Fetch bundles on-demand, encrypt in background

Bundles are now fetched on demand when a session needs to be
established. This should lessen the chance of changes to the bundles
occuring before they're used, as well as lessen the load of fetching
bundles.

Also, the message encryption is now done in a background thread, as this
can be somewhat costly if many sessions are present. This is probably
not going to be an issue in real use, but it's good practice anyway.

1 files changed, 91 insertions, 42 deletions

diff --git a/src/main/java/eu/siacs/conversations/crypto/axolotl/AxolotlService.java b/src/main/java/eu/siacs/conversations/crypto/axolotl/AxolotlService.java
index e4c0480a..54394dd2 100644
--- a/src/main/java/eu/siacs/conversations/crypto/axolotl/AxolotlService.java
+++ b/src/main/java/eu/siacs/conversations/crypto/axolotl/AxolotlService.java
@@ -1,5 +1,6 @@
 package eu.siacs.conversations.crypto.axolotl;
 
+import android.support.annotation.Nullable;
 import android.util.Base64;
 import android.util.Log;
 
@@ -42,13 +43,16 @@ import eu.siacs.conversations.Config;
 import eu.siacs.conversations.entities.Account;
 import eu.siacs.conversations.entities.Contact;
 import eu.siacs.conversations.entities.Conversation;
+import eu.siacs.conversations.entities.Message;
 import eu.siacs.conversations.parser.IqParser;
 import eu.siacs.conversations.services.XmppConnectionService;
+import eu.siacs.conversations.utils.SerialSingleThreadExecutor;
 import eu.siacs.conversations.xml.Element;
 import eu.siacs.conversations.xmpp.OnIqPacketReceived;
 import eu.siacs.conversations.xmpp.jid.InvalidJidException;
 import eu.siacs.conversations.xmpp.jid.Jid;
 import eu.siacs.conversations.xmpp.stanzas.IqPacket;
+import eu.siacs.conversations.xmpp.stanzas.MessagePacket;
 
 public class AxolotlService {
 
@@ -62,8 +66,9 @@ public class AxolotlService {
 	private final XmppConnectionService mXmppConnectionService;
 	private final SQLiteAxolotlStore axolotlStore;
 	private final SessionMap sessions;
-	private final BundleMap bundleCache;
 	private final Map<Jid, Set<Integer>> deviceIds;
+	private final FetchStatusMap fetchStatusMap;
+	private final SerialSingleThreadExecutor executor;
 	private int ownDeviceId;
 
 	public static class SQLiteAxolotlStore implements AxolotlStore {
@@ -560,7 +565,13 @@ public class AxolotlService {
 
 	}
 
-	private static class BundleMap extends AxolotlAddressMap<PreKeyBundle> {
+	private static enum FetchStatus {
+		PENDING,
+		SUCCESS,
+		ERROR
+	}
+
+	private static class FetchStatusMap extends AxolotlAddressMap<FetchStatus> {
 
 	}
 
@@ -570,7 +581,8 @@ public class AxolotlService {
 		this.axolotlStore = new SQLiteAxolotlStore(this.account, this.mXmppConnectionService);
 		this.deviceIds = new HashMap<>();
 		this.sessions = new SessionMap(axolotlStore, account);
-		this.bundleCache = new BundleMap();
+		this.fetchStatusMap = new FetchStatusMap();
+		this.executor = new SerialSingleThreadExecutor();
 		this.ownDeviceId = axolotlStore.getLocalRegistrationId();
 	}
 
@@ -793,56 +805,93 @@ public class AxolotlService {
 		}
 	}
 
-	private void createSessionsIfNeeded(Contact contact) throws NoSessionsCreatedException {
+	private boolean createSessionsIfNeeded(Conversation conversation) {
+		boolean newSessions = false;
 		Log.d(Config.LOGTAG, "Creating axolotl sessions if needed...");
-		AxolotlAddress address = new AxolotlAddress(contact.getJid().toBareJid().toString(), 0);
-		for(Integer deviceId: bundleCache.getAll(address).keySet()) {
-			Log.d(Config.LOGTAG, "Processing device ID: " + deviceId);
-			AxolotlAddress remoteAddress = new AxolotlAddress(contact.getJid().toBareJid().toString(), deviceId);
-			if(sessions.get(remoteAddress) == null) {
-				Log.d(Config.LOGTAG, "Building new sesstion for " + deviceId);
-				SessionBuilder builder = new SessionBuilder(this.axolotlStore, remoteAddress);
-				try {
-					builder.process(bundleCache.get(remoteAddress));
-					XmppAxolotlSession session = new XmppAxolotlSession(this.axolotlStore, remoteAddress);
-					sessions.put(remoteAddress, session);
-				} catch (InvalidKeyException e) {
-					Log.d(Config.LOGTAG, "Error building session for " + deviceId+ ": InvalidKeyException, " +e.getMessage());
-				} catch (UntrustedIdentityException e) {
-					Log.d(Config.LOGTAG, "Error building session for " + deviceId+ ": UntrustedIdentityException, " +e.getMessage());
-				}
-			} else {
-				Log.d(Config.LOGTAG, "Already have session for " + deviceId);
+		Jid contactJid = conversation.getContact().getJid().toBareJid();
+		Set<AxolotlAddress> addresses = new HashSet<>();
+		if(deviceIds.get(contactJid) != null) {
+			for(Integer foreignId:this.deviceIds.get(contactJid)) {
+				Log.d(Config.LOGTAG, "Found device "+account.getJid().toBareJid()+":"+foreignId);
+				addresses.add(new AxolotlAddress(contactJid.toString(), foreignId));
+			}
+		} else {
+			Log.e(Config.LOGTAG, "Have no target devices in PEP!");
+		}
+		Log.d(Config.LOGTAG, "Checking own account "+account.getJid().toBareJid());
+		if(deviceIds.get(account.getJid().toBareJid()) != null) {
+			for(Integer ownId:this.deviceIds.get(account.getJid().toBareJid())) {
+				Log.d(Config.LOGTAG, "Found device "+account.getJid().toBareJid()+":"+ownId);
+				addresses.add(new AxolotlAddress(account.getJid().toBareJid().toString(), ownId));
 			}
 		}
-		if(!this.hasAny(contact)) {
-			Log.e(Config.LOGTAG, "No Axolotl sessions available!");
-			throw new NoSessionsCreatedException(); // FIXME: proper error handling
+		for (AxolotlAddress address : addresses) {
+			Log.d(Config.LOGTAG, "Processing device: " + address.toString());
+			FetchStatus status = fetchStatusMap.get(address);
+			XmppAxolotlSession session = sessions.get(address);
+			if ( session == null && ( status == null || status == FetchStatus.ERROR) ) {
+				fetchStatusMap.put(address, FetchStatus.PENDING);
+				this.buildSessionFromPEP(conversation,  address);
+				newSessions = true;
+			} else {
+				Log.d(Config.LOGTAG, "Already have session for " +  address.toString());
+			}
 		}
+		return newSessions;
 	}
 
-	public XmppAxolotlMessage processSending(Contact contact, String outgoingMessage) throws NoSessionsCreatedException {
-		XmppAxolotlMessage message = new XmppAxolotlMessage(contact, ownDeviceId, outgoingMessage);
-		createSessionsIfNeeded(contact);
-		Log.d(Config.LOGTAG, "Building axolotl foreign headers...");
+	@Nullable
+	public XmppAxolotlMessage encrypt(Message message ){
+		final XmppAxolotlMessage axolotlMessage = new XmppAxolotlMessage(message.getContact(),
+				ownDeviceId, message.getBody());
 
-		for(XmppAxolotlSession session : findSessionsforContact(contact)) {
-//            if(!session.isTrusted()) {
-				// TODO: handle this properly
-  //              continue;
-	//        }
-			message.addHeader(session.processSending(message.getInnerKey()));
+		if(findSessionsforContact(axolotlMessage.getContact()).isEmpty()) {
+			return null;
+		}
+		Log.d(Config.LOGTAG, "Building axolotl foreign headers...");
+		for (XmppAxolotlSession session : findSessionsforContact(axolotlMessage.getContact())) {
+			Log.d(Config.LOGTAG, session.remoteAddress.toString());
+			//if(!session.isTrusted()) {
+			// TODO: handle this properly
+			//              continue;
+			//        }
+			axolotlMessage.addHeader(session.processSending(axolotlMessage.getInnerKey()));
 		}
 		Log.d(Config.LOGTAG, "Building axolotl own headers...");
-		for(XmppAxolotlSession session : findOwnSessions()) {
-	//        if(!session.isTrusted()) {
-				// TODO: handle this properly
-	  //          continue;
-		//    }
-			message.addHeader(session.processSending(message.getInnerKey()));
+		for (XmppAxolotlSession session : findOwnSessions()) {
+			Log.d(Config.LOGTAG, session.remoteAddress.toString());
+			//        if(!session.isTrusted()) {
+			// TODO: handle this properly
+			//          continue;
+			//    }
+			axolotlMessage.addHeader(session.processSending(axolotlMessage.getInnerKey()));
 		}
 
-		return message;
+		return axolotlMessage;
+	}
+
+	private void processSending(final Message message) {
+		executor.execute(new Runnable() {
+			@Override
+			public void run() {
+				MessagePacket packet = mXmppConnectionService.getMessageGenerator()
+						.generateAxolotlChat(message);
+				if (packet == null) {
+					mXmppConnectionService.markMessage(message, Message.STATUS_SEND_FAILED);
+				} else {
+					mXmppConnectionService.markMessage(message, Message.STATUS_UNSEND);
+					mXmppConnectionService.sendMessagePacket(account, packet);
+				}
+			}
+		});
+	}
+
+	public void sendMessage(Message message) {
+		boolean newSessions = createSessionsIfNeeded(message.getConversation());
+
+		if (!newSessions) {
+			this.processSending(message);
+		}
 	}
 
 	public XmppAxolotlMessage.XmppAxolotlPlaintextMessage processReceiving(XmppAxolotlMessage message) {