConnectionService.getIqGenerator().publishDeviceIds(deviceIdsCopy);
377			mXmppConnectionService.sendIqPacket(account, publish, new OnIqPacketReceived() {
378				@Override
379				public void onIqPacketReceived(Account account, IqPacket packet) {
380					if (packet.getType() != IqPacket.TYPE.RESULT) {
381						Log.d(Config.LOGTAG, getLogprefix(account) + "Error received while publishing own device id" + packet.findChild("error"));
382					}
383				}
384			});
385		}
386	}
387
388	public void publishBundlesIfNeeded(final boolean announceAfter) {
389		if (pepBroken) {
390			Log.d(Config.LOGTAG, getLogprefix(account) + "publishBundlesIfNeeded called, but PEP is broken. Ignoring... ");
391			return;
392		}
393		IqPacket packet = mXmppConnectionService.getIqGenerator().retrieveBundlesForDevice(account.getJid().toBareJid(), getOwnDeviceId());
394		mXmppConnectionService.sendIqPacket(account, packet, new OnIqPacketReceived() {
395			@Override
396			public void onIqPacketReceived(Account account, IqPacket packet) {
397				PreKeyBundle bundle = mXmppConnectionService.getIqParser().bundle(packet);
398				Map<Integer, ECPublicKey> keys = mXmppConnectionService.getIqParser().preKeyPublics(packet);
399				boolean flush = false;
400				if (bundle == null) {
401					Log.w(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Received invalid bundle:" + packet);
402					bundle = new PreKeyBundle(-1, -1, -1, null, -1, null, null, null);
403					flush = true;
404				}
405				if (keys == null) {
406					Log.w(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Received invalid prekeys:" + packet);
407				}
408				try {
409					boolean changed = false;
410					// Validate IdentityKey
411					IdentityKeyPair identityKeyPair = axolotlStore.getIdentityKeyPair();
412					if (flush || !identityKeyPair.getPublicKey().equals(bundle.getIdentityKey())) {
413						Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Adding own IdentityKey " + identityKeyPair.getPublicKey() + " to PEP.");
414						changed = true;
415					}
416
417					// Validate signedPreKeyRecord + ID
418					SignedPreKeyRecord signedPreKeyRecord;
419					int numSignedPreKeys = axolotlStore.loadSignedPreKeys().size();
420					try {
421						signedPreKeyRecord = axolotlStore.loadSignedPreKey(bundle.getSignedPreKeyId());
422						if (flush
423								|| !bundle.getSignedPreKey().equals(signedPreKeyRecord.getKeyPair().getPublicKey())
424								|| !Arrays.equals(bundle.getSignedPreKeySignature(), signedPreKeyRecord.getSignature())) {
425							Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Adding new signedPreKey with ID " + (numSignedPreKeys + 1) + " to PEP.");
426							signedPreKeyRecord = KeyHelper.generateSignedPreKey(identityKeyPair, numSignedPreKeys + 1);
427							axolotlStore.storeSignedPreKey(signedPreKeyRecord.getId(), signedPreKeyRecord);
428							changed = true;
429						}
430					} catch (InvalidKeyIdException e) {
431						Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Adding new signedPreKey with ID " + (numSignedPreKeys + 1) + " to PEP.");
432						signedPreKeyRecord = KeyHelper.generateSignedPreKey(identityKeyPair, numSignedPreKeys + 1);
433						axolotlStore.storeSignedPreKey(signedPreKeyRecord.getId(), signedPreKeyRecord);
434						changed = true;
435					}
436
437					// Validate PreKeys
438					Set<PreKeyRecord> preKeyRecords = new HashSet<>();
439					if (keys != null) {
440						for (Integer id : keys.keySet()) {
441							try {
442								PreKeyRecord preKeyRecord = axolotlStore.loadPreKey(id);
443								if (preKeyRecord.getKeyPair().getPublicKey().equals(keys.get(id))) {
444									preKeyRecords.add(preKeyRecord);
445								}
446							} catch (InvalidKeyIdException ignored) {
447							}
448						}
449					}
450					int newKeys = NUM_KEYS_TO_PUBLISH - preKeyRecords.size();
451					if (newKeys > 0) {
452						List<PreKeyRecord> newRecords = KeyHelper.generatePreKeys(
453								axolotlStore.getCurrentPreKeyId() + 1, newKeys);
454						preKeyRecords.addAll(newRecords);
455						for (PreKeyRecord record : newRecords) {
456							axolotlStore.storePreKey(record.getId(), record);
457						}
458						changed = true;
459						Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Adding " + newKeys + " new preKeys to PEP.");
460					}
461
462
463					if (changed) {
464						IqPacket publish = mXmppConnectionService.getIqGenerator().publishBundles(
465								signedPreKeyRecord, axolotlStore.getIdentityKeyPair().getPublicKey(),
466								preKeyRecords, getOwnDeviceId());
467						Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + ": Bundle " + getOwnDeviceId() + " in PEP not current. Publishing: " + publish);
468						mXmppConnectionService.sendIqPacket(account, publish, new OnIqPacketReceived() {
469							@Override
470							public void onIqPacketReceived(Account account, IqPacket packet) {
471								if (packet.getType() == IqPacket.TYPE.RESULT) {
472									Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Successfully published bundle. ");
473									if (announceAfter) {
474										Log.d(Config.LOGTAG, getLogprefix(account) + "Announcing device " + getOwnDeviceId());
475										publishOwnDeviceIdIfNeeded();
476									}
477								} else {
478									Log.d(Config.LOGTAG, getLogprefix(account) + "Error received while publishing bundle: " + packet.findChild("error"));
479								}
480							}
481						});
482					} else {
483						Log.d(Config.LOGTAG, getLogprefix(account) + "Bundle " + getOwnDeviceId() + " in PEP was current");
484						if (announceAfter) {
485							Log.d(Config.LOGTAG, getLogprefix(account) + "Announcing device " + getOwnDeviceId());
486							publishOwnDeviceIdIfNeeded();
487						}
488					}
489				} catch (InvalidKeyException e) {
490					Log.e(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Failed to publish bundle " + getOwnDeviceId() + ", reason: " + e.getMessage());
491					return;
492				}
493			}
494		});
495	}
496
497	public boolean isContactAxolotlCapable(Contact contact) {
498
499		Jid jid = contact.getJid().toBareJid();
500		AxolotlAddress address = new AxolotlAddress(jid.toString(), 0);
501		return sessions.hasAny(address) ||
502				(deviceIds.containsKey(jid) && !deviceIds.get(jid).isEmpty());
503	}
504
505	public XmppAxolotlSession.Trust getFingerprintTrust(String fingerprint) {
506		return axolotlStore.getFingerprintTrust(fingerprint);
507	}
508
509	public void setFingerprintTrust(String fingerprint, XmppAxolotlSession.Trust trust) {
510		axolotlStore.setFingerprintTrust(fingerprint, trust);
511	}
512
513	private void buildSessionFromPEP(final AxolotlAddress address) {
514		Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Building new sesstion for " + address.toString());
515		if (address.getDeviceId() == getOwnDeviceId()) {
516			throw new AssertionError("We should NEVER build a session with ourselves. What happened here?!");
517		}
518
519		try {
520			IqPacket bundlesPacket = mXmppConnectionService.getIqGenerator().retrieveBundlesForDevice(
521					Jid.fromString(address.getName()), address.getDeviceId());
522			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Retrieving bundle: " + bundlesPacket);
523			mXmppConnectionService.sendIqPacket(account, bundlesPacket, new OnIqPacketReceived() {
524				private void finish() {
525					AxolotlAddress ownAddress = new AxolotlAddress(account.getJid().toBareJid().toString(), 0);
526					if (!fetchStatusMap.getAll(ownAddress).containsValue(FetchStatus.PENDING)
527							&& !fetchStatusMap.getAll(address).containsValue(FetchStatus.PENDING)) {
528						mXmppConnectionService.keyStatusUpdated();
529					}
530				}
531
532				@Override
533				public void onIqPacketReceived(Account account, IqPacket packet) {
534					if (packet.getType() == IqPacket.TYPE.RESULT) {
535						Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Received preKey IQ packet, processing...");
536						final IqParser parser = mXmppConnectionService.getIqParser();
537						final List<PreKeyBundle> preKeyBundleList = parser.preKeys(packet);
538						final PreKeyBundle bundle = parser.bundle(packet);
539						if (preKeyBundleList.isEmpty() || bundle == null) {
540							Log.e(Config.LOGTAG, AxolotlService.getLogprefix(account) + "preKey IQ packet invalid: " + packet);
541							fetchStatusMap.put(address, FetchStatus.ERROR);
542							finish();
543							return;
544						}
545						Random random = new Random();
546						final PreKeyBundle preKey = preKeyBundleList.get(random.nextInt(preKeyBundleList.size()));
547						if (preKey == null) {
548							//should never happen
549							fetchStatusMap.put(address, FetchStatus.ERROR);
550							finish();
551							return;
552						}
553
554						final PreKeyBundle preKeyBundle = new PreKeyBundle(0, address.getDeviceId(),
555								preKey.getPreKeyId(), preKey.getPreKey(),
556								bundle.getSignedPreKeyId(), bundle.getSignedPreKey(),
557								bundle.getSignedPreKeySignature(), bundle.getIdentityKey());
558
559						try {
560							SessionBuilder builder = new SessionBuilder(axolotlStore, address);
561							builder.process(preKeyBundle);
562							XmppAxolotlSession session = new XmppAxolotlSession(account, axolotlStore, address, bundle.getIdentityKey().getFingerprint().replaceAll("\\s", ""));
563							sessions.put(address, session);
564							fetchStatusMap.put(address, FetchStatus.SUCCESS);
565						} catch (UntrustedIdentityException | InvalidKeyException e) {
566							Log.e(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Error building session for " + address + ": "
567									+ e.getClass().getName() + ", " + e.getMessage());
568							fetchStatusMap.put(address, FetchStatus.ERROR);
569						}
570
571						finish();
572					} else {
573						fetchStatusMap.put(address, FetchStatus.ERROR);
574						Log.d(Config.LOGTAG, getLogprefix(account) + "Error received while building session:" + packet.findChild("error"));
575						finish();
576						return;
577					}
578				}
579			});
580		} catch (InvalidJidException e) {
581			Log.e(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Got address with invalid jid: " + address.getName());
582		}
583	}
584
585	public Set<AxolotlAddress> findDevicesWithoutSession(final Conversation conversation) {
586		Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Finding devices without session for " + conversation.getContact().getJid().toBareJid());
587		Jid contactJid = conversation.getContact().getJid().toBareJid();
588		Set<AxolotlAddress> addresses = new HashSet<>();
589		if (deviceIds.get(contactJid) != null) {
590			for (Integer foreignId : this.deviceIds.get(contactJid)) {
591				AxolotlAddress address = new AxolotlAddress(contactJid.toString(), foreignId);
592				if (sessions.get(address) == null) {
593					IdentityKey identityKey = axolotlStore.loadSession(address).getSessionState().getRemoteIdentityKey();
594					if (identityKey != null) {
595						Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Already have session for " + address.toString() + ", adding to cache...");
596						XmppAxolotlSession session = new XmppAxolotlSession(account, axolotlStore, address, identityKey.getFingerprint().replaceAll("\\s", ""));
597						sessions.put(address, session);
598					} else {
599						Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Found device " + account.getJid().toBareJid() + ":" + foreignId);
600						addresses.add(new AxolotlAddress(contactJid.toString(), foreignId));
601					}
602				}
603			}
604		} else {
605			Log.w(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Have no target devices in PEP!");
606		}
607		if (deviceIds.get(account.getJid().toBareJid()) != null) {
608			for (Integer ownId : this.deviceIds.get(account.getJid().toBareJid())) {
609				AxolotlAddress address = new AxolotlAddress(account.getJid().toBareJid().toString(), ownId);
610				if (sessions.get(address) == null) {
611					IdentityKey identityKey = axolotlStore.loadSession(address).getSessionState().getRemoteIdentityKey();
612					if (identityKey != null) {
613						Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Already have session for " + address.toString() + ", adding to cache...");
614						XmppAxolotlSession session = new XmppAxolotlSession(account, axolotlStore, address, identityKey.getFingerprint().replaceAll("\\s", ""));
615						sessions.put(address, session);
616					} else {
617						Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Found device " + account.getJid().toBareJid() + ":" + ownId);
618						addresses.add(new AxolotlAddress(account.getJid().toBareJid().toString(), ownId));
619					}
620				}
621			}
622		}
623
624		return addresses;
625	}
626
627	public boolean createSessionsIfNeeded(final Conversation conversation) {
628		Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Creating axolotl sessions if needed...");
629		boolean newSessions = false;
630		Set<AxolotlAddress> addresses = findDevicesWithoutSession(conversation);
631		for (AxolotlAddress address : addresses) {
632			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Processing device: " + address.toString());
633			FetchStatus status = fetchStatusMap.get(address);
634			if (status == null || status == FetchStatus.ERROR) {
635				fetchStatusMap.put(address, FetchStatus.PENDING);
636				this.buildSessionFromPEP(address);
637				newSessions = true;
638			} else if (status == FetchStatus.PENDING) {
639				newSessions = true;
640			} else {
641				Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Already fetching bundle for " + address.toString());
642			}
643		}
644
645		return newSessions;
646	}
647
648	public boolean hasPendingKeyFetches(Conversation conversation) {
649		AxolotlAddress ownAddress = new AxolotlAddress(account.getJid().toBareJid().toString(), 0);
650		AxolotlAddress foreignAddress = new AxolotlAddress(conversation.getJid().toBareJid().toString(), 0);
651		return fetchStatusMap.getAll(ownAddress).containsValue(FetchStatus.PENDING)
652				|| fetchStatusMap.getAll(foreignAddress).containsValue(FetchStatus.PENDING);
653
654	}
655
656	@Nullable
657	private XmppAxolotlMessage buildHeader(Contact contact) {
658		final XmppAxolotlMessage axolotlMessage = new XmppAxolotlMessage(
659				contact.getJid().toBareJid(), getOwnDeviceId());
660
661		Set<XmppAxolotlSession> contactSessions = findSessionsforContact(contact);
662		Set<XmppAxolotlSession> ownSessions = findOwnSessions();
663		if (contactSessions.isEmpty()) {
664			return null;
665		}
666		Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Building axolotl foreign keyElements...");
667		for (XmppAxolotlSession session : contactSessions) {
668			Log.v(Config.LOGTAG, AxolotlService.getLogprefix(account) + session.getRemoteAddress().toString());
669			axolotlMessage.addDevice(session);
670		}
671		Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Building axolotl own keyElements...");
672		for (XmppAxolotlSession session : ownSessions) {
673			Log.v(Config.LOGTAG, AxolotlService.getLogprefix(account) + session.getRemoteAddress().toString());
674			axolotlMessage.addDevice(session);
675		}
676
677		return axolotlMessage;
678	}
679
680	@Nullable
681	public XmppAxolotlMessage encrypt(Message message) {
682		XmppAxolotlMessage axolotlMessage = buildHeader(message.getContact());
683
684		if (axolotlMessage != null) {
685			final String content;
686			if (message.hasFileOnRemoteHost()) {
687				content = message.getFileParams().url.toString();
688			} else {
689				content = message.getBody();
690			}
691			try {
692				axolotlMessage.encrypt(content);
693			} catch (CryptoFailedException e) {
694				Log.w(Config.LOGTAG, getLogprefix(account) + "Failed to encrypt message: " + e.getMessage());
695				return null;
696			}
697		}
698
699		return axolotlMessage;
700	}
701
702	public void preparePayloadMessage(final Message message, final boolean delay) {
703		executor.execute(new Runnable() {
704			@Override
705			public void run() {
706				XmppAxolotlMessage axolotlMessage = encrypt(message);
707				if (axolotlMessage == null) {
708					mXmppConnectionService.markMessage(message, Message.STATUS_SEND_FAILED);
709					//mXmppConnectionService.updateConversationUi();
710				} else {
711					Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Generated message, caching: " + message.getUuid());
712					messageCache.put(message.getUuid(), axolotlMessage);
713					mXmppConnectionService.resendMessage(message, delay);
714				}
715			}
716		});
717	}
718
719	public void prepareKeyTransportMessage(final Contact contact, final OnMessageCreatedCallback onMessageCreatedCallback) {
720		executor.execute(new Runnable() {
721			@Override
722			public void run() {
723				XmppAxolotlMessage axolotlMessage = buildHeader(contact);
724				onMessageCreatedCallback.run(axolotlMessage);
725			}
726		});
727	}
728
729	public XmppAxolotlMessage fetchAxolotlMessageFromCache(Message message) {
730		XmppAxolotlMessage axolotlMessage = messageCache.get(message.getUuid());
731		if (axolotlMessage != null) {
732			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Cache hit: " + message.getUuid());
733			messageCache.remove(message.getUuid());
734		} else {
735			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Cache miss: " + message.getUuid());
736		}
737		return axolotlMessage;
738	}
739
740	private XmppAxolotlSession recreateUncachedSession(AxolotlAddress address) {
741		IdentityKey identityKey = axolotlStore.loadSession(address).getSessionState().getRemoteIdentityKey();
742		return (identityKey != null)
743				? new XmppAxolotlSession(account, axolotlStore, address,
744						identityKey.getFingerprint().replaceAll("\\s", ""))
745				: null;
746	}
747
748	private XmppAxolotlSession getReceivingSession(XmppAxolotlMessage message) {
749		AxolotlAddress senderAddress = new AxolotlAddress(message.getFrom().toString(),
750				message.getSenderDeviceId());
751		XmppAxolotlSession session = sessions.get(senderAddress);
752		if (session == null) {
753			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Account: " + account.getJid() + " No axolotl session found while parsing received message " + message);
754			session = recreateUncachedSession(senderAddress);
755			if (session == null) {
756				session = new XmppAxolotlSession(account, axolotlStore, senderAddress);
757			}
758		}
759		return session;
760	}
761
762	public XmppAxolotlMessage.XmppAxolotlPlaintextMessage processReceivingPayloadMessage(XmppAxolotlMessage message) {
763		XmppAxolotlMessage.XmppAxolotlPlaintextMessage plaintextMessage = null;
764
765		XmppAxolotlSession session = getReceivingSession(message);
766		try {
767			plaintextMessage = message.decrypt(session, getOwnDeviceId());
768			Integer preKeyId = session.getPreKeyId();
769			if (preKeyId != null) {
770				publishBundlesIfNeeded(false);
771				session.resetPreKeyId();
772			}
773		} catch (CryptoFailedException e) {
774			Log.w(Config.LOGTAG, getLogprefix(account) + "Failed to decrypt message: " + e.getMessage());
775		}
776
777		if (session.isFresh() && plaintextMessage != null) {
778			sessions.put(session);
779		}
780
781		return plaintextMessage;
782	}
783
784	public XmppAxolotlMessage.XmppAxolotlKeyTransportMessage processReceivingKeyTransportMessage(XmppAxolotlMessage message) {
785		XmppAxolotlMessage.XmppAxolotlKeyTransportMessage keyTransportMessage = null;
786
787		XmppAxolotlSession session = getReceivingSession(message);
788		keyTransportMessage = message.getParameters(session, getOwnDeviceId());
789
790		if (session.isFresh() && keyTransportMessage != null) {
791			sessions.put(session);
792		}
793
794		return keyTransportMessage;
795	}
796}