feat: add resilient updates and access controls

internal/web/server.go

@@ -21,6 +21,7 @@ import (
 
 	"golang.org/x/net/idna"
 
+	"github.com/root-kdw12/hetzner-api-dyndns-records-webinterface/internal/appupdate"
 	"github.com/root-kdw12/hetzner-api-dyndns-records-webinterface/internal/config"
 	"github.com/root-kdw12/hetzner-api-dyndns-records-webinterface/internal/model"
 	"github.com/root-kdw12/hetzner-api-dyndns-records-webinterface/internal/scheduler"
@@ -36,9 +37,12 @@ type Server struct {
 	store     *store.Store
 	cipher    *secure.Cipher
 	scheduler *scheduler.Scheduler
+	updates   *appupdate.Manager
 	logger    *slog.Logger
 	templates map[string]*template.Template
 	limiter   *loginLimiter
+	dummyHash string
+	authSlots chan struct{}
 }
 
 type viewData struct {
@@ -74,6 +78,7 @@ type viewData struct {
 	ErrorPiHoles     []model.PiHoleIntegration
 	ErrorCount       int
 	PiHoleView       *piHoleView
+	SoftwareUpdate   appupdate.State
 }
 
 type flashMessage struct {
@@ -91,12 +96,12 @@ type accessZone struct {
 	ManagedTargetIDs map[int64]bool
 }
 
-func New(cfg config.Config, database *store.Store, cipher *secure.Cipher, schedule *scheduler.Scheduler, logger *slog.Logger) (*Server, error) {
+func New(cfg config.Config, database *store.Store, cipher *secure.Cipher, schedule *scheduler.Scheduler, updates *appupdate.Manager, logger *slog.Logger) (*Server, error) {
 	templates, err := loadTemplates()
 	if err != nil {
 		return nil, err
 	}
-	return &Server{config: cfg, store: database, cipher: cipher, scheduler: schedule, logger: logger, templates: templates, limiter: newLoginLimiter()}, nil
+	return &Server{config: cfg, store: database, cipher: cipher, scheduler: schedule, updates: updates, logger: logger, templates: templates, limiter: newLoginLimiter(), dummyHash: secure.PasswordTimingHash, authSlots: make(chan struct{}, 2)}, nil
 }
 
 func (s *Server) Handler() http.Handler {
@@ -144,11 +149,18 @@ func (s *Server) Handler() http.Handler {
 	mux.Handle("GET /settings", s.adminOnly(s.settingsPage))
 	mux.Handle("POST /settings", s.adminOnly(s.settingsSave))
 	mux.Handle("POST /run", s.adminOnly(s.runNow))
+	mux.Handle("GET /system", s.adminOnly(s.softwareUpdatePage))
+	mux.Handle("POST /system/update-credential", s.adminOnly(s.softwareUpdateCredentialSave))
+	mux.Handle("POST /system/check", s.adminOnly(s.softwareUpdateCheck))
+	mux.Handle("POST /system/update", s.adminOnly(s.softwareUpdateStart))
 	mux.Handle("GET /errors", s.adminOnly(s.errorsPage))
 	mux.Handle("POST /errors/clear", s.adminOnly(s.errorsClear))
-	mux.Handle("GET /security", s.authenticated(s.securityPage))
+	mux.Handle("GET /account", s.authenticated(s.accountPage))
+	mux.Handle("POST /account/password", s.authenticated(s.passwordChange))
+	mux.Handle("GET /security", s.authenticated(s.securityRedirect))
 	mux.Handle("POST /security/password", s.authenticated(s.passwordChange))
-	mux.Handle("GET /users", s.adminOnly(s.usersPage))
+	mux.Handle("GET /access", s.adminOnly(s.usersPage))
+	mux.Handle("GET /users", s.adminOnly(s.usersRedirect))
 	mux.Handle("GET /users/new", s.adminOnly(s.userNewPage))
 	mux.Handle("POST /users", s.adminOnly(s.userCreate))
 	mux.Handle("GET /users/{id}", s.adminOnly(s.userDetail))
@@ -157,6 +169,7 @@ func (s *Server) Handler() http.Handler {
 	mux.Handle("POST /users/{id}/password", s.adminOnly(s.userPasswordReset))
 	mux.Handle("GET /api/v1/status", s.adminOnly(s.statusAPI))
 	mux.Handle("GET /api/v1/scheduler", s.authenticated(s.schedulerAPI))
+	mux.Handle("GET /api/v1/software-update/status", s.adminOnly(s.softwareUpdateStatusAPI))
 	return s.securityHeaders(mux)
 }
 
@@ -226,6 +239,10 @@ func (s *Server) setup(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	if err := s.store.CreateAdmin(r.Context(), username, form["display_name"], hash); err != nil {
+		if errors.Is(err, store.ErrAdminAlreadyConfigured) {
+			http.Redirect(w, r, "/login", http.StatusSeeOther)
+			return
+		}
 		if strings.Contains(err.Error(), "UNIQUE") || strings.Contains(err.Error(), "constraint") {
 			http.Redirect(w, r, "/login", http.StatusSeeOther)
 			return
@@ -278,10 +295,15 @@ func (s *Server) login(w http.ResponseWriter, r *http.Request) {
 	}
 	username, usernameErr := normalizeUsername(r.FormValue("username"))
 	user, hash, err := s.store.GetUserByUsername(r.Context(), username)
-	if usernameErr != nil || err != nil || !user.Active || !secure.VerifyPassword(hash, r.FormValue("password")) {
+	lookupOK := usernameErr == nil && err == nil
+	if !lookupOK {
+		hash = s.dummyHash
+	}
+	passwordOK := s.verifyPassword(r.Context(), hash, r.FormValue("password"))
+	if !lookupOK || !user.Active || !passwordOK {
 		s.limiter.Fail(clientIP)
 		_ = s.store.AddAudit(r.Context(), "auth.failed", "Fehlgeschlagene Anmeldung")
-		s.renderError(w, "login", "Passwort nicht korrekt.", s.publicCSRF(w, r), map[string]string{})
+		s.renderError(w, "login", "Anmeldung nicht möglich. Prüfe deine Zugangsdaten.", s.publicCSRF(w, r), map[string]string{})
 		return
 	}
 	s.limiter.Reset(clientIP)
@@ -294,6 +316,23 @@ func (s *Server) login(w http.ResponseWriter, r *http.Request) {
 	s.redirectNotice(w, r, "/", "Angemeldet.")
 }
 
+func (s *Server) verifyPassword(ctx context.Context, hash, password string) bool {
+	if s.authSlots == nil {
+		return secure.VerifyPassword(hash, password)
+	}
+	timer := time.NewTimer(5 * time.Second)
+	defer timer.Stop()
+	select {
+	case s.authSlots <- struct{}{}:
+		defer func() { <-s.authSlots }()
+		return secure.VerifyPassword(hash, password)
+	case <-ctx.Done():
+		return false
+	case <-timer.C:
+		return false
+	}
+}
+
 func (s *Server) logout(w http.ResponseWriter, r *http.Request, session *model.Session) {
 	if !s.validSessionCSRF(r, session) {
 		http.Error(w, "Ungültige Anfrage", http.StatusForbidden)
@@ -641,7 +680,7 @@ func (s *Server) domainToken(w http.ResponseWriter, r *http.Request, session *mo
 		return
 	}
 	hash, err := s.store.PasswordHash(r.Context(), session.UserID)
-	if err != nil || !secure.VerifyPassword(hash, r.FormValue("password")) {
+	if err != nil || !s.verifyPassword(r.Context(), hash, r.FormValue("password")) {
 		s.redirectNotice(w, r, domainURL(zoneID), "Passwort nicht korrekt; Token bleibt verborgen.", "error")
 		return
 	}
@@ -1240,6 +1279,126 @@ func (s *Server) runNow(w http.ResponseWriter, r *http.Request, session *model.S
 	s.redirectNotice(w, r, "/", "Aktualisierung gestartet.")
 }
 
+func (s *Server) softwareUpdatePage(w http.ResponseWriter, r *http.Request, session *model.Session) {
+	if s.updates == nil {
+		http.Error(w, "Software-Updates sind nicht konfiguriert.", http.StatusServiceUnavailable)
+		return
+	}
+	statusCtx, cancel := context.WithTimeout(r.Context(), 750*time.Millisecond)
+	_, _ = s.updates.UpdateStatus(statusCtx)
+	cancel()
+	s.render(w, "system", viewData{Title: "Systemupdate", Page: "system", CSRF: session.CSRFToken, Flash: notice(r), User: userFromSession(session), IsAdmin: true, Now: time.Now(), SoftwareUpdate: s.updates.State()})
+}
+
+func (s *Server) softwareUpdateCredentialSave(w http.ResponseWriter, r *http.Request, session *model.Session) {
+	if s.updates == nil {
+		http.Error(w, "Software-Updates sind nicht konfiguriert.", http.StatusServiceUnavailable)
+		return
+	}
+	if err := s.parseForm(w, r); err != nil {
+		return
+	}
+	if !s.validSessionCSRF(r, session) {
+		http.Error(w, "Ungültige Anfrage", http.StatusForbidden)
+		return
+	}
+	hash, err := s.store.PasswordHash(r.Context(), session.UserID)
+	if err != nil || !s.verifyPassword(r.Context(), hash, r.FormValue("current_password")) {
+		s.redirectNotice(w, r, "/system", "Admin-Passwort ist nicht korrekt.", "error")
+		return
+	}
+	if err := s.updates.SaveCredential(r.Context(), r.FormValue("registry_username"), r.FormValue("registry_token")); err != nil {
+		s.redirectNotice(w, r, "/system", "Update-Zugang konnte nicht gespeichert werden: "+safeMessage(err), "error")
+		return
+	}
+	_ = s.store.AddAudit(r.Context(), "software_update.credential_changed", "Update-Zugang geändert durch "+session.Username)
+	s.updates.TriggerCheck()
+	s.redirectNotice(w, r, "/system", "Update-Zugang verschlüsselt gespeichert; Versionsprüfung gestartet.")
+}
+
+func (s *Server) softwareUpdateCheck(w http.ResponseWriter, r *http.Request, session *model.Session) {
+	if s.updates == nil {
+		http.Error(w, "Software-Updates sind nicht konfiguriert.", http.StatusServiceUnavailable)
+		return
+	}
+	if err := s.parseForm(w, r); err != nil {
+		return
+	}
+	if !s.validSessionCSRF(r, session) {
+		http.Error(w, "Ungültige Anfrage", http.StatusForbidden)
+		return
+	}
+	checkCtx, cancel := context.WithTimeout(r.Context(), 15*time.Second)
+	err := s.updates.CheckNow(checkCtx)
+	cancel()
+	if err != nil {
+		if errors.Is(err, appupdate.ErrCredentialMissing) {
+			s.redirectNotice(w, r, "/system#update-access", "Richte zuerst den Update-Zugang ein.", "info")
+			return
+		}
+		s.redirectNotice(w, r, "/system", "Versionsprüfung nicht möglich: "+safeMessage(err)+". Der laufende Dienst bleibt unverändert.", "error")
+		return
+	}
+	s.redirectNotice(w, r, "/system", "Versionsprüfung abgeschlossen.")
+}
+
+func (s *Server) softwareUpdateStart(w http.ResponseWriter, r *http.Request, session *model.Session) {
+	if s.updates == nil {
+		http.Error(w, "Software-Updates sind nicht konfiguriert.", http.StatusServiceUnavailable)
+		return
+	}
+	if err := s.parseForm(w, r); err != nil {
+		return
+	}
+	if !s.validSessionCSRF(r, session) {
+		http.Error(w, "Ungültige Anfrage", http.StatusForbidden)
+		return
+	}
+	version := strings.TrimSpace(r.FormValue("version"))
+	startCtx, cancel := context.WithTimeout(r.Context(), 5*time.Second)
+	err := s.updates.RequestUpdate(startCtx, version)
+	cancel()
+	if err != nil {
+		if strings.Contains(r.Header.Get("Accept"), "application/json") {
+			w.Header().Set("Content-Type", "application/json; charset=utf-8")
+			w.WriteHeader(http.StatusServiceUnavailable)
+			_ = json.NewEncoder(w).Encode(map[string]any{"accepted": false, "message": safeMessage(err)})
+			return
+		}
+		s.redirectNotice(w, r, "/system", "Update konnte nicht gestartet werden: "+safeMessage(err), "error")
+		return
+	}
+	_ = s.store.AddAudit(r.Context(), "software_update.started", "Software-Update auf "+version+" gestartet durch "+session.Username)
+	if strings.Contains(r.Header.Get("Accept"), "application/json") {
+		w.Header().Set("Content-Type", "application/json; charset=utf-8")
+		w.WriteHeader(http.StatusAccepted)
+		_ = json.NewEncoder(w).Encode(map[string]any{"accepted": true, "version": version})
+		return
+	}
+	s.redirectNotice(w, r, "/system", "Update auf "+version+" wurde gestartet.", "info")
+}
+
+func (s *Server) softwareUpdateStatusAPI(w http.ResponseWriter, r *http.Request, _ *model.Session) {
+	if s.updates == nil {
+		http.Error(w, "Software-Updates sind nicht konfiguriert.", http.StatusServiceUnavailable)
+		return
+	}
+	statusCtx, cancel := context.WithTimeout(r.Context(), 2*time.Second)
+	status, statusErr := s.updates.UpdateStatus(statusCtx)
+	cancel()
+	state := s.updates.State()
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
+	w.Header().Set("Cache-Control", "no-store")
+	_ = json.NewEncoder(w).Encode(map[string]any{
+		"agent_available": statusErr == nil,
+		"phase":           status.Phase,
+		"message":         status.Message,
+		"target_version":  status.TargetVersion,
+		"current_version": state.CurrentVersion,
+		"latest_version":  state.LatestVersion,
+	})
+}
+
 func (s *Server) errorsPage(w http.ResponseWriter, r *http.Request, session *model.Session) {
 	targets, err := s.store.ListTargetsWithErrors(r.Context())
 	if err != nil {
@@ -1277,8 +1436,12 @@ func (s *Server) errorsClear(w http.ResponseWriter, r *http.Request, session *mo
 	s.redirectNotice(w, r, "/errors", "Fehlerliste geleert.")
 }
 
-func (s *Server) securityPage(w http.ResponseWriter, r *http.Request, session *model.Session) {
-	s.render(w, "security", viewData{Title: "Sicherheit", Page: "security", CSRF: session.CSRFToken, Flash: notice(r), Mode: s.config.Mode, User: userFromSession(session), IsAdmin: session.Role == "admin", Now: time.Now()})
+func (s *Server) accountPage(w http.ResponseWriter, r *http.Request, session *model.Session) {
+	s.render(w, "security", viewData{Title: "Mein Konto", Page: "account", CSRF: session.CSRFToken, Flash: notice(r), Mode: s.config.Mode, User: userFromSession(session), IsAdmin: session.Role == "admin", Now: time.Now()})
+}
+
+func (s *Server) securityRedirect(w http.ResponseWriter, r *http.Request, _ *model.Session) {
+	http.Redirect(w, r, "/account", http.StatusPermanentRedirect)
 }
 
 func (s *Server) passwordChange(w http.ResponseWriter, r *http.Request, session *model.Session) {
@@ -1290,26 +1453,25 @@ func (s *Server) passwordChange(w http.ResponseWriter, r *http.Request, session
 		return
 	}
 	hash, err := s.store.PasswordHash(r.Context(), session.UserID)
-	if err != nil || !secure.VerifyPassword(hash, r.FormValue("current_password")) {
-		s.redirectNotice(w, r, "/security", "Aktuelles Passwort ist nicht korrekt.", "error")
+	if err != nil || !s.verifyPassword(r.Context(), hash, r.FormValue("current_password")) {
+		s.redirectNotice(w, r, "/account", "Aktuelles Passwort ist nicht korrekt.", "error")
 		return
 	}
 	if r.FormValue("new_password") != r.FormValue("confirm_password") {
-		s.redirectNotice(w, r, "/security", "Die neuen Passwörter stimmen nicht überein.", "error")
+		s.redirectNotice(w, r, "/account", "Die neuen Passwörter stimmen nicht überein.", "error")
 		return
 	}
 	newHash, err := secure.HashPassword(r.FormValue("new_password"))
 	if err != nil {
-		s.redirectNotice(w, r, "/security", err.Error(), "error")
+		s.redirectNotice(w, r, "/account", err.Error(), "error")
 		return
 	}
-	if err := s.store.UpdatePassword(r.Context(), session.UserID, newHash); err != nil {
+	if err := s.store.UpdatePasswordKeepingSession(r.Context(), session.UserID, newHash, session.ID); err != nil {
 		s.serverError(w, err)
 		return
 	}
-	_ = s.store.DeleteOtherSessions(r.Context(), session.UserID, session.ID)
 	_ = s.store.AddAudit(r.Context(), "security.password_changed", "Passwort geändert: "+session.Username)
-	s.redirectNotice(w, r, "/security", "Passwort geändert; andere eigene Sitzungen wurden abgemeldet.")
+	s.redirectNotice(w, r, "/account", "Passwort geändert; andere eigene Sitzungen wurden abgemeldet.")
 }
 
 func (s *Server) statusAPI(w http.ResponseWriter, r *http.Request, _ *model.Session) {
@@ -1338,6 +1500,7 @@ func (s *Server) schedulerAPI(w http.ResponseWriter, r *http.Request, _ *model.S
 		"next_run_unix": unixSeconds(s.scheduler.NextRunAt()),
 		"running":       s.scheduler.IsRunning(),
 		"enabled":       settings.UpdaterEnabled,
+		"last_ipv4":     settings.LastIPv4,
 	})
 }
 
@@ -1347,11 +1510,15 @@ func (s *Server) usersPage(w http.ResponseWriter, r *http.Request, session *mode
 		s.serverError(w, err)
 		return
 	}
-	s.render(w, "users", viewData{Title: "Benutzer", Page: "users", CSRF: session.CSRFToken, Flash: notice(r), User: userFromSession(session), IsAdmin: true, Users: users, Now: time.Now()})
+	s.render(w, "users", viewData{Title: "Zugriff & Sicherheit", Page: "access", CSRF: session.CSRFToken, Flash: notice(r), User: userFromSession(session), IsAdmin: true, Users: users, Now: time.Now()})
+}
+
+func (s *Server) usersRedirect(w http.ResponseWriter, r *http.Request, _ *model.Session) {
+	http.Redirect(w, r, "/access", http.StatusPermanentRedirect)
 }
 
 func (s *Server) userNewPage(w http.ResponseWriter, r *http.Request, session *model.Session) {
-	s.render(w, "user_new", viewData{Title: "Benutzer anlegen", Page: "users", CSRF: session.CSRFToken, User: userFromSession(session), IsAdmin: true, Form: map[string]string{"role": "member"}, Now: time.Now()})
+	s.render(w, "user_new", viewData{Title: "Benutzer anlegen", Page: "access", CSRF: session.CSRFToken, User: userFromSession(session), IsAdmin: true, Form: map[string]string{"role": "member"}, Now: time.Now()})
 }
 
 func (s *Server) userCreate(w http.ResponseWriter, r *http.Request, session *model.Session) {
@@ -1380,7 +1547,7 @@ func (s *Server) userCreate(w http.ResponseWriter, r *http.Request, session *mod
 		s.renderUserNewError(w, session, "Die Passwörter stimmen nicht überein.", form)
 		return
 	}
-	hash, err := secure.HashPassword(r.FormValue("password"))
+	hash, err := secure.HashProvisionedPassword(r.FormValue("password"))
 	if err != nil {
 		s.renderUserNewError(w, session, err.Error(), form)
 		return
@@ -1438,7 +1605,7 @@ func (s *Server) userDetail(w http.ResponseWriter, r *http.Request, session *mod
 		}
 		accessZones = append(accessZones, accessZone{Zone: zone, Targets: targets, DomainGranted: domainGrants[zone.ID], DomainManaged: domainManaged[zone.ID], CanCreateTargets: createTargetGrants[zone.ID], GrantedTargetIDs: targetGrants, ManagedTargetIDs: managedTargetGrants})
 	}
-	s.render(w, "user_detail", viewData{Title: managedUser.DisplayName, Page: "users", CSRF: session.CSRFToken, Flash: notice(r), User: userFromSession(session), IsAdmin: true, ManagedUser: managedUser, AccessZones: accessZones, Now: time.Now()})
+	s.render(w, "user_detail", viewData{Title: managedUser.DisplayName, Page: "access", CSRF: session.CSRFToken, Flash: notice(r), User: userFromSession(session), IsAdmin: true, ManagedUser: managedUser, AccessZones: accessZones, Now: time.Now()})
 }
 
 func (s *Server) userAccessSave(w http.ResponseWriter, r *http.Request, session *model.Session) {
@@ -1524,24 +1691,14 @@ func (s *Server) userStateSave(w http.ResponseWriter, r *http.Request, session *
 		s.redirectNotice(w, r, "/users/"+strconv.FormatInt(userID, 10), "Benutzerdaten sind ungültig.", "error")
 		return
 	}
-	if managedUser.IsAdmin() && (role != "admin" || !active) {
-		count, countErr := s.store.CountActiveAdmins(r.Context())
-		if countErr != nil {
-			s.serverError(w, countErr)
-			return
-		}
-		if count <= 1 {
+	if err := s.store.UpdateUserState(r.Context(), userID, displayName, role, active); err != nil {
+		if errors.Is(err, store.ErrLastActiveAdmin) {
 			s.redirectNotice(w, r, "/users/"+strconv.FormatInt(userID, 10), "Der letzte aktive Admin kann nicht deaktiviert oder herabgestuft werden.", "error")
 			return
 		}
-	}
-	if err := s.store.UpdateUserState(r.Context(), userID, displayName, role, active); err != nil {
 		s.serverError(w, err)
 		return
 	}
-	if role != managedUser.Role || active != managedUser.Active {
-		_ = s.store.DeleteUserSessions(r.Context(), userID)
-	}
 	_ = s.store.AddAudit(r.Context(), "user.state_updated", "Benutzer geändert: "+managedUser.Username+" durch "+session.Username)
 	s.redirectNotice(w, r, "/users/"+strconv.FormatInt(userID, 10), "Benutzerstatus gespeichert.")
 }
@@ -1576,7 +1733,6 @@ func (s *Server) userPasswordReset(w http.ResponseWriter, r *http.Request, sessi
 		s.serverError(w, err)
 		return
 	}
-	_ = s.store.DeleteUserSessions(r.Context(), userID)
 	_ = s.store.AddAudit(r.Context(), "user.password_reset", "Passwort zurückgesetzt: "+managedUser.Username+" durch "+session.Username)
 	s.redirectNotice(w, r, "/users/"+strconv.FormatInt(userID, 10), "Passwort zurückgesetzt; der Benutzer muss sich neu anmelden.")
 }
@@ -1719,6 +1875,9 @@ func (s *Server) render(w http.ResponseWriter, name string, data viewData) {
 		if settings, err := s.store.GetSettings(context.Background()); err == nil {
 			data.UpdaterEnabled = settings.UpdaterEnabled
 		}
+		if data.IsAdmin && s.updates != nil {
+			data.SoftwareUpdate = s.updates.State()
+		}
 	}
 	w.Header().Set("Content-Type", "text/html; charset=utf-8")
 	w.Header().Set("Cache-Control", "no-store")
@@ -1732,7 +1891,7 @@ func (s *Server) renderError(w http.ResponseWriter, name, message, csrf string,
 }
 
 func (s *Server) renderUserNewError(w http.ResponseWriter, session *model.Session, message string, form map[string]string) {
-	s.render(w, "user_new", viewData{Title: "Benutzer anlegen", Page: "users", CSRF: session.CSRFToken, Flash: newFlash(message, "error"), Form: form, User: userFromSession(session), IsAdmin: true, Now: time.Now()})
+	s.render(w, "user_new", viewData{Title: "Benutzer anlegen", Page: "access", CSRF: session.CSRFToken, Flash: newFlash(message, "error"), Form: form, User: userFromSession(session), IsAdmin: true, Now: time.Now()})
 }
 
 func (s *Server) serverError(w http.ResponseWriter, err error) {
@@ -1774,7 +1933,7 @@ func (s *Server) securityHeaders(next http.Handler) http.Handler {
 }
 
 func loadTemplates() (map[string]*template.Template, error) {
-	pages := []string{"setup", "login", "dashboard", "domains", "domain_new", "domain_detail", "pihole", "settings", "errors", "security", "token", "users", "user_new", "user_detail"}
+	pages := []string{"setup", "login", "dashboard", "domains", "domain_new", "domain_detail", "pihole", "settings", "errors", "security", "system", "token", "users", "user_new", "user_detail"}
 	functions := template.FuncMap{
 		"formatTime": func(value time.Time) string {
 			if value.IsZero() {
@@ -2043,15 +2202,30 @@ func remoteIP(r *http.Request) string {
 }
 
 type loginLimiter struct {
-	mu       sync.Mutex
-	attempts map[string][]time.Time
+	mu          sync.Mutex
+	attempts    map[string][]time.Time
+	lastCleanup time.Time
+}
+
+const (
+	loginAttemptLimit         = 5
+	loginAttemptWindow        = 15 * time.Minute
+	loginLimiterCleanupEvery  = time.Minute
+	loginLimiterMaxTrackedIPs = 4096
+)
+
+func newLoginLimiter() *loginLimiter {
+	return &loginLimiter{attempts: make(map[string][]time.Time), lastCleanup: time.Now()}
 }
 
-func newLoginLimiter() *loginLimiter { return &loginLimiter{attempts: make(map[string][]time.Time)} }
 func (l *loginLimiter) Allow(ip string) bool {
 	l.mu.Lock()
 	defer l.mu.Unlock()
-	cutoff := time.Now().Add(-15 * time.Minute)
+	now := time.Now()
+	if l.lastCleanup.IsZero() || now.Sub(l.lastCleanup) >= loginLimiterCleanupEvery {
+		l.cleanupLocked(now)
+	}
+	cutoff := now.Add(-loginAttemptWindow)
 	values := l.attempts[ip]
 	kept := values[:0]
 	for _, value := range values {
@@ -2059,12 +2233,22 @@ func (l *loginLimiter) Allow(ip string) bool {
 			kept = append(kept, value)
 		}
 	}
-	l.attempts[ip] = kept
-	return len(kept) < 5
+	if len(kept) == 0 {
+		delete(l.attempts, ip)
+	} else {
+		l.attempts[ip] = kept
+	}
+	if len(kept) == 0 && len(l.attempts) >= loginLimiterMaxTrackedIPs {
+		return false
+	}
+	return len(kept) < loginAttemptLimit
 }
 func (l *loginLimiter) Fail(ip string) {
 	l.mu.Lock()
 	defer l.mu.Unlock()
+	if _, exists := l.attempts[ip]; !exists && len(l.attempts) >= loginLimiterMaxTrackedIPs {
+		return
+	}
 	l.attempts[ip] = append(l.attempts[ip], time.Now())
 }
 func (l *loginLimiter) Reset(ip string) {
@@ -2072,3 +2256,21 @@ func (l *loginLimiter) Reset(ip string) {
 	defer l.mu.Unlock()
 	delete(l.attempts, ip)
 }
+
+func (l *loginLimiter) cleanupLocked(now time.Time) {
+	cutoff := now.Add(-loginAttemptWindow)
+	for ip, values := range l.attempts {
+		kept := values[:0]
+		for _, value := range values {
+			if value.After(cutoff) {
+				kept = append(kept, value)
+			}
+		}
+		if len(kept) == 0 {
+			delete(l.attempts, ip)
+		} else {
+			l.attempts[ip] = kept
+		}
+	}
+	l.lastCleanup = now
+}