From 782d889cc563f47d4ea540ce490867e596e89add Mon Sep 17 00:00:00 2001
From: Daniel Gultsch <daniel@gultsch.de>
Date: Mon, 17 Jun 2019 09:51:49 +0200
Subject: [PATCH] disallow subsequent session-accept

---
 .../xmpp/jingle/JingleConnection.java         | 25 ++++++++++---------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/src/main/java/eu/siacs/conversations/xmpp/jingle/JingleConnection.java b/src/main/java/eu/siacs/conversations/xmpp/jingle/JingleConnection.java
index 3ec9b5359..1ec5f2714 100644
--- a/src/main/java/eu/siacs/conversations/xmpp/jingle/JingleConnection.java
+++ b/src/main/java/eu/siacs/conversations/xmpp/jingle/JingleConnection.java
@@ -234,7 +234,6 @@ public class JingleConnection implements Transferable {
         } else if (packet.isAction("session-accept")) {
             returnResult = receiveAccept(packet);
         } else if (packet.isAction("session-info")) {
-            returnResult = true;
             Element checksum = packet.getChecksum();
             Element file = checksum == null ? null : checksum.findChild("file");
             Element hash = file == null ? null : file.findChild("hash", "urn:xmpp:hashes:2");
@@ -378,6 +377,9 @@ public class JingleConnection implements Transferable {
         this.initialTransport = content.hasSocks5Transport() ? Transport.SOCKS : Transport.IBB;
         this.contentName = content.getAttribute("name");
         this.transportId = content.getTransportId();
+
+        mXmppConnectionService.sendIqPacket(account, packet.generateResponse(IqPacket.TYPE.RESULT), null);
+
         if (this.initialTransport == Transport.SOCKS) {
             this.mergeCandidates(JingleCandidate.parse(content.socks5transport().getChildren()));
         } else if (this.initialTransport == Transport.IBB) {
@@ -392,7 +394,7 @@ public class JingleConnection implements Transferable {
                     return;
                 }
             } else {
-                Log.d(Config.LOGTAG, "received block size =" + receivedBlockSize);
+                Log.d(Config.LOGTAG, "received block size was null");
                 this.sendCancel();
                 this.fail();
                 return;
@@ -406,8 +408,6 @@ public class JingleConnection implements Transferable {
         }
         this.fileOffer = content.getFileOffer(this.ftVersion);
 
-        mXmppConnectionService.sendIqPacket(account, packet.generateResponse(IqPacket.TYPE.RESULT), null);
-
         if (fileOffer != null) {
             Element encrypted = fileOffer.findChild("encrypted", AxolotlService.PEP_PREFIX);
             if (encrypted != null) {
@@ -637,12 +637,17 @@ public class JingleConnection implements Transferable {
     }
 
     private boolean receiveAccept(JinglePacket packet) {
+        if (this.mJingleStatus != JINGLE_STATUS_INITIATED) {
+            Log.d(Config.LOGTAG,account.getJid().asBareJid()+": received out of order session-accept");
+            return false;
+        }
         this.mJingleStatus = JINGLE_STATUS_ACCEPTED;
         mXmppConnectionService.markMessage(message, Message.STATUS_UNSEND);
         Content content = packet.getJingleContent();
         if (content.hasSocks5Transport()) {
             mergeCandidates(JingleCandidate.parse(content.socks5transport().getChildren()));
             this.connectNextCandidate();
+            return true;
         } else if (content.hasIbbTransport()) {
             String receivedBlockSize = packet.getJingleContent().ibbTransport().getAttribute("block-size");
             if (receivedBlockSize != null) {
@@ -653,8 +658,10 @@ public class JingleConnection implements Transferable {
             }
             this.transport = new JingleInbandTransport(this, this.transportId, this.ibbBlockSize);
             this.transport.connect(onIbbTransportConnected);
+            return true;
+        } else {
+            return false;
         }
-        return true;
     }
 
     private boolean receiveTransportInfo(JinglePacket packet) {
@@ -1110,13 +1117,7 @@ public class JingleConnection implements Transferable {
     public boolean start() {
         if (account.getStatus() == Account.State.ONLINE) {
             if (mJingleStatus == JINGLE_STATUS_INITIATED) {
-                new Thread(new Runnable() {
-
-                    @Override
-                    public void run() {
-                        sendAccept();
-                    }
-                }).start();
+                new Thread(this::sendAccept).start();
             }
             return true;
         } else {