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
398				if (packet.getType() == IqPacket.TYPE.TIMEOUT) {
399					return; //ignore timeout. do nothing
400				}
401
402				if (packet.getType() == IqPacket.TYPE.ERROR) {
403					Element error = packet.findChild("error");
404					if (error == null || !error.hasChild("item-not-found")) {
405						pepBroken = true;
406						Log.w(Config.LOGTAG, AxolotlService.getLogprefix(account) + "request for device bundles came back with something other than item-not-found" + packet);
407						return;
408					}
409				}
410
411				PreKeyBundle bundle = mXmppConnectionService.getIqParser().bundle(packet);
412				Map<Integer, ECPublicKey> keys = mXmppConnectionService.getIqParser().preKeyPublics(packet);
413				boolean flush = false;
414				if (bundle == null) {
415					Log.w(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Received invalid bundle:" + packet);
416					bundle = new PreKeyBundle(-1, -1, -1, null, -1, null, null, null);
417					flush = true;
418				}
419				if (keys == null) {
420					Log.w(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Received invalid prekeys:" + packet);
421				}
422				try {
423					boolean changed = false;
424					// Validate IdentityKey
425					IdentityKeyPair identityKeyPair = axolotlStore.getIdentityKeyPair();
426					if (flush || !identityKeyPair.getPublicKey().equals(bundle.getIdentityKey())) {
427						Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Adding own IdentityKey " + identityKeyPair.getPublicKey() + " to PEP.");
428						changed = true;
429					}
430
431					// Validate signedPreKeyRecord + ID
432					SignedPreKeyRecord signedPreKeyRecord;
433					int numSignedPreKeys = axolotlStore.loadSignedPreKeys().size();
434					try {
435						signedPreKeyRecord = axolotlStore.loadSignedPreKey(bundle.getSignedPreKeyId());
436						if (flush
437								|| !bundle.getSignedPreKey().equals(signedPreKeyRecord.getKeyPair().getPublicKey())
438								|| !Arrays.equals(bundle.getSignedPreKeySignature(), signedPreKeyRecord.getSignature())) {
439							Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Adding new signedPreKey with ID " + (numSignedPreKeys + 1) + " to PEP.");
440							signedPreKeyRecord = KeyHelper.generateSignedPreKey(identityKeyPair, numSignedPreKeys + 1);
441							axolotlStore.storeSignedPreKey(signedPreKeyRecord.getId(), signedPreKeyRecord);
442							changed = true;
443						}
444					} catch (InvalidKeyIdException e) {
445						Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Adding new signedPreKey with ID " + (numSignedPreKeys + 1) + " to PEP.");
446						signedPreKeyRecord = KeyHelper.generateSignedPreKey(identityKeyPair, numSignedPreKeys + 1);
447						axolotlStore.storeSignedPreKey(signedPreKeyRecord.getId(), signedPreKeyRecord);
448						changed = true;
449					}
450
451					// Validate PreKeys
452					Set<PreKeyRecord> preKeyRecords = new HashSet<>();
453					if (keys != null) {
454						for (Integer id : keys.keySet()) {
455							try {
456								PreKeyRecord preKeyRecord = axolotlStore.loadPreKey(id);
457								if (preKeyRecord.getKeyPair().getPublicKey().equals(keys.get(id))) {
458									preKeyRecords.add(preKeyRecord);
459								}
460							} catch (InvalidKeyIdException ignored) {
461							}
462						}
463					}
464					int newKeys = NUM_KEYS_TO_PUBLISH - preKeyRecords.size();
465					if (newKeys > 0) {
466						List<PreKeyRecord> newRecords = KeyHelper.generatePreKeys(
467								axolotlStore.getCurrentPreKeyId() + 1, newKeys);
468						preKeyRecords.addAll(newRecords);
469						for (PreKeyRecord record : newRecords) {
470							axolotlStore.storePreKey(record.getId(), record);
471						}
472						changed = true;
473						Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Adding " + newKeys + " new preKeys to PEP.");
474					}
475
476
477					if (changed) {
478						IqPacket publish = mXmppConnectionService.getIqGenerator().publishBundles(
479								signedPreKeyRecord, axolotlStore.getIdentityKeyPair().getPublicKey(),
480								preKeyRecords, getOwnDeviceId());
481						Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + ": Bundle " + getOwnDeviceId() + " in PEP not current. Publishing: " + publish);
482						mXmppConnectionService.sendIqPacket(account, publish, new OnIqPacketReceived() {
483							@Override
484							public void onIqPacketReceived(Account account, IqPacket packet) {
485								if (packet.getType() == IqPacket.TYPE.RESULT) {
486									Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Successfully published bundle. ");
487									if (announceAfter) {
488										Log.d(Config.LOGTAG, getLogprefix(account) + "Announcing device " + getOwnDeviceId());
489										publishOwnDeviceIdIfNeeded();
490									}
491								} else {
492									Log.d(Config.LOGTAG, getLogprefix(account) + "Error received while publishing bundle: " + packet.findChild("error"));
493								}
494							}
495						});
496					} else {
497						Log.d(Config.LOGTAG, getLogprefix(account) + "Bundle " + getOwnDeviceId() + " in PEP was current");
498						if (announceAfter) {
499							Log.d(Config.LOGTAG, getLogprefix(account) + "Announcing device " + getOwnDeviceId());
500							publishOwnDeviceIdIfNeeded();
501						}
502					}
503				} catch (InvalidKeyException e) {
504					Log.e(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Failed to publish bundle " + getOwnDeviceId() + ", reason: " + e.getMessage());
505					return;
506				}
507			}
508		});
509	}
510
511	public boolean isContactAxolotlCapable(Contact contact) {
512
513		Jid jid = contact.getJid().toBareJid();
514		AxolotlAddress address = new AxolotlAddress(jid.toString(), 0);
515		return sessions.hasAny(address) ||
516				(deviceIds.containsKey(jid) && !deviceIds.get(jid).isEmpty());
517	}
518
519	public XmppAxolotlSession.Trust getFingerprintTrust(String fingerprint) {
520		return axolotlStore.getFingerprintTrust(fingerprint);
521	}
522
523	public void setFingerprintTrust(String fingerprint, XmppAxolotlSession.Trust trust) {
524		axolotlStore.setFingerprintTrust(fingerprint, trust);
525	}
526
527	private void buildSessionFromPEP(final AxolotlAddress address) {
528		Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Building new sesstion for " + address.toString());
529		if (address.getDeviceId() == getOwnDeviceId()) {
530			throw new AssertionError("We should NEVER build a session with ourselves. What happened here?!");
531		}
532
533		try {
534			IqPacket bundlesPacket = mXmppConnectionService.getIqGenerator().retrieveBundlesForDevice(
535					Jid.fromString(address.getName()), address.getDeviceId());
536			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Retrieving bundle: " + bundlesPacket);
537			mXmppConnectionService.sendIqPacket(account, bundlesPacket, new OnIqPacketReceived() {
538				private void finish() {
539					AxolotlAddress ownAddress = new AxolotlAddress(account.getJid().toBareJid().toString(), 0);
540					if (!fetchStatusMap.getAll(ownAddress).containsValue(FetchStatus.PENDING)
541							&& !fetchStatusMap.getAll(address).containsValue(FetchStatus.PENDING)) {
542						mXmppConnectionService.keyStatusUpdated();
543					}
544				}
545
546				@Override
547				public void onIqPacketReceived(Account account, IqPacket packet) {
548					if (packet.getType() == IqPacket.TYPE.RESULT) {
549						Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Received preKey IQ packet, processing...");
550						final IqParser parser = mXmppConnectionService.getIqParser();
551						final List<PreKeyBundle> preKeyBundleList = parser.preKeys(packet);
552						final PreKeyBundle bundle = parser.bundle(packet);
553						if (preKeyBundleList.isEmpty() || bundle == null) {
554							Log.e(Config.LOGTAG, AxolotlService.getLogprefix(account) + "preKey IQ packet invalid: " + packet);
555							fetchStatusMap.put(address, FetchStatus.ERROR);
556							finish();
557							return;
558						}
559						Random random = new Random();
560						final PreKeyBundle preKey = preKeyBundleList.get(random.nextInt(preKeyBundleList.size()));
561						if (preKey == null) {
562							//should never happen
563							fetchStatusMap.put(address, FetchStatus.ERROR);
564							finish();
565							return;
566						}
567
568						final PreKeyBundle preKeyBundle = new PreKeyBundle(0, address.getDeviceId(),
569								preKey.getPreKeyId(), preKey.getPreKey(),
570								bundle.getSignedPreKeyId(), bundle.getSignedPreKey(),
571								bundle.getSignedPreKeySignature(), bundle.getIdentityKey());
572
573						try {
574							SessionBuilder builder = new SessionBuilder(axolotlStore, address);
575							builder.process(preKeyBundle);
576							XmppAxolotlSession session = new XmppAxolotlSession(account, axolotlStore, address, bundle.getIdentityKey().getFingerprint().replaceAll("\\s", ""));
577							sessions.put(address, session);
578							fetchStatusMap.put(address, FetchStatus.SUCCESS);
579						} catch (UntrustedIdentityException | InvalidKeyException e) {
580							Log.e(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Error building session for " + address + ": "
581									+ e.getClass().getName() + ", " + e.getMessage());
582							fetchStatusMap.put(address, FetchStatus.ERROR);
583						}
584
585						finish();
586					} else {
587						fetchStatusMap.put(address, FetchStatus.ERROR);
588						Log.d(Config.LOGTAG, getLogprefix(account) + "Error received while building session:" + packet.findChild("error"));
589						finish();
590						return;
591					}
592				}
593			});
594		} catch (InvalidJidException e) {
595			Log.e(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Got address with invalid jid: " + address.getName());
596		}
597	}
598
599	public Set<AxolotlAddress> findDevicesWithoutSession(final Conversation conversation) {
600		Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Finding devices without session for " + conversation.getContact().getJid().toBareJid());
601		Jid contactJid = conversation.getContact().getJid().toBareJid();
602		Set<AxolotlAddress> addresses = new HashSet<>();
603		if (deviceIds.get(contactJid) != null) {
604			for (Integer foreignId : this.deviceIds.get(contactJid)) {
605				AxolotlAddress address = new AxolotlAddress(contactJid.toString(), foreignId);
606				if (sessions.get(address) == null) {
607					IdentityKey identityKey = axolotlStore.loadSession(address).getSessionState().getRemoteIdentityKey();
608					if (identityKey != null) {
609						Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Already have session for " + address.toString() + ", adding to cache...");
610						XmppAxolotlSession session = new XmppAxolotlSession(account, axolotlStore, address, identityKey.getFingerprint().replaceAll("\\s", ""));
611						sessions.put(address, session);
612					} else {
613						Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Found device " + account.getJid().toBareJid() + ":" + foreignId);
614						addresses.add(new AxolotlAddress(contactJid.toString(), foreignId));
615					}
616				}
617			}
618		} else {
619			Log.w(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Have no target devices in PEP!");
620		}
621		if (deviceIds.get(account.getJid().toBareJid()) != null) {
622			for (Integer ownId : this.deviceIds.get(account.getJid().toBareJid())) {
623				AxolotlAddress address = new AxolotlAddress(account.getJid().toBareJid().toString(), ownId);
624				if (sessions.get(address) == null) {
625					IdentityKey identityKey = axolotlStore.loadSession(address).getSessionState().getRemoteIdentityKey();
626					if (identityKey != null) {
627						Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Already have session for " + address.toString() + ", adding to cache...");
628						XmppAxolotlSession session = new XmppAxolotlSession(account, axolotlStore, address, identityKey.getFingerprint().replaceAll("\\s", ""));
629						sessions.put(address, session);
630					} else {
631						Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Found device " + account.getJid().toBareJid() + ":" + ownId);
632						addresses.add(new AxolotlAddress(account.getJid().toBareJid().toString(), ownId));
633					}
634				}
635			}
636		}
637
638		return addresses;
639	}
640
641	public boolean createSessionsIfNeeded(final Conversation conversation) {
642		Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Creating axolotl sessions if needed...");
643		boolean newSessions = false;
644		Set<AxolotlAddress> addresses = findDevicesWithoutSession(conversation);
645		for (AxolotlAddress address : addresses) {
646			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Processing device: " + address.toString());
647			FetchStatus status = fetchStatusMap.get(address);
648			if (status == null || status == FetchStatus.ERROR) {
649				fetchStatusMap.put(address, FetchStatus.PENDING);
650				this.buildSessionFromPEP(address);
651				newSessions = true;
652			} else if (status == FetchStatus.PENDING) {
653				newSessions = true;
654			} else {
655				Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Already fetching bundle for " + address.toString());
656			}
657		}
658
659		return newSessions;
660	}
661
662	public boolean hasPendingKeyFetches(Conversation conversation) {
663		AxolotlAddress ownAddress = new AxolotlAddress(account.getJid().toBareJid().toString(), 0);
664		AxolotlAddress foreignAddress = new AxolotlAddress(conversation.getJid().toBareJid().toString(), 0);
665		return fetchStatusMap.getAll(ownAddress).containsValue(FetchStatus.PENDING)
666				|| fetchStatusMap.getAll(foreignAddress).containsValue(FetchStatus.PENDING);
667
668	}
669
670	@Nullable
671	private XmppAxolotlMessage buildHeader(Contact contact) {
672		final XmppAxolotlMessage axolotlMessage = new XmppAxolotlMessage(
673				contact.getJid().toBareJid(), getOwnDeviceId());
674
675		Set<XmppAxolotlSession> contactSessions = findSessionsforContact(contact);
676		Set<XmppAxolotlSession> ownSessions = findOwnSessions();
677		if (contactSessions.isEmpty()) {
678			return null;
679		}
680		Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Building axolotl foreign keyElements...");
681		for (XmppAxolotlSession session : contactSessions) {
682			Log.v(Config.LOGTAG, AxolotlService.getLogprefix(account) + session.getRemoteAddress().toString());
683			axolotlMessage.addDevice(session);
684		}
685		Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Building axolotl own keyElements...");
686		for (XmppAxolotlSession session : ownSessions) {
687			Log.v(Config.LOGTAG, AxolotlService.getLogprefix(account) + session.getRemoteAddress().toString());
688			axolotlMessage.addDevice(session);
689		}
690
691		return axolotlMessage;
692	}
693
694	@Nullable
695	public XmppAxolotlMessage encrypt(Message message) {
696		XmppAxolotlMessage axolotlMessage = buildHeader(message.getContact());
697
698		if (axolotlMessage != null) {
699			final String content;
700			if (message.hasFileOnRemoteHost()) {
701				content = message.getFileParams().url.toString();
702			} else {
703				content = message.getBody();
704			}
705			try {
706				axolotlMessage.encrypt(content);
707			} catch (CryptoFailedException e) {
708				Log.w(Config.LOGTAG, getLogprefix(account) + "Failed to encrypt message: " + e.getMessage());
709				return null;
710			}
711		}
712
713		return axolotlMessage;
714	}
715
716	public void preparePayloadMessage(final Message message, final boolean delay) {
717		executor.execute(new Runnable() {
718			@Override
719			public void run() {
720				XmppAxolotlMessage axolotlMessage = encrypt(message);
721				if (axolotlMessage == null) {
722					mXmppConnectionService.markMessage(message, Message.STATUS_SEND_FAILED);
723					//mXmppConnectionService.updateConversationUi();
724				} else {
725					Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Generated message, caching: " + message.getUuid());
726					messageCache.put(message.getUuid(), axolotlMessage);
727					mXmppConnectionService.resendMessage(message, delay);
728				}
729			}
730		});
731	}
732
733	public void prepareKeyTransportMessage(final Contact contact, final OnMessageCreatedCallback onMessageCreatedCallback) {
734		executor.execute(new Runnable() {
735			@Override
736			public void run() {
737				XmppAxolotlMessage axolotlMessage = buildHeader(contact);
738				onMessageCreatedCallback.run(axolotlMessage);
739			}
740		});
741	}
742
743	public XmppAxolotlMessage fetchAxolotlMessageFromCache(Message message) {
744		XmppAxolotlMessage axolotlMessage = messageCache.get(message.getUuid());
745		if (axolotlMessage != null) {
746			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Cache hit: " + message.getUuid());
747			messageCache.remove(message.getUuid());
748		} else {
749			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Cache miss: " + message.getUuid());
750		}
751		return axolotlMessage;
752	}
753
754	private XmppAxolotlSession recreateUncachedSession(AxolotlAddress address) {
755		IdentityKey identityKey = axolotlStore.loadSession(address).getSessionState().getRemoteIdentityKey();
756		return (identityKey != null)
757				? new XmppAxolotlSession(account, axolotlStore, address,
758						identityKey.getFingerprint().replaceAll("\\s", ""))
759				: null;
760	}
761
762	private XmppAxolotlSession getReceivingSession(XmppAxolotlMessage message) {
763		AxolotlAddress senderAddress = new AxolotlAddress(message.getFrom().toString(),
764				message.getSenderDeviceId());
765		XmppAxolotlSession session = sessions.get(senderAddress);
766		if (session == null) {
767			Log.d(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Account: " + account.getJid() + " No axolotl session found while parsing received message " + message);
768			session = recreateUncachedSession(senderAddress);
769			if (session == null) {
770				session = new XmppAxolotlSession(account, axolotlStore, senderAddress);
771			}
772		}
773		return session;
774	}
775
776	public XmppAxolotlMessage.XmppAxolotlPlaintextMessage processReceivingPayloadMessage(XmppAxolotlMessage message) {
777		XmppAxolotlMessage.XmppAxolotlPlaintextMessage plaintextMessage = null;
778
779		XmppAxolotlSession session = getReceivingSession(message);
780		try {
781			plaintextMessage = message.decrypt(session, getOwnDeviceId());
782			Integer preKeyId = session.getPreKeyId();
783			if (preKeyId != null) {
784				publishBundlesIfNeeded(false);
785				session.resetPreKeyId();
786			}
787		} catch (CryptoFailedException e) {
788			Log.w(Config.LOGTAG, getLogprefix(account) + "Failed to decrypt message: " + e.getMessage());
789		}
790
791		if (session.isFresh() && plaintextMessage != null) {
792			sessions.put(session);
793		}
794
795		return plaintextMessage;
796	}
797
798	public XmppAxolotlMessage.XmppAxolotlKeyTransportMessage processReceivingKeyTransportMessage(XmppAxolotlMessage message) {
799		XmppAxolotlMessage.XmppAxolotlKeyTransportMessage keyTransportMessage = null;
800
801		XmppAxolotlSession session = getReceivingSession(message);
802		keyTransportMessage = message.getParameters(session, getOwnDeviceId());
803
804		if (session.isFresh() && keyTransportMessage != null) {
805			sessions.put(session);
806		}
807
808		return keyTransportMessage;
809	}
810}