10f80bded1b7d9204f41a6bf98ffdd21ecf86ea9
2
Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
 jaap-jan
|
8a77b7ca68 |
Say how far a connection has got while it is still being made
The connecting card set its status string once, when the tab was created, and never touched it again. Every connection therefore looked identical from the outside: one three seconds into a key exchange, one waiting out a fifteen-second timeout against a machine that is asleep, and one that had hung all drew the same "connecting…". The card now draws the five steps of getting there, each lit at the moment the handshake reports reaching it, over an amber track that fills as they finish. ◆ NOTHING ON THE LIST IS INVENTED. Every row changes state because a layer below it said so, at the instant the thing it names actually began. That is the whole reason it is worth showing, and it is why most of this commit is plumbing rather than XAML: there was no progress reporting anywhere in the stack to hook a step list onto, and a card animating plausible progress would have been indistinguishable from one that had stopped receiving any. SshConnectionPhase names four phases and deliberately not more. SSH.NET runs the entire handshake inside one ConnectAsync and raises exactly one event from the middle of it — HostKeyReceived, once the key exchange has produced a key to show — so that event is the only interior moment there is to report. Everything before it is Reaching and everything after it is Authenticating. A fifth phase in that assembly would have to be a timer, so there is not one. OpeningShell is reported by TerminalWorkspace instead, because that is where it happens: the factory's work ends with an authenticated connection, and asking for a pseudo-terminal on one is a separate round trip. The SFTP path passes null — a second connection opened behind an already-open shell has nobody watching a step list for it. The card's fifth step, "Starting the terminal", is the renderer wait and lives in the shell rather than in the SSH assembly, which has never heard of a renderer. On the first connection after a cold start it is a real wait with a real failure mode of its own — a missing WebView2 runtime — so a list that began at "reaching the host" would leave the one wait most likely to hang unnamed. Amber for the step in flight, and that follows the palette's rule rather than bending it. Green is what is true and purple is what you can press; a step still happening is neither, and it is exactly the caveat-worth-reading that amber exists for. Steps behind it go green as they become true. Nothing animates, which is the argument TransfersScreen.axaml already makes for its own track, reaching a screen with far more reason to want a spinner: a spinner is furniture invented to fill a state nobody measured, and these states are measured, so the track fills to what has finished and then waits there. A refusal keeps the step it stopped on, in red, with the ones behind it still green. That is the half a progress bar could not do, and it is the difference between "that host is not there" and "that host is there and would not have me" — a question the reason sentence alone frequently does not settle. The strip's dot goes amber while a tab is connecting, on both heads. It was grey, and so is a tab whose shell has exited: the two states in that strip with the least in common, one worth waiting for and one over. PhoneShell's own comment already recorded half of this — the dot stopped being green before anything had answered — and this is the other half. Progress is raised inline rather than through System.Progress<T>, which captures whatever synchronisation context it was constructed on and posts to it. That reads like a convenience and is really a second place the marshalling decision gets made: silently, differently under a test with no context, and out of order with respect to the failure that follows a phase. The shell marshals once, in one handler, through a new optional post parameter on MainWindowViewModel — the same seam TransfersViewModel already uses, and for the reason its own remark gives. The three Dispatcher.UIThread.Post calls that predate it are the ones this suite's comments record as out of reach; they are left alone rather than swept in here. Both heads draw the list. They differ in one place: Phone.axaml's mono class sets a colour and a size along with the family, so the caption rule names its own family instead of composing the two and asking two rules for one Foreground. The desktop's mono sets the family alone, which is why ConnectingCard does compose them. Each head also gains SHOW LOGS beside the button that gives up — the step list is this attempt and the log is every other one, which is what a connection taking too long actually raises. Seven tests, and the two that matter most run against the container rather than a fake: a real handshake reports its phases in order, and a host-key refusal never claims to have authenticated. A fake asserting what it was written to assert would have established nothing about either. The rest cover the tab advancing while the connection is gated, the step a refusal stops on, and a phase reported after the user has given up on the tab. 1,861 tests, none failing. The Android head's layout is not verified by anything. It compiles, and compiled bindings mean every new binding path resolves, but that project is not in DodoSSH.slnx, there is no test project for it and no device here — so unlike the desktop card, whose shapes the layout harness measures, these rows have not been drawn. Vertical fit is reasoned, not observed. |
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|
jaap-jan
|
211eba0666 |
Keep host key trust in the vault, and make it withdrawable
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
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