public IncomingTextMessage decrypt(Context context, IncomingTextMessage message)
    throws LegacyMessageException, InvalidMessageException, DuplicateMessageException,
           NoSessionException, UntrustedIdentityException
{
  try {
    byte[]        decoded       = transportDetails.getDecodedMessage(message.getMessageBody().getBytes());
    SignalMessage signalMessage = new SignalMessage(decoded);
    SessionCipher sessionCipher = new SessionCipher(signalProtocolStore, new SignalProtocolAddress(message.getSender(), 1));
    byte[]        padded        = sessionCipher.decrypt(signalMessage);
    byte[]        plaintext     = transportDetails.getStrippedPaddingMessageBody(padded);

    if (message.isEndSession() && "TERMINATE".equals(new String(plaintext))) {
      signalProtocolStore.deleteSession(new SignalProtocolAddress(message.getSender(), 1));
    }

    return message.withMessageBody(new String(plaintext));
  } catch (IOException | IllegalArgumentException | NullPointerException e) {
    throw new InvalidMessageException(e);
  }
}
 

public IncomingEncryptedMessage decrypt(Context context, IncomingPreKeyBundleMessage message)
    throws InvalidVersionException, InvalidMessageException, DuplicateMessageException,
           UntrustedIdentityException, LegacyMessageException
{
  try {
    byte[]              decoded       = transportDetails.getDecodedMessage(message.getMessageBody().getBytes());
    PreKeySignalMessage preKeyMessage = new PreKeySignalMessage(decoded);
    SessionCipher       sessionCipher = new SessionCipher(signalProtocolStore, new SignalProtocolAddress(message.getSender(), 1));
    byte[]              padded        = sessionCipher.decrypt(preKeyMessage);
    byte[]              plaintext     = transportDetails.getStrippedPaddingMessageBody(padded);

    return new IncomingEncryptedMessage(message, new String(plaintext));
  } catch (IOException | InvalidKeyException | InvalidKeyIdException e) {
    throw new InvalidMessageException(e);
  }
}
 

private SenderMessageKey getSenderKey(SenderKeyState senderKeyState, int iteration)
    throws DuplicateMessageException, InvalidMessageException
{
  SenderChainKey senderChainKey = senderKeyState.getSenderChainKey();

  if (senderChainKey.getIteration() > iteration) {
    if (senderKeyState.hasSenderMessageKey(iteration)) {
      return senderKeyState.removeSenderMessageKey(iteration);
    } else {
      throw new DuplicateMessageException("Received message with old counter: " +
                                          senderChainKey.getIteration() + " , " + iteration);
    }
  }

  if (iteration - senderChainKey.getIteration() > 2000) {
    throw new InvalidMessageException("Over 2000 messages into the future!");
  }

  while (senderChainKey.getIteration() < iteration) {
    senderKeyState.addSenderMessageKey(senderChainKey.getSenderMessageKey());
    senderChainKey = senderChainKey.getNext();
  }

  senderKeyState.setSenderChainKey(senderChainKey.getNext());
  return senderChainKey.getSenderMessageKey();
}
 

public void testNoSession() throws InvalidMessageException, LegacyMessageException, NoSessionException, DuplicateMessageException {
    InMemorySenderKeyStore aliceStore = new InMemorySenderKeyStore();
    InMemorySenderKeyStore bobStore   = new InMemorySenderKeyStore();

    GroupSessionBuilder aliceSessionBuilder = new GroupSessionBuilder(aliceStore);
    GroupSessionBuilder bobSessionBuilder   = new GroupSessionBuilder(bobStore);

    GroupCipher aliceGroupCipher = new GroupCipher(aliceStore, GROUP_SENDER);
    GroupCipher bobGroupCipher   = new GroupCipher(bobStore, GROUP_SENDER);

    SenderKeyDistributionMessage sentAliceDistributionMessage     = aliceSessionBuilder.create(GROUP_SENDER);
    SenderKeyDistributionMessage receivedAliceDistributionMessage = new SenderKeyDistributionMessage(sentAliceDistributionMessage.serialize());

//    bobSessionBuilder.process(GROUP_SENDER, receivedAliceDistributionMessage);

    byte[] ciphertextFromAlice = aliceGroupCipher.encrypt("smert ze smert".getBytes());
    try {
      byte[] plaintextFromAlice  = bobGroupCipher.decrypt(ciphertextFromAlice);
      throw new AssertionError("Should be no session!");
    } catch (NoSessionException e) {
      // good
    }
  }
 

public void testBasicEncryptDecrypt()
    throws LegacyMessageException, DuplicateMessageException, InvalidMessageException, NoSessionException
{
  InMemorySenderKeyStore aliceStore = new InMemorySenderKeyStore();
  InMemorySenderKeyStore bobStore   = new InMemorySenderKeyStore();

  GroupSessionBuilder aliceSessionBuilder = new GroupSessionBuilder(aliceStore);
  GroupSessionBuilder bobSessionBuilder   = new GroupSessionBuilder(bobStore);

  GroupCipher aliceGroupCipher = new GroupCipher(aliceStore, GROUP_SENDER);
  GroupCipher bobGroupCipher   = new GroupCipher(bobStore, GROUP_SENDER);

  SenderKeyDistributionMessage sentAliceDistributionMessage     = aliceSessionBuilder.create(GROUP_SENDER);
  SenderKeyDistributionMessage receivedAliceDistributionMessage = new SenderKeyDistributionMessage(sentAliceDistributionMessage.serialize());
  bobSessionBuilder.process(GROUP_SENDER, receivedAliceDistributionMessage);

  byte[] ciphertextFromAlice = aliceGroupCipher.encrypt("smert ze smert".getBytes());
  byte[] plaintextFromAlice  = bobGroupCipher.decrypt(ciphertextFromAlice);

  assertTrue(new String(plaintextFromAlice).equals("smert ze smert"));
}
 

public void testLargeMessages() throws InvalidMessageException, LegacyMessageException, NoSessionException, DuplicateMessageException {
  InMemorySenderKeyStore aliceStore = new InMemorySenderKeyStore();
  InMemorySenderKeyStore bobStore   = new InMemorySenderKeyStore();

  GroupSessionBuilder aliceSessionBuilder = new GroupSessionBuilder(aliceStore);
  GroupSessionBuilder bobSessionBuilder   = new GroupSessionBuilder(bobStore);

  GroupCipher aliceGroupCipher = new GroupCipher(aliceStore, GROUP_SENDER);
  GroupCipher bobGroupCipher   = new GroupCipher(bobStore, GROUP_SENDER);

  SenderKeyDistributionMessage sentAliceDistributionMessage     = aliceSessionBuilder.create(GROUP_SENDER);
  SenderKeyDistributionMessage receivedAliceDistributionMessage = new SenderKeyDistributionMessage(sentAliceDistributionMessage.serialize());
  bobSessionBuilder.process(GROUP_SENDER, receivedAliceDistributionMessage);

  byte[] plaintext = new byte[1024 * 1024];
  new Random().nextBytes(plaintext);

  byte[] ciphertextFromAlice = aliceGroupCipher.encrypt(plaintext);
  byte[] plaintextFromAlice  = bobGroupCipher.decrypt(ciphertextFromAlice);

  assertTrue(Arrays.equals(plaintext, plaintextFromAlice));
}
 

private byte[] decrypt(SignalServiceProtos.Envelope envelope, byte[] ciphertext)
    throws InvalidVersionException, InvalidMessageException, InvalidKeyException,
           DuplicateMessageException, InvalidKeyIdException, UntrustedIdentityException,
           LegacyMessageException, NoSessionException
{
  SignalProtocolAddress sourceAddress = new SignalProtocolAddress(envelope.getSource(), envelope.getSourceDevice());
  SessionCipher         sessionCipher = new SessionCipher(signalProtocolStore, sourceAddress);

  byte[] paddedMessage;

  if (envelope.getType() == Type.PREKEY_BUNDLE) {
    paddedMessage = sessionCipher.decrypt(new PreKeySignalMessage(ciphertext));
      //纠正remote register id
      SessionRecord sessionRecord = signalProtocolStore.loadSession(sourceAddress);
      if (sessionRecord.getSessionState().getRemoteRegistrationId() == 0) {
          sessionRecord.getSessionState().setRemoteRegistrationId(envelope.getSourceRegistration());
          signalProtocolStore.storeSession(sourceAddress, sessionRecord);
      }

  } else if (envelope.getType() == Type.CIPHERTEXT) {
    paddedMessage = sessionCipher.decrypt(new SignalMessage(ciphertext));
  } else {
    throw new InvalidMessageException("Unknown type: " + envelope.getType());
  }

  PushTransportDetails transportDetails = new PushTransportDetails(sessionCipher.getSessionVersion());
  return transportDetails.getStrippedPaddingMessageBody(paddedMessage);
}
 

private void handleSecureMessage(MasterSecret masterSecret, long messageId, long threadId,
                                 IncomingTextMessage message)
    throws NoSessionException, DuplicateMessageException,
           InvalidMessageException, LegacyMessageException,
           UntrustedIdentityException
{
  EncryptingSmsDatabase database  = DatabaseFactory.getEncryptingSmsDatabase(context);
  SmsCipher             cipher    = new SmsCipher(new SilenceSignalProtocolStore(context, masterSecret, message.getSubscriptionId()));
  IncomingTextMessage   plaintext = cipher.decrypt(context, message);

  database.updateMessageBody(masterSecret, messageId, plaintext.getMessageBody());

  if (message.isEndSession()) SecurityEvent.broadcastSecurityUpdateEvent(context, threadId);
}
 

private void handleXmppExchangeMessage(MasterSecret masterSecret, long messageId, long threadId,
                                       IncomingXmppExchangeMessage message)
   throws NoSessionException, DuplicateMessageException, InvalidMessageException, LegacyMessageException
{
  EncryptingSmsDatabase database = DatabaseFactory.getEncryptingSmsDatabase(context);
  database.markAsXmppExchange(messageId);
}
 

/**
 * Decrypt a SenderKey group message.
 *
 * @param senderKeyMessageBytes The received ciphertext.
 * @param callback   A callback that is triggered after decryption is complete,
 *                    but before the updated session state has been committed to the session
 *                    DB.  This allows some implementations to store the committed plaintext
 *                    to a DB first, in case they are concerned with a crash happening between
 *                    the time the session state is updated but before they're able to store
 *                    the plaintext to disk.
 * @return Plaintext
 * @throws LegacyMessageException
 * @throws InvalidMessageException
 * @throws DuplicateMessageException
 */
public byte[] decrypt(byte[] senderKeyMessageBytes, DecryptionCallback callback)
    throws LegacyMessageException, InvalidMessageException, DuplicateMessageException,
           NoSessionException
{
  synchronized (LOCK) {
    try {
      SenderKeyRecord record = senderKeyStore.loadSenderKey(senderKeyId);

      if (record.isEmpty()) {
        throw new NoSessionException("No sender key for: " + senderKeyId);
      }

      SenderKeyMessage senderKeyMessage = new SenderKeyMessage(senderKeyMessageBytes);
      SenderKeyState   senderKeyState   = record.getSenderKeyState(senderKeyMessage.getKeyId());

      senderKeyMessage.verifySignature(senderKeyState.getSigningKeyPublic());

      SenderMessageKey senderKey = getSenderKey(senderKeyState, senderKeyMessage.getIteration());

      byte[] plaintext = getPlainText(senderKey.getIv(), senderKey.getCipherKey(), senderKeyMessage.getCipherText());

      callback.handlePlaintext(plaintext);

      senderKeyStore.storeSenderKey(senderKeyId, record);

      return plaintext;
    } catch (org.whispersystems.libsignal.InvalidKeyException | InvalidKeyIdException e) {
      throw new InvalidMessageException(e);
    }
  }
}
 

public void testOutOfOrder()
    throws LegacyMessageException, DuplicateMessageException, InvalidMessageException, NoSessionException
{
  InMemorySenderKeyStore aliceStore = new InMemorySenderKeyStore();
  InMemorySenderKeyStore bobStore   = new InMemorySenderKeyStore();

  GroupSessionBuilder aliceSessionBuilder = new GroupSessionBuilder(aliceStore);
  GroupSessionBuilder bobSessionBuilder   = new GroupSessionBuilder(bobStore);

  SenderKeyName aliceName = GROUP_SENDER;

  GroupCipher aliceGroupCipher = new GroupCipher(aliceStore, aliceName);
  GroupCipher bobGroupCipher   = new GroupCipher(bobStore, aliceName);

  SenderKeyDistributionMessage aliceDistributionMessage =
      aliceSessionBuilder.create(aliceName);

  bobSessionBuilder.process(aliceName, aliceDistributionMessage);

  ArrayList<byte[]> ciphertexts = new ArrayList<>(100);

  for (int i=0;i<100;i++) {
    ciphertexts.add(aliceGroupCipher.encrypt("up the punks".getBytes()));
  }

  while (ciphertexts.size() > 0) {
    int    index      = randomInt() % ciphertexts.size();
    byte[] ciphertext = ciphertexts.remove(index);
    byte[] plaintext  = bobGroupCipher.decrypt(ciphertext);

    assertTrue(new String(plaintext).equals("up the punks"));
  }
}
 

public void testTooFarInFuture() throws DuplicateMessageException, InvalidMessageException, LegacyMessageException, NoSessionException {
  InMemorySenderKeyStore aliceStore = new InMemorySenderKeyStore();
  InMemorySenderKeyStore bobStore   = new InMemorySenderKeyStore();

  GroupSessionBuilder aliceSessionBuilder = new GroupSessionBuilder(aliceStore);
  GroupSessionBuilder bobSessionBuilder   = new GroupSessionBuilder(bobStore);

  SenderKeyName aliceName = GROUP_SENDER;

  GroupCipher aliceGroupCipher = new GroupCipher(aliceStore, aliceName);
  GroupCipher bobGroupCipher   = new GroupCipher(bobStore, aliceName);

  SenderKeyDistributionMessage aliceDistributionMessage = aliceSessionBuilder.create(aliceName);

  bobSessionBuilder.process(aliceName, aliceDistributionMessage);

  for (int i=0;i<2001;i++) {
    aliceGroupCipher.encrypt("up the punks".getBytes());
  }

  byte[] tooFarCiphertext = aliceGroupCipher.encrypt("notta gonna worka".getBytes());
  try {
    bobGroupCipher.decrypt(tooFarCiphertext);
    throw new AssertionError("Should have failed!");
  } catch (InvalidMessageException e) {
    // good
  }
}
 

public void testMessageKeyLimit() throws Exception {
  InMemorySenderKeyStore aliceStore = new InMemorySenderKeyStore();
  InMemorySenderKeyStore bobStore   = new InMemorySenderKeyStore();

  GroupSessionBuilder aliceSessionBuilder = new GroupSessionBuilder(aliceStore);
  GroupSessionBuilder bobSessionBuilder   = new GroupSessionBuilder(bobStore);

  SenderKeyName aliceName = GROUP_SENDER;

  GroupCipher aliceGroupCipher = new GroupCipher(aliceStore, aliceName);
  GroupCipher bobGroupCipher   = new GroupCipher(bobStore, aliceName);

  SenderKeyDistributionMessage aliceDistributionMessage = aliceSessionBuilder.create(aliceName);

  bobSessionBuilder.process(aliceName, aliceDistributionMessage);

  List<byte[]> inflight = new LinkedList<>();

  for (int i=0;i<2010;i++) {
    inflight.add(aliceGroupCipher.encrypt("up the punks".getBytes()));
  }

  bobGroupCipher.decrypt(inflight.get(1000));
  bobGroupCipher.decrypt(inflight.get(inflight.size()-1));

  try {
    bobGroupCipher.decrypt(inflight.get(0));
    throw new AssertionError("Should have failed!");
  } catch (DuplicateMessageException e) {
    // good
  }
}
 

private void storeRetrievedMms(MasterSecret masterSecret, String contentLocation,
                               long messageId, long threadId, EncodedStringValue pduFrom, 
                               EncodedStringValue[] pduTo, EncodedStringValue[] pduCc, PduBody pduBody,
                               long date, boolean isSecure, int subscriptionId)
    throws MmsException, NoSessionException, DuplicateMessageException, InvalidMessageException,
           LegacyMessageException
{
  MmsDatabase           database    = DatabaseFactory.getMmsDatabase(context);
  SingleUseBlobProvider provider    = SingleUseBlobProvider.getInstance();
  String                from        = null;
  List<String>          to          = new LinkedList<>();
  List<String>          cc          = new LinkedList<>();
  String                body        = null;
  List<Attachment>      attachments = new LinkedList<>();

  if (pduFrom != null) {
    from = Util.toIsoString(pduFrom.getTextString());
  }

  if (pduTo != null) {
    for (EncodedStringValue toValue : pduTo) {
      to.add(Util.toIsoString(toValue.getTextString()));
    }
  }

  if (pduCc != null) {
    for (EncodedStringValue ccValue : pduCc) {
      cc.add(Util.toIsoString(ccValue.getTextString()));
    }
  }

  if (pduBody != null) {
    body = PartParser.getMessageText(pduBody);
    PduBody media = PartParser.getSupportedMediaParts(pduBody);

    for (int i=0;i<media.getPartsNum();i++) {
      PduPart part = media.getPart(i);

      if (part.getData() != null) {
        byte[]  decodedDigest = null;

        if (isSecure) {
          PduPart digestPart  = pduBody.getPartByName(Util.toIsoString(part.getName()) + ".digest");
          byte[]  digestBytes = null;

          if (digestPart != null) {
            digestBytes = digestPart.getData();
          }

          if (digestBytes != null) {
            decodedDigest = Base64.decode(digestBytes, Base64.NO_WRAP);
          }

          if (decodedDigest != null) {
            Log.w(TAG, "Available digest for part name " + Util.toIsoString(part.getName()) + " (content id " + Util.toIsoString(part.getContentId()) + "): " + Hex.toString(decodedDigest));
          } else {
            Log.w(TAG, "No available digest for part name " + Util.toIsoString(part.getName()) + " (content id " + Util.toIsoString(part.getContentId()) + ")");
          }
        }

        Uri uri = provider.createUri(part.getData());
        attachments.add(new UriAttachment(uri, Util.toIsoString(part.getContentType()),
                                          AttachmentDatabase.TRANSFER_PROGRESS_DONE,
                                          part.getData().length, decodedDigest));
      }
    }
  }

  IncomingMediaMessage message = new IncomingMediaMessage(from, to, cc, body, date * 1000L, attachments, subscriptionId);

  Pair<Long, Long> messageAndThreadId;

  if (isSecure) {
    messageAndThreadId = database.insertSecureDecryptedMessageInbox(masterSecret, message,
                                                                    threadId);
  } else {
    messageAndThreadId = database.insertMessageInbox(masterSecret, message,
                                                     contentLocation, threadId);
  }

  database.delete(messageId);
  MessageNotifier.updateNotification(context, masterSecret, message.getSubscriptionId());
}
 

public void testBasicRatchet()
    throws LegacyMessageException, DuplicateMessageException, InvalidMessageException, NoSessionException
{
  InMemorySenderKeyStore aliceStore = new InMemorySenderKeyStore();
  InMemorySenderKeyStore bobStore   = new InMemorySenderKeyStore();

  GroupSessionBuilder aliceSessionBuilder = new GroupSessionBuilder(aliceStore);
  GroupSessionBuilder bobSessionBuilder   = new GroupSessionBuilder(bobStore);

  SenderKeyName aliceName = GROUP_SENDER;

  GroupCipher aliceGroupCipher = new GroupCipher(aliceStore, aliceName);
  GroupCipher bobGroupCipher   = new GroupCipher(bobStore, aliceName);

  SenderKeyDistributionMessage sentAliceDistributionMessage =
      aliceSessionBuilder.create(aliceName);
  SenderKeyDistributionMessage receivedAliceDistributionMessage =
      new SenderKeyDistributionMessage(sentAliceDistributionMessage.serialize());

  bobSessionBuilder.process(aliceName, receivedAliceDistributionMessage);

  byte[] ciphertextFromAlice  = aliceGroupCipher.encrypt("smert ze smert".getBytes());
  byte[] ciphertextFromAlice2 = aliceGroupCipher.encrypt("smert ze smert2".getBytes());
  byte[] ciphertextFromAlice3 = aliceGroupCipher.encrypt("smert ze smert3".getBytes());

  byte[] plaintextFromAlice   = bobGroupCipher.decrypt(ciphertextFromAlice);

  try {
    bobGroupCipher.decrypt(ciphertextFromAlice);
    throw new AssertionError("Should have ratcheted forward!");
  } catch (DuplicateMessageException dme) {
    // good
  }

  byte[] plaintextFromAlice2  = bobGroupCipher.decrypt(ciphertextFromAlice2);
  byte[] plaintextFromAlice3  = bobGroupCipher.decrypt(ciphertextFromAlice3);

  assertTrue(new String(plaintextFromAlice).equals("smert ze smert"));
  assertTrue(new String(plaintextFromAlice2).equals("smert ze smert2"));
  assertTrue(new String(plaintextFromAlice3).equals("smert ze smert3"));
}
 

public void testLateJoin() throws NoSessionException, InvalidMessageException, LegacyMessageException, DuplicateMessageException {
  InMemorySenderKeyStore aliceStore = new InMemorySenderKeyStore();
  InMemorySenderKeyStore bobStore   = new InMemorySenderKeyStore();

  GroupSessionBuilder aliceSessionBuilder = new GroupSessionBuilder(aliceStore);


  SenderKeyName aliceName = GROUP_SENDER;

  GroupCipher aliceGroupCipher = new GroupCipher(aliceStore, aliceName);


  SenderKeyDistributionMessage aliceDistributionMessage = aliceSessionBuilder.create(aliceName);
  // Send off to some people.

  for (int i=0;i<100;i++) {
    aliceGroupCipher.encrypt("up the punks up the punks up the punks".getBytes());
  }

  // Now Bob Joins.
  GroupSessionBuilder bobSessionBuilder = new GroupSessionBuilder(bobStore);
  GroupCipher         bobGroupCipher    = new GroupCipher(bobStore, aliceName);


  SenderKeyDistributionMessage distributionMessageToBob = aliceSessionBuilder.create(aliceName);
  bobSessionBuilder.process(aliceName, new SenderKeyDistributionMessage(distributionMessageToBob.serialize()));

  byte[] ciphertext = aliceGroupCipher.encrypt("welcome to the group".getBytes());
  byte[] plaintext  = bobGroupCipher.decrypt(ciphertext);

  assertEquals(new String(plaintext), "welcome to the group");
}
 

/**
 * Decrypt a SenderKey group message.
 *
 * @param senderKeyMessageBytes The received ciphertext.
 * @return Plaintext
 * @throws LegacyMessageException
 * @throws InvalidMessageException
 * @throws DuplicateMessageException
 */
public byte[] decrypt(byte[] senderKeyMessageBytes)
    throws LegacyMessageException, DuplicateMessageException, InvalidMessageException, NoSessionException
{
  return decrypt(senderKeyMessageBytes, new NullDecryptionCallback());
}