Three ways the cold-start path could lose the database.
A box enrolled before the PRF change could never cold-start again. UnwrapKey
still read v1 blobs, but the only caller stopped supplying the v1 secret: the
assertion handler sends the PRF output and nothing looks up the credential
public key any more. On such a box the daemon read the blob, took the v1
branch, failed to decrypt, and stayed locked while a valid passkey was
asserted at it. The escape hatch was gone too, because WrapKeyFn was wired
only in env-key mode and a locked boot is by definition the mode with no env
key. The recovery was to put MAVEN_DB_KEY back in the environment, which is
the thing cold-start unlock exists to avoid. AssertFinish now retries a failed
PRF unwrap with the credential public key, and WrapKeyFn is wired in locked
mode too, so the box that came up on a v1 blob can be moved to v2.
Wrapping ran on every successful assertion. That made a routine step-up
rewrite the one file that opens the database, under whatever 32 bytes the page
posted. A compromised /auth/webauthn converted one legitimate touch into
permanent offline recovery of the at-rest key, and a second enrolled
authenticator silently locked out the first. Wrapping is now an act of its
own: a plain assertion may write the blob only when none exists, and replacing
one takes the rewrite button, which is the only caller that sets the new
explicit flag. The daemon still refuses to overwrite a v2 blob that does not
open under the presented secret.
The write was os.WriteFile, which truncates in place. A power cut between the
truncate and the write left a zero-length blob and no previous contents, on
the path of every step-up. It is now a temp file in the same directory, fsync,
rename, fsync of the directory.
Two smaller things on the same path. The v2 unwrap checked the secret length
but not the all-zero case the wrap side rejects, so the two ends disagreed
about what a valid secret is. And the handler logged "daemon unlocked via
credential" when an env-key daemon had answered unknown method, and again when
an already-unlocked daemon had done nothing.
Left alone deliberately: the PRF value is client-supplied and not covered by
the assertion signature. That is inherent to PRF key wrapping, since the salt
has to be fixed for the blob to open on the next boot. It is recorded as a
known property where the secret enters the handler.
Found in review of #77.
Cold-start unlock wrapped the database key under the credential *public* key.
A public key is public: mavweb writes it verbatim to passkeys.json, normally in
the same state dir as db_key.wrapped, so anyone holding both files recovered the
database key offline with no authenticator involved. The wrapped blob was a
plaintext key with extra steps.
The secret is now the WebAuthn PRF extension output — 32 bytes the authenticator
computes over a fixed salt and never stores anywhere. The blob gains a version:
v2: "MVNKW2\x00" || salt || nonce || AES-256-GCM(key), magic as AAD
v1: salt || nonce || AES-256-GCM(key) (read-only)
v1 still opens so an existing deployment is not bricked, and reports itself so
the daemon can log a SECURITY line telling him to re-enroll. Nothing writes v1.
The magic is authenticated, so a v2 blob cannot be stripped and re-read as v1.
Four other defects on the same path:
- The locked-boot store was opened on an IPC goroutine inside UnlockFn and
never closed. Close is what re-encrypts the tmpfs working copy back over
the ciphertext, so every write of a cold-started session was lost silently
on the next boot. daemonLock now owns the store and seals it at shutdown.
- MethodUnlock was reachable by anything on the box; the socket is same-uid
and cannot authenticate its caller. It now requires a passkey assertion
that mavweb verified first.
- Concurrent unlocks would each open a store and wire a daemon. One at a
time, and never a second one.
- The hand-rolled HKDF keyed the expand step with the salt instead of the
PRK. Replaced with crypto/hkdf.
Key wrapping moves from enrolment to the first assertion, because create() does
not produce a PRF result on most authenticators — only a support flag. An
authenticator without PRF now writes no wrapped file at all rather than one
that looks protected and is not, and the page says so.
Verified: make build, make test. New tests cover the v2 round trip, a wrong
secret, every single-bit tamper, truncation, the v1 downgrade attempt, legacy
v1 reads, non-32-byte and all-zero secrets, the ipc wire field, locked-mode
default-deny, a forged assertion never reaching the unlock path, seal-on-
shutdown after a cold start, and that nothing in the state dir contains the
plaintext key. The PRF round trip against real hardware is a QA step.
Vikunja #14
- Add CalendarEvents method to recordingAPI in auth_test.go
- Add CalendarEvents method to fakeCore in handlers_test.go
Co-Authored-By: opencode <opencode@anthropic.com>
Add a local PasskeySession that handleTools checks before processing
any POST action (enable/disable). If the session hasn't been asserted
within the 5-minute TTL, return 403 Forbidden.
Changes:
- webauthn/session.go: add IsStepUp() convenience method (nil-safe)
- webauthn.go: PasskeyHandle holds a *PasskeySession; AssertFinish
calls session.Assert() after IPC step-up
- main.go: create stepUpSession, pass to handleTools and
newPasskeyHandle; handleTools returns 403 if !session.IsStepUp()
- handlers_test.go: update TestEnableTool_NoInProcessAuthGate to
expect 403; add TestEnableTool_WithAuthGate_RequiresStepUp for
the happy path with asserted session; update all 10 call sites
Completes the three in-flight open items and fixes the away-fallthrough bug.
Item 7 — passkey step-up (WebAuthn):
- internal/webauthn: ES256/P-256 register + assert with real ecdsa signature
verification, minimal CBOR/COSE decode, PasskeySession (L2→L3 on assert,
decays after TTL). Drop the RS256 offer we can't verify (register-ok/
assert-fail trap). Verify rpIdHash + UP/UV flags in FinishAssertion — UV is
the step-up gesture. Round-trip test with negative cases (tampered sig,
missing UV, wrong origin).
- cmd/mavweb: /auth/passkey enroll+assert page (the only surface that can do
a WebAuthn gesture) + the four begin/finish endpoints. Without this the
daemon's PasskeySession swap leaves /tools enable permanently blocked.
- daemon wires PasskeySession as the auth Session + srv.StepUp; policy gates
MethodAssertStepUp at AuthRead.
Item 5 — tools page: DisableTool through store/ipc/client/wire; /tools grows a
disable action and a link to the passkey page. Lifecycle test.
Item 6 — note RAG: PhraseQuery on the phraser (LLM-composed answer over top-k
notes, raw-notes fallback); IntentQuery routes through it. Stub returns a
deterministic summary.
Item 2 — away-fallthrough: on ErrVoiceNoSession the dispatcher now reroutes
through the AWAY table (sev3→ntfy, sev4→telegram-repeat-til-ack, sev≤2→drop)
instead of silently dropping / mis-routing to the present-list remainder.
Covers DispatchNudge + DispatchReminder. 4 tests.
Also: re-add ProposeTool to CoreAPI (dropped in a comment rewrite), fix
missing imports + a duplicate block left mid-edit, drop dead AssertStepUpFunc,
gitignore /mavcaldav.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
kami