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DodoSSH/README.md
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jaap-jan a628762cd1 Add /me and enrollment with the identity-provider key binding (M1)
The last backend piece of M1. A client can now log in, discover it must
enroll, publish its identity key, and get a usable personal vault.

Enrollment is one indivisible act. One transaction writes the key, its
wraps, the device, the key log entry, the vault and the vault key grant,
because none of them is useful alone: a key with no vault leaves a user
unable to store anything, and a vault with no grant is a container nobody
can ever open -- including its owner, since only the client can wrap the
key and it has already moved on.

Two independent checks run, and neither substitutes for the other. The
Ed25519 self-signature proves possession of the private key. The
identity-provider binding proves whose key it is: the client hashed its
statement, used the hash as an OIDC nonce, and the resulting ID token is
the provider's signature over exactly those public keys. This server
cannot mint that signature, so it cannot invent a key for a user who never
enrolled -- which is the attack that would otherwise let an operator read
every vault by publishing its own key as yours.

The binding token is stored verbatim, not just summarised. Clients must
repeat the check against the provider's JWKS fetched directly, and storing
only our conclusion would ask them to trust the server about the one
question the design exists to avoid trusting it about.

Key log appends take a deployment-wide advisory lock. The falsification
matters more than the passing test: with the lock removed,
Enroll_ConcurrentEnrollmentsByDifferentUsers_LeaveAnUnbrokenChain fails
with entry 11 linked to the wrong predecessor. Different users trip no
unique index, so without serialising they all read the same head and the
chain forks -- indistinguishable from the key substitution the log exists
to make detectable, and permanent, because the log is append-only.

Enrollment is idempotent. Vault ids and keys are client-chosen, so a
client whose response was lost re-sends the identical body and gets the
identical result. Without that, a lost response leaves a user enrolled
against a vault they never learned the id of.

Contract change, breaking the v0.1 freeze deliberately. EnrollmentRequest
had DevicePublicKey but no wrap to go with it, which is unsatisfiable:
only the holder of the secret bundle can seal it, so the server could
never fill the gap. Added DeviceWrappedPrivateKey, and PersonalVault so
enrollment can be atomic rather than leaving an unopenable vault behind
two endpoints that do not exist yet. No client exists and no package is
published, which is exactly when PublicAPI.Unshipped.txt expects this.

Sync now requires the Enrolled policy, which until now was a stub whose
name promised a check it never made. The sync denial tests use enrolled
intruders instead of unenrolled ones -- an unenrolled caller is stopped
before the vault check runs, which would have left those tests passing
without exercising the thing they exist to prove.

Also fixed: omitting kdfParameters from the JSON body was a 500. A
record's non-nullable parameters are a compile-time promise, not a runtime
one.

268 tests pass, zero warnings on a clean rebuild, format clean.
2026-07-28 16:06:35 +02:00

99 lines
3.9 KiB
Markdown

# 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, key wrapping
DodoSSH.Domain entities and invariants, no EF
DodoSSH.Infrastructure DbContext, configurations, migrations
DodoSSH.Api the host
tests/ one test project per source project
docs/adr/ architecture decision records
```
## Building
Requires the .NET SDK pinned in [`global.json`](global.json) (10.0.x).
```bash
dotnet build DodoSSH.slnx
```
```bash
dotnet test DodoSSH.slnx
```
Run the API locally:
```bash
dotnet run --project src/DodoSSH.Api
```
It listens on `http://localhost:5233`, serving `/healthz/live`, `/healthz/ready` and — in
Development — `/openapi/v1.json`.
### 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.
*Backend done:* the DSH1 crypto core, the data model, sync push/pull for hosts, `/me`, and
enrollment with the identity-provider key binding. *Remaining:* the desktop client, and the two
spikes that gate it — the Linux WebView and SSH.NET's `window-change`. Both need a Linux and a
macOS machine, so neither has run yet.
- **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
Not yet chosen.