Fixes

bramble-core/src/main/java/org/briarproject/bramble/mailbox/AbstractMailboxSession.java

@@ -252,7 +252,7 @@ public abstract class AbstractMailboxSession implements Runnable {
 
 		StreamContext ctx =
 				keyManager
-						.getStreamContext(targetContactId, MailboxConstants.ID);
+						.getStreamContext(c, MailboxConstants.ID);
 
 		if (ctx == null)
 			throw new IOException("Could not allocated stream context");

bramble-core/src/main/java/org/briarproject/bramble/mailbox/PrivateMailboxSession.java

@@ -3,6 +3,7 @@ package org.briarproject.bramble.mailbox;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.mailbox.MailboxInfo;
 import org.briarproject.bramble.api.sync.SyncSessionFactory;
 import org.briarproject.bramble.api.transport.KeyManager;
 import org.briarproject.bramble.api.transport.StreamContext;
@@ -75,6 +76,8 @@ public class PrivateMailboxSession extends AbstractMailboxSession {
 			return;
 		}
 
+		if (encryptedStream == null)
+			return;
 		MailboxRequest req =
 				new MailboxRequestStore(mailboxInfo.getAliasId(),
 						encryptedStream);