fix: fix user import with multiple credentials

Fix user import with multiple credential and the same user handle. Check if the user handle already exists and associate the credential with it otherwise create a new user handle in the database.

backend/cmd/user/importer.go

@@ -147,20 +147,29 @@ func (i *Importer) createWebauthnCredential(userID uuid.UUID, webauthnCredential
 	}
 
 	if webauthnCredential.UserHandle != nil {
-		userHandleID, err := uuid.NewV4()
+		existingUserHandle, err := i.persister.GetWebauthnCredentialUserHandlePersisterWithConnection(i.tx).GetByHandle(*webauthnCredential.UserHandle)
 		if err != nil {
 			return err
 		}
 
-		userHandle := models.WebauthnCredentialUserHandle{
-			ID:        userHandleID,
-			UserID:    userID,
-			Handle:    *webauthnCredential.UserHandle,
-			CreatedAt: i.importTimestamp,
-			UpdatedAt: i.importTimestamp,
+		if existingUserHandle != nil {
+			webauthnCredentialModel.UserHandleID = &existingUserHandle.ID
+		} else {
+			userHandleID, err := uuid.NewV4()
+			if err != nil {
+				return err
+			}
+
+			userHandle := models.WebauthnCredentialUserHandle{
+				ID:        userHandleID,
+				UserID:    userID,
+				Handle:    *webauthnCredential.UserHandle,
+				CreatedAt: i.importTimestamp,
+				UpdatedAt: i.importTimestamp,
+			}
+			webauthnCredentialModel.UserHandle = &userHandle
+			webauthnCredentialModel.UserHandleID = &userHandleID
 		}
-		webauthnCredentialModel.UserHandle = &userHandle
-		webauthnCredentialModel.UserHandleID = &userHandleID
 	}
 
 	err := i.persister.GetWebauthnCredentialPersisterWithConnection(i.tx).Create(webauthnCredentialModel)

backend/persistence/persister.go

@@ -52,6 +52,8 @@ type Persister interface {
 	GetSessionPersisterWithConnection(tx *pop.Connection) SessionPersister
 	GetOTPSecretPersister() OTPSecretPersister
 	GetOTPSecretPersisterWithConnection(tx *pop.Connection) OTPSecretPersister
+	GetWebauthnCredentialUserHandlePersister() WebauthnCredentialUserHandlePersister
+	GetWebauthnCredentialUserHandlePersisterWithConnection(tx *pop.Connection) WebauthnCredentialUserHandlePersister
 	Transaction(func(tx *pop.Connection) error) error
 }
 
@@ -276,3 +278,11 @@ func (p *persister) GetSessionPersister() SessionPersister {
 func (p *persister) GetSessionPersisterWithConnection(tx *pop.Connection) SessionPersister {
 	return NewSessionPersister(tx)
 }
+
+func (p *persister) GetWebauthnCredentialUserHandlePersister() WebauthnCredentialUserHandlePersister {
+	return NewWebauthnCredentialUserHandlePersister(p.DB)
+}
+
+func (p *persister) GetWebauthnCredentialUserHandlePersisterWithConnection(tx *pop.Connection) WebauthnCredentialUserHandlePersister {
+	return NewWebauthnCredentialUserHandlePersister(tx)
+}

backend/persistence/webauthn_credential_user_handle_persister.go

@@ -0,0 +1,34 @@
+package persistence
+
+import (
+	"database/sql"
+	"errors"
+	"fmt"
+	"github.com/gobuffalo/pop/v6"
+	"github.com/teamhanko/hanko/backend/persistence/models"
+)
+
+type WebauthnCredentialUserHandlePersister interface {
+	GetByHandle(string) (*models.WebauthnCredentialUserHandle, error)
+}
+
+func NewWebauthnCredentialUserHandlePersister(db *pop.Connection) WebauthnCredentialUserHandlePersister {
+	return &webauthnCredentialUserHandlePersister{db: db}
+}
+
+type webauthnCredentialUserHandlePersister struct {
+	db *pop.Connection
+}
+
+func (p *webauthnCredentialUserHandlePersister) GetByHandle(handle string) (*models.WebauthnCredentialUserHandle, error) {
+	handleModel := models.WebauthnCredentialUserHandle{}
+	err := p.db.Where("handle = ?", handle).First(&handleModel)
+	if err != nil && errors.Is(err, sql.ErrNoRows) {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, fmt.Errorf("failed to get handleModel: %w", err)
+	}
+
+	return &handleModel, nil
+}