4 Commits

Include renames

Author	SHA1	Message	Date
jaap-jan	82966af37b	Let a connection be reached through a proxy on this machine's loopback ... Step 1 of docs/reaching-a-host-you-cannot-dial.md, and it is not the step that document said it was. SshConnectionRequest carries an optional SshLoopbackProxy and BuildConnectionInfo hands SSH.NET its proxy ConnectionInfo when there is one. Nothing passes one yet: the callers are jump hosts and the relay, which are steps 2 and 3. ◆ THE BRIDGE WAS THE WRONG FIRST STEP, AND BUILDING IT WOULD HAVE BEEN THE MISTAKE THIS DOCUMENT IS ABOUT. ADR 0004 says the relay's loopback bridge "also provides ProxyJump via a SOCKS5 dynamic forward — one mechanism, two features", and the plan took that to mean the bridge was the shared foundation. It is not: ForwardedPortDynamic *is* the listener for a jump host — SSH.NET accepts on it, speaks SOCKS5 on it and tunnels through the bastion — so nothing is left for a bridge of ours to do on that path. The relay is the case with no SshClient to hang a forward off, so it is the bridge's only consumer, and the bridge belongs in the commit that uses it. What the two actually share is one level down and a tenth of the size: being told to reach a target through a loopback proxy while staying about the target. That is what this is. Three properties, one test each. A port and nothing else, so a proxy anywhere but loopback cannot be expressed. The failure that shape rules out is an open SOCKS proxy on the user's network for the life of a shell, which nothing would report — so it is made unrepresentable rather than validated, on the same grounds AuthenticationChoice carries a kind. SOCKS5 rather than a dumb pipe, which is what keeps host key pinning honest. The target's own name and port stay in the request, travel to the proxy in the CONNECT, and are what the gate pins — so a machine reached through a bastion is pinned under its own name instead of under 127.0.0.1 on whatever ephemeral port that day's forward got, which is not an identity at all. A pipe would have meant handing SSH.NET a stand-in and remembering everywhere else that it was one. And a proxy that is not listening fails as a connection error rather than as an unknown host key. The gate turns "no host key seen" into a fingerprint prompt, and a connection that never reached a server has seen none either; the prompt would offer to fix the wrong thing, with no fingerprint to show. TWO THINGS THE TESTS MEASURED RATHER THAN ASSUMED, both found by the first run failing. The target is resolved at the *bastion*, not here — a SOCKS CONNECT names it and the far end looks it up. So the test asks for localhost:2222, the address inside the container, and the published port this host would use means nothing there. That is not a quirk of the fixture; it is what ProxyJump means, and it is why an ssh_config writes the target's internal address beside its jump host. Getting it wrong is a SOCKS "general failure" that names neither end. And the test server refuses forwarding. linuxserver/openssh-server ships AllowTcpForwarding no, which a dynamic forward does not notice — opening one asks the server nothing — so every connection through it is refused at channel-open and reported as the same general failure. The fixture patches it and HUPs sshd. There are two sshd_config files in that image and the running server uses /config/sshd/sshd_config; the first attempt patched /etc/ssh/sshd_config, which is the one a search finds first, changed the text and nothing else, and left the failure exactly where it was. VERIFIED. Build clean with no new warnings, 85 tests in Client.Ssh.Tests against the real sshd, and the solution builds. The proxy test was seen to fail — proxy.Port + 1 in BuildConnectionInfo — and seen green again. An earlier mutation attempt did not compile, and the log said 85 passing because the run never started and the previous log was still on disk; the second attempt deletes the log first, which is worth copying whenever a mutation "passes". dotnet format reports one pre-existing IDE1006 in DodoSSH.Api/Features/Events/EventsEndpoint.cs, in a project nothing here touches. Left alone.	2026-08-07 13:48:15 +02:00
jaap-jan	04faef6597	Move files to and from a host over SFTP ... M2's file transfer, built bottom-up: an SFTP session on the SSH layer, a transfer queue in a project of its own, and the two-pane browser the design asked for replacing the screen that said it did not exist. Remote listings carry names, sizes, modification times and a real drwxr-xr-x — nothing in this repository could render a POSIX mode before — and the queue moves one file at a time with progress, throughput and resume. The design import assumed this would be an SFTP subsystem channel on ISshConnection, beside the shell on a transport that is already up. SSH.NET does not offer that: SftpClient derives from BaseClient and owns its own transport, and there is no supported way to hand it an SshClient's session. So file transfer opens a second authenticated connection, and it is named for that rather than dressed up as a channel — OpenSftpAsync is on ISftpSessionFactory, not on a connection. The difference is visible to a user: the host records a second login, and a host whose password is typed each time asks for it again on this screen. It goes through the same host key gate, the same pin and the same two refusals a shell does, so a fingerprint approved for a terminal is approved here and one approved here reaches the other machines with the next sync. docs/design-import-gaps.md is corrected, and marked as the one row where what shipped differs from what it predicted. Nothing is written at its final name until it is complete. Every transfer goes to a .dodossh-part file beside its destination and is renamed into place at the end, so an interrupted transfer can never be mistaken for a finished one — which matters most for what this screen is actually for, which is copying a build artefact onto a server and then running it. A destination that already exists is refused outright rather than overwritten: the queue has no way to ask, and silently replacing a file somebody's process is serving is the worse of the two failures. The remote pane has DELETE and MKDIR so that refusal is not a dead end. A test against the container pins the assumption underneath all of this — that SFTP's rename does not clobber. Resume works within a run of the application and not across a restart, and the limit is deliberate rather than unfinished. Nothing records which source wrote a part file, and resuming one on the strength of its name matching is how a corrupt artefact gets delivered with nothing reporting a failure; a part file found at startup is started over. Making it survive a restart needs the preferences store this client still has not got. The offset a resume starts at is the part file's own length rather than the transfer's recorded progress: a cancellation can land between a write completing and the counter moving, and only one of those two is a fact about the bytes that are there. The queue and its connection outlive a lock, as shells do. LockAsync already argues that locking must not destroy work in flight — it is what somebody does when they walk away from the machine, which is exactly when a long transfer is most likely to be running — so TransfersViewModel is created once and the vault is attached on unlock and detached on lock. What locking takes is the host list, and it has to: those rows carry decrypted secrets. DodoSSH.Client.Transfer is a new project rather than more of Client.Ssh. The two answer different questions — one is about reaching a host, the other about moving bytes and what to do when moving them stops halfway — and this is the only client project that deliberately touches the local filesystem. Three defects the tests found, none of which review would have. SftpPath.Name answered an empty string for the root. NavigateRemoteAsync wrapped itself in the busy guard, so navigating from inside another command did nothing at all and the remote pane simply stayed empty after connecting, with no failure anywhere to explain it. And opening an SFTP session per test made two handshakes per test — this client learns a host key by being refused — which pushed the SSH assembly past sshd's MaxStartups and failed a different few unrelated tests each run; the session is shared through the fixture now, with the reason written where the next person will hit it. 1004 tests green across 18 projects, 24 of them new: the SFTP subsystem against the OpenSSH container, the queue against a real temporary directory and a fake host, and three more layout measurements because a screen this window has never laid out is a screen never checked. Not verified: the screen has not been looked at running. The layout harness measures it at the window's minimum in three shapes, which is the class of defect that has shipped here before, but reaching it in the application needs the compose stack, the migrations, the API and a browser sign-in. What is still absent — the status bar's transfer count, dragging between the panes, transferring a directory, and sftp over a bastion — is in docs/design-import-gaps.md.	2026-07-31 11:07:29 +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
jaap-jan	eb354bcdd9	Add the SSH session layer and the terminal data plane ... The throughput harness the plan requires before any UI, plus the SSH plumbing under it. 94 new tests, no WebView involved. Credit-based flow control is what makes `yes` survivable. A terminal renders at 60 Hz at best while a remote produces output as fast as the network allows, and the difference has to accumulate somewhere or be refused. Credit is reserved *before* reading, never after: because the pump cannot read more than the renderer has room for, the coalescing buffer is bounded by the window rather than by how fast the remote can talk. When credit runs out the pump stops reading, SSH's own receive window closes, and the remote sshd blocks -- backpressure to the source with no custom protocol. Verified by falsification, not just by passing: with the credit gate removed three tests fail, including the throughput harness's bounded-memory assertion. Acknowledgements are clamped because they cross into JavaScript, where a buggy or hostile page could otherwise claim to have rendered a gigabyte and talk the host into an unbounded read. Host key trust is enforced by *failing* the connection rather than prompting inside the handshake. SSH.NET raises verification synchronously, so consulting the user there would block the handshake on a UI round trip and deadlock the first time the prompt needed the UI thread. Unknown host and changed key become distinct exceptions the caller resolves asynchronously. A mismatch has no retry path at all: a dialog offering to continue is how users are trained to click through the one warning that actually indicates interception. A legitimately rebuilt server is handled by removing the pin in settings, away from the moment of connecting. The data plane serves the renderer page from the same loopback listener as the socket, which makes Origin predictable -- always http://127.0.0.1:{port} -- where a WebView virtual-host mapping would give a different origin per backend and nothing to validate. The token is substituted at serve time, so it never touches disk and never appears in a URL. Being clear about what that buys: not protection from a process running as this user, which can read our memory anyway, but from a page in the user's browser attempting WebSocket connections to loopback ports, which is a real and routine thing. Two bugs the tests caught. The accept loop handled connections serially, so an upgraded WebSocket parked it inside the receive loop and every later request went unanswered -- the page's own script among them. The suite hung rather than failed, which is how I found it. And SHA-1 is unavoidable here: RFC 6455 mandates it for Sec-WebSocket-Accept, where it authenticates nothing. Suppressed narrowly with that reasoning; the alternative, HttpListener.AcceptWebSocketAsync, throws PlatformNotSupportedException off Windows.	2026-07-28 21:58:55 +02:00