242280ce6bbae430b33176c3767b3a383e950787
1
Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
 jaap-jan
|
6185d74800 |
Write down the two things a user is promised and does not get
Two plans, both for the same class of defect: a control or a code that a user is told to rely on, backed by storage and by nothing else. Neither is started; what follows is the reasoning, so that starting is not where it gets thought about. ── UNLOCKING WITHOUT THE PASSPHRASE ───────────────────────────────────────────────────────────────────── Every account is issued a recovery code at enrollment. The client generates it, wraps the identity bundle under KEK_rc, the server stores that wrap as UserKeyWrapKind.Recovery, and both heads work to make sure the user writes it down — the phone raises FLAG_SECURE for that screen alone and will not let anybody past it. Nothing can use it. SessionOpener has UnlockAsync and UnlockWithDeviceAsync, and there is no third. Walk the failure through: forget the passphrase, and the bundle cannot be unwrapped, so no vault key opens and every item is unreadable. Signing out and back in returns the same passphrase wrap. The device key would be the other door, and sign-out withdraws it — which is the advice the unlock screen gives for exactly this situation. The loss is total and permanent, and the thing built to prevent it is inert. The docs already disagree with each other about this, which is how it surfaced. manual-checks §10.2 calls the code "the only thing standing between a forgotten passphrase and an unrecoverable vault"; android-port says losing it *along with* the passphrase is what makes a vault unrecoverable; README says signing out is the only answer and nothing can recover one. The third is the true one today. More than half the work is already done and one piece of it was done on purpose: LocalCacheKey derives from the identity bundle rather than from MK — crypto.md §3.2, changed 2026-07-30 — specifically so an unlock that never computes MK can still read the cache it wrote. What is missing is an endpoint to serve the wrap, an unlock path, and a way to set a new passphrase afterwards, without which the account unlocks with a one-time code forever. That last step is the same re-wrap a change-passphrase feature needs, so it delivers both. Two traps are recorded because both would produce a code that verifies nowhere. The derivation uses the displayed string *including its dashes*, so the unlock must canonicalise to the printed form rather than strip it; and the recovery wrap uses a different Argon2 profile to the passphrase one (64 MiB against 256), so it must derive from the parameters served with the wrap rather than from a profile constant. ── REACHING A HOST YOU CANNOT DIAL ────────────────────────────────────────────────────────────────────── This started as "delete the dead jump-host field" and inverted twice. HostSecret.JumpHostIds is stored, validated, encoded and three-way merged, and nothing reads it or writes it — the ssh_config importer looks like the writer and is not; it records ProxyJump as an option and a note saying DodoSSH cannot honour it. The first draft recommended deleting it. That was wrong twice over. ADR 0004's last consequence had already designed the implementation — a loopback TCP bridge for the relay, and "the same bridge provides ProxyJump via a SOCKS5 dynamic forward", one mechanism and two features — which the pinned SSH.NET 2025.1.0 supports through ForwardedPortDynamic and ProxyTypes.Socks5, checked in Renci.SshNet.xml rather than remembered. And the stored shape is right: an ordered list of host ids is what a chain is, the merge arm is correct, and the missing schema version is a line to add. ◆ Looking properly found the same shape one field over, where it costs something. RelayEnabled is also stored, merged and never read by the connect path — but it is user-settable, and both heads draw a checkbox promising it. Ticking it moves the host's address and port out of the encrypted payload into plaintext columns, which ADR 0004 calls the single deliberate concession in the design, and then the client dials directly anyway. The privacy is spent and the feature is not delivered. That is a defect rather than a gap, and it is step 0. The comparison the plan turns on: the relay reaches what the *deployment* can reach and the jump host reaches what a *machine in the keychain* can reach, so they are not substitutes. On a self-hosted box outside the target's network the relay reaches nothing the laptop could not. And the privacy ordering is the opposite way round from the ADR's framing — the relay costs a plaintext address, the jump host costs nothing, because the operator is not in it. Both documents carry a section on what their own earlier reasoning got wrong, which for the second one is the load-bearing part: "nothing reads this field" was read as evidence of a mistake when it was evidence of an unfinished feature — and the same sentence one field over would have found the checkbox that is lying. |