Five findings from the latest review on #758 (2 medium, 3 nit):
Medium:
- browser_oauth_routes.oauth_login_callback + oauth_routes.oauth_callback_nextcloud:
fail closed with 400 when the oauth_session row is unknown/expired. Previously
both callbacks fell through with code_verifier="" and expected_nonce=None,
silently bypassing the PKCE + nonce protections introduced in earlier rounds.
Symmetric unit tests pin both contracts.
- token_utils.verify_id_token: use secrets.compare_digest for the nonce check
instead of short-circuit !=. Mirrors the sibling PKCE verifier comparison;
closes the last secret-equality timing-side-channel surface in the auth path.
Nit:
- Tighten the comment at all 4 mcp_authorization_code/code_verifier store +
retrieve sites so a future refactor sees the field reuse immediately
(renaming the column requires a schema migration).
- _should_use_secure_cookies: explicit string normalisation instead of
bool(settings.cookie_secure). Dynaconf normally coerces but tests / direct
settings.set calls can leave the raw string in place — bool("false") is True.
New parametrized unit tests cover the coercion matrix + http/https fallback.
- oauth_routes.py:591 f-string log converted to lazy %s formatting (folded into
the Flow 2 callback rewrite).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Seven findings from the latest review on #758 (3 medium, 4 low/nit):
Medium:
- storage.py: replace 5 ``assert self.cipher is not None`` sites with
explicit ``RuntimeError`` so missing TOKEN_ENCRYPTION_KEY can't silently
become an AttributeError under ``python -O``
- session_backend.py: document the silent-invalidation invariant —
refresh-token TTL expiry without explicit logout deliberately makes
the browser session unusable; future readers must not relax it
- server/oauth_tools.py: drop user_id from the Flow 2 session_id
identifier — use ``flow2_{secrets.token_hex(16)}`` so audit logs and
DB rows don't carry user_id in the session_id field
Low / nit:
- token_utils.py: drop _fetch_locks dict entry in finally so a probed
deployment can't grow the lock dict without bound; coalescing test
now pins the invariant with len(_fetch_locks) == 0
- browser_oauth_routes.py: strip trailing slash from settings.nextcloud_host
before constructing the well-known URL so a host configured as
``https://cloud.example.com/`` doesn't produce a double-slash
- browser_oauth_routes.py: add comment explaining the three-layer CSRF
policy on the mcp_session cookie set (SameSite=Lax + POST-only logout
+ Origin/Referer check)
- oauth_routes.py: convert all 23 f-string log calls to lazy %-style
per the CLAUDE.md / memory feedback_lazy_logging convention
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Seven findings from the latest review on #758, plus a regression test
catching the substance of the cache-stampede fix:
- verify_id_token: widen id_token annotation to str | None to match
callers passing nc_token_response.get("id_token")
- extract_user_id_from_token: use JSON-RPC reserved error code -32001
instead of -1
- _get_cached: per-URL anyio.Lock dict + meta-lock coalesces concurrent
cache misses into a single IdP fetch (mirrors token_broker.py idiom)
- delete_browser_session: collapse SELECT+DELETE into atomic
DELETE ... RETURNING user_id (SQLite >= 3.35)
- new test_origin_normalise.py: parametrized port/scheme/host equivalence
cases for the CSRF Origin guard
- browser_oauth_routes: correct misleading "PR #758 finding 5" cross-
references (finding 5 was Fernet-key hardening, not CSRF)
- ASProxySession.nonce: make required, drop spurious "legacy session"
default; reword the in-flight `or None` comment to reflect that
ASProxySession is purely in-memory
- new test_get_cached_coalesces_concurrent_misses: pins the
cache-stampede protection — fires 10 concurrent _get_cached calls and
asserts exactly one HTTP fetch
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
- oauth_login_callback's integrated-mode token-exchange branch now reuses
the shared discovery cache via get_oidc_discovery (round-2 finding 1).
- AS proxy flow now generates an OIDC nonce in oauth_authorize, stores it
on ASProxySession, forwards it to the IdP, and passes it as
expected_nonce to verify_id_token in _oauth_callback_as_proxy
(round-2 finding 2).
- Consolidate the two parallel discovery caches: oauth_routes' local
_discovery_cache and _get_cached_discovery are removed; all callers
now go through token_utils.get_oidc_discovery, which acquires the
follow_redirects=True knob it needs for Nextcloud installs without
pretty URLs (round-2 finding 3).
- Demote per-user INFO logs in oauth_tools.py (check_logged_in,
get_provisioning_status) to DEBUG; the elicitation auth URL is no
longer logged because it contains a sensitive state token
(round-2 finding 4).
Also pin nonce binding behaviour with a new unit test that asserts
_oauth_callback_as_proxy forwards session.nonce to verify_id_token, and
update test mocks to track the cache consolidation.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Blocking:
- AS proxy callback now calls verify_id_token before caching the proxy
code so a tampered IdP response can't smuggle identity claims.
Important:
- Browser OAuth flow generates and verifies an OIDC nonce; new alembic
migration 006 adds the nonce column to oauth_sessions.
- _origin_matches_self logs a warning when CSRF check is bypassed.
- oauth_tools.py uses get_shared_storage instead of fresh handles.
Nits:
- New token_utils.get_oidc_discovery shares the 5-minute cache with
verify_id_token; oauth_login (integrated) and _revoke_refresh_token_at_idp
now use it instead of issuing fresh discovery fetches.
- Drop typing.Optional from oauth_tools.py in favour of X | None.
CI:
- test.yml generates an ephemeral Fernet TOKEN_ENCRYPTION_KEY per run
with openssl, removing the dependency on a missing repo secret.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Addresses the two remaining 🟡 findings from the PR #758 follow-up review:
1. extract_user_id_from_token previously fell back to "default_user" when
the verified access token had no sub claim. In a multi-tenant deployment
a malformed IdP token could have bucketed every request under a single
sentinel user, risking cross-tenant data exposure. The function now
raises McpError on that branch; the BasicAuth no-token sentinel path is
preserved.
2. oauth_callback_nextcloud (Flow 2) read the PKCE code_verifier from
oauth_sessions but never deleted the row, leaving the verifier valid for
the full 10-minute TTL. The row is now deleted eagerly inside the same
branch, mirroring oauth_login_callback in browser_oauth_routes.
Also wires TOKEN_ENCRYPTION_KEY through the docker-compose step in the CI
test workflow so the integration matrix can boot — every job had been
failing fast on the ${TOKEN_ENCRYPTION_KEY:?...} interpolation guard added
in PR #758 finding 5.
Tests pin both fixes (test_token_utils_user_id.py,
test_oauth_callback_session_cleanup.py).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Six findings from the latest claude-bot review on PR #758:
- JWKS cache had no kid-miss refresh path (Medium): on IdP key
rotation every login failed for up to _OIDC_CACHE_TTL. Evict
and refetch once before raising, per OIDC core §10.1.1.
- _should_use_secure_cookies fell back to nextcloud_host scheme,
but the cookie is issued by the MCP server. Switch to
settings.nextcloud_mcp_server_url so split-scheme deployments
get the right Secure flag.
- _origin_matches_self compared raw netloc strings, which include
the port. Browsers omit default ports per RFC 6454 §6.2; an
mcp_server_url like :443 falsely 403'd every legitimate logout.
Normalise (scheme, host, port) tuples with default ports stripped.
- delete_oauth_session exists in storage.py — drop the stale
"we don't have this method" comment and call it eagerly so
replays can't be processed and the table doesn't accumulate
completed-but-not-yet-expired browser-login rows.
- extract_user_id_from_token's unused ctx param renamed to _ctx
to signal "intentionally unused" at the signature level.
- provisioning_decorator instantiated RefreshTokenStorage per
call. Switch to get_shared_storage() for the lock-protected
process-wide singleton.
Plus pre-push self-review catch: lazy-logging on the unchanged
except arm in session_backend.py.
Adds 5 regression tests:
- JWKS rotation: success on refetch
- JWKS rotation: still-missing-kid surfaces original error
- JWKS rotation: network error during refresh wrapped as
IdTokenVerificationError
- default-port CSRF: explicit :443 in config + portless Origin
- default-port CSRF: portless config + explicit :443 in Origin
- scheme-mismatch CSRF: same host, different scheme rejected
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Addresses all 9 findings from the review on PR #758:
Blocking:
- _revoke_refresh_token_at_idp now reads config from oauth_ctx["config"]
(the production-shaped nested dict). Previously read flat keys, causing
IdP revocation to silently no-op in production. Test fixtures rebuilt
to the realistic nested shape so the bug can't regress unnoticed.
- HTML error responses in oauth_login_callback now wrap IdP-controlled
error_body, str(e), and the attacker-controlled error/error_description
query params in html_escape. New test_browser_oauth_xss.py pins this.
Important:
- New _safe_next_url helper validates the ?next= query param at write
time (oauth_login), in oauth_logout, and on read from the session row
in oauth_login_callback. Blocks https://, // (protocol-relative), and
CRLF/whitespace injection.
- verify_id_token now caches discovery + JWKS (5-min TTL) using the
same pattern as oauth_routes._get_cached_discovery. New caching
regression test pins to one fetch per URL across multiple calls.
- /oauth/logout is now POST-only at the route layer (defeats passive
CSRF via <img src>). oauth_logout also validates Origin/Referer
against the configured mcp_server_url. Logout UI in user_info.html
converted from <a href> to <form method="post">.
- New storage.cleanup_expired_browser_sessions() called from the hourly
cleanup loop in app.py — previously these rows accumulated for users
who never explicitly logged out.
Nits:
- Demoted INFO logs that leaked oauth_config.keys() / client_id /
token-storage state to DEBUG. Operator-relevant outcome lines
(login successful, refresh token stored, logged out) stay INFO.
- verify_id_token algorithms widened to RS256, PS256, ES256 — covers
Azure AD (PS256) and Cognito/some Keycloak realms (ES256). Symmetric
and "none" remain off the allowlist.
- Migrated all Optional[X] usages in auth/storage.py to X | None per
CLAUDE.md.
Breaking change: GET /oauth/logout now returns 405. The in-tree logout
UI was migrated to a POST form; any external bookmark or curl-based
caller that relied on GET will need to switch.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Pre-launch hardening for the hosted Astrolabe Cloud offering. Addresses
all five findings raised in #626 (Tim Kaufmann, code review of v0.65.0).
Re-verified against master before fixing.
Finding 3 (LLM-controllable user_id) — drop user_id from the public
signatures of provision_nextcloud_access, revoke_nextcloud_access,
check_provisioning_status, check_logged_in. Tool wrappers now always
derive identity from the verified AccessToken; user_id is no longer
accepted as MCP input. Adds parameterized CI-guard test that locks the
schema.
Finding 2 (predictable session cookie) — replace mcp_session=<user_id>
cookie with a cryptographically random session_id mapped server-side
(new browser_sessions table, alembic 005). Cookie value is opaque,
expires, revocable. SessionAuthBackend looks up user_id via the new
mapping and additionally requires a refresh token to fail closed.
Finding 4 (logout doesn't revoke refresh token) — oauth_logout now
calls the IdP revocation_endpoint (RFC 7009) when advertised, deletes
the stored refresh token regardless, and clears the browser_sessions
row. Cleanup is best-effort: logout always 302s.
Finding 1 (unverified ID token decodes) — verify_id_token helper does
JWKS signature + issuer + audience + exp + nonce checks per OIDC core
3.1.3.7. Used by both OAuth callback handlers (browser + MCP). Removes
the four "verify_signature: False" decodes that previously trusted IdP
claims unconditionally. Drops dead-code _validate_token_audience in
token_broker. Refactors token_utils + provisioning_decorator to read
user_id from the verified AccessToken instead of re-decoding the JWT.
Finding 5 (hardcoded Fernet keys in docker-compose.yml) — replace the
three inline TOKEN_ENCRYPTION_KEY values with required env var
interpolation; document in env.sample.
Test coverage: 4 new unit test modules (signature pinning, browser
sessions, ID-token verification, logout + revoke + session backend).
693 unit tests pass; ruff/format/ty clean.
Migration note: existing browser admin-UI sessions become invalid on
rollout (cookies are looked up against the new browser_sessions table,
which starts empty). Users re-login. MCP API access is unaffected.
Tracked on Astrolabe Cloud POC board card #37.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
- Add 429 retry with exponential backoff to register_client() (fixes CI
oauth matrix failures from parallel DCR requests)
- Make client_id, redirect_uri, and PKCE mandatory at token endpoint
- Add null-checks for discovery_url and OAuth credentials in proxy flows
- Add OIDC discovery document caching with 5-min TTL
- Add per-IP rate limiting on /oauth/register DCR proxy
- Discover DCR endpoint from OIDC discovery instead of hardcoding
- Extract extract_user_id_from_token to auth/token_utils.py (breaks
circular imports between server/ and auth/ layers)
- Add TTL scope cache in scope_authorization.py (avoids DB hit per tool)
- Add defense-in-depth scope validation in storage layer
- Broaden elicitation exception handling with graceful fallback
- Add idempotentHint to nc_auth_check_status, return "pending" status
after accepted elicitation, add polling interval to description
- Change ALL_SUPPORTED_SCOPES from tuple to frozenset for O(1) lookups
- Replace Optional[str] with str | None throughout config.py
- Use default_factory for ProxyCodeEntry/ASProxySession dataclasses
- Add proxy code/session cleanup to background loop
- Fix OIDC verification CI step to only run for oauth/login-flow modes
- Add unit tests for access.py REST endpoints (10 tests)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
