fix(messenger)_: make sure display name is legit before sending (#5496)

FIxes https://github.com/status-im/status-desktop/issues/15284

Somehow, the display name could get messed up and when it happened, no message could be received, because we also validate the display name on reception.

I think the problem for the particular user happened because the special display name was added before we enforced it, or through the sync.

protocol/messenger.go

@@ -29,6 +29,7 @@ import (
 	"github.com/ethereum/go-ethereum/p2p"
 	"github.com/status-im/status-go/account"
 	"github.com/status-im/status-go/appmetrics"
+	utils "github.com/status-im/status-go/common"
 	"github.com/status-im/status-go/connection"
 	"github.com/status-im/status-go/contracts"
 	"github.com/status-im/status-go/deprecation"
@@ -902,6 +903,25 @@ func (m *Messenger) Start() (*MessengerResponse, error) {
 		return nil, err
 	}
 
+	displayName, err := m.settings.DisplayName()
+	if err != nil {
+		return nil, err
+	}
+	if err := utils.ValidateDisplayName(&displayName); err != nil {
+		// Somehow a wrong display name was saved. We need to update it so that others accept our messages
+		pubKey, err := m.settings.GetPublicKey()
+		if err != nil {
+			return nil, err
+		}
+		replacementDisplayName := pubKey[:12]
+		m.logger.Warn("unaccepted display name was saved to the setting, reverting to pubkey substring", zap.String("displayName", displayName), zap.String("replacement", replacementDisplayName))
+
+		if err := m.SetDisplayName(replacementDisplayName); err != nil {
+			// We do not return the error as we do not want to block the login for it
+			m.logger.Warn("error setting display name", zap.Error(err))
+		}
+	}
+
 	return response, nil
 }
 

protocol/messenger_backup_handler.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/golang/protobuf/proto"
 
+	utils "github.com/status-im/status-go/common"
 	"github.com/status-im/status-go/images"
 	"github.com/status-im/status-go/multiaccounts/errors"
 	"github.com/status-im/status-go/multiaccounts/settings"
@@ -112,16 +113,23 @@ func (m *Messenger) handleBackedUpProfile(message *protobuf.BackedUpProfile, bac
 		Profile: &wakusync.BackedUpProfile{},
 	}
 
-	err := m.SaveSyncDisplayName(message.DisplayName, message.DisplayNameClock)
+	err := utils.ValidateDisplayName(&message.DisplayName)
-	if err != nil && err != errors.ErrNewClockOlderThanCurrent {
+	if err != nil {
-		return err
+		// Print a warning and set the display name to the account name, but don't stop the recovery
-	}
+		m.logger.Warn("invalid display name found", zap.Error(err))
-
-	response.SetDisplayName(message.DisplayName)
-
-	// if we already have a newer clock, then we don't need to update the display name
-	if err == errors.ErrNewClockOlderThanCurrent {
 		response.SetDisplayName(m.account.Name)
+	} else {
+		err = m.SaveSyncDisplayName(message.DisplayName, message.DisplayNameClock)
+		if err != nil && err != errors.ErrNewClockOlderThanCurrent {
+			return err
+		}
+
+		response.SetDisplayName(message.DisplayName)
+
+		// if we already have a newer clock, then we don't need to update the display name
+		if err == errors.ErrNewClockOlderThanCurrent {
+			response.SetDisplayName(m.account.Name)
+		}
 	}
 
 	syncWithBackedUpImages := false

protocol/messenger_backup_test.go

@@ -7,6 +7,7 @@ import (
 	"reflect"
 	"testing"
 
+	v1protocol "github.com/status-im/status-go/protocol/v1"
 	"github.com/status-im/status-go/protocol/wakusync"
 
 	"github.com/stretchr/testify/suite"
@@ -228,6 +229,31 @@ func (s *MessengerBackupSuite) TestBackupProfile() {
 	s.Require().Equal(clock, lastBackup)
 }
 
+func (s *MessengerBackupSuite) TestBackupProfileWithInvalidDisplayName() {
+	// Create bob1
+	bob1 := s.m
+
+	state := ReceivedMessageState{
+		Response: &MessengerResponse{},
+	}
+
+	err := bob1.HandleBackup(
+		&state,
+		&protobuf.Backup{
+			Profile: &protobuf.BackedUpProfile{
+				DisplayName: "bad-display-name_eth",
+			},
+			Clock: 1,
+		},
+		&v1protocol.StatusMessage{},
+	)
+	// The backup will still work, but the display name will be skipped
+	s.Require().NoError(err)
+	storedBob1DisplayName, err := bob1.settings.DisplayName()
+	s.Require().NoError(err)
+	s.Require().Equal("", storedBob1DisplayName)
+}
+
 func (s *MessengerBackupSuite) TestBackupSettings() {
 	s.T().Skip("flaky test")
 	const (