Files
DodoSSH/README.md
T
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

6.2 KiB

DodoSSH

A self-hosted, team-oriented SSH client with an end-to-end encrypted vault.

Manage hosts, credentials and keys in a desktop app; sync them across your devices and share them with teammates through a server you run yourself. The server stores ciphertext and never holds a key — the operator cannot read the credentials it stores.

Status: early development. See the milestone plan for what exists today.

Why

Teams either scatter SSH credentials across individual ~/.ssh directories with no sharing story, or pay per-seat for a hosted product that holds their infrastructure credentials. DodoSSH keeps the convenience of a synced, shareable vault while remaining self-hostable and zero-knowledge.

Architecture

Component Choice
Backend ASP.NET Core on .NET 10, PostgreSQL + EF Core
Client Avalonia (C#) for Windows/Linux/macOS; terminal pane is a WebView running xterm.js
Auth OIDC, provider-agnostic (Entra ID, Keycloak, Auth0, Authentik)
Vault End-to-end encrypted; X25519 + Ed25519 + XChaCha20-Poly1305, Argon2id unlock
Connections Client-direct SSH by default, with an optional raw-TCP server relay

Two consequences worth knowing before you read further:

  • Revocation is not retroactive. A removed member keeps what they already downloaded. The real remediation is rotating the SSH credential, so offboarding is built around a rotation checklist rather than a button that implies more than it delivers.
  • No session recording in relay mode. The relay forwards SSH ciphertext, so it cannot see commands. That is the cost of the relay not being able to read your traffic.

The reasoning behind each major decision is recorded in docs/adr/, starting with the E2EE trust model.

Repository layout

src/
  DodoSSH.Contracts        DTOs shared with the client — the real API contract
  DodoSSH.Crypto           DSH1 envelope, AAD derivation, the key hierarchy
  DodoSSH.Domain           entities and invariants, no EF
  DodoSSH.Infrastructure   DbContext, configurations, migrations
  DodoSSH.Api              the server
  DodoSSH.Client.Auth      OIDC code+PKCE on a loopback redirect, and the key binding
  DodoSSH.Client.Api       the typed server client, and client-side enrollment
  DodoSSH.Client.Domain    the decrypted item model and the three-way merge — no I/O at all
  DodoSSH.Client.Storage   the local cache: ciphertext mirror, outbox, offline unlock material
  DodoSSH.Client.Sync      the pull/apply/push loop and the conflict policy
  DodoSSH.Client.Session   where a profile lives, unlocking it, and getting one in the first place
  DodoSSH.Client.Ssh       connections, PTY shells, host key trust
  DodoSSH.Client.Terminal  the loopback data plane and credit-based flow control
  DodoSSH.Client.App       Avalonia; the only project that knows about a UI toolkit
tests/                     one test project per source project
docs/adr/                  architecture decision records

Everything under src/DodoSSH.Client.* except App is deliberately free of Avalonia. That is the seam that lets the SSH layer, the terminal's flow control and the OIDC flow be tested without a UI toolkit or a browser engine — which is most of why they are testable at all.

Building

Requires the .NET SDK pinned in global.json (10.0.x).

dotnet build DodoSSH.slnx
dotnet test DodoSSH.slnx

Run the API locally:

dotnet run --project src/DodoSSH.Api

It listens on http://localhost:5233, serving /healthz/live, /healthz/ready and — in Development — /openapi/v1.json.

Development and testing are currently Windows-only. Anything known or suspected to differ on Linux and macOS is tracked in docs/platform-flags.md, along with the deployment gotchas that have already cost time once. Read it before assuming something works off-Windows.

Conventions the build enforces

  • Warnings are errors. dotnet format --verify-no-changes gates CI.
  • Package versions are centralised in Directory.Packages.props; packages.lock.json is committed and CI restores in locked mode.
  • BannedSymbols.txt bans DateTime.UtcNow (use TimeProvider), Guid.NewGuid (use CreateVersion7), sync-over-async, MD5/SHA1 and PBKDF2.
  • Public members of DodoSSH.Contracts must be declared in PublicAPI.Unshipped.txt, so a contract change is a build error rather than a client-side surprise.

Milestones

  • M0 — foundation. Repo structure, build conventions, CI, ADRs. Done.

  • M1 — vertical slice. OIDC login → enroll → create a host → open a shell. Server done: the DSH1 crypto core, the data model, sync push/pull for hosts, /me, and enrollment with the identity-provider key binding. Client done: the key hierarchy, the OIDC flow with the key binding, SSH connections with host key trust, the terminal data plane, the encrypted local cache with the sync client — offline unlock, an outbox and a field-level three-way merge, conflict matrix green — and an Avalonia shell that is vault-backed: server URL → browser sign-in → enroll → unlock → host list → terminal. The shell's whole path is covered by tests against an in-memory server, so the states that matter most (the recovery code that cannot be skipped, the unlock that needs no network) are checked rather than remembered. Remaining: the manual end-to-end run against the real API and a real Keycloak from deploy/docker-compose.dev.yml, which is what M1's definition of done actually asks for.

    Known gaps in the client, stated rather than implied by the interface: credentials are not a synced entity type yet, so a connection still asks for a password; known host keys live in memory for one session instead of in the vault; and no device key is registered, so the passphrase is needed on every launch until the OS keystore is wired.

  • M2 — full personal vault, robust sync, relay.

  • M3 — teams, sharing, ACLs.

  • M4 — hardening and ops, packaging, self-hosting guide.

  • M5 — multi-provider OIDC, key rotation, per-item content keys.

Licence

MIT.