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.
3.9 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, 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 (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.
Conventions the build enforces
- Warnings are errors.
dotnet format --verify-no-changesgates CI. - Package versions are centralised in
Directory.Packages.props;packages.lock.jsonis committed and CI restores in locked mode. BannedSymbols.txtbansDateTime.UtcNow(useTimeProvider),Guid.NewGuid(useCreateVersion7), sync-over-async, MD5/SHA1 and PBKDF2.- Public members of
DodoSSH.Contractsmust be declared inPublicAPI.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'swindow-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.