Commit Graph
7 Commits
Author SHA1 Message Date
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
jaap-jan 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.
2026-07-28 21:13:35 +02:00
jaap-jan 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.
2026-07-28 16:52:09 +02:00
jaap-jan 98d29bff37 Add HTTP integration harness and the sync authorization matrix (M1)
ci / build and test (ubuntu) (push) Has been cancelled
ci / build (windows) (push) Has been cancelled
27 end-to-end tests over the real HTTP pipeline, against a PostgreSQL container and a
stubbed identity provider. This closes the gap the previous commit flagged.

Authentication is genuinely exercised, not bypassed. StubIdentityProvider serves real OIDC
discovery and JWKS via WireMock and signs tokens with a real RSA key, so the application's
own JwtBearer pipeline validates issuer, audience, signature, lifetime and claims. A
TestAuthHandler that short-circuits authentication would hide exactly the claim-mapping
mistakes that cause real authorization holes. Proven by rejecting: no token, a foreign
signing key, the wrong audience, the wrong issuer, and an expired token.

Authorization denials — the tests that matter most:
- Another user's vault is 404, not 403, for both pull and push. A distinct
  "exists but forbidden" answer is an existence oracle for other tenants' vault ids.
- A denied push writes nothing: no host row and no change-log entry. A denial that still
  mutated state would be worse than no check at all.
- A team vault is denied until M3 rather than falling through to a permissive default.

Behaviour covered: push/pull round trip, cursor advance (and that an empty pull does not
rewind the cursor, which would replay history), tampered cursor rejection, stale-version
conflict returning server state without overwriting, operation-id replay reported Duplicate
and applied once, a mixed batch applying the good and reporting the bad, relay field
enforcement both ways, delete clearing the relay address, tombstones carrying no payload,
and JIT provisioning happening exactly once.

Two configuration problems found by running it:
- appsettings.json carried empty-string placeholders for the connection string and OIDC
  authority. Under minimal hosting those beat anything a test registers via
  ConfigureAppConfiguration, because Program.cs adds its own sources after that callback
  runs. Removed them outright — an empty placeholder turns "not configured" into
  "configured as empty", which defeats failing fast. Tests now use DODOSSH_ environment
  variables, which Program.cs adds last.
- My first fix for minting an expired test token derived notBefore from the expiry, which
  put nbf fourteen minutes in the future for normal tokens and made every valid token 401.
  It needs the earlier of now-1min and exp-1min.

Verified: 0 warnings on a clean rebuild, 173 tests pass (up from 146), format clean.
2026-07-28 15:11:43 +02:00
jaap-jan eaf68c86b0 Add data model, DbContext and initial migration (M1)
Schema for identity, vaults, grants, hosts and the sync change log, verified against a
real PostgreSQL 18 container rather than an in-memory provider: partial unique indexes,
CHECK constraints, citext and identity-always columns are all provider behaviour that an
in-memory fake would not exercise.

Invariants pushed into the database, so they hold even when application code has a bug:
- ck_host_relay_target is a security boundary, not tidiness. A host may carry a plaintext
  hostname and port ONLY when relay is deliberately enabled. Both directions are tested;
  the important one is that relay-disabled hosts cannot carry an address, since otherwise
  a bug would silently give the server infrastructure visibility it was never granted.
- ck_vault_owner: exactly one of owner_user_id or team_id, or permission resolution would
  have no defined answer.
- ck_vault_key_grant_recipient: member grants name a user; recovery and escrow grants are
  wrapped to a key and must not.
- ck_user_key_wrap_kdf: a password-derived wrap without its parameters is permanently
  unopenable, so a partial write is rejected outright.

Present from the first migration on purpose:
- GrantKind (Member/Recovery/Escrow). Recovery cannot be bolted on later — every vault
  created before it existed would be unrecoverable by design.
- team and team_membership, though team features are M3. Adding them later would mean
  introducing a foreign key on a live vault table.
- Host.ContentKeyId, reserved for per-item content keys wrapped to individual users.
- user_key as its own table, so key rotation does not require altering the user row.

Two things verified rather than assumed:
- Npgsql's UseXminAsConcurrencyToken helper no longer exists in EF 10, so xmin is mapped
  directly in XminConcurrency. The generated migration *looks* like it creates an xmin
  column; it does not. Confirmed by inspecting pg_attribute (attnum -2, a system column)
  and by grepping the emitted DDL. A test pins both, because had it created a real column
  PostgreSQL would have rejected the name.
- EF Core is now pinned centrally. The Npgsql provider asks for 10.0.4 while
  EntityFrameworkCore.Design pulls 10.0.10, and because Design is PrivateAssets=all that
  higher version does not flow to referencing projects — producing a CS1705 in any test
  project referencing Infrastructure.

Also commits artifacts/schema/v0.1.sql, the idempotent script, as the baseline for future
upgrade tests.

Verified: 0 warnings, 122 tests pass (27 new against Postgres), format clean.
2026-07-28 14:17:37 +02:00
jaap-jan 3a81f3c90b Restructure into src/tests and add build foundation (M0)
Moves the scaffold to src/DodoSSH.Api and establishes the repo conventions the rest
of the milestones build on.

Structure:
- src/{Contracts,Crypto,Domain,Infrastructure,Api}, tests/{Contracts,Crypto,Domain}.Tests
- DodoSSH.slnx rewritten with src/ and tests/ solution folders

Build:
- Directory.Build.props centralises TFM, nullable, deterministic builds and
  TreatWarningsAsErrors; Directory.Packages.props pins every version centrally
- packages.lock.json committed so CI restores in locked mode
- NuGet.config clears machine-level sources, which both fixes NU1507 under central
  package management and makes restore reproducible off this machine
- Microsoft.OpenApi pinned to 2.11.0: ASP.NET Core 10.0.10 resolves 2.0.0, which is
  covered by GHSA-v5pm-xwqc-g5wc (high, patched in 2.7.5)

Analyzers:
- AnalysisLevel is Recommended, not All. With warnings-as-errors, All turns opinionated
  naming rules into build breaks and trains people to blanket-suppress.
- BannedSymbols.txt bans DateTime.UtcNow (TimeProvider), Guid.NewGuid (CreateVersion7),
  sync-over-async, MD5/SHA1, PBKDF2 and SecureString
- CA1711/CA1724 disabled: both are .NET Framework CAS-era naming rules
- PublicApiAnalyzers on Contracts only, since that assembly is the client's real contract

API:
- weather-forecast template removed
- UseHttpsRedirection removed; TLS terminates at the reverse proxy and redirecting
  behind one causes loops
- /healthz/{live,ready,startup}. Liveness deliberately checks no dependencies so a
  transient database outage cannot restart the container and kill live SSH sessions.

Notes:
- No coverage collector yet. Microsoft.Testing.Extensions.CodeCoverage pulls an MTP 1.x
  MSBuild extension that throws TypeLoadException against the MTP 2.3.x xunit.v3 brings.
  Coverage gates are an M3 concern; revisit with an MTP 2.x-aligned version then.

Verified: dotnet build (0 warnings), 17 tests pass, format check clean, API serves
health and OpenAPI endpoints.
2026-07-28 12:25:34 +02:00
jaap-jan 1138291d79 Add pristine dotnet new webapi scaffold
Baseline commit of the untouched template so the M0 restructure lands as a
reviewable diff rather than appearing as the initial state.

Includes .gitignore and .gitattributes only; no source changes.
2026-07-28 12:09:24 +02:00