Merge pull request 'Correctly Handle Messages from Unknown Peers' (#332) from first_contact into master

Reviewed-on: #332

discussion was had about permissions, tracking unknowns, and querying vals of unknowns and changes were made to protect getVal requests, and since the meaning of isApproved is changing to rename isAllowed.

this is to smooth the introduction process of new peers, following a twitter DM style. Protection is still afforded for anyone with BlockUnknownPeers enabled.

Previously described schemes in the 2020 Feb doc on getVal and new peer experience around this that still haven’t been implemented are further shelved for now

peer/cwtch_peer.go

@@ -573,6 +573,9 @@ func (cp *cwtchPeer) Shutdown() {
 }
 
 func (cp *cwtchPeer) StoreMessage(onion string, messageTxt string, sent time.Time) {
+	if cp.GetContact(onion) == nil {
+		cp.AddContact(onion, onion, model.AuthUnknown)
+	}
 	cp.mutex.Lock()
 	cp.Profile.AddMessageToContactTimeline(onion, messageTxt, sent)
 	cp.mutex.Unlock()
@@ -620,18 +623,21 @@ func (cp *cwtchPeer) eventHandler() {
 
 			log.Debugf("NewGetValMessageFromPeer for %v%v from %v\n", scope, path, onion)
 
-			if scope == attr.PublicScope {
-				val, exists := cp.GetAttribute(attr.GetPublicScope(path))
-				resp := event.NewEvent(event.SendRetValMessageToPeer, map[event.Field]string{event.RemotePeer: onion, event.Exists: strconv.FormatBool(exists)})
-				resp.EventID = ev.EventID
-				if exists {
-					resp.Data[event.Data] = val
-				} else {
-					resp.Data[event.Data] = ""
-				}
-				log.Debugf("Responding with SendRetValMessageToPeer exists:%v data: %v\n", exists, val)
+			remotePeer := cp.GetContact(onion)
+			if remotePeer != nil && remotePeer.Authorization == model.AuthApproved {
+				if scope == attr.PublicScope {
+					val, exists := cp.GetAttribute(attr.GetPublicScope(path))
+					resp := event.NewEvent(event.SendRetValMessageToPeer, map[event.Field]string{event.RemotePeer: onion, event.Exists: strconv.FormatBool(exists)})
+					resp.EventID = ev.EventID
+					if exists {
+						resp.Data[event.Data] = val
+					} else {
+						resp.Data[event.Data] = ""
+					}
+					log.Debugf("Responding with SendRetValMessageToPeer exists:%v data: %v\n", exists, val)
 
-				cp.eventBus.Publish(resp)
+					cp.eventBus.Publish(resp)
+				}
 			}
 
 		/***** Non default but requestable handlable events *****/

protocol/connections/engine.go

@@ -195,18 +195,22 @@ func (e *engine) isBlocked(onion string) bool {
 	return authorization.(model.Authorization) == model.AuthBlocked
 }
 
-func (e *engine) isApproved(onion string) bool {
+func (e *engine) isAllowed(onion string) bool {
 	authorization, known := e.authorizations.Load(onion)
 	if !known {
+		log.Errorf("attempted to lookup authorization of onion not in map...that should never happen")
 		return false
 	}
-	return authorization.(model.Authorization) == model.AuthApproved
+	if e.blockUnknownContacts {
+		return authorization.(model.Authorization) == model.AuthApproved
+	}
+	return authorization.(model.Authorization) != model.AuthBlocked
 }
 
 func (e *engine) createPeerTemplate() *PeerApp {
 	peerAppTemplate := new(PeerApp)
 	peerAppTemplate.IsBlocked = e.isBlocked
-	peerAppTemplate.IsApproved = e.isApproved
+	peerAppTemplate.IsAllowed = e.isAllowed
 	peerAppTemplate.MessageHandler = e.handlePeerMessage
 	peerAppTemplate.OnAcknowledgement = e.ignoreOnShutdown2(e.peerAck)
 	peerAppTemplate.OnAuth = e.ignoreOnShutdown(e.peerAuthed)

protocol/connections/peerapp.go

@@ -18,7 +18,7 @@ type PeerApp struct {
 	MessageHandler    func(string, string, string, []byte)
 	RetValHandler     func(string, []byte, []byte)
 	IsBlocked         func(string) bool
-	IsApproved        func(string) bool
+	IsAllowed         func(string) bool
 	OnAcknowledgement func(string, string)
 	OnAuth            func(string)
 	OnClose           func(string)
@@ -48,7 +48,7 @@ func (pa *PeerApp) NewInstance() tapir.Application {
 	newApp := new(PeerApp)
 	newApp.MessageHandler = pa.MessageHandler
 	newApp.IsBlocked = pa.IsBlocked
-	newApp.IsApproved = pa.IsApproved
+	newApp.IsAllowed = pa.IsAllowed
 	newApp.OnAcknowledgement = pa.OnAcknowledgement
 	newApp.OnAuth = pa.OnAuth
 	newApp.OnClose = pa.OnClose
@@ -101,7 +101,7 @@ func (pa *PeerApp) listen() {
 					pa.getValRequests.Delete(peerMessage.ID)
 				}
 			default:
-				if pa.IsApproved(pa.connection.Hostname()) {
+				if pa.IsAllowed(pa.connection.Hostname()) {
 					pa.MessageHandler(pa.connection.Hostname(), peerMessage.ID, peerMessage.Context, peerMessage.Data)
 
 					// Acknowledge the message