/**
* Copyright (C) 2011 Whisper Systems
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package com.securecomcode.text.service;
import android.content.Context;
import android.content.Intent;
import android.util.Log;
import android.util.Pair;
import com.securecomcode.text.crypto.DecryptingQueue;
import com.securecomcode.text.crypto.KeyExchangeProcessor;
import com.securecomcode.text.crypto.KeyExchangeProcessorV2;
import com.securecomcode.text.crypto.MasterSecretUtil;
import com.securecomcode.text.crypto.protocol.KeyExchangeMessage;
import org.whispersystems.textsecure.crypto.LegacyMessageException;
import com.securecomcode.text.database.DatabaseFactory;
import com.securecomcode.text.database.EncryptingSmsDatabase;
import com.securecomcode.text.database.SmsDatabase;
import com.securecomcode.text.notifications.MessageNotifier;
import com.securecomcode.text.protocol.WirePrefix;
import com.securecomcode.text.recipients.Recipient;
import com.securecomcode.text.recipients.RecipientFactory;
import com.securecomcode.text.recipients.RecipientFormattingException;
import com.securecomcode.text.sms.IncomingEncryptedMessage;
import com.securecomcode.text.sms.IncomingKeyExchangeMessage;
import com.securecomcode.text.sms.IncomingPreKeyBundleMessage;
import com.securecomcode.text.sms.IncomingTextMessage;
import com.securecomcode.text.sms.MultipartSmsMessageHandler;
import com.securecomcode.text.sms.SmsTransportDetails;
import com.securecomcode.text.util.TextSecurePreferences;
import org.whispersystems.textsecure.crypto.InvalidKeyException;
import org.whispersystems.textsecure.crypto.InvalidMessageException;
import org.whispersystems.textsecure.crypto.InvalidVersionException;
import org.whispersystems.textsecure.crypto.MasterSecret;
import org.whispersystems.textsecure.crypto.protocol.PreKeyWhisperMessage;
import org.whispersystems.textsecure.crypto.protocol.WhisperMessage;
import org.whispersystems.textsecure.storage.InvalidKeyIdException;
import org.whispersystems.textsecure.storage.RecipientDevice;
import java.io.IOException;
import java.util.List;
public class SmsReceiver {
private MultipartSmsMessageHandler multipartMessageHandler = new MultipartSmsMessageHandler();
private final Context context;
public SmsReceiver(Context context) {
this.context = context;
}
private IncomingTextMessage assembleMessageFragments(List<IncomingTextMessage> messages) {
IncomingTextMessage message = new IncomingTextMessage(messages);
if (WirePrefix.isEncryptedMessage(message.getMessageBody()) ||
WirePrefix.isKeyExchange(message.getMessageBody()) ||
WirePrefix.isPreKeyBundle(message.getMessageBody()) ||
WirePrefix.isEndSession(message.getMessageBody()))
{
return multipartMessageHandler.processPotentialMultipartMessage(message);
} else {
return message;
}
}
private Pair<Long, Long> storeSecureMessage(MasterSecret masterSecret, IncomingTextMessage message) {
Pair<Long, Long> messageAndThreadId = DatabaseFactory.getEncryptingSmsDatabase(context)
.insertMessageInbox(masterSecret, message);
if (masterSecret != null) {
DecryptingQueue.scheduleDecryption(context, masterSecret, messageAndThreadId.first,
messageAndThreadId.second,
message.getSender(), message.getSenderDeviceId(),
message.getMessageBody(), message.isSecureMessage(),
message.isKeyExchange(), message.isEndSession());
}
return messageAndThreadId;
}
private Pair<Long, Long> storeStandardMessage(MasterSecret masterSecret, IncomingTextMessage message) {
EncryptingSmsDatabase encryptingDatabase = DatabaseFactory.getEncryptingSmsDatabase(context);
SmsDatabase plaintextDatabase = DatabaseFactory.getSmsDatabase(context);
if (masterSecret != null) {
return encryptingDatabase.insertMessageInbox(masterSecret, message);
} else if (MasterSecretUtil.hasAsymmericMasterSecret(context)) {
return encryptingDatabase.insertMessageInbox(MasterSecretUtil.getAsymmetricMasterSecret(context, null), message);
} else {
return plaintextDatabase.insertMessageInbox(message);
}
}
private Pair<Long, Long> storePreKeyWhisperMessage(MasterSecret masterSecret,
IncomingPreKeyBundleMessage message)
{
Log.w("SmsReceiver", "Processing prekey message...");
try {
Recipient recipient = RecipientFactory.getRecipientsFromString(context, message.getSender(), false).getPrimaryRecipient();
RecipientDevice recipientDevice = new RecipientDevice(recipient.getRecipientId(), message.getSenderDeviceId());
KeyExchangeProcessorV2 processor = new KeyExchangeProcessorV2(context, masterSecret, recipientDevice);
SmsTransportDetails transportDetails = new SmsTransportDetails();
byte[] rawMessage = transportDetails.getDecodedMessage(message.getMessageBody().getBytes());
PreKeyWhisperMessage preKeyExchange = new PreKeyWhisperMessage(rawMessage);
if (processor.isTrusted(preKeyExchange)) {
processor.processKeyExchangeMessage(preKeyExchange);
WhisperMessage ciphertextMessage = preKeyExchange.getWhisperMessage();
String bundledMessageBody = new String(transportDetails.getEncodedMessage(ciphertextMessage.serialize()));
IncomingEncryptedMessage bundledMessage = new IncomingEncryptedMessage(message, bundledMessageBody);
Pair<Long, Long> messageAndThreadId = storeSecureMessage(masterSecret, bundledMessage);
Intent intent = new Intent(KeyExchangeProcessorV2.SECURITY_UPDATE_EVENT);
intent.putExtra("thread_id", messageAndThreadId.second);
intent.setPackage(context.getPackageName());
context.sendBroadcast(intent, KeyCachingService.KEY_PERMISSION);
return messageAndThreadId;
}
} catch (InvalidKeyException e) {
Log.w("SmsReceiver", e);
message.setCorrupted(true);
} catch (InvalidVersionException e) {
Log.w("SmsReceiver", e);
message.setInvalidVersion(true);
} catch (InvalidKeyIdException e) {
Log.w("SmsReceiver", e);
message.setStale(true);
} catch (IOException e) {
Log.w("SmsReceive", e);
message.setCorrupted(true);
} catch (InvalidMessageException e) {
Log.w("SmsReceiver", e);
message.setCorrupted(true);
} catch (RecipientFormattingException e) {
Log.w("SmsReceiver", e);
message.setCorrupted(true);
}
return storeStandardMessage(masterSecret, message);
}
private Pair<Long, Long> storeKeyExchangeMessage(MasterSecret masterSecret,
IncomingKeyExchangeMessage message)
{
if (masterSecret != null && TextSecurePreferences.isAutoRespondKeyExchangeEnabled(context)) {
try {
Recipient recipient = RecipientFactory.getRecipientsFromString(context, message.getSender(), false).getPrimaryRecipient();
RecipientDevice recipientDevice = new RecipientDevice(recipient.getRecipientId(), message.getSenderDeviceId());
KeyExchangeMessage exchangeMessage = KeyExchangeMessage.createFor(message.getMessageBody());
KeyExchangeProcessor processor = KeyExchangeProcessor.createFor(context, masterSecret, recipientDevice, exchangeMessage);
if (processor.isStale(exchangeMessage)) {
message.setStale(true);
} else if (processor.isTrusted(exchangeMessage)) {
message.setProcessed(true);
Pair<Long, Long> messageAndThreadId = storeStandardMessage(masterSecret, message);
processor.processKeyExchangeMessage(exchangeMessage, messageAndThreadId.second);
return messageAndThreadId;
}
} catch (InvalidVersionException e) {
Log.w("SmsReceiver", e);
message.setInvalidVersion(true);
} catch (InvalidKeyException e) {
Log.w("SmsReceiver", e);
message.setCorrupted(true);
} catch (InvalidMessageException e) {
Log.w("SmsReceiver", e);
message.setCorrupted(true);
} catch (RecipientFormattingException e) {
Log.w("SmsReceiver", e);
message.setCorrupted(true);
} catch (LegacyMessageException e) {
Log.w("SmsReceiver", e);
message.setLegacyVersion(true);
}
}
return storeStandardMessage(masterSecret, message);
}
private Pair<Long, Long> storeMessage(MasterSecret masterSecret, IncomingTextMessage message) {
if (message.isSecureMessage()) return storeSecureMessage(masterSecret, message);
else if (message.isPreKeyBundle()) return storePreKeyWhisperMessage(masterSecret, (IncomingPreKeyBundleMessage) message);
else if (message.isKeyExchange()) return storeKeyExchangeMessage(masterSecret, (IncomingKeyExchangeMessage) message);
else if (message.isEndSession()) return storeSecureMessage(masterSecret, message);
else return storeStandardMessage(masterSecret, message);
}
private void handleReceiveMessage(MasterSecret masterSecret, Intent intent) {
if (intent.getExtras() == null) return;
List<IncomingTextMessage> messagesList = intent.getExtras().getParcelableArrayList("text_messages");
IncomingTextMessage message = assembleMessageFragments(messagesList);
if (message != null) {
Pair<Long, Long> messageAndThreadId = storeMessage(masterSecret, message);
MessageNotifier.updateNotification(context, masterSecret, messageAndThreadId.second);
}
}
public void process(MasterSecret masterSecret, Intent intent) {
if (SendReceiveService.RECEIVE_SMS_ACTION.equals(intent.getAction())) {
handleReceiveMessage(masterSecret, intent);
}
}
}