Files
wraith/docs/architecture/open-questions.md
glm-5.1 41062d810e docs: add configuration architecture research
Explore static/dynamic config split, hot-reloadable auth via ArcSwap,
forwarding policy, multi-transport listeners, and config file format.
Documents three problems: no auth hot-reload, no forwarding access control,
no structured config beyond CLI flags.

Key findings:
- Static config (transport, TLS, host key) loaded once at startup
- Dynamic config (auth, forwarding, rate limits) reloadable via ArcSwap
- ForwardingPolicy with rule-based allow/deny, first-match evaluation
- Multi-transport: Server spawns Vec<ListenerConfig> sharing auth config
- WebTransport out of scope for now (requires separate auth model)
- Proposes ADR-020 (static/dynamic split), ADR-021 (forwarding policy),
  ADR-022 (multi-transport listeners)

Adds OQ-12 through OQ-17 to open-questions.md.
2026-06-04 09:40:58 +00:00

137 lines
8.1 KiB
Markdown

---
status: reviewed
last_updated: 2026-06-02
---
# Open Questions
## Transport
### OQ-01: TLS certificate management strategy
- **Origin**: [server.md](server.md)
- **Status**: ~~resolved~~
- **Priority**: ~~medium~~
- **Resolution**: ADR-008 — Support both domain-based and IP-based ACME/Let's Encrypt auto-provisioning, plus manual certs. Domain-based uses standard certbot-style flow with HTTP-01/TLS-ALPN-01 challenges. IP-based uses short-lived certs via TLS-ALPN-01 on port 443. Manual certs via `--tls-cert`/`--tls-key` always supported. Implementation uses `rustls-acme` or similar pure-Rust ACME client.
- **Cross-references**: [ADR-008](decisions/008-acme-lets-encrypt.md), Server spec, TlsTransport implementation
### OQ-02: iroh relay configuration defaults
- **Origin**: [transport.md](transport.md)
- **Status**: ~~resolved~~
- **Priority**: ~~low~~
- **Resolution**: ADR-009 — Default to n0's free relay servers. Allow override via `--iroh-relay <url>`. Document self-hosted relay setup. This matches iroh's own defaults and minimizes friction for testing/development.
- **Cross-references**: [ADR-009](decisions/009-default-iroh-relay.md), Transport spec
### OQ-05: Transport chaining support in CLI
- **Origin**: [transport.md](transport.md)
- **Status**: ~~resolved~~
- **Priority**: ~~low~~
- **Resolution**: ADR-010 — Support `--transport iroh --proxy socks5://...` natively in the CLI. iroh's endpoint builder accepts proxy configuration directly, so the implementation is minimal. Other transport combinations (TCP+TLS) are already implicit.
- **Cross-references**: [ADR-010](decisions/010-transport-chaining-cli.md), Transport spec
## Client
### OQ-06: SSH config file parsing
- **Origin**: [client.md](client.md)
- **Status**: ~~resolved~~
- **Priority**: ~~low~~
- **Resolution**: ADR-011 — No `~/.ssh/config` parsing, no custom config file. Configuration is programmatic-first: CLI flags, library API structs (`ConnectOptions`, `ServeOptions`), and environment variables. Cross-platform path issues (`~` expansion) are avoided. The library API is the primary interface; if config files are needed later, they can be a separate layer.
- **Cross-references**: [ADR-011](decisions/011-no-ssh-config-programmatic-api.md), Client spec
## Server
### OQ-07: ACME/Let's Encrypt support
- **Origin**: [server.md](server.md)
- **Status**: ~~resolved~~
- **Priority**: ~~medium~~
- **Resolution**: ADR-008 — Same resolution as OQ-01. Both domain-based (standard, domain-bound, auto-renewing) and IP-based (short-lived, no domain required) ACME flows are supported. The domain-based path requires port 80 or DNS access for challenges. The IP-based path uses TLS-ALPN-01 on port 443 and requires the ACME client to run continuously.
- **Cross-references**: [ADR-008](decisions/008-acme-lets-encrypt.md), Server spec, TlsTransport
### OQ-08: Connection limits and rate limiting
- **Origin**: [server.md](server.md)
- **Status**: ~~resolved~~
- **Priority**: ~~low~~
- **Resolution**: ADR-013 — Two-layer approach: (1) Structured logging of auth attempts and connections at INFO level for fail2ban integration on Linux — matches our production fail2ban setup with nftables and systemd journal. (2) Built-in rate limiting: `--max-connections-per-ip` and `--max-auth-attempts` flags providing platform-independent abuse protection.
- **Cross-references**: [ADR-013](decisions/013-fail2ban-friendly-logging.md), Server spec, Production fail2ban docs
### OQ-04: Authentication beyond Ed25519 keys
- **Origin**: [client.md](client.md), [server.md](server.md)
- **Status**: ~~resolved~~
- **Priority**: ~~low~~
- **Resolution**: ADR-012 — Ed25519 public key (default, unchanged) + OpenSSH certificate authority support (new, important for multi-user). No password authentication over SSH channels. If a local SOCKS5 proxy needs its own auth, that's a separate concern. Cert-authority makes multi-user management practical: one CA entry in `authorized_keys` instead of N individual keys. Certificates support expiry and restrictions.
- **Cross-references**: [ADR-012](decisions/012-auth-ed25519-and-cert-authority.md), Client spec, Server spec
## TUN
### OQ-03: Windows TUN support scope
- **Origin**: [tun-shim.md](tun-shim.md)
- **Status**: ~~resolved~~
- **Priority**: ~~low~~
- **Resolution**: ADR-014 — TUN is deferred entirely from the wraith project. For VPN-like behavior, users run `tun2proxy --proxy socks5://127.0.0.1:1080` alongside wraith. This eliminates all TUN-related scope questions (Windows, TCP reconstruction, etc.).
- **Cross-references**: [ADR-014](decisions/014-defer-tun-recommend-socks5-proxy.md)
### OQ-09: TCP reconstruction approach for TUN
- **Origin**: [tun-shim.md](tun-shim.md)
- **Status**: ~~resolved~~
- **Priority**: ~~medium~~
- **Resolution**: ADR-014 — TUN is deferred from wraith. tun2proxy (external tool) handles this if users need VPN-like behavior.
- **Cross-references**: [ADR-014](decisions/014-defer-tun-recommend-socks5-proxy.md)
## NAPI / PubSub
### OQ-10: NAPI wrapper API surface
- **Origin**: [napi-and-pubsub.md](napi-and-pubsub.md)
- **Status**: ~~resolved~~
- **Priority**: ~~medium~~
- **Resolution**: ADR-016 — Expose both `connect()` and `serve()` from the start. Both are fundamental operations needed by the pubsub event target system (spokes use `connect()`, hubs could use `serve()`). The NAPI layer is transport-agnostic — it doesn't know about pubsub's `EventEnvelope`. The pubsub adapter wraps the `Duplex` stream. This ensures the NAPI wrapper is reusable for any stream-based protocol, not tied specifically to pubsub.
- **Cross-references**: [ADR-016](decisions/016-napi-expose-connect-and-serve.md), napi-and-pubsub.md
### OQ-11: napi-rs vs uniffi for FFI bridge
- **Origin**: [napi-and-pubsub.md](napi-and-pubsub.md)
- **Status**: ~~resolved~~
- **Priority**: ~~low~~
- **Resolution**: ADR-015 — Use napi-rs. It's the standard for Node.js native addons, matches our primary consumer (TypeScript/Node.js), and has the best ecosystem and documentation. If future Python or mobile consumers are needed, a separate uniffi layer can be added — the Rust core doesn't change.
- **Cross-references**: [ADR-015](decisions/015-napi-rs-for-ffi-bridge.md), napi-and-pubsub.md
## Configuration
### OQ-12: Per-user forwarding scope vs global rules
- **Origin**: [research/configuration.md](../research/configuration.md)
- **Status**: open
- **Priority**: medium
- **Resolution**: (pending)
- **Cross-references**: ADR-020 (proposed)
### OQ-13: Config file auto-reload via file watching
- **Origin**: [research/configuration.md](../research/configuration.md)
- **Status**: resolved
- **Priority**: low
- **Resolution**: No file watching. CLI loads once at startup; NAPI/hub reload explicitly. File watching is a potential attack vector and unnecessary complexity for a security tool.
- **Cross-references**: ADR-020 (proposed)
### OQ-14: ArcSwap vs RwLock for dynamic config
- **Origin**: [research/configuration.md](../research/configuration.md)
- **Status**: resolved
- **Priority**: low
- **Resolution**: ArcSwap. Lock-free reads on the hot path (every auth check, every channel open). `RwLock` adds contention. `arc-swap` is small (~500 lines) and well-maintained.
- **Cross-references**: ADR-020 (proposed)
### OQ-15: TLS + WebTransport + iroh QUIC listener coexistence
- **Origin**: [research/configuration.md](../research/configuration.md)
- **Status**: open
- **Priority**: medium
- **Resolution**: (pending — needs R&D in WebTransport transport session)
- **Cross-references**: ADR-022 (proposed)
### OQ-16: Transport-specific forwarding policy (e.g., WebTransport clients restricted to wraith-* channels)
- **Origin**: [research/configuration.md](../research/configuration.md)
- **Status**: open
- **Priority**: low
- **Resolution**: (pending — defer to forwarding policy design)
- **Cross-references**: ADR-021 (proposed)
### OQ-17: Transport-aware auth layer (SSH keys vs API keys for non-SSH transports)
- **Origin**: [research/configuration.md](../research/configuration.md)
- **Status**: open
- **Priority**: medium
- **Resolution**: (pending — defer until non-SSH transport is implemented)
- **Cross-references**: ADR-020 (proposed), OQ-15