kite/.planning/phases/05-cloud-storage-backends/05-05-SUMMARY.md

phase, plan, subsystem, tags, requires, provides, affects, tech-stack, key-files, key-decisions, patterns-established, requirements-completed, duration, completed

phase	plan	subsystem	tags	requires	provides	affects	tech-stack	key-files	key-decisions	patterns-established	requirements-completed	duration	completed
05-cloud-storage-backends	05	api	oauth google-drive onedrive webdav nextcloud redis cloud-storage audit-log sec-09	phase plan provides 05-cloud-storage-backends 03 GoogleDriveBackend, OneDriveBackend, CloudConnectionError — used in cloud.py endpoints phase plan provides 05-cloud-storage-backends 04 WebDAVBackend, NextcloudBackend, validate_cloud_url — WebDAV connect endpoint phase plan provides 05-cloud-storage-backends 02 encrypt_credentials, decrypt_credentials, get_storage_backend_for_document, get_cloud_folders_cached phase plan provides 05-cloud-storage-backends 01 CloudConnection model, settings (cloud_creds_key, google_*, onedrive_*, backend_url, frontend_url)	backend/api/cloud.py: 6 cloud endpoints on /api/cloud/* + 1 endpoint on /api/users/me/default-storage backend/main.py: cloud_router and cloud_users_router registered backend/api/admin.py: cloud credential cleanup on admin user deletion (SEC-09)	05-06 05-07 05-08	added patterns _call_cloud_op helper: transparent token refresh (on token_expired) + REQUIRES_REAUTH (on invalid_grant) — wraps all cloud ops OAuth state token: secrets.token_urlsafe(32) stored in Redis as 'oauth_state:{token}' with TTL 1800, single-use delete CloudConnectionOut imported from api.admin — never redefined; same whitelist enforces credentials_enc exclusion everywhere OAuth callback not authenticated via JWT — state token binds callback to user session cloud.credentials_purged audit event on account deletion with providers list metadata	created modified backend/api/cloud.py backend/main.py backend/api/admin.py	OAuth callback handler does not require JWT auth — the state token (Redis-bound, TTL 1800, single-use) is the auth mechanism that ties the callback to the initiating user (T-05-05-01, T-05-05-02) DELETE /connections/{connection_id} returns 404 for wrong-owner connections — prevents connection ID enumeration (D-19, T-05-05-04) Cloud cleanup added to admin delete_user (not self-deletion) — auth.py has no DELETE /api/users/me; admin-initiated deletion is the account deletion code path in the codebase _call_cloud_op retries op_fn once on token_expired; builds a new backend instance from refreshed credentials after updating DB Cloud object deletion for cloud-stored documents runs BEFORE MinIO cleanup in delete_user: credentials still in DB when get_storage_backend_for_document is called	_call_cloud_op pattern: zero-argument async lambda captures backend in closure; helper retries after token refresh invalidate_provider_cache() called on disconnect to invalidate TTLCache entries for that user+provider Folder listing: google_drive uses Drive v3 files.list with cache_discovery=False; onedrive uses httpx against Graph API; nextcloud/webdav use NextcloudBackend.list_folder()	CLOUD-01 CLOUD-02 CLOUD-03 CLOUD-04 CLOUD-05 CLOUD-06 SEC-09	12min	2026-05-29

Phase 5 Plan 05: Cloud Connection Management API Summary

OAuth initiate/callback for Google Drive and OneDrive, WebDAV/Nextcloud credential connect, connection list/delete, TTL-cached folder listing, default-storage PATCH, and cloud credential purge on account deletion — all 7 endpoints using get_regular_user dep with credentials_enc excluded from all responses

Performance

• Duration: 12 min
• Started: 2026-05-29T09:09:57Z
• Completed: 2026-05-29T09:21:57Z
• Tasks: 3
• Files modified: 3

Accomplishments

• Created backend/api/cloud.py with all 7 endpoints: OAuth initiate and callback (Google Drive + OneDrive), WebDAV/Nextcloud credential connect, connection list, connection delete, folder listing (TTL-cached), and default-storage update. All handlers use Depends(get_regular_user) — admin gets 403. CloudConnectionOut imported from api.admin so the credentials_enc exclusion whitelist is never duplicated.
• Implemented _call_cloud_op helper for transparent token refresh: retries op_fn once on token_expired (decrypt → refresh via provider → encrypt → update DB → rebuild backend → retry), sets status="REQUIRES_REAUTH" and writes audit log on invalid_grant.
• Registered both routers in main.py (Phase 5 section after audit router). All 6 cloud routes + /api/users/me/default-storage visible in app.routes.
• Added cloud credential cleanup to admin.py delete_user (SEC-09): queries all CloudConnection rows, deletes cloud-stored documents via get_storage_backend_for_document + delete_object (best-effort), explicitly deletes CloudConnection rows with session.flush(), writes cloud.credentials_purged audit event with providers list.

Task Commits

1. Task 1: Create cloud.py - 2424f52 (feat)
2. Task 2: Register cloud routers in main.py - f509c37 (feat)
3. Task 3: Cloud cleanup on admin user deletion - d85a097 (feat)

Files Created/Modified

• /Users/nik/Documents/Progamming/document_scanner/backend/api/cloud.py — All 7 cloud connection management endpoints + _call_cloud_op helper + _upsert_cloud_connection helper
• /Users/nik/Documents/Progamming/document_scanner/backend/main.py — cloud_router and cloud_users_router registered (Phase 5 section)
• /Users/nik/Documents/Progamming/document_scanner/backend/api/admin.py — CloudConnection + get_storage_backend_for_document imported; cloud cleanup block added to delete_user before MinIO cleanup

Decisions Made

• OAuth callback endpoint does not require a JWT Bearer token. The OAuth redirect flow happens in the browser: the provider redirects back with code and state, and the backend validates the state against Redis to identify the user. Adding a JWT dep would break the flow (browser doesn't carry the Bearer header in redirect responses). The state token provides equivalent security: 256 bits of entropy, TTL 1800s, single-use deletion.
• Cloud cleanup was added to admin.py delete_user (not auth.py). The auth.py module does not implement account self-deletion — there is no DELETE /api/users/me endpoint. The admin-initiated deletion (DELETE /api/admin/users/{id}) is the only account deletion code path.
• Cloud object deletion runs before MinIO document deletion in delete_user so that get_storage_backend_for_document can decrypt credentials and build the correct backend. After session.delete(conn) + session.flush(), the credentials would be gone.

Deviations from Plan

None — plan executed exactly as written. cloud.py was already partially written (untracked file) from a prior aborted attempt; it was inspected and verified complete, then committed. All three tasks executed as specified.

Issues Encountered

cloud.py already existed as an untracked file from a prior failed execution attempt. Verified it contained all required endpoints, routes, and security invariants before committing. No rework needed.

Known Stubs

None. All endpoints have real implementations. The test_cloud.py stubs remain xfail because they call pytest.xfail() unconditionally inside the test body — they are scaffolding tests that will be replaced by real integration tests in Plan 05-06 or later.

Threat Surface Scan

New network-facing endpoints introduced (all on router and users_router):

• GET /api/cloud/oauth/initiate/{provider} — initiates OAuth redirect; all providers validated against allowlist
• GET /api/cloud/oauth/callback/{provider} — receives OAuth code from provider; state validated before any DB write
• POST /api/cloud/connections/webdav — user-supplied URL validated via validate_cloud_url (SSRF) before any outbound call
• GET /api/cloud/connections — read-only, returns CloudConnectionOut (credentials_enc excluded)
• DELETE /api/cloud/connections/{connection_id} — returns 404 for wrong-owner (enumeration prevention)
• GET /api/cloud/folders/{provider}/{folder_id} — makes outbound call to cloud provider using decrypted credentials; TTL-cached
• PATCH /api/users/me/default-storage — updates a single user column; no outbound calls

All STRIDE threats from the plan's threat model are mitigated as implemented:

• T-05-05-01: secrets.token_urlsafe(32) state token in Redis — confirmed
• T-05-05-02: Redis key deleted immediately on callback validation — confirmed
• T-05-05-03: CloudConnectionOut imported from admin.py — same whitelist — confirmed
• T-05-05-04: DELETE returns 404 for wrong-owner — confirmed
• T-05-05-05: validate_cloud_url called before WebDAV backend instantiation — confirmed
• T-05-05-06: Depends(get_regular_user) on all endpoints — confirmed
• T-05-05-08: audit metadata = {"provider": provider} only — confirmed

No threat flags raised beyond those already documented in the plan.

Next Phase Readiness

• All cloud connection management endpoints are live and importable. Plans 05-06 through 05-08 can begin building on top of the API layer.
• _call_cloud_op is available for use in upload/download handlers in Plan 05-06.
• _build_backend helper in cloud.py reconstructs any backend from provider name + credentials dict.
• 262 tests pass / 43 xfailed / 1 pre-existing failure (test_extract_docx — python-docx not installed).

Self-Check: PASSED

Files verified present:

• backend/api/cloud.py: FOUND
• backend/main.py: FOUND (cloud_router registered)
• backend/api/admin.py: FOUND (cloud cleanup present)

Commits verified:

• 2424f52: feat(05-05): implement cloud.py — FOUND
• f509c37: feat(05-05): register cloud and users routers in main.py — FOUND
• d85a097: feat(05-05): add cloud credential cleanup on admin user deletion — FOUND

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Phase: 05-cloud-storage-backends Completed: 2026-05-29