fix(communication): enforce room and project membership boundaries

backend/src/modules/communication-access.ts

@@ -0,0 +1,28 @@
+import { and, eq } from "drizzle-orm"
+import { authProfiles, projects } from "../../db/schema"
+
+export function chatError(message: string, statusCode = 403): never {
+    throw Object.assign(new Error(message), { statusCode })
+}
+
+export function assertCustomRoomKey(key: string) {
+    if (key === "allgemein" || /^(direct|project)_/.test(key)) {
+        chatError("Dieser Raumschlüssel ist für Systemräume reserviert", 409)
+    }
+}
+
+export function managesProjects(req: any): boolean {
+    return Boolean(req.user?.is_admin || req.hasPermission?.("organisation.projects.write"))
+}
+
+export async function projectChatAccess(db: any, req: any, projectId?: number) {
+    const tenantId = Number(req.user?.tenant_id)
+    const conditions = [eq(projects.tenant, tenantId), eq(projects.archived, false)]
+    if (projectId !== undefined) conditions.push(eq(projects.id, projectId))
+    const rows = await db.select().from(projects).where(and(...conditions))
+    if (managesProjects(req)) return rows
+    const profiles = await db.select({ id: authProfiles.id }).from(authProfiles)
+        .where(and(eq(authProfiles.tenant_id, tenantId), eq(authProfiles.user_id, req.user.user_id)))
+    const profileIds = new Set(profiles.map((profile: any) => profile.id))
+    return rows.filter((project: any) => (project.profiles || []).some((id: string) => profileIds.has(id)))
+}