From: t3sserakt <t3ss@posteo.de>
Date: Wed, 22 Jan 2020 17:30:53 +0000 (+0100)
Subject: added logic for checking the peer that created a connection with monotonic time
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=5bd6288c9418b86501dc9a948b10356dd3064d8f;p=oweals%2Fgnunet.git

added logic for checking the peer that created a connection with monotonic time
---

diff --git a/src/cadet/cadet_protocol.h b/src/cadet/cadet_protocol.h
index 91c716609..67c76755b 100644
--- a/src/cadet/cadet_protocol.h
+++ b/src/cadet/cadet_protocol.h
@@ -85,10 +85,16 @@ struct GNUNET_CADET_ConnectionCreateMessage
   uint32_t options GNUNET_PACKED;
 
   /**
-   * Infomation of known tunnel state to keep two peers synced. (xrs,t3ss)
-   * FIXME: find better var name.
+   *  This monotonic time is set, if a peer likes to trigger a KX, but is not
+   *  the peer that should start the KX. (xrs,t3ss)
    */
-  int tunnel_up;
+  struct GNUNET_TIME_Absolute monotime;
+
+  /**
+   *  We sign the monotime. The receiving peer can check the signature, to verify
+   *  the sending peer.
+   */
+  struct GNUNET_CRYPTO_EddsaSignature monotime_sig;
 
   /**
    * ID of the connection
diff --git a/src/cadet/gnunet-service-cadet_connection.c b/src/cadet/gnunet-service-cadet_connection.c
index de304aed7..a6c3e51d4 100644
--- a/src/cadet/gnunet-service-cadet_connection.c
+++ b/src/cadet/gnunet-service-cadet_connection.c
@@ -622,11 +622,11 @@ send_create (void *cls)
 
   // check for tunnel state and define tunnel_up (xrs,t3ss)
   t = GCP_get_tunnel (cc->destination, GNUNET_YES);
-  if (NULL != t) 
+  if (NULL != t && (GCT_get_estate(t) == CADET_TUNNEL_KEY_UNINITIALIZED) && 
+                            (GCT_alice_or_betty (GCP_get_id(cc->destination)) == GNUNET_NO)) 
   {
-    create_msg->tunnel_up = (GCT_get_estate(t) == CADET_TUNNEL_KEY_UNINITIALIZED) && 
-                            (GCT_alice_or_betty (GCP_get_id(cc->destination)) == GNUNET_NO) 
-                            ? GNUNET_NO : GNUNET_YES;
+    create_msg->monotime = GNUNET_TIME_absolute_get_monotonic(we_need_config_handle_here);
+    create_msg->monotime_sig = create_monotime_sig(create_msg->monotime);
   }
 
   pids = (struct GNUNET_PeerIdentity *) &create_msg[1];
diff --git a/src/cadet/gnunet-service-cadet_core.c b/src/cadet/gnunet-service-cadet_core.c
index 595392875..7fc131114 100644
--- a/src/cadet/gnunet-service-cadet_core.c
+++ b/src/cadet/gnunet-service-cadet_core.c
@@ -826,7 +826,7 @@ handle_connection_create (
     t = GCP_get_tunnel (sender, GNUNET_YES);
 
     // Check for CADET state in case the other side has lost the tunnel (xrs,t3ss)
-    if ((GNUNET_NO == msg->tunnel_up) &&
+    if ((NULL != msg->monotime) && check_monotime_sig(msg)
         (CADET_TUNNEL_KEY_OK == GCT_get_estate(t)))
     {
       GCT_change_estate (t, CADET_TUNNEL_KEY_UNINITIALIZED);