nmode's Git Repositories - signal-cli/blob - lib/src/main/java/org/asamk/signal/manager/helper/AccountHelper.java

   1 package org.asamk.signal.manager.helper;
   2
   3 import org.asamk.signal.manager.api.CaptchaRequiredException;
   4 import org.asamk.signal.manager.api.DeviceLinkUrl;
   5 import org.asamk.signal.manager.api.IncorrectPinException;
   6 import org.asamk.signal.manager.api.InvalidDeviceLinkException;
   7 import org.asamk.signal.manager.api.NonNormalizedPhoneNumberException;
   8 import org.asamk.signal.manager.api.PinLockedException;
   9 import org.asamk.signal.manager.api.RateLimitException;
  10 import org.asamk.signal.manager.internal.SignalDependencies;
  11 import org.asamk.signal.manager.jobs.SyncStorageJob;
  12 import org.asamk.signal.manager.storage.SignalAccount;
  13 import org.asamk.signal.manager.util.KeyUtils;
  14 import org.asamk.signal.manager.util.NumberVerificationUtils;
  15 import org.asamk.signal.manager.util.Utils;
  16 import org.signal.core.util.Base64;
  17 import org.signal.libsignal.protocol.IdentityKeyPair;
  18 import org.signal.libsignal.protocol.InvalidKeyException;
  19 import org.signal.libsignal.protocol.SignalProtocolAddress;
  20 import org.signal.libsignal.protocol.state.KyberPreKeyRecord;
  21 import org.signal.libsignal.protocol.state.SignedPreKeyRecord;
  22 import org.signal.libsignal.protocol.util.KeyHelper;
  23 import org.signal.libsignal.usernames.BaseUsernameException;
  24 import org.signal.libsignal.usernames.Username;
  25 import org.slf4j.Logger;
  26 import org.slf4j.LoggerFactory;
  27 import org.whispersystems.signalservice.api.account.ChangePhoneNumberRequest;
  28 import org.whispersystems.signalservice.api.crypto.UntrustedIdentityException;
  29 import org.whispersystems.signalservice.api.push.ServiceId.ACI;
  30 import org.whispersystems.signalservice.api.push.ServiceId.PNI;
  31 import org.whispersystems.signalservice.api.push.ServiceIdType;
  32 import org.whispersystems.signalservice.api.push.SignalServiceAddress;
  33 import org.whispersystems.signalservice.api.push.SignedPreKeyEntity;
  34 import org.whispersystems.signalservice.api.push.exceptions.AlreadyVerifiedException;
  35 import org.whispersystems.signalservice.api.push.exceptions.AuthorizationFailedException;
  36 import org.whispersystems.signalservice.api.push.exceptions.DeprecatedVersionException;
  37 import org.whispersystems.signalservice.api.push.exceptions.UsernameIsNotReservedException;
  38 import org.whispersystems.signalservice.api.push.exceptions.UsernameMalformedException;
  39 import org.whispersystems.signalservice.api.push.exceptions.UsernameTakenException;
  40 import org.whispersystems.signalservice.api.util.DeviceNameUtil;
  41 import org.whispersystems.signalservice.internal.push.KyberPreKeyEntity;
  42 import org.whispersystems.signalservice.internal.push.OutgoingPushMessage;
  43 import org.whispersystems.signalservice.internal.push.SyncMessage;
  44 import org.whispersystems.signalservice.internal.push.exceptions.MismatchedDevicesException;
  45
  46 import java.io.IOException;
  47 import java.util.ArrayList;
  48 import java.util.HashMap;
  49 import java.util.List;
  50 import java.util.Objects;
  51 import java.util.Optional;
  52 import java.util.concurrent.TimeUnit;
  53
  54 import okio.ByteString;
  55
  56 import static org.asamk.signal.manager.config.ServiceConfig.PREKEY_MAXIMUM_ID;
  57 import static org.whispersystems.signalservice.internal.util.Util.isEmpty;
  58
  59 public class AccountHelper {
  60
  61     private static final Logger logger = LoggerFactory.getLogger(AccountHelper.class);
  62
  63     private final Context context;
  64     private final SignalAccount account;
  65     private final SignalDependencies dependencies;
  66
  67     private Callable unregisteredListener;
  68
  69     public AccountHelper(final Context context) {
  70         this.account = context.getAccount();
  71         this.dependencies = context.getDependencies();
  72         this.context = context;
  73     }
  74
  75     public void setUnregisteredListener(final Callable unregisteredListener) {
  76         this.unregisteredListener = unregisteredListener;
  77     }
  78
  79     public void checkAccountState() throws IOException {
  80         if (account.getLastReceiveTimestamp() == 0) {
  81             logger.info("The Signal protocol expects that incoming messages are regularly received.");
  82         } else {
  83             var diffInMilliseconds = System.currentTimeMillis() - account.getLastReceiveTimestamp();
  84             long days = TimeUnit.DAYS.convert(diffInMilliseconds, TimeUnit.MILLISECONDS);
  85             if (days > 7) {
  86                 logger.warn(
  87                         "Messages have been last received {} days ago. The Signal protocol expects that incoming messages are regularly received.",
  88                         days);
  89             }
  90         }
  91         try {
  92             updateAccountAttributes();
  93             context.getPreKeyHelper().refreshPreKeysIfNecessary();
  94             if (account.getAci() == null || account.getPni() == null) {
  95                 checkWhoAmiI();
  96             }
  97             if (!account.isPrimaryDevice() && account.getPniIdentityKeyPair() == null) {
  98                 context.getSyncHelper().requestSyncPniIdentity();
  99             }
 100             if (account.getPreviousStorageVersion() < 4
 101                     && account.isPrimaryDevice()
 102                     && account.getRegistrationLockPin() != null) {
 103                 migrateRegistrationPin();
 104             }
 105             if (account.getUsername() != null && account.getUsernameLink() == null) {
 106                 try {
 107                     tryToSetUsernameLink(new Username(account.getUsername()));
 108                 } catch (BaseUsernameException e) {
 109                     logger.debug("Invalid local username");
 110                 }
 111             }
 112         } catch (DeprecatedVersionException e) {
 113             logger.debug("Signal-Server returned deprecated version exception", e);
 114             throw e;
 115         } catch (AuthorizationFailedException e) {
 116             account.setRegistered(false);
 117             throw e;
 118         }
 119     }
 120
 121     public void checkWhoAmiI() throws IOException {
 122         final var whoAmI = dependencies.getAccountManager().getWhoAmI();
 123         final var number = whoAmI.getNumber();
 124         final var aci = ACI.parseOrThrow(whoAmI.getAci());
 125         final var pni = PNI.parseOrThrow(whoAmI.getPni());
 126         if (number.equals(account.getNumber()) && aci.equals(account.getAci()) && pni.equals(account.getPni())) {
 127             return;
 128         }
 129
 130         updateSelfIdentifiers(number, aci, pni);
 131     }
 132
 133     private void updateSelfIdentifiers(final String number, final ACI aci, final PNI pni) {
 134         account.setNumber(number);
 135         account.setAci(aci);
 136         account.setPni(pni);
 137         if (account.isPrimaryDevice() && account.getPniIdentityKeyPair() == null) {
 138             account.setPniIdentityKeyPair(KeyUtils.generateIdentityKeyPair());
 139         }
 140         account.getRecipientTrustedResolver().resolveSelfRecipientTrusted(account.getSelfRecipientAddress());
 141         context.getUnidentifiedAccessHelper().rotateSenderCertificates();
 142         dependencies.resetAfterAddressChange();
 143         context.getGroupV2Helper().clearAuthCredentialCache();
 144         context.getAccountFileUpdater().updateAccountIdentifiers(account.getNumber(), account.getAci());
 145         context.getJobExecutor().enqueueJob(new SyncStorageJob());
 146     }
 147
 148     public void setPni(
 149             final PNI updatedPni,
 150             final IdentityKeyPair pniIdentityKeyPair,
 151             final String number,
 152             final int localPniRegistrationId,
 153             final SignedPreKeyRecord pniSignedPreKey,
 154             final KyberPreKeyRecord lastResortKyberPreKey
 155     ) throws IOException {
 156         updateSelfIdentifiers(number != null ? number : account.getNumber(), account.getAci(), updatedPni);
 157         account.setNewPniIdentity(pniIdentityKeyPair, pniSignedPreKey, lastResortKyberPreKey, localPniRegistrationId);
 158         context.getPreKeyHelper().refreshPreKeysIfNecessary(ServiceIdType.PNI);
 159     }
 160
 161     public void startChangeNumber(
 162             String newNumber, boolean voiceVerification, String captcha
 163     ) throws IOException, CaptchaRequiredException, NonNormalizedPhoneNumberException, RateLimitException {
 164         final var accountManager = dependencies.createUnauthenticatedAccountManager(newNumber, account.getPassword());
 165         String sessionId = NumberVerificationUtils.handleVerificationSession(accountManager,
 166                 account.getSessionId(newNumber),
 167                 id -> account.setSessionId(newNumber, id),
 168                 voiceVerification,
 169                 captcha);
 170         NumberVerificationUtils.requestVerificationCode(accountManager, sessionId, voiceVerification);
 171     }
 172
 173     public void finishChangeNumber(
 174             String newNumber, String verificationCode, String pin
 175     ) throws IncorrectPinException, PinLockedException, IOException {
 176         for (var attempts = 0; attempts < 5; attempts++) {
 177             try {
 178                 finishChangeNumberInternal(newNumber, verificationCode, pin);
 179                 break;
 180             } catch (MismatchedDevicesException e) {
 181                 logger.debug("Change number failed with mismatched devices, retrying.");
 182                 try {
 183                     dependencies.getMessageSender().handleChangeNumberMismatchDevices(e.getMismatchedDevices());
 184                 } catch (UntrustedIdentityException ex) {
 185                     throw new AssertionError(ex);
 186                 }
 187             }
 188         }
 189     }
 190
 191     private void finishChangeNumberInternal(
 192             String newNumber, String verificationCode, String pin
 193     ) throws IncorrectPinException, PinLockedException, IOException {
 194         final var pniIdentity = KeyUtils.generateIdentityKeyPair();
 195         final var encryptedDeviceMessages = new ArrayList<OutgoingPushMessage>();
 196         final var devicePniSignedPreKeys = new HashMap<Integer, SignedPreKeyEntity>();
 197         final var devicePniLastResortKyberPreKeys = new HashMap<Integer, KyberPreKeyEntity>();
 198         final var pniRegistrationIds = new HashMap<Integer, Integer>();
 199
 200         final var selfDeviceId = account.getDeviceId();
 201         SyncMessage.PniChangeNumber selfChangeNumber = null;
 202
 203         final var deviceIds = new ArrayList<Integer>();
 204         deviceIds.add(SignalServiceAddress.DEFAULT_DEVICE_ID);
 205         final var aci = account.getAci();
 206         final var accountDataStore = account.getSignalServiceDataStore().aci();
 207         final var subDeviceSessions = accountDataStore.getSubDeviceSessions(aci.toString())
 208                 .stream()
 209                 .filter(deviceId -> accountDataStore.containsSession(new SignalProtocolAddress(aci.toString(),
 210                         deviceId)))
 211                 .toList();
 212         deviceIds.addAll(subDeviceSessions);
 213
 214         final var messageSender = dependencies.getMessageSender();
 215         for (final var deviceId : deviceIds) {
 216             // Signed Prekey
 217             final var signedPreKeyRecord = KeyUtils.generateSignedPreKeyRecord(KeyUtils.getRandomInt(PREKEY_MAXIMUM_ID),
 218                     pniIdentity.getPrivateKey());
 219             final var signedPreKeyEntity = new SignedPreKeyEntity(signedPreKeyRecord.getId(),
 220                     signedPreKeyRecord.getKeyPair().getPublicKey(),
 221                     signedPreKeyRecord.getSignature());
 222             devicePniSignedPreKeys.put(deviceId, signedPreKeyEntity);
 223
 224             // Last-resort kyber prekey
 225             final var lastResortKyberPreKeyRecord = KeyUtils.generateKyberPreKeyRecord(KeyUtils.getRandomInt(
 226                     PREKEY_MAXIMUM_ID), pniIdentity.getPrivateKey());
 227             final var kyberPreKeyEntity = new KyberPreKeyEntity(lastResortKyberPreKeyRecord.getId(),
 228                     lastResortKyberPreKeyRecord.getKeyPair().getPublicKey(),
 229                     lastResortKyberPreKeyRecord.getSignature());
 230             devicePniLastResortKyberPreKeys.put(deviceId, kyberPreKeyEntity);
 231
 232             // Registration Id
 233             var pniRegistrationId = -1;
 234             while (pniRegistrationId < 0 || pniRegistrationIds.containsValue(pniRegistrationId)) {
 235                 pniRegistrationId = KeyHelper.generateRegistrationId(false);
 236             }
 237             pniRegistrationIds.put(deviceId, pniRegistrationId);
 238
 239             // Device Message
 240             final var pniChangeNumber = new SyncMessage.PniChangeNumber.Builder().identityKeyPair(ByteString.of(
 241                             pniIdentity.serialize()))
 242                     .signedPreKey(ByteString.of(signedPreKeyRecord.serialize()))
 243                     .lastResortKyberPreKey(ByteString.of(lastResortKyberPreKeyRecord.serialize()))
 244                     .registrationId(pniRegistrationId)
 245                     .newE164(newNumber)
 246                     .build();
 247
 248             if (deviceId == selfDeviceId) {
 249                 selfChangeNumber = pniChangeNumber;
 250             } else {
 251                 try {
 252                     final var message = messageSender.getEncryptedSyncPniInitializeDeviceMessage(deviceId,
 253                             pniChangeNumber);
 254                     encryptedDeviceMessages.add(message);
 255                 } catch (UntrustedIdentityException | IOException | InvalidKeyException e) {
 256                     throw new RuntimeException(e);
 257                 }
 258             }
 259         }
 260
 261         final var sessionId = account.getSessionId(newNumber);
 262         final var result = NumberVerificationUtils.verifyNumber(sessionId,
 263                 verificationCode,
 264                 pin,
 265                 context.getPinHelper(),
 266                 (sessionId1, verificationCode1, registrationLock) -> {
 267                     final var accountManager = dependencies.getAccountManager();
 268                     try {
 269                         Utils.handleResponseException(accountManager.verifyAccount(verificationCode1, sessionId1));
 270                     } catch (AlreadyVerifiedException e) {
 271                         // Already verified so can continue changing number
 272                     }
 273                     return Utils.handleResponseException(accountManager.changeNumber(new ChangePhoneNumberRequest(
 274                             sessionId1,
 275                             null,
 276                             newNumber,
 277                             registrationLock,
 278                             pniIdentity.getPublicKey(),
 279                             encryptedDeviceMessages,
 280                             Utils.mapKeys(devicePniSignedPreKeys, Object::toString),
 281                             Utils.mapKeys(devicePniLastResortKyberPreKeys, Object::toString),
 282                             Utils.mapKeys(pniRegistrationIds, Object::toString))));
 283                 });
 284
 285         final var updatePni = PNI.parseOrThrow(result.first().getPni());
 286         if (updatePni.equals(account.getPni())) {
 287             logger.debug("PNI is unchanged after change number");
 288             return;
 289         }
 290
 291         handlePniChangeNumberMessage(selfChangeNumber, updatePni);
 292     }
 293
 294     public void handlePniChangeNumberMessage(
 295             final SyncMessage.PniChangeNumber pniChangeNumber, final PNI updatedPni
 296     ) {
 297         if (pniChangeNumber.identityKeyPair != null
 298                 && pniChangeNumber.registrationId != null
 299                 && pniChangeNumber.signedPreKey != null) {
 300             logger.debug("New PNI: {}", updatedPni);
 301             try {
 302                 setPni(updatedPni,
 303                         new IdentityKeyPair(pniChangeNumber.identityKeyPair.toByteArray()),
 304                         pniChangeNumber.newE164,
 305                         pniChangeNumber.registrationId,
 306                         new SignedPreKeyRecord(pniChangeNumber.signedPreKey.toByteArray()),
 307                         pniChangeNumber.lastResortKyberPreKey != null
 308                                 ? new KyberPreKeyRecord(pniChangeNumber.lastResortKyberPreKey.toByteArray())
 309                                 : null);
 310             } catch (Exception e) {
 311                 logger.warn("Failed to handle change number message", e);
 312             }
 313         }
 314     }
 315
 316     public static final int USERNAME_MIN_LENGTH = 3;
 317     public static final int USERNAME_MAX_LENGTH = 32;
 318
 319     public void reserveUsername(String nickname) throws IOException, BaseUsernameException {
 320         final var currentUsername = account.getUsername();
 321         if (currentUsername != null) {
 322             final var currentNickname = currentUsername.substring(0, currentUsername.indexOf('.'));
 323             if (currentNickname.equals(nickname)) {
 324                 try {
 325                     refreshCurrentUsername();
 326                 } catch (IOException | BaseUsernameException e) {
 327                     logger.warn("[reserveUsername] Failed to refresh current username, trying to claim new username");
 328                 }
 329                 return;
 330             }
 331         }
 332
 333         final var candidates = Username.candidatesFrom(nickname, USERNAME_MIN_LENGTH, USERNAME_MAX_LENGTH);
 334         final var candidateHashes = new ArrayList<String>();
 335         for (final var candidate : candidates) {
 336             candidateHashes.add(Base64.encodeUrlSafeWithoutPadding(candidate.getHash()));
 337         }
 338
 339         final var response = dependencies.getAccountManager().reserveUsername(candidateHashes);
 340         final var hashIndex = candidateHashes.indexOf(response.getUsernameHash());
 341         if (hashIndex == -1) {
 342             logger.warn("[reserveUsername] The response hash could not be found in our set of candidateHashes.");
 343             throw new IOException("Unexpected username response");
 344         }
 345
 346         logger.debug("[reserveUsername] Successfully reserved username.");
 347         final var username = candidates.get(hashIndex);
 348
 349         final var linkComponents = dependencies.getAccountManager().confirmUsernameAndCreateNewLink(username);
 350         account.setUsername(username.getUsername());
 351         account.setUsernameLink(linkComponents);
 352         account.getRecipientStore().resolveSelfRecipientTrusted(account.getSelfRecipientAddress());
 353         logger.debug("[confirmUsername] Successfully confirmed username.");
 354     }
 355
 356     public void refreshCurrentUsername() throws IOException, BaseUsernameException {
 357         final var localUsername = account.getUsername();
 358         if (localUsername == null) {
 359             return;
 360         }
 361
 362         final var whoAmIResponse = dependencies.getAccountManager().getWhoAmI();
 363         final var serverUsernameHash = whoAmIResponse.getUsernameHash();
 364         final var hasServerUsername = !isEmpty(serverUsernameHash);
 365         final var username = new Username(localUsername);
 366         final var localUsernameHash = Base64.encodeUrlSafeWithoutPadding(username.getHash());
 367
 368         if (!hasServerUsername) {
 369             logger.debug("No remote username is set.");
 370         }
 371
 372         if (!Objects.equals(localUsernameHash, serverUsernameHash)) {
 373             logger.debug("Local username hash does not match server username hash.");
 374         }
 375
 376         if (!hasServerUsername || !Objects.equals(localUsernameHash, serverUsernameHash)) {
 377             logger.debug("Attempting to resynchronize username.");
 378             try {
 379                 tryReserveConfirmUsername(username);
 380             } catch (UsernameMalformedException | UsernameTakenException | UsernameIsNotReservedException e) {
 381                 logger.debug("[confirmUsername] Failed to reserve confirm username: {} ({})",
 382                         e.getMessage(),
 383                         e.getClass().getSimpleName());
 384                 account.setUsername(null);
 385                 account.setUsernameLink(null);
 386                 throw e;
 387             }
 388         } else {
 389             logger.debug("Username already set, not refreshing.");
 390         }
 391     }
 392
 393     private void tryReserveConfirmUsername(final Username username) throws IOException {
 394         final var usernameLink = account.getUsernameLink();
 395
 396         if (usernameLink == null) {
 397             dependencies.getAccountManager()
 398                     .reserveUsername(List.of(Base64.encodeUrlSafeWithoutPadding(username.getHash())));
 399             logger.debug("[reserveUsername] Successfully reserved existing username.");
 400             final var linkComponents = dependencies.getAccountManager().confirmUsernameAndCreateNewLink(username);
 401             account.setUsernameLink(linkComponents);
 402             logger.debug("[confirmUsername] Successfully confirmed existing username.");
 403         } else {
 404             final var linkComponents = dependencies.getAccountManager().reclaimUsernameAndLink(username, usernameLink);
 405             account.setUsernameLink(linkComponents);
 406             logger.debug("[confirmUsername] Successfully reclaimed existing username and link.");
 407         }
 408     }
 409
 410     private void tryToSetUsernameLink(Username username) {
 411         for (var i = 1; i < 4; i++) {
 412             try {
 413                 final var linkComponents = dependencies.getAccountManager().createUsernameLink(username);
 414                 account.setUsernameLink(linkComponents);
 415                 break;
 416             } catch (IOException e) {
 417                 logger.debug("[tryToSetUsernameLink] Failed with IOException on attempt {}/3", i, e);
 418             }
 419         }
 420     }
 421
 422     public void deleteUsername() throws IOException {
 423         dependencies.getAccountManager().deleteUsername();
 424         account.setUsername(null);
 425         logger.debug("[deleteUsername] Successfully deleted the username.");
 426     }
 427
 428     public void setDeviceName(String deviceName) {
 429         final var privateKey = account.getAciIdentityKeyPair().getPrivateKey();
 430         final var encryptedDeviceName = DeviceNameUtil.encryptDeviceName(deviceName, privateKey);
 431         account.setEncryptedDeviceName(encryptedDeviceName);
 432     }
 433
 434     public void updateAccountAttributes() throws IOException {
 435         dependencies.getAccountManager().setAccountAttributes(account.getAccountAttributes(null));
 436     }
 437
 438     public void addDevice(DeviceLinkUrl deviceLinkInfo) throws IOException, InvalidDeviceLinkException {
 439         var verificationCode = dependencies.getAccountManager().getNewDeviceVerificationCode();
 440
 441         try {
 442             dependencies.getAccountManager()
 443                     .addDevice(deviceLinkInfo.deviceIdentifier(),
 444                             deviceLinkInfo.deviceKey(),
 445                             account.getAciIdentityKeyPair(),
 446                             account.getPniIdentityKeyPair(),
 447                             account.getProfileKey(),
 448                             account.getOrCreatePinMasterKey(),
 449                             verificationCode);
 450         } catch (InvalidKeyException e) {
 451             throw new InvalidDeviceLinkException("Invalid device link", e);
 452         }
 453         account.setMultiDevice(true);
 454         context.getJobExecutor().enqueueJob(new SyncStorageJob());
 455     }
 456
 457     public void removeLinkedDevices(int deviceId) throws IOException {
 458         dependencies.getAccountManager().removeDevice(deviceId);
 459         var devices = dependencies.getAccountManager().getDevices();
 460         account.setMultiDevice(devices.size() > 1);
 461     }
 462
 463     public void migrateRegistrationPin() throws IOException {
 464         var masterKey = account.getOrCreatePinMasterKey();
 465
 466         context.getPinHelper().migrateRegistrationLockPin(account.getRegistrationLockPin(), masterKey);
 467         dependencies.getAccountManager().enableRegistrationLock(masterKey);
 468     }
 469
 470     public void setRegistrationPin(String pin) throws IOException {
 471         var masterKey = account.getOrCreatePinMasterKey();
 472
 473         context.getPinHelper().setRegistrationLockPin(pin, masterKey);
 474         dependencies.getAccountManager().enableRegistrationLock(masterKey);
 475
 476         account.setRegistrationLockPin(pin);
 477     }
 478
 479     public void removeRegistrationPin() throws IOException {
 480         // Remove KBS Pin
 481         context.getPinHelper().removeRegistrationLockPin();
 482         dependencies.getAccountManager().disableRegistrationLock();
 483
 484         account.setRegistrationLockPin(null);
 485     }
 486
 487     public void unregister() throws IOException {
 488         // When setting an empty GCM id, the Signal-Server also sets the fetchesMessages property to false.
 489         // If this is the primary device, other users can't send messages to this number anymore.
 490         // If this is a linked device, other users can still send messages, but this device doesn't receive them anymore.
 491         dependencies.getAccountManager().setGcmId(Optional.empty());
 492
 493         account.setRegistered(false);
 494         unregisteredListener.call();
 495     }
 496
 497     public void deleteAccount() throws IOException {
 498         try {
 499             context.getPinHelper().removeRegistrationLockPin();
 500         } catch (IOException e) {
 501             logger.warn("Failed to remove registration lock pin");
 502         }
 503         account.setRegistrationLockPin(null);
 504
 505         dependencies.getAccountManager().deleteAccount();
 506
 507         account.setRegistered(false);
 508         unregisteredListener.call();
 509     }
 510
 511     public interface Callable {
 512
 513         void call();
 514     }
 515 }