DodoSSH/README.md

# 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](#milestones) 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/`](docs/adr/), starting with
[the E2EE trust model](docs/adr/0001-e2ee-trust-model.md).

## 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`](global.json) (10.0.x).

```bash
dotnet build DodoSSH.slnx
```

```bash
dotnet test DodoSSH.slnx
```

The tests need a Docker daemon. Everything that touches the database, the identity provider or an SSH
server uses Testcontainers rather than a stub or a shared instance, so there is nothing to start first and
nothing to clean up after — but with no daemon those suites fail rather than skip.

## Running it

Four commands, in order. The first two are once per machine.

**1. The development dependencies** — PostgreSQL and Keycloak, with the `dodossh` realm imported:

```bash
docker compose -f deploy/docker-compose.dev.yml up -d
```

**2. The schema.** The API never migrates anything: it fails readiness while a migration is pending, and
says which one. `dotnet-ef` is pinned in `.config/dotnet-tools.json`, so run `dotnet tool restore` first if
you have not:

```bash
dotnet ef database update --project src/DodoSSH.Infrastructure
```

With nothing else configured this targets the compose stack above. Set `DODOSSH_DESIGN_CONNECTION` to point
it at another database.

**3. The server:**

```bash
dotnet run --project src/DodoSSH.Api
```

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

**4. The desktop client:**

```bash
dotnet run --project src/DodoSSH.Client.App
```

In the app, enter `http://localhost:5233` as the server. Your browser opens for sign-in — the realm ships
`alice` / `alice` — then choose a vault passphrase and **write down the recovery code**, which cannot be
skipped and cannot be recovered from the server. You can then add a host and open a shell on it. Keycloak's
admin console is at `http://localhost:18080` (`admin` / `admin`).

Three of M1's known gaps are visible immediately, so they are worth expecting rather than diagnosing: a
connection asks for the host's password every time, because credentials are not a synced entity type yet;
host key trust lasts one session, because known hosts do not live in the vault yet; and unlock asks for the
passphrase on every launch, because no device key is registered.

### End-to-end verification

One suite runs against a real server rather than a stub. It needs a Docker daemon and nothing else, so it
is part of the ordinary test run:

```bash
dotnet test tests/DodoSSH.SystemTests
```

It brings up PostgreSQL, Keycloak and an OpenSSH server in containers, applies the committed migrations,
starts the API as a child process out of its own build output, and then drives the real client: sign in
through Keycloak, enroll, unlock, create a host, sync it, read it back on a second simulated machine,
unlock again with no network, and open a shell on the `sshd`. Roughly 25 seconds once the images are
pulled.

What makes it worth its weight is that it consumes the artefacts that ship — the realm file from
`deploy/keycloak`, the EF migrations, the API's own `appsettings` — rather than a fixture written to match
them. On its first run it found a loopback redirect URI the realm registered in a form Keycloak rejects,
and a JSON configuration gap that made the whole sync surface unreachable from the real client while every
other test passed. Both are the same class of bug: two sides of a stub agreeing with each other about
something the specification never said.

The one value it cannot take from a committed file is `Oidc:Authority`, since the container's port is
assigned at start. Everything that authority points at is still the real realm.

Development and testing are currently **Windows-only**. Anything known or suspected to differ on
Linux and macOS is tracked in [`docs/platform-flags.md`](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`](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 *state
  machine* 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.

  Its *layout* is not covered by anything, and that gap has already cost a shipped defect: the setup and
  unlock screens were layered over the terminal's WebView, which on Windows is a native child window that
  cannot be covered, so they rendered sliced with their buttons unclickable. No test in this repository
  loads a `.axaml` file, and a headless one could not have caught this — there is no native window in
  headless, so it would have rendered perfectly and confirmed the wrong belief. Screens get looked at, or
  they are unverified.
  *Verified end to end:* `tests/DodoSSH.SystemTests` drives the whole slice against a real Keycloak, a
  real API, a real PostgreSQL and a real `sshd` — sign-in, the identity-provider key binding, enrollment,
  offline unlock, a host through the vault to a second machine, and an interactive shell. See
  [End-to-end verification](#end-to-end-verification).

  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](LICENSE).