The security core of slice 4: hub-supplied intent is no longer trusted for
destructive change. The gate fronts the per-guest queue's executor, so every
mutation passes it. Reuses internal/authz for all crypto (surface untouched).
- Classifier (doc 03 §4): benign vs destructive by provenance + data-bearing-
ness, NOT by verb. Destroy/overwrite of customer data is destructive unless
agent-internal provenance (same-journaled-txn create, or agent-tagged scratch)
makes it benign — and that provenance is journal-recorded, NEVER hub-sourced.
Unknown op class fails safe to destructive.
- Reversibility gate: benign -> allowed unsigned; destructive -> requires a
verified, role-scoped, action-bound operator signature, else pending_signature
and never executed. Every decision audited (signal, never the guard).
- Signed-op consuming layer over authz.Verifier.Verify (locked pipeline
untouched): role-scoping (doc 04 §4 — recovery=rotation only, operational=
ordinary destructive + planned rotation) + op-to-action binding (op+host+
guest+params must match the gated action).
- Signed-job orchestration: idempotency dedupe by nonce + journal-wrapped
execution via an injected DestructiveExecutor (nil this slice — inert).
- Crash recovery (Note 1): Engine.Recover consumes the journal InFlight() set at
startup (resume-or-rollback) — covers an op that crashed after the POST and
before its terminal record, which idempotency dedupe alone cannot. Added
TaskStatusOnce to the GuestAPI seam. Wired into daemon startup.
- Note 2: memory comparison canonicalized to MiB (desiredMemoryMiB) so a
non-MiB-aligned MemoryBytes converges in one pass, not perpetual drift.
- Daemon: builds the verifier from config signers (none = nil verifier, the
common slice-4 state), the gate (+SlogAudit), runs Recover before mutating.
Adversarial matrix proven against the REAL authz.Verifier with in-test-minted
SSHSIGs (framing replicated in reconcile's test binary; authz untouched, no
signing added to the verify-only package): unsigned job + unsigned desired-state
delta -> pending_signature; unknown signer/expired/replay-across-restart/wrong
host -> typed authz rejections; wrong guest/op/params -> binding_mismatch;
recovery key on ordinary destructive -> role_denied; hub-supplied scratch tag
ignored -> refused; valid+role+target+fresh nonce -> accepted then replay
rejected. Full module race-clean + vet-clean on the Linux build server.
Inert this slice: no destructive deltas served until slice 10; the destructive
path is classified, gated, and tested but not wired to live execution.
CHECKPOINT: Phase B complete (slice 4 done). Awaiting validation.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
