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https://github.com/Such-Software/smirk-backend-core.git
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jwinterm
b03b9cb90d
The last operator subsystem: a user who no longer trusts the backend can reach in and delete their data. Action-bound and two-phase. - migration 20260626000003: erasure_requests (user_id ON DELETE SET NULL so the completed tombstone survives the user delete; one-live-request-per-user partial unique index; due index). - Proof model (§5.2): every action is a fresh NIP-98 signed action (purpose erasure_request/confirm/cancel/export) bound to a single-use challenge nonce + canonical descriptor + (confirm/cancel) the explicit erasure_id. A session token is NEVER sufficient. Erasure targets only the users.id the proof's key resolves to (via linked nostr_pubkey); leaked identifiers are never selectors. Nonce consumed AFTER signature checks (forged sig can't burn a victim's nonce). - Public routes (proof-gated): POST /account/erasure/challenge, /account/erasure (request; ABSENT-user path returns identical shape — no account-existence oracle), /account/erasure/:id/confirm (revokes live sessions), DELETE /account/erasure/:id (cancel during grace), POST /account/export (see-before- delete; omits view keys; audited). - Execution (§5.7): a background sweeper claims confirmed-past-grace rows (FOR UPDATE SKIP LOCKED) and runs ONE fail-closed tx: purge login_events (the origin/asset/time quasi-identifier; default) or anonymize; scrub audit PII; DELETE users (schema cascades wallets/sessions/keys/owned slatepacks, SET NULL on counterparty/audit/login links); tombstone; hash-chained account_erasure_completed audit. - config: ERASURE_GRACE_PERIOD_HOURS (72h default); validate() requires the integrity secret + PUBLIC_API_URL when erasure is enabled. - 1 L1 test: export -> request -> confirm -> execute -> account gone, plus the absent-user constant-shape path. Scope (v1, documented): live primary. No at-rest view key exists to crypto-shred (stateless-forward), so backup residue is bounded by retention-window docs, not crypto-shred (non-v1 per decisions ledger). Deferred: LWS de-registration queue + read-back probe (operators run their own LWS), audit cross-reference scrub on OTHER users' rows, restore_attempt salted-rotated fingerprint, retention sweepers, NIP-17 DM warning, in-flight-value blockers (no swaps/tips in the clean core), hard per-day export rate cap, /admin/erasure/stuck observability. Routes are off the public OpenAPI for now (stable contract; annotate later).
26 lines
1.2 KiB
SQL
26 lines
1.2 KiB
SQL
-- Self-service erasure requests (operator §5.3).
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--
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-- Two-phase (request -> confirm) with a grace window before execution. The row
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-- is keyed by user_id while live (execution needs it), but ON DELETE SET NULL so
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-- the COMPLETED tombstone survives the user delete with the link scrubbed.
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-- subject_hash is sha256(npub) — an opaque tombstone id, never the raw npub.
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CREATE TABLE erasure_requests (
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id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
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user_id UUID REFERENCES users (id) ON DELETE SET NULL,
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subject_hash TEXT NOT NULL,
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status TEXT NOT NULL DEFAULT 'pending', -- pending | confirmed | completed | cancelled
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requested_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
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scheduled_for TIMESTAMPTZ NOT NULL,
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confirmed_at TIMESTAMPTZ,
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completed_at TIMESTAMPTZ,
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cancelled_at TIMESTAMPTZ
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);
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-- At most one live (pending/confirmed) request per user.
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CREATE UNIQUE INDEX erasure_requests_active_user
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ON erasure_requests (user_id) WHERE status IN ('pending', 'confirmed');
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-- Drives the execution sweeper.
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CREATE INDEX idx_erasure_requests_due
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ON erasure_requests (scheduled_for) WHERE status = 'confirmed';
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