Fix some bugs with PKWM padding and attachment detection.

libaxolotl/src/main/java/org/whispersystems/libaxolotl/SessionCipher.java

@@ -274,6 +274,17 @@ public class SessionCipher {
     }
   }
 
+  public int getSessionVersion() {
+    synchronized (SESSION_LOCK) {
+      if (!sessionStore.containsSession(recipientId, deviceId)) {
+        throw new IllegalStateException(String.format("No session for (%d, %d)!", recipientId, deviceId));
+      }
+
+      SessionRecord record = sessionStore.loadSession(recipientId, deviceId);
+      return record.getSessionState().getSessionVersion();
+    }
+  }
+
   private ChainKey getOrCreateChainKey(SessionState sessionState, ECPublicKey theirEphemeral)
       throws InvalidMessageException
   {

library/src/org/whispersystems/textsecure/api/crypto/TextSecureCipher.java

@@ -1,5 +1,7 @@
 package org.whispersystems.textsecure.api.crypto;
 
+import android.util.Log;
+
 import com.google.protobuf.InvalidProtocolBufferException;
 
 import org.whispersystems.libaxolotl.DuplicateMessageException;
@@ -30,18 +32,14 @@ import static org.whispersystems.textsecure.push.PushMessageProtos.PushMessageCo
 
 public class TextSecureCipher {
 
-  private final SessionCipher        sessionCipher;
+  private final SessionCipher sessionCipher;
-  private final PushTransportDetails transportDetails;
 
   public TextSecureCipher(AxolotlStore axolotlStore, long recipientId, int deviceId) {
-    int sessionVersion = axolotlStore.loadSession(recipientId, deviceId)
+    this.sessionCipher = new SessionCipher(axolotlStore, recipientId, deviceId);
-                                     .getSessionState().getSessionVersion();
-
-    this.transportDetails = new PushTransportDetails(sessionVersion);
-    this.sessionCipher    = new SessionCipher(axolotlStore, recipientId, deviceId);
   }
 
   public CiphertextMessage encrypt(byte[] unpaddedMessage) {
+    PushTransportDetails transportDetails = new PushTransportDetails(sessionCipher.getSessionVersion());
     return sessionCipher.encrypt(transportDetails.getPaddedMessageBody(unpaddedMessage));
   }
 
@@ -63,7 +61,9 @@ public class TextSecureCipher {
         throw new InvalidMessageException("Unknown type: " + envelope.getType());
       }
 
-      PushMessageContent content = PushMessageContent.parseFrom(transportDetails.getStrippedPaddingMessageBody(paddedMessage));
+      PushTransportDetails transportDetails = new PushTransportDetails(sessionCipher.getSessionVersion());
+      PushMessageContent   content          = PushMessageContent.parseFrom(transportDetails.getStrippedPaddingMessageBody(paddedMessage));
+
       return createTextSecureMessage(envelope, content);
     } catch (InvalidProtocolBufferException e) {
       throw new InvalidMessageException(e);

library/src/org/whispersystems/textsecure/api/messages/TextSecureMessage.java

@@ -27,11 +27,16 @@ public class TextSecureMessage {
 
   public TextSecureMessage(long timestamp, TextSecureGroup group, List<TextSecureAttachment> attachments, String body, boolean secure, boolean endSession) {
     this.timestamp   = timestamp;
-    this.attachments = Optional.fromNullable(attachments);
     this.body        = Optional.fromNullable(body);
     this.group       = Optional.fromNullable(group);
     this.secure      = secure;
     this.endSession  = endSession;
+
+    if (attachments != null && !attachments.isEmpty()) {
+      this.attachments = Optional.of(attachments);
+    } else {
+      this.attachments = Optional.absent();
+    }
   }
 
   public long getTimestamp() {

src/org/thoughtcrime/securesms/jobs/PushDecryptJob.java

@@ -101,6 +101,10 @@ public class PushDecryptJob extends MasterSecretJob {
       else if (message.isGroupUpdate())              handleGroupMessage(masterSecret, envelope, message);
       else if (message.getAttachments().isPresent()) handleMediaMessage(masterSecret, envelope, message);
       else                                           handleTextMessage(masterSecret, envelope, message);
+
+      if (envelope.isPreKeyWhisperMessage()) {
+        ApplicationContext.getInstance(context).getJobManager().add(new RefreshPreKeysJob(context));
+      }
     } catch (InvalidVersionException e) {
       Log.w(TAG, e);
       handleInvalidVersionMessage(masterSecret, envelope);

src/org/thoughtcrime/securesms/push/SecurityEventListener.java

@@ -2,15 +2,16 @@ package org.thoughtcrime.securesms.push;
 
 import android.content.Context;
 
-import org.thoughtcrime.securesms.ApplicationContext;
 import org.thoughtcrime.securesms.crypto.SecurityEvent;
 import org.thoughtcrime.securesms.database.DatabaseFactory;
-import org.thoughtcrime.securesms.jobs.RefreshPreKeysJob;
 import org.thoughtcrime.securesms.recipients.RecipientFactory;
 import org.thoughtcrime.securesms.recipients.Recipients;
 import org.whispersystems.textsecure.api.TextSecureMessageSender;
 
 public class SecurityEventListener implements TextSecureMessageSender.EventListener {
+
+  private static final String TAG = SecurityEventListener.class.getSimpleName();
+
   private final Context context;
 
   public SecurityEventListener(Context context) {
@@ -23,10 +24,6 @@ public class SecurityEventListener implements TextSecureMessageSender.EventListe
     long       threadId   = DatabaseFactory.getThreadDatabase(context).getThreadIdFor(recipients);
 
     SecurityEvent.broadcastSecurityUpdateEvent(context, threadId);
-
-    ApplicationContext.getInstance(context)
-                      .getJobManager()
-                      .add(new RefreshPreKeysJob(context));
   }
 
 }