2 Commits

Include renames

Author	SHA1	Message	Date
jaap-jan	d5b1a73182	Move the keys when a membership changes, not just the flag ... Adding somebody to a team granted them nothing readable and removing them rotated nothing. Both were honest — the interface said so in as many words — and both left the actual work to a button somebody had to remember to press, on a machine that happened to hold the key. Adding now wraps every team vault this machine can open to the new member, and removing revokes their grants and moves each of those vaults to a fresh key that goes to whoever is left. The rotation is where the design had to be decided rather than written. A vault key is per generation and an item carries the generation it was sealed under, so advancing the vault and withdrawing the old grants would make everything already stored unreadable to everybody, including whoever pressed the button. So earlier grants are kept: a member holds one per generation, /me serves them as PriorKeyWraps, and VaultKeyring holds a key per generation — the newest for writing, the item's own for reading, chosen per item on every read path. Sharing issues one grant per generation held, because a recipient handed only the current key would open the vault to find most of it undecryptable; revocation takes every generation, because leaving the history behind leaves them able to read everything written before the rotation. The bump itself is one server transaction. POST /vaults/{id}/rekey must name exactly current + 1 and the vault's xmin token makes that binding, so two admins rotating at once do not both walk away believing they succeeded — the second is refused and told to read the vault again. The server contributes the moment and no cryptography: it cannot generate the key, cannot tell that the one it is handed differs from the old one, and checks that the caller held the old one the only way it can, by requiring a live grant at the current generation. What this does not do is re-encrypt what is already stored, and the product says so rather than the reassuring version: everything written from the rotation onwards is unreadable to the person who left, and nothing about the past changes. That half is deferred and is safe to add incrementally precisely because a vault at mixed generations stays readable. ADR 0010 records the alternatives — revoking the old grants, chaining each key under its successor, re-sealing every item in one request against a server that caps a push at 500 operations — and why each was rejected. Two things fell out of the change rather than being asked for. The grant listing would have shown a member once per generation, so it now returns one row per holder carrying the best key they hold, which is what makes a row below the vault's generation mean "still owed the new key". And MarkUnreadable gives up the write target as well as reporting: a client whose vault was rotated elsewhere would otherwise have gone on sealing items under its superseded key — readable to its author, unreadable to everybody else, with nothing to show for it.	2026-08-03 23:05:40 +02:00
jaap-jan	95816de0c5	Share a vault with a team, without the server holding a key ... M3's teams, sharing and ACLs. Teams with roles, a public-key directory, the append-only key log served for clients to check it against, team-owned vaults, and vault key grants wrapped by a client and stored opaquely by the server. VaultAccessService resolves team membership to PermissionFlags, so a viewer may pull and may not push; the desktop client reads and syncs every vault it holds a key for, and a real TEAMS screen replaces the one that said it did not exist. No migration: team, team_membership, vault.team_id and vault_key_grant have all been there since the first one, which is what carrying two unused tables bought. Membership is authorisation. A grant is access. The obvious model is one concept — "access", with a role attached, handed out by the server — and this architecture cannot implement it: a vault key is sealed to each member's X25519 key, and only a client holding the plaintext can seal it for somebody else. So "give Bob access" decomposes into a database write and a wrap, which happen on different machines. Adding a member makes the server serve them the vault; it cannot make it readable. VaultSummary.WrappedVaultKey is null in the meantime and the vault appears in their list saying it is waiting for a key, because hiding it until a grant existed would have been tidier and would have implied the server was the thing granting access. The screen says the same thing after every add, in the status line. ADR 0009 records the whole decision. Sharing verifies or refuses. A directory lookup is a claim by the server about a third party's public key, and wrapping to an unverified claim hands the vault to whoever made it — no amount of transport security helps, because the server is inside the threat model. KeyLogAudit reads the whole log, recomputes every entry's hash from its own contents, checks the chain from genesis, and refuses unless the offered key appears in it unchanged. There is no override flag: one that exists gets used on the day the log is briefly unreachable, and the resulting grant is indistinguishable from a correct one afterwards. What it still cannot promise is that the key is the right person's, so the fingerprint comes back for an out-of-band comparison and the success message says so every time. A test corrupts the fake server's log by one byte and watches the client refuse rather than warn. The roles are only the ones that are enforceable. There is no ConnectOnly, despite the design asking for one and TeamRole having room: SSH terminates on the client, so a session needs the credential's plaintext on that machine, and "may connect but may not read the key" cannot be enforced here. Shipping it as an option in a dropdown would have been a lie. Connect rides along with Read and is documented as an interface hint. Removal is named for what it does — it revokes grants and flags the vault for rekey, and claims nothing about what is already on somebody's laptop. Three things are deliberately absent, and each is a refusal rather than an omission. The rekey itself, because re-wrapping every item's data key under a new vault key needs a client holding the current one; the server records that a rotation is owed and the interface reports it, which is more honest than a button that only appears to do it. Ownership transfer, because allowing an owner to be removed without one leaves a team nobody can administer. And cross-vault host key trust: a pin in a team vault is listed but not consulted at connect time, because any member with Write could otherwise pre-approve a fingerprint another member's client then trusts silently for a host in their own vault. Scoping trust properly needs a scope on the SSH connect path, which IKnownHostStore has not got; until then the narrow direction is the safe one and the cost is in the README rather than hidden. Reading now spans vaults and writing still does not. Every list on the vault and hosts screens covers each vault the keyring opened, rows carry the vault they came from, and an edit goes back to that vault rather than to the active one — writing it to the active vault would fork the item and only show up when a colleague wondered why their change never arrived. A new item goes wherever a picker says, defaulting to the personal vault and never moving on its own, because an item filed into a team's vault is visible to that team and moving it back means deleting and retyping. The sidebar heading stops naming one vault once there are two, and each row names its own. The server checks what it can and nothing it cannot. It will not record a grant for a key its recipient no longer holds, for a superseded generation, or for somebody who is not in the team — each of those would otherwise surface days later at the far end as a tag failure indistinguishable from corruption. It does not verify the wrap or the signature, and the grant service says so: that would be a convenience and never the boundary, and would put an asymmetric implementation on a machine that is supposed to hold no keys. Two bugs the tests found. TeamsViewModel's busy gate blocked its own reload, so a team created a moment earlier was missing from the list it had just been added to. And syncing every vault turned a failure from an exception into a report, which made a background pass announce an unreachable vault once a minute — the exact behaviour AnAutomaticPassThatFails_LeavesTheStatusAlone exists to prevent. The fact is recorded and the message swallowed, as it was before; pressing Sync still names the vault and the reason. Also fixes a build break this branch started with: QuickConnectTests was never updated when M2 added ISftpSessionFactory to the shell's constructor, so nothing built at all.	2026-07-31 12:18:28 +02:00