5fccd5382447da62d66173c51a70b5faab3332cb
4
Commits
| Author | SHA1 | Message | Date | |
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 jaap-jan
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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. |
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jaap-jan
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94f66be5e8 |
Add the OIDC client: PKCE loopback sign-in and the key binding flow
Authorization Code with PKCE on a loopback redirect, per RFC 6749, RFC 7636 and RFC 8252. Zero package references: the flow is fully specified, and the one thing a library would own for us -- nonce generation and validation -- is exactly what the key binding needs to control. Duende's OidcClient generates and validates its own nonce as an internal detail, and the binding requires the nonce be a specific value: the hash of the key statement being enrolled. Fighting that is worse than owning the flow. AuthorizeKeyBindingAsync is the client half of the primary trust anchor. It runs a second authorization with nonce set to the statement hash and prompt=login, so the ID token that returns is the provider's signature over exactly those public keys, attesting to a user present now rather than to a session opened at some unknown earlier time. It requests only openid -- a second refresh token would be one more long-lived credential for no benefit -- and rejects a token whose nonce is not the one it asked for, because enrolling that would store evidence verifying against keys we are not publishing. The nonce is read without validating the ID token's signature. Sanctioned by OIDC Core 3.1.3.7: for a token received by direct communication with the token endpoint, TLS server authentication may stand in for signature checking. That reasoning does not extend to another user's binding, which arrives via the DodoSSH server and must be verified against JWKS fetched directly -- the directory work in M3. Raw TcpListener rather than HttpListener for the redirect: an ephemeral port can be bound and read atomically instead of picking one and hoping it is still free, there is no HTTP.SYS URL-ACL question on Windows, and the whole surface is one request line. It answers 404 on other paths and keeps waiting, because a browser asks for /favicon.ico first and treating that as the callback would abort every sign-in. 127.0.0.1 rather than localhost: RFC 8252 permits either, but the name resolves through the hosts file. 20 tests, driving the real listener over TCP with a fake browser that actually fetches the redirect -- injecting a fabricated callback would skip the parsing, path filtering and response writing that can break. Mostly negative, because the loopback port is reachable by every local process: a response with the wrong state is rejected *and* never reaches the token endpoint, metadata declaring an issuer other than its own authority is rejected (RFC 8414 3.3, without which a mix-up attack works), a provider offering only 'plain' is fatal rather than a silent downgrade, and the verifier sent is checked against the challenge advertised so PKCE is not theatre that only fails in production. Two bugs caught by writing the tests: the authorize URL builder dropped client_id entirely after a refactor, and CancellationTokenSource.CancelAfter has no TimeProvider overload -- so the browser timeout is now constructed with the clock and a test can advance it instead of waiting five minutes. |
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jaap-jan
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885fb17bdc |
Clear the SSH gate: window-change reaches the remote, and licence as MIT
Licence is MIT, set solution-wide rather than only on the packable project: DodoSSH.Contracts is published so clients can build against it, and a package with no licence expression is one a corporate policy scanner rejects outright. The SSH.NET spike is the M1 client gate and it passes. SSH.NET 2025.1.0 exposes ShellStream.ChangeWindowSize, but a method existing is not the remote observing it, so the tests read `stty size` back from a real sshd after resizing rather than asserting the call did not throw. Repeated resizes each take effect too, which matters because dragging a window edge produces a stream of them. The IChannelSession fallback is not needed. Also verified against a real sshd: password and public-key auth, that the host key arrives as a raw blob we can fingerprint ourselves rather than reading SSH.NET's MD5 property, and that refusing the key via CanTrust actually aborts the connection -- without which the TOFU dialog would be decoration. Kept as a permanent suite, not deleted after the spike. An upgrade that silently stopped sending the request would present as wrapped output only after a resize, which is easy to misattribute to the terminal emulator. Two bugs in the test itself, both worth naming because either would have been read as "resize does not work": - A PTY emits CRLF, and the anchored regex rejected the CR. The output visibly contained `24 80` while the match failed. - Each read can begin with output still buffered from the previous command, including its size line. Taking the first match would have reported the pre-resize size. platform-flags.md now records window-change as resolved rather than unverified -- a stale flag is worse than none -- plus the three real SSH.NET limits found on the way: ShellStream does not override ReadAsync so every idle session parks a pool thread, one connection cannot serve both SshClient and SftpClient, and agent forwarding needs an upstream change. |
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jaap-jan
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b7325b78ca |
Record the platform flags that were only in conversation
Development and testing are Windows-only, so anything unverified elsewhere needs to be written down or it gets assumed to work. Several of these have already cost time once: PostgreSQL 18 moving its data directory silently gives a carried-over compose file an empty volume, and a loopback-bound Tomcat beat Docker's 0.0.0.0 publish for `localhost`, making every Keycloak realm 404 while the container looked healthy. The largest entry is the Avalonia WebView on Linux, which remains the biggest risk in the plan and is why the terminal sits behind ITerminalHost. Also records two things this milestone deliberately left undone -- no rate limiting on the enrollment and sync write paths until M2, and /me not touching last_seen_at_utc -- so neither reads later as an oversight. |