Public Access
jaap-jan
b15af836a3
docs/crypto.md is now the normative, frozen specification. This had to land before anything else in M1: the server holds ciphertext and no keys, so it can never re-encrypt, and a format change after users hold data is a coordinated client rewrite with no rollback. Specification: - DSH1 envelope layout, canonical 64-byte AAD encoding, SealTo construction, key hierarchy, Argon2id profiles, fingerprints, and the change rules for each version field. - AAD encoding is fixed-width binary rather than delimited string concatenation, so no field value can forge a field boundary. This supersedes the illustrative form sketched in ADR 0001, which now points here. - UUIDs are RFC 4122 big-endian. Guid.ToByteArray() emits the first three groups little-endian and would have made our ciphertext unreadable by any other implementation of this spec, failing only at a cross-implementation boundary. Verified rather than assumed: - PrimitiveAvailabilityTests proves X25519, Ed25519, XChaCha20-Poly1305, Argon2id and HKDF-SHA512 all function on net10.0. NSec 26.4.0 targets net9.0 and is consumed by forward compatibility; this closes one of the two package questions the plan flagged. - Argon2Profile exists because NSec's MemorySize is in KIBIBYTES, not bytes. Passing bytes gives either a 256 GiB allocation or a 256 KiB KDF that cracks instantly. The type takes mebibytes so the unit cannot be got wrong at a call site. Found by benchmarking: the first measurements were ~1000x too slow, which turned out to be 19 GiB of work. - Parameters measured, not guessed: 256 MiB/t=4 is 323 ms on this machine; the table of candidates is in the spec. Implementation and tests (83 total, up from 17): - AadDescriptor, DshEnvelope, DshCrypto (Seal/Open/SealTo/OpenSealed/fingerprints). - Decryption returns null rather than throwing: ciphertext comes from a server that is explicitly not trusted, so a failed tag is an expected outcome. - Envelope readers reject unknown algorithms and any non-zero flag bit, so an envelope that is not fully understood fails closed. - Executable form of the spec's substitution claims: a server cannot move ciphertext between resources, roll back a key generation or item version, repurpose a payload as metadata, or confuse the two constructions. - Golden vectors in tests/fixtures/crypto/vectors.json guard the format. Mutation-checked: a one-byte schema version change trips four tests including the guard. Two build-infrastructure bugs found and fixed along the way: - .editorconfig forced camelCase on const and static readonly fields. PascalCase is the .NET convention for both; the config was wrong, not the code. - The golden fixture was resolved with [CallerFilePath], which ContinuousIntegrationBuild rewrites to /_/... under deterministic source paths. It passed locally and would have failed only in CI. Now copied to the output directory and read from there.
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. Gated on
freezing
DodoSSH.Contractsand the crypto AAD, plus two client spikes (Linux WebView, SSH.NET window-change). - 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.