Routes the MCP index_repository handler and the graph UI's POST /api/index
through a single decision function. The UI route previously checked only that
root_path was a directory, so an operator's configured boundary held on one
entry point and not the other; it now canonicalizes first and applies the same
policy, answering 403 with the reason.
The decision is two-tier, because a bare default-deny would refuse every
first run and a bare opt-in leaves the default open:
- Breadth is always enforced, with nothing configured. Filesystem, drive and
share roots, top-level system trees, the home directory itself and
credential directories are refused as indexing roots out of the box.
- Containment in a declared root applies once CBM_ALLOWED_ROOT is set or a
grant exists, and is evaluated first so a path outside a configured root is
reported as exactly that.
Three things the tests caught, each a real defect rather than a test fix:
- On macOS /etc, /tmp and /var are firmlinked under /private, so
canonicalizing "/etc" yields "/private/etc" and counted two deep — sailing
past a minimum of two, missing the very path being guarded. Depth now
discounts a leading "private" component.
- An earlier draft refused any root containing the cache directory. That was
over-claimed: the indexer only parses recognised source files and a graph
database is binary SQLite it would never extract. Refusing a whole root is
also the wrong remedy where the concern does hold — not walking the cache
is. Removed, with the reasoning recorded at the site.
- Rewording the refusal to "outside every allowed root" broke an assertion
matching "outside the allowed root", and that test's early return skipped
its CBM_ALLOWED_ROOT cleanup, leaking the variable into every later test in
the suite. The original wording is kept and guidance appended instead.
Worth remembering: these contracts match strings, not properties.
Docs updated in the same change, since both env-var tables said "unset
imposes no restriction" and that is no longer true: CONFIGURATION.md and
README.md describe the two tiers, and CONFIGURATION.md lists the always-
refused roots along with the two limits that matter — this constrains scope
rather than sensitivity, and the credential list is a denylist that raises the
cost of a mistake rather than closing the class. SECURITY.md's supported-
versions table was still on 0.8.x and now reads 0.9.x.
Signed-off-by: Martin Vogel <martin.vogel.tech@gmail.com>
Martin Vogel
7fa5b07718
