Commit Graph
12 Commits
Author SHA1 Message Date
jaap-jan 23eca3a21b Merge branch 'main' into claude/m3-implementation-57f9d7
ci / build and test (push) Failing after 2s
Three files conflicted, and two of the resolutions are more than a choice of
side.

QuickConnectTests had both branches fixing the same build break — main's M2
merge left the shell's constructor with an ISftpSessionFactory nobody passed.
Main's version wins because it carries a comment saying why the palette never
needs a session.

VaultSession's conflict is adjacent edits: main added the remembered sign-in
members and this branch changed SyncAsync's summary from "the active vault" to
"one vault". Both kept.

VaultViewModel is the one that matters. Main taught the background pass to
report a sync that had to start over, on the grounds that a machine which
silently re-read a whole vault has had something happen to it; this branch
turned a pass into one report per readable vault. Taking either side alone
would have lost the other, so ResyncedFromStart is now one of the conditions
IsWorthReporting checks, per vault.

Merging also broke something neither branch could have caught alone, and the
build would not have said a word. SyncOnceAsync cleared LastSyncFailed
unconditionally, which was right while a pass was one vault and a failure was
an exception that never reached that line. A failure is now a report — one
unreachable team vault must not stop the others syncing — so the flag was being
cleared over a vault that had just failed, lighting the titlebar SYNCED. It is
computed from the report instead, in the one place both callers go through, so
the manual command gets it as well as the loop. The background pass still
swallows the message and keeps the fact, which is what
AnAutomaticPassThatFails_LeavesTheStatusAlone is there to hold it to.

Two comments the auto-merge left describing a world with one vault in it: the
SCOPES rail's, which said team vaults are refused by the access service, and
the host sidebar's "One heading, for one vault".
2026-07-31 12:26:59 +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
jaap-jan 0b261c4d39 Stay signed in, come back online by itself, and let a machine be given up
Three things a machine that has been set up could not do. Unlock now takes
Enter, which is the gesture everybody makes after typing a password and which
did nothing until they found the button.

Signing in survives a relaunch. The refresh token is kept in the local cache,
sealed under the vault's own cache key, so a later launch resumes the session
through the refresh grant with no browser and nobody present — and because it
is sealed under that key, only an unlocked vault can resume it. A locked
client therefore cannot reach the server at all, which is a consequence worth
stating rather than working around; docs/crypto.md §3.2 records it. Every sync
pass asks the shell for a connection rather than reading one captured at
unlock, so a laptop that unlocked on a train is online within a minute of
finding a network, with nothing pressed. Unlocking itself still never waits on
a socket.

Signing out empties this machine: the profile, the cached items, the outbox
and this machine's device key, with the account's row withdrawn when the
server can be reached. It asks first and says what it costs — the outbox count
when the vault is open, an admission that it cannot be counted when it is not,
and the shells that keep running either way. The vault is on the server and is
untouched, which is what makes the same button the only honest answer to a
forgotten passphrase, so it is on the unlock screen as well as in preferences.
It cannot end the session at the identity provider, and says so.

Two defects surfaced on the way. The synchronisation pass that runs when the
vault opens never ran at all: the loop is started from inside the unlock
command, so the busy flag it yields to was raised by that command — the first
sync was a minute late on every launch. And signing in from preferences while
unlocked threw an unlock screen over an open vault whose keys were still in
memory.

The unlock card and the new confirmation live in their own controls because
MainWindow cannot be laid out headless, so markup left inside it is markup no
test can measure; both are now measured at the window's minimum size in the
shapes that grow. What is still unverified is the composed window itself.
2026-07-31 11:07:36 +02:00
jaap-jan 94e11f5e38 update packages
ci / build and test (ubuntu) (push) Canceled after 0s
ci / build (windows) (push) Canceled after 0s
2026-07-31 10:12:05 +02:00
jaap-jan f86791e817 Finish revoking a device, instead of half of it
ForgetDeviceAsync stopped this machine unlocking without a passphrase and left
the server's row exactly where it was, so the account went on listing a device
nobody could account for. ADR 0007 recorded that as a deliberate gap needing an
endpoint. This is the endpoint, and the two things that turned up behind it.

DELETE /api/v1/me/devices/{id}. The device row is not the dangerous half: a
kind=device wrap is the user's identity bundle sealed to a key somebody may be
holding, and that is what has to go. It goes on the foreign key's cascade rather
than a second statement, and RevokeDevice_TakesItsWrapWithIt asserts the cascade
rather than trusting the configuration to keep saying so.

Scoped to the caller's own account, which is the only authorisation check there
is. The id is an unguessable v7 GUID, but unguessable is not a permission —
without the scope one user could withdraw another's device key by pasting an id
they saw once, and the victim's next launch would ask for a passphrase with no
explanation. 404 rather than 403 for somebody else's device, so a stranger does
not learn the id exists.

Never refused for being the last device. ADR 0001 makes an enrolled device a
recovery path, so removing the last one does cost the user something — but the
machine being revoked is most likely the one they have just lost, and a server
that argued about it would be refusing the one request that has to work
immediately. The passphrase wrap is untouched either way, which
RevokeDevice_LeavesThePassphraseWrapAlone pins.

--- Two things found on the way ---

Registering twice from one machine left two devices on the account. The server
is idempotent on the public key, but the client generates a fresh key pair every
call and the keystore holds one — so the second registration orphaned a wrap
whose private half had just been overwritten, which is precisely the leftover
this change exists to remove. Registering now withdraws the previous device.
Found by a test that asserted the property and failed.

And the fakes were lying about it. FakeAccountServer's comment claimed the real
service's idempotence while handing back a fresh Guid on every call, which is
invisible until something revokes by id — at which point a test would be
revoking an id the server never issued, and passing. Both fakes now issue one id
per public key and drop the wrap with the device, as the cascade does.

--- Reachable at all ---

ForgetDeviceAsync had exactly one caller and it was a test, so "Stop unlocking
here" now sits in the account bar where "Use Windows Hello here" was. Its own
flag rather than the negation of that one: a machine with no TPM and a machine
that is already registered are both "cannot register", and only the second has
anything to take back.

No confirmation prompt, deliberately. The cost of pressing it by accident is one
passphrase and one re-registration; the cost of a dialog is a moment's
hesitation at the point somebody has realised a machine is in the wrong hands.

Offline it does the local half and says so rather than refusing. Whether this
machine may unlock itself is decided entirely by the local cache and the local
keystore — the unlock path never asks the server — so forgetting here is what
actually revokes, and "you are offline, so this machine will go on unlocking
itself" would be the worst available answer. DeviceRevocation.LocalOnly is what
the interface reports and the status line explains what is left to do.

The local half runs first for the same reason, and the keystore call is the
first thing in the method that can yield: on Windows it raises a consent dialog,
and a dialog wants the thread it was called from. That ordering is currently
load-bearing and shakier than it looks — see the open device-unlock hang.

Four mutations, all caught: dropping the user scope from the server query
(1 test), skipping the stale-device revoke on re-registration (2), skipping the
server call in ForgetDeviceAsync (2), and the earlier version of the client that
never called it at all.

930 tests green across 16 projects, 13 of them new. Zero warnings, format clean.
2026-07-30 17:33:31 +02:00
jaap-jan 573f5d5668 Keep the device key in the TPM, behind a consent Windows enforces
The last of ADR 0007's three pieces, and it does not implement what that ADR
originally decided — because writing it exposed a flaw in the decision.

The ADR said "a Windows Hello gesture gating a protected blob". That does not
deliver what the rest of the document claims for it: a gate inside the process is
not a gate. A store that showed a prompt and then read a DPAPI blob would be
bypassed by malware that skipped the prompt, read the file and called
CryptUnprotectData itself — which is exactly the attacker the whole decision was
made against, and exactly the reason DPAPI alone was rejected. The presence
requirement has to be a condition of using the key, enforced below the
application, or it is decoration.

So the device key is encrypted to an RSA key created in the Microsoft Platform
Crypto Provider — the TPM — under CngUIProtectionLevels.ProtectKey. Windows
requires consent to use that key, so the prompt is not something this code can be
talked out of showing. Malware can ask for the key; it cannot answer the dialog.
That is strictly stronger than the ADR described, and most of what option D was
being saved for: the wrapping key genuinely never leaves hardware. The X25519
device key still lands in memory to open the wrap, because DSH1 fixes that wrap at
a curve the TPM cannot do — the remaining gap, and now a smaller step than it was.

CngKey is in-box, so this needed no WinRT projection and no Windows target
framework. Which is worth stating plainly because the opposite was planned: the
piece was scoped as "where the Windows TFM lands", and it turned out a platform
guard on one class was enough. Client.App and its two test projects stay on
net10.0.

Two things were measured on real hardware rather than assumed, and the second
changed the shape of the work.

The platform provider works here and holds an RSA key — confirmed by creating and
deleting one before writing anything that depended on it.

And ProtectKey prompts at key *creation*, not only at use. The comment in the
first draft of this file said the opposite, with a confident explanation: sealing
uses only the public half, so it should be silent. It is not. CngKey.Create blocks
on a dialog, because the policy means "protect this key with a PIN" and Windows
asks the user to set that up there and then. Found by writing tests around save
and forget and watching the suite hang for ten minutes waiting for somebody to
type one.

That has two consequences worth knowing before touching this file. SaveAsync is
user-facing code — it belongs on a UI thread, behind a button somebody pressed,
never on a background pass. And almost nothing in the store can be covered
automatically: two tests remain, availability and the empty-blob case, both of
which provably reach no dialog. Disabling the UI policy to make the rest testable
would remove the one property worth having.

The interface offers two things and hides both where they cannot work. "Use
Windows Hello" appears on the unlock screen only when this machine has a cached
wrap and a keystore still willing to release the key; "Use Windows Hello here"
appears in the account bar only when the machine can keep a key and has not
already registered one, so it is spent once used. Absent rather than disabled, in
both cases: a greyed-out button on a machine that never had a TPM reads as
something broken, and the passphrase box beside it is not a fallback — it is the
ordinary way in.

Both unlock paths now share AdoptAsync rather than each opening the known-host
store, building the vault and starting auto-sync. The ordering in there is
load-bearing and a second copy would be a second chance to get it wrong.

The shell's tests drive a fake keystore. Not for speed: the real one prompts on
every save and load, so a suite using it would block forever. What the shell has
to get right is which buttons appear and what happens when one is pressed, and a
fake answers exactly that. It is shared from Client.Session.Tests by source link
rather than reimplemented.

882 tests green, 6 of them new. Zero warnings, dotnet format clean.

Not verified, and not verifiable here: the dialogs. Whether the consent prompt
appears at the right moments, reads sensibly, and returns to a usable window when
declined needs the application run by a person on a machine with a TPM. That is
the remaining half of outstanding item #7, and it is now the only thing between
this feature and being finished.
2026-07-30 15:17:30 +02:00
jaap-jan 1faea42b94 Unlock with this machine's device key, without a passphrase or a network
The second of ADR 0007's three pieces: the seam a keystore plugs into, the wrap
cached where an offline unlock can reach it, and the unlock path itself. What is
still missing is the keystore — UnavailableDeviceKeyStore is what the application
composes for now, so behaviour is unchanged until piece three lands.

IDeviceKeyStore holds exactly 32 bytes, and only because the cache key moved
first. It would have had to hold the local cache key alongside the X25519 scalar —
a second live secret at rest, going stale on every passphrase change — had
7016ce3 not re-keyed that to the identity bundle. ADeviceUnlock_ReadsTheSameCache
ThePassphraseWrote is the test that ties the two commits together: under the old
derivation this session would have opened the identity and then found its own
cache unreadable.

The wrap is cached at registration rather than fetched at unlock, which is the
whole point. The one unlock path that exists to save the user typing must not be
the one that only works online; a laptop on a plane is precisely where a gesture
should help.

Every way this fails returns a status rather than throwing, because none of them
are exceptional — a cancelled fingerprint prompt is the most ordinary thing in
this file. Three statuses rather than one, because the caller says a different
sentence for each: no device registered (the normal state of a machine nobody
opted in on), the machine would not release the key (declined gesture, or a Hello
key invalidated by a PIN reset — deliberately indistinguishable, since the remedy
does not differ), and the key was released and did not open the wrap (a rotated
identity, which will never succeed again and needs re-registering). A keystore
returning the wrong number of bytes lands in the third rather than crashing the
unlock screen.

The subtle defect this could have shipped is in UnlockStore.Apply. That method
runs on every sign-in from a /me response, which knows nothing about this
machine's keystore — so assigning the device columns unconditionally would delete
the wrap on the next launch, and the user's fingerprint would stop working for no
visible reason and no error anywhere. The columns are therefore written only when
the incoming material carries them, with AttachDeviceAsync and DetachDeviceAsync
as the only paths that set them deliberately. Mutation tested: removing the guard
fails RefreshingTheProfile_DoesNotDiscardTheDeviceWrap and nothing else.

RegisterDeviceAsync lives on VaultSession because sealing the bundle is the one
step only an open session can do, and the session is the bundle's custodian.
Everything else arrives as a parameter, exactly as SyncAsync takes its transport,
so the session still knows nothing about how either the wire or the keystore is
implemented. Its steps are ordered so a failure cannot leave a lie behind: the key
is generated, saved locally, and only then registered with the server. A server
row whose private half was never stored is a device that can never unlock and that
the account claims can — worse than not offering the feature at all — so the write
that could produce it happens after the one that prevents it.

ForgetDeviceAsync is deliberately half a job, and says so. It stops this machine
unlocking without a passphrase, which is what a user turning the feature off means,
but the server's wrap row survives and the account will go on listing a device
that cannot unlock. Deleting it needs an endpoint that does not exist yet. Half
with the gap recorded beats a method whose name promises the other half.

The client cache gained two nullable columns and a migration, generated rather
than hand-written this time.

876 tests green, 10 of them new. Zero warnings, dotnet format clean.

Remaining: the Windows Hello store and the unlock-screen UI. That is where the
Windows target framework lands, and where automated testing stops — a gesture
needs hardware and a person, so the last piece is the one that has to be looked at
rather than asserted.
2026-07-30 13:37:35 +02:00
jaap-jan 7016ce36f1 Key the local cache to the identity, not to the door it was opened through
Groundwork for a device key, and a spec change rather than a feature. ADR 0007
records the decision it clears the way for: a Windows Hello gesture guarding a
protected blob, with the passphrase kept as a permanent fallback.

The reason that decision needed this first is that a device key cannot open a
session on its own. SessionOpener derived two things from the passphrase master
key — the bundle, and the local cache key — and a device wrap is
SealTo(device_x25519_pk), which yields the bundle and never computes a master key
at all. A device unlock could therefore have opened the identity and still not
read the cache it had itself written.

So LocalCacheKey now derives from the bundle: dsh1/localcache/v1 → v2, specified
in crypto.md §3.2. Every wrap that opens a vault ends up holding the bundle, so
every door reaches the same cache.

Extract-and-expand, not expand alone. Everything derived from the master key uses
HKDF-Expand directly, which is sound because an Argon2id output is uniformly
random over its whole length. The bundle's encoding is not — it opens with a
fixed 14-byte label and carries a version, a generation and a timestamp before
reaching any key material — so it needs the extract step to become a pseudorandom
key first.

Two consequences fell out, both improvements and neither the point:

- A passphrase change no longer discards the local cache. The bundle is unchanged
  by a re-wrap, so the cache key is too. Under v1 changing a passphrase silently
  orphaned every cached row and the next launch re-pulled the whole vault.
- Recovery-code unlock is fixed before it ships. It derives a different master key
  from a different secret and a different salt, so under v1 it would have had the
  same defect as the device path, and nobody would have noticed until it landed.

The cache becomes unreadable exactly when the identity is rotated, which is the
correct moment to discard it. Existing caches are discarded and re-pulled on
upgrade — already the specified behaviour for a stale cache, and the reason the
label is versioned rather than reused: a v1 cache must fail to open rather than
decrypt to nonsense.

One stated guarantee got weaker and now says so. crypto.md §10 claimed locking
meant "nothing on disk can be read again without the passphrase." Where a device
wrap exists that is no longer true, and it would have been untrue under either
candidate design — the alternative was storing a copy of the cache key in the
device blob, which is the same door with an extra key lying next to it. The
wording now points at ADR 0007, because what guards the device key is a platform
decision and not a property of this specification.

A golden vector was quietly lying, which is the part worth reading twice. The
"local-cache" entry pinned HKDF-SHA512-Expand over a fixed PRK — a construction
the cache key no longer uses. Regenerating it would have produced a green suite
describing a derivation this code does not perform. It is replaced by a vector
over a bundle whose every byte is pinned: the label, version 1, generation 1, a
fixed timestamp and two recognisable key scalars, all visible in the fixture so a
second implementation can check itself against it. UserSecretBundle.TryDecode is
internal for this, because Create draws fresh randomness and so can never produce
a reproducible input.

Mutation tested, and this one earns its keep: dropping the extract step now fails
CommittedVectors_MatchCurrentImplementation. The vector it replaced could not
have caught that, because it never touched the bundle at all.

One test became false and says so. ARecordSealedUnderAnotherPassphrase is now
ARecordSealedByAnotherIdentity: a different passphrase deliberately no longer
changes the cache key, and TheLocalCacheKey_SurvivesAPassphraseChange pins that.
What must still be unreadable is another user's cache. CacheHarness therefore
generates an identity rather than deriving from a passphrase, and has no
passphrase parameter left — the cache key is not a question about passphrases any
more.

SyncHarness's two simulated machines now derive the same cache key, which is what
keying on the bundle means: they are the same user holding the same identity. They
still have separate cache databases, so nothing is shared between them but the key
that would open either. Both harnesses lost a MasterKey field that existed only to
make a protector.

858 tests green. Zero warnings, dotnet format clean.

Not done: the device key itself. Three pieces remain, and the middle one was a
discovery rather than a plan — EnrollmentService.AddDevice runs only during
enrollment, so every already-enrolled account, which is all of them, needs an
endpoint to add a device wrap while unlocked. The client proves possession by
producing the wrap, so that shape falls out of the crypto. After that: the
protector seam with the wrap cached locally for offline unlock, then the Hello
implementation and the unlock-screen UI, which is where the Windows TFM lands and
where automated testing stops.
2026-07-30 12:46:55 +02:00
jaap-jan 211eba0666 Keep host key trust in the vault, and make it withdrawable
ci / build and test (ubuntu) (push) Canceled after 0s
ci / build (windows) (push) Canceled after 0s
A fingerprint approved once is now approved on every machine and survives a
restart, because host key trust is a vault item type rather than a dictionary
that dies with the process. InMemoryKnownHostStore was what shipped, so the user
was asked to verify a fingerprint on every single connection — which is the gap
most likely to train somebody to click through the one warning that actually
matters. A warning that appears when nothing is wrong teaches that nothing is
ever wrong.

The fourth item type, and like the third it cost no sync logic: a row, an EF
configuration, a migration, a server kind; a secret, a codec, a merge, a cipher,
a repository facade and a session property. One row in the client registry. The
reconciler, the mirror, the repository, the outbox and the pull filter were not
touched. SyncEntityType.KnownHostKey and AadResourceType.KnownHostKey were
already reserved, so neither the contract nor docs/crypto.md changed.

One item per (host, port, algorithm), because a server legitimately offers
several host keys and which one gets negotiated is not ours to predict. Pinning
per endpoint would make an algorithm change indistinguishable from an attack.

The label is derived rather than stored, which is the one place this type
departs from the other three. A user never names a pin — there is nothing to
name it after but the three fields it already has — and a stored label is a
second copy of data that can disagree with the first after a merge. Relabel
returns the secret unchanged, and says why.

The store answers the handshake without touching the disk. SshNetConnectionFactory
calls FindAsync from inside SSH.NET's synchronous HostKeyReceived event, over
.GetAwaiter().GetResult(), which cannot be avoided; doing SQLite I/O plus an AEAD
open per lookup there would put the handshake behind the cache. So decryption
happens in OpenAsync and RefreshAsync — on unlock and after each sync pass,
exactly where the host and key lists already reload — and FindAsync is a
dictionary read under a lock with no await inside it.

That snapshot is where the one real bug in this change lived. Install originally
merged the live pins over the freshly loaded snapshot, to protect a TrustAsync
that had landed while the read was in flight. It would also have resurrected
every pin the user had just forgotten, and stopped a withdrawal made on another
machine from ever taking effect — the store would have healed the deletion back
into existence on every refresh. Replacing wholesale and discarding the read
instead is correct because writes are the rare case: every write bumps a
generation counter, and a refresh whose stamp is stale throws itself away rather
than winning. Nothing found this but reading the method again; it is the kind of
mistake that passes every test written before it, because the test that catches
it is the one the bug tells you to write.

Forgetting is new, and persistence is what made it mandatory rather than
convenient. A mismatch is a hard refusal with no way to continue — deliberately,
and that stays — so pinning a key permanently is also a way to make a
legitimately rebuilt server permanently unreachable. Before this change the pin
died at exit and the problem solved itself; now it does not.

ForgetAsync drops every algorithm for an endpoint, and it is reachable from the
host editor rather than from the warning. Putting it on the mismatch banner would
have made it two clicks from "this may be an attack" to "connect anyway", which
is the affordance the hard refusal exists to deny. The banner already promised
the key could be removed in the host's settings; that promise is now true and
points at the button.

Trust recorded on another machine becomes visible at the next sync pass, not
immediately, and that is a decision rather than an oversight. The failure it
produces is a first-contact prompt for a host a colleague approved a minute ago:
answerable, and self-correcting on the next pass. The opposite trade — polling
the vault on the handshake thread to close a one-minute window — buys nothing
and costs the property above. The dangerous direction is not reachable at all: a
pin recorded here enters the snapshot as part of recording it, so a refresh can
never discard a local trust decision.

The server learns nothing, and this is the item type where the temptation was
real. A plaintext host column would let a known-hosts screen sort and page
without decrypting anything, and it would hand the operator the map of every
user's estate — assembled, as these things are, out of facts that are each
individually harmless. A host row concedes an address only when relay is
switched on and the database refuses to store one otherwise (ADR 0004); there is
no equivalent excuse here. The table has no column to put one in, and the EF
configuration says so where somebody adding it would be standing.

Two things about the migration in this commit are worth knowing, because both
came out of getting it wrong.

It was hand-written first, including its .Designer.cs, and that version is not
what is here. Verifying it turned up something that had been quietly assumed:
Migration_AppliedCleanly_WithNoPendingModelChanges does not check the model
snapshot. It asserts that migrations applied and that none are pending, which a
wrong snapshot satisfies perfectly — the snapshot only matters as the diff base
for the *next* migrations add, so an incorrect one passes the whole suite and
corrupts the following migration instead. The real check is to generate a
throwaway migration and confirm its Up and Down come out empty. They did, and
the generated designer was byte-identical to the transcribed one across all 1255
lines, so the hand-written work was in fact correct.

Then dotnet ef migrations remove --no-build deleted the wrong migration. With
--no-build the tool reads the previously compiled assembly rather than the files
on disk, and the probe had just changed which migration was last, so it removed
AddKnownHostKeyItem and reverted the snapshot. That turned out to leave exactly
the right diff base, so the migration here is EF's own output rather than a
transcription — a better outcome than the one that was interrupted, arrived at
by accident. Never pass --no-build to migrations remove.

Mutation tested, all three sabotages detected: dropping the algorithm from
KnownHostIdentity.For, merging instead of replacing in Install, and pointing
KnownHostKeyCipher at PortForward — which is what a cast from the wire enum's 10
would silently produce. Each is caught both by an assertion about the mechanism
and by a behavioural test that never mentions it; the resource-type sabotage is
caught by the table from d10a38d and nothing else, which is what that table is
for.

The end-to-end slice now approves the real sshd's host key through the vault,
pushes it, and reads it back on the second simulated machine — including a check
that the server learned no address, and that the second machine answers null for
an algorithm never offered.

845 tests green. Zero warnings, dotnet format clean.

Three things are deliberately not fixed. A tombstone queued over a create that
was never pushed is refused by the server as Invalid and parked; that is
pre-existing for all four item types, and the fix belongs in
VaultItemRepository.DeleteAsync rather than here. Deleting a host, or changing
its address, orphans its pins — both are correct as trust decisions, since a pin
describes an endpoint and not a bookmark, but nothing surfaces the leftovers.
And there is no interface listing pins at all: trust is created at the connect
prompt and withdrawn in the host editor. A known-hosts list is where the orphans
would become visible, and it wants the vault column rework first, for the same
reason the credential editor does.
2026-07-30 11:00:39 +02:00
jaap-jan e24012b039 Sync credentials as a vault item type, and bind one to a host
Closes the largest remaining M1 gap in the data layer: a username and password
can live in the vault, sync between machines, and be named by a host as how it
authenticates. What is not here is the interface for creating one — see the end
of this message.

The third item type, and the first one that cost almost nothing to add. Server:
a VaultCredential row, an EF configuration, a migration, and a CredentialKind.
Client: a secret, a codec, a merge, a cipher, a kind, a repository facade and a
session property. No new reconciliation logic, no change to the sync engine, no
client cache migration. That was the whole point of the item-kind seam, and this
is the evidence it holds.

The narrowest type of the three on plaintext, and not for symmetry. A host has a
deliberate concession — the relay needs an address it can resolve. A key has a
fingerprint, public by nature, which this client still declines to send. A
password has no part that is safe to expose: not its length, not a hash, not a
hint. So CredentialKind refuses every plaintext field there is, hydrates none,
and the table has no column to put one in.

HostSecret.CredentialId is the password counterpart of SshKeyId, and the two are
mutually exclusive. SSH itself would happily try a key and fall back to a
password, but a host naming both leaves "how does this authenticate?" without a
single answer — the interface, the connect path and the user would each be free
to guess differently. TryValidate refuses it. One consequence was not
anticipated: "a full host" stops being a coherent idea, which is what broke
AFullHost_RoundTrips and is now written into that test.

The schema version became a ladder rather than a maximum: credential-bound is 3,
key-bound is 2, neither is still 1. Adding credentials therefore does not drag
every key-bound host in every vault onto a version that clients understanding
keys perfectly well would refuse to edit. A test pins exactly that, because it is
the property the whole content-dependent-version rule exists to provide, and the
obvious implementation would quietly lose it.

Two tests had become false and said so:

- Push_AnUnsupportedEntityType_IsInvalidNotAFailedBatch used Credential as its
  example of a type this server does not implement. It now asks the server's own
  registry what is still missing, so it cannot go stale again, and skips with a
  reason if that set ever empties.
- ThePullFilterNamesEveryTypeThisBuildSynchronises pinned the exact list, which
  is what it is for.

Also fixes ten nullable warnings — eight in SyncEndpointTests, two in a test file
added earlier today. Neither set was introduced here; both were invisible until
an unrelated change forced their project to recompile, which means the
zero-warning claims made earlier in this work only ever covered what happened to
be rebuilt.

777 tests green. Zero warnings, dotnet format clean.

Not done, and deliberately: the credential interface. The vault column is 340
pixels wide and already holds two lists and two editors, kept from clipping its
own buttons at the window's minimum height only by the one-editor-at-a-time rule
added earlier today. A third list and a third editor would recreate that defect
rather than avoid it, so the column needs a shape decision first. Credentials
sync; they cannot yet be created in the interface.
2026-07-29 21:09:08 +02:00
jaap-jan e3fd3e1728 Sync and authenticate with SSH keys on the client
Completes the client half of SSH keys: they sync alongside hosts, appear in
their own list, and can be selected to authenticate a connection instead of
typing a password.

The reconciler and the repository were Host-typed throughout, so the choice was
to generalise them or to keep a second copy per item type. Generalised, because
ItemReconciler's whole premise is that the pull and the push paths must answer
the same collision the same way — two copies would drift the first time one of
them was fixed. What is genuinely per-type now arrives through
IItemKind<TSecret>: the cipher, the merge, the plaintext columns, and the noun
to use when telling a person what happened to their item. Generic where the
server's IItemKind is not, and for the reason that reverses there — the client
needs the concrete type, because it merges field by field.

The pull filter is derived from the same registry that builds the reconcilers.
That is the specific failure being designed out: an item type that encrypts,
merges and lists perfectly and is never once requested from the server, so it
works on the machine that made it and exists nowhere else.

No client cache migration. The item table's primary key and the outbox's unique
index already carry the entity type, and AadResourceTypes already mapped SshKey
— so a host and a key may share an id and never see each other's rows, which
SshKeySyncTests now arranges deliberately.

A key hands the server nothing in plaintext. There is a public_key_fingerprint
column and it would be accepted; leaving it null is deliberate. A fingerprint is
not secret but it is a stable identifier for a key pair, so filling it would let
an operator tell which of their users hold the same key and correlate one across
vaults, for a column nothing reads. The design allows itself one plaintext
concession — the relay address, which the relay cannot work without — and this
is not that.

A key is chosen per connection rather than bound to a host, which works the way
ssh -i does. Binding one needs a field on HostSecret and therefore a payload
schema bump, which makes every host written afterwards read-only on an older
build; worth doing deliberately rather than as a side effect of adding keys.

Three things this found, all of them by being falsified rather than by review:

- Making the reconciler generic silently turned a record comparison into
  reference equality, because == on a type parameter is not value equality. The
  effect would have been a conflict recorded on every pass for an unacknowledged
  create that had in fact landed. Sabotaging the fix left all 73 tests passing —
  nothing covered that branch — so ConflictMatrixTests now has
  AnUnacknowledgedCreateThatDidLand_IsDroppedQuietly, which fails without it.

- A test asserting that a blank passphrase reaches SSH.NET as null was vacuous:
  it exercised the editor, not the credential path, and passed with the guard
  deleted. Resolved by making SshKeySecret.Passphrase normalise an empty string
  to null, so there is one spelling of one state — which also keeps two clients
  from producing different payload bytes for an identical key. That exposed a
  wider gap: SshKeySecret, its codec and its merge had no direct unit tests at
  all. They have 25 now.

- The reason first given for that normalisation was false. It claimed SSH.NET
  rejects a passphrase supplied for an unprotected key; measured against a real
  sshd it ignores it and authenticates anyway. Corrected everywhere it was
  stated and recorded in docs/platform-flags.md. The same test file also closes
  a real hole: SshPrivateKeyCredential had never been exercised against a
  server, because the existing key test builds SSH.NET's auth method directly
  and bypasses the path a vault-held key actually takes.

Only one editor may be open at a time. Both sit in the same 340-pixel column as
Auto rows and their heights together exceed it at the window's minimum size, so
two open editors put the lower one's Save and Cancel past the bottom edge — the
same failure this window already shipped once with the setup screens. Expressed
as a state rule because that is the only form of it this repository can check:
nothing here loads a .axaml. The refusal keeps what was typed, since in the key
editor that is a pasted private key the user may have nowhere else.

The end-to-end slice now carries a key as well as a host, so both item types go
through the real API, the real PostgreSQL and the real crypto in one pass — the
three hand-kept mappings between enums that do not line up are the reason that
is worth doing rather than trusting the unit suites.

735 tests green, including the container-backed SSH and end-to-end suites. Zero
warnings, dotnet format clean.
2026-07-29 20:27:23 +02:00
jaap-jan 49f617b450 Wire the Avalonia shell to the vault
The host list now comes from the vault instead of from a form. A fresh
machine takes a server URL, signs in through the browser, enrolls, and
from then on opens with the passphrase alone.

DodoSSH.Client.Session is the composition layer: where a profile lives,
how it unlocks, and how a machine gets one. ClientPaths picks a
non-roaming per-OS directory — %LOCALAPPDATA% and never %APPDATA%,
because a SQLite cache that roams between two machines is a corrupt one,
and each machine's outbox is its own. SessionOpener needs no transport at
all and could not reach one if it wanted to; that is the offline unlock,
asserted rather than asserted about. A wrong passphrase, a stale KDF and a
grant revoked by a rekey are three different answers, because the remedies
are three different things and telling someone to retype a passphrase that
was never the problem is worse than saying nothing.

The shell's states are the onboarding story. The recovery code gets its
own state that cannot be clicked past: it exists for one moment, losing it
with the passphrase loses the vault, and there is no server-side reset by
design. It is dropped from memory on confirmation rather than merely
hidden.

Sign-in is a delegate over IVaultServer, so the whole state machine runs
in a test against an in-memory server — no browser, no identity provider,
no toolkit. The view models are plain observable objects, which is what
makes that possible. What it does not cover is whether the XAML binds to
the right names; that needs a rendered tree and Avalonia.Headless, and is
its own piece of work.

Three things found by doing it rather than by reading it:

- Pooled SQLite connections keep the database file open after the last
  context is disposed. On Windows that means locked, so the application
  could never replace its own cache — and a test could not clean up after
  itself, which is how it surfaced. Dispose now clears the pool.
- EF's SQLite provider puts the database in WAL mode, so the cache is
  three files. A comment in ClientCacheFactory claimed the opposite;
  reading PRAGMA journal_mode off a real launch settled it. WAL is the
  right mode here — a sync pass writes while the interface reads — so the
  comment was wrong on the merits as well as on the fact.
- Enrolling a device key with nowhere to keep the private half would put a
  wrap on the server nobody can open and make the device list claim this
  machine can unlock without a passphrase. Device binding is now optional
  and the shell declines it until the OS keystore is wired.

Verified on Windows: the client created %LOCALAPPDATA%\DodoSSH\cache.db
and migrated it on first launch, and msedgewebview2 held an established
connection to the data plane while the unlock overlay covered it — which
is the point of covering the WebView rather than collapsing it, since a
NativeWebView that is never laid out is never realised.

630 tests, up from 593. The recovery-code gate and the offline unlock were
each verified by breaking them and watching the right test fail.

Still to do for M1's actual definition of done: the manual run against the
real API and a real Keycloak. Credentials are not a synced entity type
yet, so a connection still asks for a password, and the interface says so
rather than implying otherwise.
2026-07-29 11:02:19 +02:00