3d3d0bc95f2f8bc6ec994c016453e95c9b082d5f
3
Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
|
|
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.
|
||
|
|
a628762cd1 |
Add /me and enrollment with the identity-provider key binding (M1)
The last backend piece of M1. A client can now log in, discover it must enroll, publish its identity key, and get a usable personal vault. Enrollment is one indivisible act. One transaction writes the key, its wraps, the device, the key log entry, the vault and the vault key grant, because none of them is useful alone: a key with no vault leaves a user unable to store anything, and a vault with no grant is a container nobody can ever open -- including its owner, since only the client can wrap the key and it has already moved on. Two independent checks run, and neither substitutes for the other. The Ed25519 self-signature proves possession of the private key. The identity-provider binding proves whose key it is: the client hashed its statement, used the hash as an OIDC nonce, and the resulting ID token is the provider's signature over exactly those public keys. This server cannot mint that signature, so it cannot invent a key for a user who never enrolled -- which is the attack that would otherwise let an operator read every vault by publishing its own key as yours. The binding token is stored verbatim, not just summarised. Clients must repeat the check against the provider's JWKS fetched directly, and storing only our conclusion would ask them to trust the server about the one question the design exists to avoid trusting it about. Key log appends take a deployment-wide advisory lock. The falsification matters more than the passing test: with the lock removed, Enroll_ConcurrentEnrollmentsByDifferentUsers_LeaveAnUnbrokenChain fails with entry 11 linked to the wrong predecessor. Different users trip no unique index, so without serialising they all read the same head and the chain forks -- indistinguishable from the key substitution the log exists to make detectable, and permanent, because the log is append-only. Enrollment is idempotent. Vault ids and keys are client-chosen, so a client whose response was lost re-sends the identical body and gets the identical result. Without that, a lost response leaves a user enrolled against a vault they never learned the id of. Contract change, breaking the v0.1 freeze deliberately. EnrollmentRequest had DevicePublicKey but no wrap to go with it, which is unsatisfiable: only the holder of the secret bundle can seal it, so the server could never fill the gap. Added DeviceWrappedPrivateKey, and PersonalVault so enrollment can be atomic rather than leaving an unopenable vault behind two endpoints that do not exist yet. No client exists and no package is published, which is exactly when PublicAPI.Unshipped.txt expects this. Sync now requires the Enrolled policy, which until now was a stub whose name promised a check it never made. The sync denial tests use enrolled intruders instead of unenrolled ones -- an unenrolled caller is stopped before the vault check runs, which would have left those tests passing without exercising the thing they exist to prove. Also fixed: omitting kdfParameters from the JSON body was a 500. A record's non-nullable parameters are a compile-time promise, not a runtime one. 268 tests pass, zero warnings on a clean rebuild, format clean. |
||
|
|
06d04b490b |
Freeze DodoSSH.Contracts v0.1 (M1)
The second M1 gate. This assembly, not the OpenAPI document, is the client's contract, so PublicApiAnalyzers now tracks all 540 public members: a renamed DTO property becomes a build error rather than a runtime deserialisation failure on someone's laptop. Contract surface: - EncryptedPayload carries the envelope plus the KeyGeneration and AadVersion columns needed to recompute AAD, since AAD is derived from the row rather than transmitted. - Sync: push with per-operation status (Applied/Conflict/Forbidden/Invalid/Duplicate) so one stale item cannot block a whole offline queue; a Conflict returns the server's row for client-side three-way merge, because the server cannot merge ciphertext. - Enrollment: KeyStatement whose hash becomes the OIDC nonce, so the identity provider signs over the public keys and this server cannot fabricate a key for a user who never enrolled. - Meta and .well-known configuration: capability negotiation instead of URL versioning, which is what a self-hosted product needs when client and server upgrade independently. - SyncPlaintextFields deliberately has no label or name field. ACL admin runs client-side where names can be decrypted, so the server never needs a searchable title. Two design problems found by writing the tests rather than assuming: - Hand-constructing JsonSerializerOptions and merely pointing its resolver at the context silently discards every source-generated setting. JsonSerializerDefaults.Web replaces NumberHandling.Strict with AllowReadingFromString, so "1" would be accepted where 1 is meant — invisible until two implementations disagree. Callers now use ResponseOptions or StrictRequestOptions; StrictRequestOptions is derived by copying so it cannot drift. - StrictRequestOptions had a static-initialisation cycle: it read the generated Default property from the same type's initialiser and got null. Now lazy. Requests reject unmapped members so a client typo is a 400; responses tolerate them so an older client can read a newer server. Enums cross the wire as strings, so reordering one cannot silently reinterpret stored data. Also: excluded source-generator output from PublicApiAnalyzers. The JSON generator emits a public member per serialisable type, which would have added hundreds of mechanical entries and drowned the ones describing the actual wire contract. And disabled MA0048's one-type-per-file rule: splitting SyncPullRequest from SyncPullResponse makes a reviewer open two files to understand one endpoint. Verified: 0 warnings, 95 tests pass, format clean. |