1 Commits

Author	SHA1	Message	Date
Jakob Wennberg	ece6eca922	fix(storage): drop the client-side DELETE policy on the documents bucket (#1254) ... * fix(storage): drop the client-side DELETE policy on the documents bucket 20240101000024 documents this bucket as WORM: "No UPDATE or DELETE policies". That described the repo, not production. Production carries a users_delete_own_documents policy that exists in no migration file: FOR DELETE TO authenticated USING (bucket_id = 'documents' AND (storage.foldername(name))[2] = auth.uid()::text) Under it, the uploading user can delete the storage bytes of any document they uploaded under the legacy documents/{userId}/... layout, using nothing but their normal browser token. That includes documents linked to a posted verifikat, which are rakenskapsinformation under the BFL 7 kap 2 § seven-year retention duty. deleteDocument()'s linked-check and the block_document_deletion() trigger both guard the document_attachments ROW, not the object: the row survives, still pointing at a file that is gone. Reproduced against a local replay of the full migration stream: with the policy present the uploader's own DELETE removes the object; with it dropped the same statement matches zero rows. Company-scoped keys were never exposed (their second path segment is the company id, not auth.uid()), so this only ever reached the legacy layout, which is where most documents still live. Safe because every in-app remove() on this bucket already runs on the service role, covered by service_role_all_documents. Deliberately narrow: users_read_own_documents and users_upload_own_documents stay. The Phase B backfill from 20260726092000 has not run, so dropping the legacy SELECT policy now would make existing documents unreadable. That is Phase C. The pg-real test asserts no DELETE and no UPDATE policy over the bucket under ANY name: the hole arrived under a name this repo never used, so pinning a name would not have caught it. Refs #1208 Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> * test(storage): make the WORM ratchet see FOR ALL and WITH CHECK policies Review caught two blind spots in the ratchet, both fair. It matched only polcmd 'd' and 'w', but polcmd '*' (FOR ALL) grants DELETE and UPDATE just as effectively, and FOR ALL is the shape the one legitimate policy on this table already uses, so a hostile one would look unremarkable in the catalogue. It also read only polqual, so an UPDATE policy carrying its bucket restriction in WITH CHECK was invisible. Both assertions now run through one helper that covers d/w/*, concatenates USING and WITH CHECK, and filters by grantee so service_role_all_documents (how the application does its authorized deletes) is excluded while every client-reachable role is not. A policy granted to PUBLIC has an empty polroles, which is the most permissive case there is, so it is treated as client-reachable rather than as "no roles". Matching on the substring rather than the exact `bucket_id = 'documents'` shape pg_get_expr emits today: a policy written as bucket_id::text or with the comparison reversed would slip past a stricter match, and for a WORM ratchet a false alarm is cheap while a silent hole is not. Adds a probe case that creates a FOR ALL policy and asserts the helper sees it, so the main assertion cannot pass vacuously. That case earned its keep immediately: it caught that node-postgres hands back a raw string for a name[] column, so the role filter needed rolname::text to work at all. Verified against a local replay of the full migration stream: red with the original prod FOR DELETE policy present, red with a FOR ALL probe, green without either. Full pg-real suite 933 passed. Refs #1208 Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> * test(storage): catch a destructive policy that names no bucket at all Adversarial review of the previous commit found the ratchet still failed open, and reproduced it: a policy with no bucket_id predicate covers EVERY bucket, documents included, so gating on the bucket name discarded exactly the widest hole. The concrete shape is Supabase's own stock "Enable delete for users based on user_id" template, USING (auth.uid() = owner), which is the single most likely form of a future dashboard edit. A destructive policy is now in scope unless it provably cannot reach this bucket, i.e. only a bucket_id predicate naming some other bucket exempts it. The behavioural assertions had the matching blind spot: fixtures were seeded without an owner, so an owner-based policy matched NULL and the DELETE reported 0 rows for the wrong reason. Objects now carry an owner the way storage-api stamps them in production, so those tests fail loudly instead of passing by accident. Two probes pin both directions: a bucketless policy must be reported (and is shown to really permit the delete), and a policy scoped to another bucket must not be, so the ratchet cannot start crying wolf on receipts or sie-files and get switched off. Verified against a local replay of the full migration stream: red with the stock bucketless template installed, green without it. Full pg-real suite 935 passed. Refs #1208 Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> --------- Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>	2026-07-28 18:34:55 +02:00