intotheeast-com-content/plugins/cache-on-save/classes/EntryScopeGuard.php

<?php
namespace Grav\Plugin\Shared;

use Grav\Common\Grav;
use Grav\Common\Page\Interfaces\PageInterface;

/**
 * Single source of truth for the R6 server-side scope guard, shared by BOTH
 * enforcement points so they cannot diverge (KTD5):
 *   - the save/publish path (cache-on-save onFormValidationProcessed), and
 *   - the delete path (entry-actions API route).
 *
 * Two independent checks, both required:
 *   1. isOwner()  — the acting user is the configured site owner, NOT merely any
 *      authenticated account (the super-admin `tester` also authenticates).
 *   2. resolveActiveDailyChild() — the target resolves, through the page tree,
 *      to a real DIRECT child of the active trip's `dailies` container. Resolving
 *      via $pages->find() + a parent-route assertion (never raw path concatenation)
 *      closes the traversal hole where a string like `/…/dailies/../other/entry.md`
 *      prefix-matches the active dailies but points elsewhere.
 */
class EntryScopeGuard
{
    /**
     * Active trip's dailies container route ("/trips/<slug>/dailies"), or null
     * when site.active_trip is unset. Accepts a full route or a bare slug.
     */
    public static function dailiesRoute(Grav $grav): ?string
    {
        $active = $grav['config']->get('site.active_trip');
        $active = is_string($active) ? trim($active) : '';
        if ($active === '') {
            return null;
        }
        $trip = trim($active, '/');
        if (strpos($trip, 'trips/') !== 0) {
            $trip = 'trips/' . $trip;
        }
        return '/' . $trip . '/dailies';
    }

    /**
     * True only when the current user is authenticated AND their username equals
     * site.owner_username. Gating on authentication alone would grant rights to
     * every account, including the super-admin `tester` (KTD8).
     */
    public static function isOwner(Grav $grav): bool
    {
        $user = $grav['user'] ?? null;
        if (!$user || empty($user->authenticated)) {
            return false;
        }
        return self::isOwnerUser($grav, $user);
    }

    /**
     * Owner check for an explicit user object — used by the API delete route,
     * whose authenticated user comes from the request (api_user attribute), not
     * $grav['user']. Same rule: username must equal site.owner_username.
     */
    public static function isOwnerUser(Grav $grav, $user): bool
    {
        if (!$user || !isset($user->username)) {
            return false;
        }
        $owner = $grav['config']->get('site.owner_username');
        return is_string($owner) && $owner !== '' && $user->username === $owner;
    }

    /**
     * A safe single path segment: non-empty, no separators, no dot-traversal.
     */
    public static function isSafeSegment(string $segment): bool
    {
        if ($segment === '' || $segment === '.' || $segment === '..') {
            return false;
        }
        if (strpbrk($segment, '/\\') !== false) {
            return false;
        }
        return strpos($segment, '..') === false;
    }

    /**
     * The folder segment carried by a hidden edit_path value. post-form.js sets
     * edit_path to "<entry-route>/entry.md", so basename(dirname()) is the entry's
     * own folder name (its route's last segment) — the same value stock
     * add-page-by-form derives for the in-place write.
     */
    public static function segmentFromEditPath(string $editPath): string
    {
        $editPath = trim($editPath);
        if ($editPath === '') {
            return '';
        }
        return basename(dirname($editPath));
    }

    /**
     * Resolve a safe segment to the page that is a DIRECT child of $parentRoute,
     * or null when the segment is unsafe, the page does not exist, or its parent
     * is not exactly $parentRoute. Resolving via $pages->find() + a parent-route
     * assertion (never raw path concatenation) is what closes the traversal hole;
     * both public resolvers below share this one body so they cannot drift.
     */
    private static function resolveChildOf(Grav $grav, string $parentRoute, string $segment): ?PageInterface
    {
        if (!self::isSafeSegment($segment)) {
            return null;
        }
        $pages = $grav['pages'];
        // In the API request context the page tree is lazily disabled; enable it
        // so find() can resolve (mirrors the api plugin's own resolvePageByRoute).
        // Idempotent — a no-op in the frontend save-path context.
        if (method_exists($pages, 'enablePages')) {
            $pages->enablePages();
        }
        $page = $pages->find($parentRoute . '/' . $segment);
        if ($page === null) {
            return null;
        }
        $parent = $page->parent();
        if ($parent === null || $parent->route() !== $parentRoute) {
            return null;
        }
        return $page;
    }

    /**
     * Resolve a folder segment to the page that is a DIRECT child of the active
     * trip's dailies container, or null when the segment is unsafe, no active trip
     * is set, the page does not exist, or its parent is not the active dailies.
     */
    public static function resolveActiveDailyChild(Grav $grav, string $segment): ?PageInterface
    {
        $dailies = self::dailiesRoute($grav);
        if ($dailies === null) {
            return null;
        }
        return self::resolveChildOf($grav, $dailies, $segment);
    }

    /**
     * Resolve a slug to the trip page that is a DIRECT child of /trips, or null
     * when the segment is unsafe, the page does not exist, or its parent is not
     * /trips. The trip-scoped analogue of resolveActiveDailyChild, used by the
     * publish/unpublish route (KTD4).
     *
     * Unlike the front-end listing collections, this does NOT filter on published
     * state: find() must return drafts so the owner can republish an unpublished
     * trip from the listing (R7).
     */
    public static function resolveTripChild(Grav $grav, string $slug): ?PageInterface
    {
        return self::resolveChildOf($grav, '/trips', $slug);
    }
}