expand RNS whitelist: allow GET /, /about, /pages, /tags, /share via gateway

src/tinyweb/app.py

@@ -73,11 +73,22 @@ def load_or_create_identity():
     return identity
 
 
-# Remote peers on the Reticulum mesh can only reach a narrow, read-only surface.
+# Remote peers on the Reticulum mesh can reach read-only public pages.
-# Any other method/path is rejected here — CSRF cannot authenticate mesh callers
+# Only GET is allowed; POST is blocked because CSRF cannot authenticate
-# (the attacker controls both the "cookie" and the "form" side of the check), so
+# mesh callers (the attacker controls both the "cookie" and the "form" side).
-# gating by whitelist is the only safe option.
+_RNS_ALLOWED_GET = {
-_RNS_ALLOWED = {("GET", "/api/sites")}
+    "/", "/about", "/api/sites", "/share/preview",
+}
+
+_RNS_ALLOWED_PREFIXES = ("/pages", "/tags", "/api/sites")
+
+
+def _rns_is_allowed(method, path):
+    if method != "GET":
+        return False
+    if path in _RNS_ALLOWED_GET:
+        return True
+    return any(path.startswith(p) for p in _RNS_ALLOWED_PREFIXES)
 
 
 def rns_request_handler(path, data, request_id, link_id, remote_identity, requested_at):
@@ -85,7 +96,7 @@ def rns_request_handler(path, data, request_id, link_id, remote_identity, reques
         data = {"method": "GET", "path": "/", "query": {}, "body": {}, "gateway_host": ""}
     method = data.get("method", "GET")
     req_path = data.get("path", "/")
-    if (method, req_path) not in _RNS_ALLOWED:
+    if not _rns_is_allowed(method, req_path):
         return {
             "status": 403,
             "content_type": "text/plain; charset=utf-8",