With Security:Acl:Enabled=true, a session holding any grant narrower than
Cluster could not browse the served address space at all — confirmed by the
live gate.
Mechanism. Both realm trees hang under ONE anchor folder minted in
CreateAddressSpace: NodeId("OtOpcUa", <raw ns>). ResolveParentFolder parents
every top-level raw folder AND every top-level UNS area under it, and the
Browse override throws BadUserAccessDenied for the WHOLE call when its source
node is denied. DataPlaneAuthorizer.BuildScope split that identifier like a
path, producing {Kind: Raw, Segments: ["OtOpcUa"]} — but trie grant paths are
["raw", <RawPath segments…>] and "OtOpcUa" is never a path segment, so
PermissionTrie.HasBrowseTransit failed at the realm-child lookup and
CollectMatches yielded only Cluster-scoped grants. Deny, at the front door.
The trie already handled a zero-segment scope as "the realm root, itself an
ancestor of everything granted in that realm" (PermissionTrie.cs:101-118) —
no production path had ever produced that scope. This wires it up.
- V3NodeIds.SharedRootFolderId names the anchor identity; CreateAddressSpace
now mints the NodeId/BrowseName/DisplayName from it (behaviour-identical,
makes the coupling explicit).
- BuildScope maps that identifier (realm-qualified to Raw — in the UNS
namespace s=OtOpcUa is an ordinary Area) onto the zero-segment Raw scope.
- Evaluate adds a second-realm OR-leg for Browse on the anchor only: it fronts
both trees, so a principal whose only Browse grant lives in the UNS tree
still enters through this raw node. Browse only; transit confers navigation,
never read/write/subscribe.
- No trie, evaluator or builder change. No reordering above the decision cache
— key revocation is still re-checked before the lookup — and the cache key
is unchanged (the combined verdict caches under the anchor's own
identifier/realm; a generation advance clears it).
Falsifications actually run (implement-then-revert-the-line, plus one
genuine red-first):
- DataPlaneAuthorizerTests: the 7 new facts were written BEFORE the fix and 4
went red (the 3 deny-only ones passed vacuously, as a deny-only test must).
- Deleting the UNS OR-leg reddens exactly one fact,
The_shared_root_folder_is_browsable_on_a_uns_only_browse_grant (26/27 pass).
- Dropping the realm qualification from IsSharedRootFolder reddens exactly
A_uns_area_named_like_the_anchor_gets_no_anchor_semantics. Its first draft
did NOT catch this — a raw-only grant is refused either way; the
discriminating grant had to be an unrelated UNS one, whose own transit marks
the zero-segment UNS scope the un-qualified mapping would land on.
- Disabling the BuildScope anchor branch reddens the new end-to-end fact
NodeManagerStage6EnforcementTests.The_shared_root_folder_is_browsable_on_a_narrow_grant_and_still_filters
(real booted server, real Browse dispatch: BadUserAccessDenied on the whole
call), which also pins that the reference filter still withholds the
non-granted sibling.
- Core PermissionTrieBrowseTransitTests gains 3 characterization facts pinning
the previously-dead realm-root branch (transit true for the granting realm's
root, false for the other realm's, false without the Browse bit). These were
green on arrival — the trie was always correct; nothing called it.
Tests: Core 351 -> 354 passed; OpcUaServer 482 -> 490 passed. Build clean.
Joseph Doherty
89630ee418