Commit Graph
13 Commits
Author SHA1 Message Date
jaap-jan 69bc9e270b Let a team be joined only by somebody who is already here
An invitation decided access from an assertion about an address. Everything else
in this model decides it from something a person did — an admin naming an
account, a key holder wrapping a vault key to a key they verified — and this was
the one place a token's email claim was the thing that let somebody in.

It was guarded as tightly as that can be guarded: the claim was refused outright
on an unverified or absent `email_verified`, with no setting to relax it. But the
guard and the risk were the same shape. The whole defence was one boolean sent by
a system the deployment does not control.

So `POST /teams/{id}/members` is the only way in, and an address with no account
is refused with `no-such-account` — which is now the end of the road rather than
the signal to invite. Both clients say the remedy: that person signs in here
once, which is what creates the account, and then they can be added. The desktop
leaves the address in the box, because a message telling you to come back later
is one you act on later.

Gone with it: the `team_invitation` table, the claim hook in the sign-in path,
and `Oidc:EmailVerifiedClaim`, which that hook was the only reader of. Nothing in
the server now reads the email claim to decide anything.

Pending invitations are dropped rather than converted. Converting one would mean
creating a membership because an address matched, which is the property being
removed — and an invitation to an address that did have an account here had
already been claimed by the hourly sweep, so what is left is offers to people who
never arrived.

Two tests carry the property rather than the feature: the endpoint inventory
asserts the three routes are absent, and the API suite adds an address that has
no account, watches the refusal, then signs that address in and checks it joined
nothing. Without the second half, a server that merely renamed the deferred path
would pass.
2026-08-05 08:28:57 +02:00
jaap-jan 8d2f4c8ffb Merge branch 'claude/main-page-group-hierarchy-3a3210'
ci / build and test (push) Successful in 1m27s
ci / android head (push) Failing after 5s
ci / api image (push) Successful in 21s
2026-08-04 10:26:20 +02:00
jaap-jan 5d447da532 Take a rotated vault's contents onto the new key as well
Rotating a vault re-keyed the vault and not its contents, which was the deal
struck last time: everything already stored stayed sealed under the generation it
was written with, every remaining member kept the older keys, and the guarantee
was narrowed to "nothing written from now on". That left one gap worth closing —
somebody who walked off with the old key could still open old ciphertext they
later got hold of — and the reason it was safe to defer is the reason it was
cheap to add. A vault at mixed generations reads perfectly well, so the pass that
moves items across can stop half way and be run again.

VaultResealer walks the vault and rewrites each item as an ordinary upsert
against the version the server holds. It never decodes the plaintext: an item is
opened and the same bytes are sealed again under a fresh data key, so an item
written by a newer client crosses a rotation untouched rather than being
re-encoded through this build's codec and quietly losing the fields this build
has no concept of. It also means nothing in the pass knows what an item is, which
is why one loop covers every type including the ones added after it. A conflict
is counted and skipped rather than merged — there is nothing to merge, since no
content changes — and the next pass picks the item up at the version the other
client left.

The half that a pass over stored items cannot see is a change queued before the
rotation and pushed after it, which would put a brand-new item into the vault
under the key the person who just left still holds. So the push path re-seals a
stale payload as it dispatches it, writing the revision back to the outbox first
so that a retry sends the same bytes rather than a fresh envelope. Between the
two, nothing reaches the server under a superseded generation at all. Queued
items are therefore deliberately left alone by the pass: rewriting one there
would overwrite the user's unpushed work with the version the server holds, which
is the one thing a re-keying pass must never do.

Removal runs it last, after a sync — a mirror that is behind produces a batch of
conflicts instead of a re-sealed vault — and the status line distinguishes the two
guarantees, because they are not the same: a vault fully re-sealed is closed to
the person who left, and one with items outstanding is closed only to what
happens next.

Six tests, and three mutations run against them: making the re-seal return the
payload unchanged fails five of the six, making the push path skip re-sealing
fails the queued-edit test and only that one, and counting conflicts as applied
fails the write-elsewhere test. One of the six was wrong before it was right — it
modelled a third-party write by re-pushing an existing payload at a bumped
version, which no real client would do, and it took reading the AAD to see that
the test was lying rather than the code.
2026-08-04 10:18:14 +02:00
jaap-jan 27bb1deb5d Say what the docs describe, in the order they describe it
A tidy across docs/, and every change is either something that had drifted
from the code or something a reader would trip over. Nothing here is a rewrite:
the audit documents keep their audit-time text, because that is what the scope
was decided against, and corrections are marked in place the way each file
already marks them.

The one that matters is crypto.md. Section 4.3's resourceType table stopped at
13 while CryptoSpec.AadResourceType has carried ConnectionLogEntry = 14,
ActivityLogEntry = 15 and ObjectStore = 16 since the logs and the buckets
shipped — and items have been sealed under all three. That file is normative, so
a table three item kinds behind the code is the sort of gap somebody
reimplementing this would build against. Nothing on the wire or on disk changes;
the list now says what the code has been doing, and it notes the thing that
makes it worth reading carefully — 14, 15 and 16 are the first members that are
not a fixed offset from their SyncEntityType counterparts, because 12 and 13
closed a hole and pushed the two enums apart.

manual-checks.md had Phase 3 in an order nobody could follow: 3.2b, then 3.2a,
then 3.4a, then 3.3. The letters are not the problem — they exist so a check can
keep its number for life, which is what lets HostGridTests cite 7.6 and
platform-flags.md cite 3.6-3.8 — so the sections are reordered and the numbers
are untouched, and the intro now says the convention out loud rather than
leaving the next person to infer it from two orphaned letters. Phases 8 and 9
got the horizontal rule every other phase has. The Phase 3 preamble still said
"a sidebar that now draws headings", which has been two different interfaces for
a while: the desktop's grid of cards and the phone's flat list.

7.6 cited MovingAHostToAGroup_FilesItAndLeavesItSelected, which was renamed in
the commit before this one. Every other Type.Member citation across all six
files was checked against src/ and tests/ the same way; those two were the only
ones pointing at nothing.

design-import-gaps.md's v3 section described the grid of cards without saying it
holds one level, and its Groups row still said the sidebar emits one heading per
group — true of the phone and not of the desktop. The team-groups row said a
host a teammate filed "shows under UNGROUPED", which is now only half the story
and the interesting half is why: the chip resolves through groupsById, which is
every readable vault, while the level resolves through Groups, which is the
active vault alone — so the card sits at the outermost level with its group's
name still on it. Verified against both call sites rather than reasoned about.

android-port.md's destination inventory is the desktop as it stood when the
audit was taken and is deliberately left that way, with a note at its head
saying so and two inline corrections where a reader would otherwise be misled:
the rail lost FILES and S3 to fixed tabs, and the hosts sidebar became a grid —
which is exactly why the headings this head draws are the phone's alone now.

adding-hosts-on-the-phone.md is a plan marked built, so its two open questions
are answered in place: GroupId did get into the merge test's with block, and the
server test that asserts a plaintext ParentId is refused survived under a name
that says what it means. Its "found on the way" note is marked still open,
because it is: LocalCacheProtector.For has no arm for ConnectionLogEntry,
ActivityLogEntry or ObjectStore, so ConflictStore.Record still throws for all
three. That outlived the phases that shipped them, which is the drift a note
like that exists to prevent.

No code changed, so the suite is untouched at 1522 passing.
2026-08-04 10:15:02 +02:00
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 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 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 5a899afd78 Decide what Lock does to a running shell, and say it
Pressing Lock nulled and disposed the vault view model and touched nothing else.
TerminalWorkspace is injected from App.axaml.cs and outlives every lock, so the SSH
connection, the pty and the pump all kept running while the window said "Unlock your
vault" — and since 0500e43 collapsed the WebView while locked, that live session was
invisible as well as unstopped. CloseSessionAsync was reachable in production only from
DisposeAsync, i.e. shutdown. None of this was written down anywhere, so it was neither a
policy nor a bug, which is the actual problem.

Shells now deliberately outlive the lock, and every layer says so.

The reason to prefer this over making Lock a disconnect: locking is what a person does
when they walk away from the machine, which is exactly when a long upgrade, build or
transfer is most likely to be in flight. Ending every shell would make Lock a button that
destroys work, and the predictable response is to stop pressing it and leave the vault
open instead. The idle auto-lock this will grow decides it outright — an unattended
timeout that killed a running job would be worse than the exposure it removes. Closing
the channel also buys less than it looks: the session was authorised at connect time by a
credential the remote verified itself, and no vault key participates in keeping it alive,
so locking cannot retroactively un-authorise it any more than removing a member can.

Stated honestly rather than implied, because the lock screen is what hides it:

- The unlock screen shows how many shells are still connected, and that locking closes
  the vault and not the connections — so a machine still holding authenticated SSH
  channels does not present itself as merely "locked". Shown only when there is something
  to disclose. Quitting is what ends them, and the text admits that.
- The Lock button carries the same thing in a tooltip, since its name implies the
  opposite of what it does to a shell.
- README lists it as a third architecture consequence beside non-retroactive revocation,
  which is the same shape of honest limit; docs/crypto.md §10 records it as a threat-model
  boundary; TerminalWorkspace and LockAsync carry the argument next to the code.

LiveSessionCount deliberately does not count dictionary entries. Nothing removes a
session when the remote closes the channel by itself — RunSessionAsync only drops the
renderer registration — so sessions.Count would report a shell that exited half an hour
ago as still running, on the one screen where a user is deciding whether it is safe to
walk away. A completed Run task is what "the shell is gone" actually looks like. While
locked the number can only fall, since opening a session needs the vault, so a stale
value over-reports rather than under-reports.

Both new tests fail when the policy is reverted: the count test times out against
sessions.Count, and the shell test reports "workspace.LiveSessionCount should be 1 but was
0" when Lock closes sessions. ShellFlowTests also stops building its workspace with a real
SshNetConnectionFactory that nothing ever called, which had made the suite's independence
from the network a coincidence rather than a property.

Verified by hand with a live shell, which nothing had done: a harness mirroring
MainWindow.axaml's 340,* grid with a real NativeWebView, the shipped WebAssets, a real
sshd in a container, and an ISshShellSession decorator recording every window-change the
remote is actually told about. Across lock and unlock, no window-change reached the remote
at all, stty size answered 50 118 before and after, the renderer's own buffer came back
byte for byte with the wrapped line intact, and the session stayed live throughout. A
control run that never hides the WebView behaves identically, so nothing above is startup
or idle behaviour. Keystrokes injected while locked reach nothing: twelve of twelve
SendInput events accepted with the harness confirmed as the foreground window, no probe
character in the remote's output, and a following Ctrl-U answered BEL, so nothing was
queued in the line editor either. A hidden WS_CHILD window is not eligible for keyboard
focus, which is what makes surviving the lock defensible rather than merely convenient.

Correction to a claim made in f80b3d4: terminal.js's guard comment listed "a host that
hides the WebView while the vault is locked" among the paths that reach a degenerate fit.
It does not. Collapsing the control hides a native child window without resizing it, so
the page still reports paneWidth 840 and paneHeight 760 with unchanged cols and rows, no
ResizeObserver callback fires and the fit never runs. Establishing that rather than
assuming it: the same cycle with MINIMUM_FITTABLE_PIXELS patched to 0 — the guard fully
disabled — is equally clean. The guard is still right for minimising and for a splitter
dragged to the edge; it is simply not what makes locking safe, and must not be cited as
though it were.

Recorded, not fixed:

- Nothing closes one terminal from the interface, so a user reading "1 shell is still
  connected" can only act on it by quitting. CloseSessionAsync is tested and correct;
  VaultViewModel discards the session id it would need.
- A session whose remote exits keeps its ISshConnection, and the thread ShellStream parks,
  until the process ends.
- Suspected and seen once: before the harness waited for the window's scale to settle, a
  DPI settle pushed a 2202x1328 pane for a window 1180 logical units wide and a later
  re-push reflowed the wrapped line. Three later runs at RenderScaling 1.00 never showed
  it, so it is filed as a lead, not a finding.
- WebView2 fails to initialise with CO_E_SERVER_EXEC_FAILURE when the host executable
  sits under a very long path. Cost an hour on the harness; relevant to packaging.
2026-07-29 14:44:02 +02:00
jaap-jan 8d2416a602 Add the encrypted local cache and the sync client
Three new client projects, and the wire-contract fix they needed.

DodoSSH.Client.Domain holds the decrypted item model and the three-way
merge, with no I/O at all — so the suite that decides whether a
credential can be lost runs in milliseconds with nothing to mock.
Scalars defer to the server on a genuine clash so every replica resolves
the same triple identically and two clients cannot ping-pong; directives
merge per name so two people each adding one both keep theirs; the jump
chain merges as a whole value because its order is the route. Whatever
loses is returned rather than dropped.

DodoSSH.Client.Storage is EF Core on SQLite, no SQLCipher: the rows are
already ciphertext, so an encrypted file would protect protected bytes
at the cost of a native dependency. It keeps the server's state and the
outbox in separate tables, which is what preserves the common ancestor a
merge needs. One pending operation per item, enforced by a unique index.

DodoSSH.Client.Sync is the pull/apply/push loop. Pulling never decrypts
— a change with no local work pending is plumbed as ciphertext — so a
first sync of thousands of items does not run twice as many AEAD
operations for nothing.

Contracts: EncryptedPayload gains WrappedDataKey and DataKeyId. The
specification has required a per-item data key since crypto.md §3, the
columns have existed since the first migration and DshAad.ItemPayload
binds the id, but this record had nowhere to put either — so a
spec-compliant item could not be transmitted at all. Found by writing
the client that has to produce one. Also closes a hole in
AadResourceType, which had no value for the HostTag and HostCredential
that SyncEntityType has always listed.

Four bugs the tests found, not review:

- SQLite refuses to order or compare its own DateTimeOffset mapping, and
  throws at execution rather than model build. Collecting tombstones and
  listing conflicts are both that shape, so this was a crash waiting for
  the first user with a deleted host. Timestamps are integers now, by
  convention so a later field cannot be the one left unconverted.
- SQLitePCLRaw 2.1.11, which EF resolves, is covered by
  GHSA-2m69-gcr7-jv3q. Pinned forward as a family.
- Resurrecting content from a remote deletion cleared the original
  before queueing the copy. Two transactions, so a crash between them
  lost the work; reversed, and the rescued id is derived from the
  tombstone so a replay coalesces instead of duplicating.
- Several equality assertions went through Shouldly's ShouldBe, which
  compares IEnumerable element-wise and so tested nothing about the
  Equals these types exist to provide. Corrected; the falsification that
  caught it went from 2 failures to 6.

The push response's cursor is deliberately ignored. It sits after this
client's own writes, so adopting it skips anything another client
committed at a lower sequence in the window between a pull and a push —
permanently. Re-reading one's own writes is idempotent and costs a page.
The Contracts doc that invited the shortcut now says so.

593 tests, up from 448. The delete-versus-edit rules, the ancestor
retention, the fresh operation id on coalesce and the cursor safeguard
were each verified by breaking them and watching the right test fail.
2026-07-29 10:27:37 +02:00
jaap-jan a878c2b6bb Add the server client and client-side enrollment
A typed client over DodoSSH.Contracts, and the orchestration that turns a
passphrase into an enrolled identity: generate keys, have the identity
provider sign over them, wrap the bundle three ways, create the personal
vault, publish.

Ordering here is forced, not chosen. The secret bundle's AAD binds to the
server-assigned user id, so /me has to be read before anything can be
wrapped -- which is exactly why /me provisions the account and returns its id
even while reporting that enrollment is required. That constraint was
designed into the server earlier; this is the first code that depends on it.

The grant tuple now has a real canonical encoding (crypto.md 7.3) rather
than the placeholder signature I would otherwise have had to invent and then
keep. §7 named the tuple without specifying how to encode it; this fills that
in with the same conventions as 7.1, and the self-grant at enrollment is
already in its final format. The signature covers SHA-256(wrappedKey) rather
than the key, so a verifier can check attribution without holding the vault
key at all.

The most valuable tests are the negative ones about the request body: the
server is meant to be unable to read what it stores, and a refactor that put
a passphrase or a private key into the enrollment request would be invisible
to every other test in the repository. So one asserts the body contains
neither the passphrase, the recovery code, nor any private key in base64 or
hex. Another opens the same bundle three ways -- passphrase, recovery code and
device key -- which is what makes a passphrase change a one-row update.

ClientEnrollment depends on IKeyBindingAuthorizer rather than the whole
OidcClient. It needs exactly one capability, and depending on the full client
would drag discovery and token exchange into every test of key binding.

Two things fixed while building it. The recovery code buffer was sized one
separator short, so every enrollment threw IndexOutOfRange -- caught
immediately because nine of ten tests failed identically. And the crypto
enum collided with Domain.GrantKind in the server, so it is GrantPurpose
there; the numeric values still have to match, which the doc and a test both
say.

448 tests pass, zero warnings on a clean rebuild, format clean.
2026-07-28 22:42:56 +02:00
jaap-jan e65d738912 Add the client key hierarchy: bundle, master key, vault and item keys
Everything crypto.md section 3 describes below the identity key, which is
what the desktop client needs before it can enroll or store anything.

DshAad gives every descriptor in the specification a named constructor. The
AAD binding is the most valuable structural property in the design -- it is
what stops a server holding every ciphertext from pasting one row's bytes
onto another, rolling a row back to a superseded generation, or replaying a
revoked grant -- and all of it depends on callers getting purpose, resource
type and ids right at every single call site. Hand-constructing descriptors
makes that a matter of care; picking a method name makes it a matter of
spelling.

UserSecretBundle holds private keys in libsodium's guarded, mlocked
allocations rather than a byte[], so they are not paged out and do not land
in a core dump. They are created exportable, deliberately: re-wrapping the
same bundle for a passphrase change or a new device needs to re-encode it,
and the alternative -- a long-lived managed array so the keys need not be
exportable -- keeps the identical secret in strictly worse memory. Every
export is into a buffer zeroed before the method returns.

Two spec changes, both found by implementing it, which is the argument for
writing code before calling a spec frozen:

- MK is 64 bytes, not 32. Skipping HKDF-Extract is correct for an Argon2id
  output (RFC 5869 3.3), but it means MK *is* the PRK, and .NET's
  HKDF.Expand rejects a PRK shorter than the hash output -- so a 32-byte MK
  cannot be expanded with SHA-512 at all. Widening it keeps the specified
  primitive; the alternatives were dropping to SHA-256 or adding an Extract
  step that conditions nothing.
- The bundle encoding is a fixed 92-byte layout rather than canonical CBOR.
  Canonicality is not load-bearing here -- unlike a key statement the bundle
  is never hashed or signed, only encrypted -- so CBOR's one advantage does
  not apply, while its canonicalisation rules are a real source of
  cross-implementation disagreement. It also costs a dependency
  System.Formats.Cbor is not in the shared framework. Safe to change now
  and not later: no bundle has ever been stored.

53 new tests. The encoding is checked against an independent codec written
in the test rather than by round-tripping production code against itself --
a round trip passes just as happily when both directions are wrong the same
way, and this format cannot change after one bundle is stored. The pinned
92-byte hex constant is the golden vector for the layout.

Most of the rest are negative, because a binding is only demonstrated by
the substitutions that fail: a wrap for another user, a grant from a
superseded generation, a payload pasted onto another item, a metadata blob
offered as a payload, a version rolled back.
2026-07-28 21:02:52 +02:00
jaap-jan d2a2ed8a29 Specify the key statement encoding and key log chain (crypto.md 7.1, 7.2)
Section 7 always required "a canonical, length-prefixed encoding" for
signatures without ever specifying one. That gap had to be closed before
enrollment could exist: the client hashes the key statement and uses the
result as an OIDC nonce, so the provider signs over those exact bytes. Two
implementations disagreeing by one byte produce two nonces and an
enrollment nobody can verify -- and it only shows up against a real
provider, never in a local test.

JSON cannot be the hashed form. Property order, number formatting, Unicode
escaping and whitespace all vary between serialisers. So the statement is
transmitted as JSON and hashed as a fixed binary encoding, and the two are
independent by construction.

Three details are load-bearing rather than stylistic:

- The presence byte before each string is what makes the encoding
  injective. Without it an absent email and an empty one encode
  identically, and two different statements share a binding.
- Timestamps truncate to milliseconds. PostgreSQL stores microseconds, so
  a statement that has been through the database must still hash to what
  the client hashed. The same applies to the key log, where an entry that
  cannot reproduce its own hash after being read back makes the chain
  unverifiable.
- The key log entry hash deliberately excludes the database sequence. It
  is unknown until the insert runs, and order already follows the hash
  links -- so a renumbered or gapped sequence column cannot silently
  reorder history.

KeyStatementFields is separate from Contracts.KeyStatement on purpose: one
may gain JSON fields freely, the other cannot change without invalidating
every stored binding, and Crypto must not depend on the contract assembly.
KeyStatementDriftTests makes a field added to one and not the other a
build failure, because a wire field outside the binding is unauthenticated
data the server can change undetected.

54 new tests and two new golden vector sections. The vectors pin the
absent-versus-empty email case and confirm that an offset-bearing
sub-millisecond timestamp encodes identically to its truncated UTC form.
Only additions to vectors.json; nothing existing moved.
2026-07-28 16:06:11 +02:00
jaap-jan b15af836a3 Freeze DSH1 crypto specification and implement the core (M1)
docs/crypto.md is now the normative, frozen specification. This had to land before
anything else in M1: the server holds ciphertext and no keys, so it can never
re-encrypt, and a format change after users hold data is a coordinated client rewrite
with no rollback.

Specification:
- DSH1 envelope layout, canonical 64-byte AAD encoding, SealTo construction, key
  hierarchy, Argon2id profiles, fingerprints, and the change rules for each version field.
- AAD encoding is fixed-width binary rather than delimited string concatenation, so no
  field value can forge a field boundary. This supersedes the illustrative form sketched
  in ADR 0001, which now points here.
- UUIDs are RFC 4122 big-endian. Guid.ToByteArray() emits the first three groups
  little-endian and would have made our ciphertext unreadable by any other implementation
  of this spec, failing only at a cross-implementation boundary.

Verified rather than assumed:
- PrimitiveAvailabilityTests proves X25519, Ed25519, XChaCha20-Poly1305, Argon2id and
  HKDF-SHA512 all function on net10.0. NSec 26.4.0 targets net9.0 and is consumed by
  forward compatibility; this closes one of the two package questions the plan flagged.
- Argon2Profile exists because NSec's MemorySize is in KIBIBYTES, not bytes. Passing bytes
  gives either a 256 GiB allocation or a 256 KiB KDF that cracks instantly. The type takes
  mebibytes so the unit cannot be got wrong at a call site. Found by benchmarking: the
  first measurements were ~1000x too slow, which turned out to be 19 GiB of work.
- Parameters measured, not guessed: 256 MiB/t=4 is 323 ms on this machine; the table of
  candidates is in the spec.

Implementation and tests (83 total, up from 17):
- AadDescriptor, DshEnvelope, DshCrypto (Seal/Open/SealTo/OpenSealed/fingerprints).
- Decryption returns null rather than throwing: ciphertext comes from a server that is
  explicitly not trusted, so a failed tag is an expected outcome.
- Envelope readers reject unknown algorithms and any non-zero flag bit, so an envelope
  that is not fully understood fails closed.
- Executable form of the spec's substitution claims: a server cannot move ciphertext
  between resources, roll back a key generation or item version, repurpose a payload as
  metadata, or confuse the two constructions.
- Golden vectors in tests/fixtures/crypto/vectors.json guard the format. Mutation-checked:
  a one-byte schema version change trips four tests including the guard.

Two build-infrastructure bugs found and fixed along the way:
- .editorconfig forced camelCase on const and static readonly fields. PascalCase is the
  .NET convention for both; the config was wrong, not the code.
- The golden fixture was resolved with [CallerFilePath], which ContinuousIntegrationBuild
  rewrites to /_/... under deterministic source paths. It passed locally and would have
  failed only in CI. Now copied to the output directory and read from there.
2026-07-28 13:18:29 +02:00