Tenant-Feature Phase 3: Auth-Middleware verdrahtet

- TenantSlug in User-Struct + GetSessionUser per JOIN befüllt
- middleware.go: RequireAuth, RequireAdmin, RequireTenantAccess
- router.go: alle Routen mit passendem Middleware-Stack gesichert

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

server/backend/internal/httpapi/middleware.go

@@ -0,0 +1,102 @@
+package httpapi
+
+import (
+	"context"
+	"net/http"
+	"net/url"
+
+	"git.az-it.net/az/morz-infoboard/server/backend/internal/store"
+)
+
+// contextKey is an unexported type for context keys in this package.
+// Using a named type prevents collisions with keys from other packages.
+type contextKey int
+
+const (
+	contextKeyUser contextKey = iota
+)
+
+// UserFromContext returns the authenticated *store.User stored in ctx,
+// or nil if none is present.
+func UserFromContext(ctx context.Context) *store.User {
+	u, _ := ctx.Value(contextKeyUser).(*store.User)
+	return u
+}
+
+// RequireAuth returns middleware that validates the morz_session cookie.
+// On success it stores the *store.User in the request context and calls next.
+// On failure it redirects to /login?next=<current-path>.
+func RequireAuth(authStore *store.AuthStore) func(http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			cookie, err := r.Cookie("morz_session")
+			if err != nil {
+				redirectToLogin(w, r)
+				return
+			}
+
+			user, err := authStore.GetSessionUser(r.Context(), cookie.Value)
+			if err != nil {
+				redirectToLogin(w, r)
+				return
+			}
+
+			ctx := context.WithValue(r.Context(), contextKeyUser, user)
+			next.ServeHTTP(w, r.WithContext(ctx))
+		})
+	}
+}
+
+// RequireAdmin is middleware that allows only users with role "admin".
+// It must be chained after RequireAuth (so a user is present in context).
+// On failure it responds with 403 Forbidden.
+func RequireAdmin(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		user := UserFromContext(r.Context())
+		if user == nil || user.Role != "admin" {
+			http.Error(w, "Forbidden", http.StatusForbidden)
+			return
+		}
+		next.ServeHTTP(w, r)
+	})
+}
+
+// RequireTenantAccess is middleware that allows access only when the
+// authenticated user belongs to the tenant identified by the {tenantSlug}
+// path value, or when the user has role "admin" (admins can access everything).
+// It must be chained after RequireAuth.
+func RequireTenantAccess(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		user := UserFromContext(r.Context())
+		if user == nil {
+			http.Error(w, "Forbidden", http.StatusForbidden)
+			return
+		}
+		// Admins bypass tenant isolation.
+		if user.Role == "admin" {
+			next.ServeHTTP(w, r)
+			return
+		}
+		tenantSlug := r.PathValue("tenantSlug")
+		if tenantSlug != "" && user.TenantSlug != tenantSlug {
+			http.Error(w, "Forbidden", http.StatusForbidden)
+			return
+		}
+		next.ServeHTTP(w, r)
+	})
+}
+
+// chain applies a list of middleware to a handler, wrapping outermost first.
+// chain(m1, m2, m3)(h) == m1(m2(m3(h)))
+func chain(h http.Handler, middlewares ...func(http.Handler) http.Handler) http.Handler {
+	for i := len(middlewares) - 1; i >= 0; i-- {
+		h = middlewares[i](h)
+	}
+	return h
+}
+
+// redirectToLogin issues a 303 redirect to /login with the current path as ?next=.
+func redirectToLogin(w http.ResponseWriter, r *http.Request) {
+	target := "/login?next=" + url.QueryEscape(r.URL.RequestURI())
+	http.Redirect(w, r, target, http.StatusSeeOther)
+}

server/backend/internal/httpapi/router.go

@@ -96,58 +96,74 @@ func registerManageRoutes(mux *http.ServeMux, d RouterDeps) {
 	mux.HandleFunc("POST /login", manage.HandleLoginPost(d.AuthStore, d.Config))
 	mux.HandleFunc("POST /logout", manage.HandleLogoutPost(d.AuthStore))
 
+	// Shorthand middleware combinators for this router.
+	authOnly := func(h http.Handler) http.Handler {
+		return chain(h, RequireAuth(d.AuthStore))
+	}
+	authAdmin := func(h http.Handler) http.Handler {
+		return chain(h, RequireAuth(d.AuthStore), RequireAdmin)
+	}
+	authTenant := func(h http.Handler) http.Handler {
+		return chain(h, RequireAuth(d.AuthStore), RequireTenantAccess)
+	}
+
 	// ── Admin UI ──────────────────────────────────────────────────────────
-	mux.HandleFunc("GET /admin", manage.HandleAdminUI(d.TenantStore, d.ScreenStore))
+	mux.Handle("GET /admin",
-	mux.HandleFunc("POST /admin/screens/provision", manage.HandleProvisionUI(d.TenantStore, d.ScreenStore))
+		authAdmin(http.HandlerFunc(manage.HandleAdminUI(d.TenantStore, d.ScreenStore))))
-	mux.HandleFunc("POST /admin/screens", manage.HandleCreateScreenUI(d.TenantStore, d.ScreenStore))
+	mux.Handle("POST /admin/screens/provision",
-	mux.HandleFunc("POST /admin/screens/{screenId}/delete", manage.HandleDeleteScreenUI(d.ScreenStore))
+		authAdmin(http.HandlerFunc(manage.HandleProvisionUI(d.TenantStore, d.ScreenStore))))
+	mux.Handle("POST /admin/screens",
+		authAdmin(http.HandlerFunc(manage.HandleCreateScreenUI(d.TenantStore, d.ScreenStore))))
+	mux.Handle("POST /admin/screens/{screenId}/delete",
+		authAdmin(http.HandlerFunc(manage.HandleDeleteScreenUI(d.ScreenStore))))
 
 	// ── Playlist management UI ────────────────────────────────────────────
-	mux.HandleFunc("GET /manage/{screenSlug}",
+	mux.Handle("GET /manage/{screenSlug}",
-		manage.HandleManageUI(d.TenantStore, d.ScreenStore, d.MediaStore, d.PlaylistStore))
+		authOnly(http.HandlerFunc(manage.HandleManageUI(d.TenantStore, d.ScreenStore, d.MediaStore, d.PlaylistStore))))
-	mux.HandleFunc("POST /manage/{screenSlug}/upload",
+	mux.Handle("POST /manage/{screenSlug}/upload",
-		manage.HandleUploadMediaUI(d.MediaStore, d.ScreenStore, uploadDir))
+		authOnly(http.HandlerFunc(manage.HandleUploadMediaUI(d.MediaStore, d.ScreenStore, uploadDir))))
-	mux.HandleFunc("POST /manage/{screenSlug}/items",
+	mux.Handle("POST /manage/{screenSlug}/items",
-		manage.HandleAddItemUI(d.PlaylistStore, d.MediaStore, d.ScreenStore, notifier))
+		authOnly(http.HandlerFunc(manage.HandleAddItemUI(d.PlaylistStore, d.MediaStore, d.ScreenStore, notifier))))
-	mux.HandleFunc("POST /manage/{screenSlug}/items/{itemId}",
+	mux.Handle("POST /manage/{screenSlug}/items/{itemId}",
-		manage.HandleUpdateItemUI(d.PlaylistStore, notifier))
+		authOnly(http.HandlerFunc(manage.HandleUpdateItemUI(d.PlaylistStore, notifier))))
-	mux.HandleFunc("POST /manage/{screenSlug}/items/{itemId}/delete",
+	mux.Handle("POST /manage/{screenSlug}/items/{itemId}/delete",
-		manage.HandleDeleteItemUI(d.PlaylistStore, notifier))
+		authOnly(http.HandlerFunc(manage.HandleDeleteItemUI(d.PlaylistStore, notifier))))
-	mux.HandleFunc("POST /manage/{screenSlug}/reorder",
+	mux.Handle("POST /manage/{screenSlug}/reorder",
-		manage.HandleReorderUI(d.PlaylistStore, d.ScreenStore, notifier))
+		authOnly(http.HandlerFunc(manage.HandleReorderUI(d.PlaylistStore, d.ScreenStore, notifier))))
-	mux.HandleFunc("POST /manage/{screenSlug}/media/{mediaId}/delete",
+	mux.Handle("POST /manage/{screenSlug}/media/{mediaId}/delete",
-		manage.HandleDeleteMediaUI(d.MediaStore, d.ScreenStore, uploadDir, notifier))
+		authOnly(http.HandlerFunc(manage.HandleDeleteMediaUI(d.MediaStore, d.ScreenStore, uploadDir, notifier))))
 
 	// ── JSON API — screens ────────────────────────────────────────────────
-	// Self-registration: called by agent on startup (must be before /{tenantSlug}/ routes)
+	// Self-registration: no auth (player calls this on startup).
 	mux.HandleFunc("POST /api/v1/screens/register",
 		manage.HandleRegisterScreen(d.TenantStore, d.ScreenStore))
-	mux.HandleFunc("GET /api/v1/tenants/{tenantSlug}/screens",
+	mux.Handle("GET /api/v1/tenants/{tenantSlug}/screens",
-		manage.HandleListScreens(d.TenantStore, d.ScreenStore))
+		authTenant(http.HandlerFunc(manage.HandleListScreens(d.TenantStore, d.ScreenStore))))
-	mux.HandleFunc("POST /api/v1/tenants/{tenantSlug}/screens",
+	mux.Handle("POST /api/v1/tenants/{tenantSlug}/screens",
-		manage.HandleCreateScreen(d.TenantStore, d.ScreenStore))
+		authTenant(http.HandlerFunc(manage.HandleCreateScreen(d.TenantStore, d.ScreenStore))))
 
 	// ── JSON API — media ──────────────────────────────────────────────────
-	mux.HandleFunc("GET /api/v1/tenants/{tenantSlug}/media",
+	mux.Handle("GET /api/v1/tenants/{tenantSlug}/media",
-		manage.HandleListMedia(d.TenantStore, d.MediaStore))
+		authTenant(http.HandlerFunc(manage.HandleListMedia(d.TenantStore, d.MediaStore))))
-	mux.HandleFunc("POST /api/v1/tenants/{tenantSlug}/media",
+	mux.Handle("POST /api/v1/tenants/{tenantSlug}/media",
-		manage.HandleUploadMedia(d.TenantStore, d.MediaStore, uploadDir))
+		authTenant(http.HandlerFunc(manage.HandleUploadMedia(d.TenantStore, d.MediaStore, uploadDir))))
-	mux.HandleFunc("DELETE /api/v1/media/{id}",
+	mux.Handle("DELETE /api/v1/media/{id}",
-		manage.HandleDeleteMedia(d.MediaStore, uploadDir))
+		authOnly(http.HandlerFunc(manage.HandleDeleteMedia(d.MediaStore, uploadDir))))
 
 	// ── JSON API — playlists ──────────────────────────────────────────────
+	// Player fetches its playlist — no auth required.
 	mux.HandleFunc("GET /api/v1/screens/{screenId}/playlist",
 		manage.HandlePlayerPlaylist(d.ScreenStore, d.PlaylistStore))
-	mux.HandleFunc("GET /api/v1/playlists/{screenId}",
+	mux.Handle("GET /api/v1/playlists/{screenId}",
-		manage.HandleGetPlaylist(d.ScreenStore, d.PlaylistStore))
+		authOnly(http.HandlerFunc(manage.HandleGetPlaylist(d.ScreenStore, d.PlaylistStore))))
-	mux.HandleFunc("POST /api/v1/playlists/{playlistId}/items",
+	mux.Handle("POST /api/v1/playlists/{playlistId}/items",
-		manage.HandleAddItem(d.PlaylistStore, d.MediaStore, notifier))
+		authOnly(http.HandlerFunc(manage.HandleAddItem(d.PlaylistStore, d.MediaStore, notifier))))
-	mux.HandleFunc("PATCH /api/v1/items/{itemId}",
+	mux.Handle("PATCH /api/v1/items/{itemId}",
-		manage.HandleUpdateItem(d.PlaylistStore, notifier))
+		authOnly(http.HandlerFunc(manage.HandleUpdateItem(d.PlaylistStore, notifier))))
-	mux.HandleFunc("DELETE /api/v1/items/{itemId}",
+	mux.Handle("DELETE /api/v1/items/{itemId}",
-		manage.HandleDeleteItem(d.PlaylistStore, notifier))
+		authOnly(http.HandlerFunc(manage.HandleDeleteItem(d.PlaylistStore, notifier))))
-	mux.HandleFunc("PUT /api/v1/playlists/{playlistId}/order",
+	mux.Handle("PUT /api/v1/playlists/{playlistId}/order",
-		manage.HandleReorder(d.PlaylistStore, notifier))
+		authOnly(http.HandlerFunc(manage.HandleReorder(d.PlaylistStore, notifier))))
-	mux.HandleFunc("PATCH /api/v1/playlists/{playlistId}/duration",
+	mux.Handle("PATCH /api/v1/playlists/{playlistId}/duration",
-		manage.HandleUpdatePlaylistDuration(d.PlaylistStore))
+		authOnly(http.HandlerFunc(manage.HandleUpdatePlaylistDuration(d.PlaylistStore))))
 }

server/backend/internal/store/auth.go

@@ -18,6 +18,7 @@ import (
 type User struct {
 	ID           string    `json:"id"`
 	TenantID     string    `json:"tenant_id"`
+	TenantSlug   string    `json:"tenant_slug"`
 	Username     string    `json:"username"`
 	PasswordHash string    `json:"-"`
 	Role         string    `json:"role"`
@@ -64,14 +65,16 @@ func (s *AuthStore) CreateSession(ctx context.Context, userID string, ttl time.D
 
 // GetSessionUser returns the user associated with sessionID if the session is still valid.
 // Returns pgx.ErrNoRows when the session does not exist or has expired.
+// TenantSlug is populated via JOIN on tenants.
 func (s *AuthStore) GetSessionUser(ctx context.Context, sessionID string) (*User, error) {
 	row := s.pool.QueryRow(ctx,
-		`select u.id, u.tenant_id, u.username, u.password_hash, u.role, u.created_at
+		`select u.id, u.tenant_id, coalesce(t.slug, ''), u.username, u.password_hash, u.role, u.created_at
 		   from sessions se
 		   join users u on u.id = se.user_id
+		   left join tenants t on t.id = u.tenant_id
 		  where se.id = $1
 		    and se.expires_at > now()`, sessionID)
-	return scanUser(row)
+	return scanUserWithSlug(row)
 }
 
 // DeleteSession removes the session with the given ID.
@@ -158,6 +161,21 @@ func scanUser(row interface {
 	return &u, nil
 }
 
+// scanUserWithSlug scans a row that includes tenant_slug as the third column.
+func scanUserWithSlug(row interface {
+	Scan(dest ...any) error
+}) (*User, error) {
+	var u User
+	err := row.Scan(&u.ID, &u.TenantID, &u.TenantSlug, &u.Username, &u.PasswordHash, &u.Role, &u.CreatedAt)
+	if err != nil {
+		if err == pgx.ErrNoRows {
+			return nil, pgx.ErrNoRows
+		}
+		return nil, fmt.Errorf("scan user: %w", err)
+	}
+	return &u, nil
+}
+
 func scanSession(row interface {
 	Scan(dest ...any) error
 }) (*Session, error) {