Fixed race condition for link initiators on timed out link establishment

RNS/Link.py

@@ -264,6 +264,7 @@ class Link:
         self.had_outbound()
 
     def validate_proof(self, packet):
+        try:
             if self.status == Link.PENDING:
                 if self.initiator and len(packet.data) == RNS.Identity.SIGLENGTH//8+Link.ECPUBSIZE//2:
                     peer_pub_bytes = packet.data[RNS.Identity.SIGLENGTH//8:RNS.Identity.SIGLENGTH//8+Link.ECPUBSIZE//2]
@@ -276,6 +277,9 @@ class Link:
                     signature = packet.data[:RNS.Identity.SIGLENGTH//8]
                     
                     if self.destination.identity.validate(signature, signed_data):
+                        if self.status != Link.PENDING:
+                            raise IOError("Invalid link state for proof validation")
+
                         self.rtt = time.time() - self.request_time
                         self.attached_interface = packet.receiving_interface
                         self.__remote_identity = self.destination.identity
@@ -300,6 +304,11 @@ class Link:
                     else:
                         RNS.log("Invalid link proof signature received by "+str(self)+". Ignoring.", RNS.LOG_DEBUG)
         
+        except Exception as e:
+            self.status = Link.CLOSED
+            RNS.log("An error ocurred while validating link request proof on "+str(self)+".", RNS.LOG_ERROR)
+            RNS.log("The contained exception was: "+str(e), RNS.LOG_ERROR)
+
 
     def identify(self, identity):
         """
@@ -520,16 +529,16 @@ class Link:
                     next_check = self.request_time + self.establishment_timeout
                     sleep_time = next_check - time.time()
                     if time.time() >= self.request_time + self.establishment_timeout:
-                        if self.initiator:
-                            RNS.log("Timeout waiting for link request proof", RNS.LOG_DEBUG)
-                        else:
-                            RNS.log("Timeout waiting for RTT packet from link initiator", RNS.LOG_DEBUG)
-
                         self.status = Link.CLOSED
                         self.teardown_reason = Link.TIMEOUT
                         self.link_closed()
                         sleep_time = 0.001
 
+                        if self.initiator:
+                            RNS.log("Timeout waiting for link request proof", RNS.LOG_DEBUG)
+                        else:
+                            RNS.log("Timeout waiting for RTT packet from link initiator", RNS.LOG_DEBUG)
+
                 elif self.status == Link.ACTIVE:
                     activated_at = self.activated_at if self.activated_at != None else 0
                     last_inbound = max(max(self.last_inbound, self.last_proof), activated_at)
@@ -847,7 +856,7 @@ class Link:
                 try:
                     self.fernet = Fernet(self.derived_key)
                 except Exception as e:
-                    RNS.log("Could not "+str(self)+" instantiate Fernet while performin encryption on link. The contained exception was: "+str(e), RNS.LOG_ERROR)
+                    RNS.log("Could not instantiate Fernet while performin encryption on link "+str(self)+". The contained exception was: "+str(e), RNS.LOG_ERROR)
                     raise e
 
             return self.fernet.encrypt(plaintext)

RNS/Transport.py

@@ -1741,6 +1741,8 @@ class Transport:
     def activate_link(link):
         RNS.log("Activating link "+str(link), RNS.LOG_EXTREME)
         if link in Transport.pending_links:
+            if link.status != Link.PENDING:
+                raise IOError("Invalid link state for link activation")
             Transport.pending_links.remove(link)
             Transport.active_links.append(link)
             link.status = RNS.Link.ACTIVE

RNS/_version.py

@@ -1 +1 @@
-__version__ = "0.5.4"
+__version__ = "0.5.5"