signalmeow/receiving: handle sync messages sent to PNIs properly

* store destination E.164 numbers received in sync messages
* fetch PNI identity from server if it isn't found in database when handling
  PNI signature message

pkg/connector/chatinfo.go

@@ -50,15 +50,15 @@ func (s *SignalClient) GetUserInfo(ctx context.Context, ghost *bridgev2.Ghost) (
 	return s.contactToUserInfo(contact), nil
 }
 
-func (s *SignalClient) GetChatInfo(ctx context.Context, portal *bridgev2.Portal) (*bridgev2.PortalInfo, error) {
+func (s *SignalClient) GetChatInfo(ctx context.Context, portal *bridgev2.Portal) (*bridgev2.ChatInfo, error) {
 	userID, groupID, err := parsePortalID(portal.ID)
 	if err != nil {
 		return nil, err
 	}
 	if groupID != "" {
 		return s.getGroupInfo(ctx, groupID, 0)
 	} else {
-		aci, pni := serviceIDToACIAndPNI(userID)
+		aci, pni := userID.ToACIAndPNI()
 		contact, err := s.Client.Store.RecipientStore.LoadAndUpdateRecipient(ctx, aci, pni, nil)
 		if err != nil {
 			return nil, err
@@ -251,11 +251,3 @@ func makeAvatarPathID(avatarPath string) networkid.AvatarID {
 	}
 	return networkid.AvatarID("path:" + avatarPath)
 }
-
-func serviceIDToACIAndPNI(serviceID libsignalgo.ServiceID) (aci, pni uuid.UUID) {
-	if serviceID.Type == libsignalgo.ServiceIDTypeACI {
-		return serviceID.UUID, uuid.Nil
-	} else {
-		return uuid.Nil, serviceID.UUID
-	}
-}

pkg/libsignalgo/serviceid.go

@@ -81,6 +81,14 @@ func NewACIServiceID(uuid uuid.UUID) ServiceID {
 	}
 }
 
+func (s ServiceID) ToACIAndPNI() (aci, pni uuid.UUID) {
+	if s.Type == ServiceIDTypeACI {
+		return s.UUID, uuid.Nil
+	} else {
+		return uuid.Nil, s.UUID
+	}
+}
+
 func (s ServiceID) IsEmpty() bool {
 	return s.UUID == uuid.Nil
 }

pkg/signalmeow/receiving.go

@@ -734,6 +734,13 @@ func (cli *Client) handleDecryptedResult(
 					log.Err(err).Msg("Sync message destination parse error")
 					return err
 				}
+				if syncSent.GetDestinationE164() != "" {
+					aci, pni := syncDestinationServiceID.ToACIAndPNI()
+					_, err = cli.Store.RecipientStore.UpdateRecipientE164(ctx, aci, pni, syncSent.GetDestinationE164())
+					if err != nil {
+						log.Err(err).Msg("Failed to update recipient E164 after receiving sync message")
+					}
+				}
 			}
 			if destination == nil && syncSent.GetMessage().GetGroupV2() == nil && syncSent.GetEditMessage().GetDataMessage().GetGroupV2() == nil {
 				log.Warn().Msg("sync message sent destination is nil")
@@ -913,7 +920,18 @@ func (cli *Client) handlePNISignatureMessage(ctx context.Context, sender libsign
 	if err != nil {
 		return fmt.Errorf("failed to get identity for PNI %s: %w", pni, err)
 	} else if pniIdentity == nil {
-		return fmt.Errorf("identity not found for PNI %s", pni)
+		zerolog.Ctx(ctx).Debug().
+			Stringer("aci", sender.UUID).
+			Stringer("pni", pni).
+			Msg("Fetching PNI identity for signature verification as it wasn't found in store")
+		err = cli.FetchAndProcessPreKey(ctx, pniServiceID, 0)
+		if err != nil {
+			return fmt.Errorf("failed to fetch prekey for PNI %s after identity wasn't found in store: %w", pni, err)
+		} else if pniIdentity, err = cli.Store.IdentityKeyStore.GetIdentityKey(ctx, pniServiceID); err != nil {
+			return fmt.Errorf("failed to get identity for PNI %s after fetching: %w", pni, err)
+		} else if pniIdentity == nil {
+			return fmt.Errorf("identity not found for PNI %s even after fetching", pni)
+		}
 	}
 	aciIdentity, err := cli.Store.IdentityKeyStore.GetIdentityKey(ctx, sender)
 	if err != nil {