Commit Graph
4 Commits
Author SHA1 Message Date
jaap-jan f80b3d4351 Harden the WebView collapse, and replace its evidence with a measurement
An adversarial review of 0500e43 did not refute the fix but closed the gap I
had left open and found three hazards around it. A standalone spike — a 60-line
Avalonia app with no DodoSSH code — reproduces the airspace bug on a 340,* grid,
and a second harness mirroring the data plane's handshake measures what I had
only reasoned about: with IsVisible=false set before the window is ever shown,
the adapter is created, the page is fetched and the WebSocket 101 is sent, with
frames arriving over the socket while hidden. A cold WebView2 profile behaves
the same. Revealing recomputes bounds in about 7 ms.

So the docs no longer cite "35 msedgewebview2 processes" as the confirmation
that the renderer attaches. A process count cannot show that a socket was
accepted — the same shape of mistake, one level down, as the one that entry was
already correcting. It now cites the handshake, quotes Avalonia's maintainer on
airspace being by design, and links the still-open upstream issue.

Three changes to the fix itself:

- terminal.js skips the fit below 40px in either axis. The vendored fit addon
  floors its proposal at 2 columns by 1 row rather than refusing, so a
  degenerate viewport reflows the *remote* pty through window-change and
  mangles wrapped scrollback unrecoverably. Reachable today by minimising, and
  by dragging a splitter to the edge once splits land — a guard where the sizes
  arrive, not a special case for one caller.
- FallbackValue=False on the binding. A compiled binding with no DataContext
  yields UnsetValue, IsVisible falls back to true, and the occlusion returns
  silently. Not reachable at runtime; it is what the previewer does.
- The comment now says why it must be IsVisible on this control: detaching
  destroys the native control and the whole WebView2 process tree, so
  conditional content would pay a cold start per unlock, and hoisting the
  binding to an ancestor is unverified because NativeWebView's own
  bounds-and-scaling re-push fires only for its own IsVisible.

Also recorded, not fixed: hiding does not suspend the page (visibilityState
stays "visible" and rAF keeps firing at ~115/s, which is *why* the handshake
completes while hidden); the conflict log can squeeze the terminal row toward
nothing; and nothing hands the terminal Win32 focus after Connect, so the first
keystrokes go to the shell's UI rather than the remote shell.
2026-07-29 13:42:23 +02:00
jaap-jan 0500e43e02 Stop the terminal's WebView painting over the setup screens
The shell layered its setup and unlock screens over the terminal, which does
not work: NativeWebView attaches a real Win32 child HWND through
NativeControlHost, and a child window composites above everything its parent
paints regardless of visual-tree z-order. The cards rendered sliced at the
terminal column's left edge; at the window's default width every one of their
buttons fell inside the WebView's rectangle, so the flow could only be
completed by keyboard, and a click in that region handed Win32 focus to
WebView2 so the text boxes silently stopped accepting keystrokes.

The WebView is now collapsed while the vault is not unlocked. The comment
that previously forbade this — hiding it means never realising it — was
wrong: NativeControlHost creates the native attachment on attach to the
visual tree, never consulting layout or visibility, and NativeWebView replays
a Source assigned before its adapter exists. A collapsed WebView still starts
WebView2, loads the page and lets the renderer attach. Confirmed: 35
msedgewebview2 processes with the control collapsed. What the first
connection after unlocking actually depends on is the existing await on
WaitForRendererAsync, since the data plane drops frames when no renderer is
attached.

Also fixes the second visible defect: the default server URL was
https://localhost:7217, the API's *second* launch profile, while the README,
its appsettings and a plain `dotnet run` all use http://localhost:5233 — so
nothing was listening, and an HTTPS client against a plaintext port reports
"The SSL connection could not be established", which reads as a certificate
problem. The default now matches, a missing scheme is rejected by name
instead of parsing as scheme "localhost", and that specific TLS failure now
suggests http://. Both new tests fail when the fixes are reverted.

Corrections to claims I made earlier and should not have:

- docs/platform-flags.md asserted the opposite of the mechanism above and
  cited an established msedgewebview2 connection as verification. That
  observation was taken while the overlay was showing but, because of this
  very bug, the WebView was uncovered and in plain view — so it confirmed
  only that a visible WebView is realised. A process-level check cannot
  verify a rendering claim. The entry was also filed under "Local cache".
- ITerminalHost was documented as the live seam the app plugs into, with a
  stub standing in for headless tests. It has no implementation anywhere and
  no test uses it; the view navigates the control directly. It also counted
  Avalonia.Controls.WebView and NativeWebView as two interchangeable
  backends when they are one component, with the Linux backend backwards.
- The README claimed the shell's whole path was covered by tests. Its state
  machine is; its layout is covered by nothing, and a headless test could
  not have caught this — headless has no native window, so it would have
  rendered correctly and confirmed the wrong belief.

Verified by screenshotting the running app: the card renders complete and
centred at the default size, with the button clickable.
2026-07-29 13:26:30 +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
jaap-jan 5fccd53824 Add the Avalonia app and the xterm renderer, and fix two real bugs
The terminal works end to end. A new integration test drives a real sshd in
a container through a real PTY, the real pump, the real loopback WebSocket
with its token and origin checks, and a ClientWebSocket standing in for the
page: the login banner arrives, typed input round-trips, and `stty size`
reports the 100x30 the session asked for. The only untested link left is
xterm drawing bytes it was handed.

The WebView is de-risked on Windows, which was the plan's largest risk. Not
by assertion: with the app running there is an established TCP connection
from msedgewebview2 to the data plane port, so WebView2 launched, navigated
to the loopback page, executed terminal.js, and completed the WebSocket
handshake against the real token and origin checks. Linux remains unproven
and the package's own release notes now corroborate the concern -- Linux uses
a WPE backend, and it ships a NativeWebDialog described as useful where
embedded WebViews may be unavailable.

Two bugs found by building it, both of which would have shipped:

- ShellStream.Write buffers and needs an explicit Flush. Without one a
  keystroke is accepted, reported as written, and never reaches the remote:
  the terminal displays output perfectly and simply stops responding to
  input. SSH.NET's own WriteLine flushes, which is why the earlier spike
  never hit it. Found by isolating the pump against real SSH and reading
  BytesRead=51 -- banner and prompt through, nothing after.
- The Windows app manifest needs a supportedOS list, or Avalonia's native
  control host fails outright and the terminal never starts.

Also fixed a genuinely flaky test I happened to catch: SyncCursorTests
tampered with the *last* base64url character, whose low bits the decoder
ignores when the input length is not a multiple of three -- so a tampered
cursor sometimes decoded to identical bytes and verified. It failed roughly
one run in thirty, depending on a random key. Now tampers the penultimate
character, which is fully significant at every length; 40 consecutive runs
are clean.

xterm 6.0.0 plus the fit and webgl addons are vendored as UMD bundles rather
than built with npm, so a clean clone needs only the .NET SDK. Provenance
and licences are recorded next to them, along with the UMD global names
terminal.js depends on -- a bundle that switched to ES modules would load
without error and leave Terminal undefined.

The renderer acknowledges output from term.write's completion callback, not
on receipt. Acknowledging early would return flow-control credit for bytes
the screen has not caught up with, which is the one thing the credit window
exists to measure.

TerminalWorkspace moved into DodoSSH.Client.Terminal: it has no Avalonia
dependency, and having it there is what let the end-to-end test exist at all.

404 tests pass, zero warnings on a clean rebuild, format clean.
2026-07-28 22:30:42 +02:00