Document the second pass and what is still open

README.md

@@ -41,7 +41,10 @@ python3 sigil.py code bigpickle /tmp/demo.key         # hand a human a code
 python3 sigil.py redeem X3ZB-NTLG                     # -> human_via_agent token
 python3 sigil.py whoami "$TOKEN"                      # kind, scopes, may_act_as_agent
 python3 sigil.py events bigpickle                     # audit trail
-python3 sigil.py verify-chain                         # is the log intact?
+python3 sigil.py checkpoint /tmp/demo.key bigpickle   # sign the audit head
+python3 sigil.py verify-chain                         # chain + checkpoints
+python3 sigil.py revoke bigpickle --reason "incident" # or --until UNIX
+python3 sigil.py sweep                                # prune stale rows
 ```
 
 ## Tests
@@ -50,10 +53,10 @@ python3 sigil.py verify-chain                         # is the log intact?
 python3 -m unittest discover -s tests -v
 ```
 
-80 tests. They cover the refusals, not just the happy paths: replayed
+106 tests. They cover the refusals, not just the happy paths: replayed
 signatures, wrong keys, expired nonces, single-use codes, scope escalation, and
-the invariant below. `test_hardening.py` has one test per defect found in
+the invariant below. `test_hardening.py` and `test_production.py` have one test
-review, so any of them regressing brings that defect back.
+per defect found in review, so any of them regressing brings that defect back.
 
 ## The invariant
 
@@ -85,9 +88,14 @@ no extra capability. Waiting for a code does not eat into it — an earlier draf
 anchored the session to issue time, which quietly handed out less than promised.
 
 **Nothing is minted from a name.** `issue_code` takes an agent *session*, not an
-agent id, and `verify_chain` exists so tampering is detectable. A function that
+agent id. A human session requires a `GrantedCode`, which only a redeemed code
-accepts a string and returns authority is how "who is this?" quietly becomes
+can produce. A function that accepts a string and returns authority is how
-unanswerable.
+"who is this?" quietly becomes unanswerable.
+
+**Suspension and death are different statements.** `revoke` with no end time is
+permanent; `revoke --until` is a pause that lapses on its own. An incident
+response that ends should not need a re-enrolment, and a dead identity should
+not come back because a clock ran out.
 
 ## Status
 
@@ -96,6 +104,11 @@ A hardening pass closed the defects below. Each is now covered by a test.
 | Found in review | Now |
 |---|---|
 | `issue_code()` trusted an agent name, so it minted authority from a string | Takes an agent session; agent derived from it |
+| Human sessions were mintable from a bare agent name | Requires a `GrantedCode`, constructible only by redeeming |
+| Audit log recorded 4 of 8 code characters (20 bits left) | Logs a truncated digest instead |
+| No `revoke` operation existed, only an unused column | `revoke` with optional end time; sessions killed, challenges dropped |
+| Chain was unkeyed, so a database-level attacker could rewrite it | Signed checkpoints; `verify-chain` checks both |
+| No busy timeout, so concurrent writers failed instantly | `busy_timeout`, WAL, rollback on error |
 | One-time code redeemable many times in a race (753 times in 200 trials) | Atomic compare-and-set; 300 races, one success each |
 | Bootstrap secret spendable more than once | Atomic compare-and-set |
 | Signed nonce verifiable more than once | Nonce claimed before the signature is judged |
@@ -109,21 +122,25 @@ A hardening pass closed the defects below. Each is now covered by a test.
 
 Still open, and these are the reasons not to ship it yet:
 
-- **No independent review.** Everything above is self-review. Self-review finds
+- **No independent review.** Everything above is self-review, twice over. Self-
-  the bugs you thought of. It does not find the ones you did not. This needs
+  review finds the bugs you thought of; it does not find the ones you did not.
-  someone else, ideally a cryptographer, before it guards anything real.
+  This needs someone else, ideally a cryptographer, before it guards anything
-- **The chain is unkeyed.** Each event folds in the previous digest, so an
+  real. This is the blocking item, and the only one that code cannot close.
-  accidental edit or deletion is caught. An attacker with write access to the
-  database can recompute the chain. For a real commitment, checkpoint the head
-  digest somewhere the database cannot reach, or sign it.
 - **The service around this is unwritten.** TLS, CSRF, session transport, secret
-  storage and the HTTP routes are not here. The library refuses to mint
+  storage and the HTTP routes. The library refuses to mint authority from a
-  authority from a name; a route that forgets to pass a session still cannot,
+  name, so a route that forgets to authenticate fails closed, but that is only
-  but that is only as good as the integration.
+  as good as the integration.
-- **Revocation has no expiry semantics.** Revoking works; scheduled or
+- **Checkpoints need somewhere to live.** A signed checkpoint inside the same
-  self-expiring revocation does not.
+  database is still only as good as the database. Real deployment wants the head
-- **No key recovery.** Rotate and you lose the old sessions. There is no escrow,
+  digest anchored off-box — published, or countersigned elsewhere — and this
-  which is a deliberate choice, not an oversight.
+  does not do that for you.
+- **No key recovery.** Rotate and the old sessions die, which is the point. There
+  is no escrow. Deliberate, not an oversight.
+- **Rate limits are in-process.** They are per-`Store`, so several processes
+  behind a load balancer each get their own quota. Fine for a single writer,
+  wrong for a fleet.
+- **SQLite, single node.** Fine for one agent or a modest service. It does not
+  shard, and there is no replication story.
 
 The tests assert the logic is correct. They do not make it safe.