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Depend on published smartthings-local package, rewrite README

Browse Source 
Now that mbillow/localthings#8's protocol fixes are merged upstream and
smartthings-local 0.1.0 is on PyPI, drop the vendored ocf/coap_dtls.py +
ocf/observe_refresh.py transport (dead code, never instantiated) and the
duplicated ocf_root_ca.pem in favor of the real package. manifest.json and
requirements-dev.txt now pin smartthings-local>=0.1.0 instead of the
unmerged git branch.

README rewritten from scratch — it still described the old standalone
MQTT-bridge (samsung_appliance/, main.py, docker-compose bridge) that this
repo moved off of; it now documents the real architecture: a native HA
custom component with config-flow-driven cert minting and a per-device-type
capability registry, with the protocol layer split out to smartthings-local.
This commit is contained in:
Marc Billow
2026-07-07 22:08:02 -05:00
parent db2148467b
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# SmartThings-Local
# Local Things
**Local-first Home Assistant integration for newer-generation Samsung connected appliances.** One process supervises multiple appliances (dryer + oven currently), each over its own CoAP-DTLS session, publishing state + writes through MQTT with HA auto-discovery — no SmartThings cloud round-trip for any of it.
**A native Home Assistant custom integration for local control of newer-generation Samsung connected appliances.** No cloud round-trip, no MQTT broker, no separate bridge process — add a device through HA's normal *Settings → Devices & Services* flow and it talks CoAP-over-DTLS straight to the appliance on your LAN.
<img width="778" height="367" alt="image" src="https://github.com/user-attachments/assets/cc1dca15-f272-4625-a13c-2dc82283ff95" />
> ### Proof of concept — collaborators wanted
> ### Where things live
>
> This is working code running in my home and I rely on it daily, but it's a **proof of concept**, not a polished product. No unit tests; one person's hardware as the validation set (one dryer model, one oven model); hand-rolled MQTT-based integration instead of a proper HA custom component; "wired-but-untested" comments scattered through the oven descriptor; brittle to per-firmware quirks (the "oven doesn't push OBSERVE on options writes" finding is the kind of thing that needs ongoing care).
> This project split into two repos partway through development:
>
> **I would love for someone to take this further and build a proper HA integration out of it.** All the protocol research is done — DTLS auth via Samsung's published cloud identity, token-stable Block2 reads, OBSERVE-then-fetchback notifications, write semantics, the optimistic-publish-then-verify pattern, brick-avoiding resource boundaries — and the descriptor pattern is the seed of a clean per-appliance abstraction. The HA-side polish that's missing is custom-component shape: config flow, native entity classes, async-Python DTLS instead of MQTT round-trips, error surfacing into HA's notification system, support across more firmware versions, and someone who actually lives in the HA codebase.
> - **[`smartthings-local`](https://github.com/QuiteYellow/SmartThings-Local)** (PyPI package) — the reusable protocol layer: DTLS session handling, CoAP wire encoding, Block2 reads, bounded retry/retransmit, inter-request rate limiting, cert-chain validation. No HA dependency; usable from any Python project.
> - **This repo** — the Home Assistant integration built on top of it: config flow, a per-device-type capability registry, the polling coordinator, and all the HA entity classes.
>
> If you're that person, get in touch — happy to co-author, hand off, or hand over entirely.
> `custom_components/localthings/manifest.json` pulls in `smartthings-local` from PyPI like any other HA integration dependency.
### What you get
- **Multi-appliance, one container.** Single Docker service holds N DTLS sessions in parallel, one per appliance, sharing one MQTT client. Adding an appliance class is ~150 lines and one descriptor file.
- **Bounded state latency.** Hot-tier resources (job state, door, operational state) refresh on a sub-second cadence regardless of whether the appliance has internet. Worst-case lag is the tier interval (≤1s idle, ≤500ms during an active cycle on the dryer).
- **Writes that work**: dryer Start/Pause/Stop, course selection, wrinkle prevent; oven lamp (light entity), sound, fast preheat, setpoint slider, mode select, stop.
- **Optimistic publish + verify**: HA sees the new value the instant the device 2.04-confirms the write; the PollScheduler verifies on its next tier tick (after a 4s defer past Samsung's fetchback-revert window).
- **HA Energy Dashboard ready** (dryer): live watts + cumulative kWh as `total_increasing`.
- **Bridge logs tagged per-appliance** with `<class>.<serial>` once each device's serial is read on connect — `dryer.<serial>` vs `oven.<serial>` interleaved in the same log stream, easy to grep.
- **Zero HA YAML.** Every entity is auto-discovered via MQTT discovery.
- **Your state stays on your LAN.** Bridge → broker → HA. Samsung's cloud sees nothing from HA. *(The appliance still maintains its own TLS session to Samsung — appliance design, not ours.)*
- **Auto-detected device type.** Add a host + your CA credentials in the UI; the integration reads the appliance's `oneUiVersion` and picks the matching capability registry (dryer, oven, dishwasher, refrigerator) itself. No per-model descriptor to write for a new unit of a type that's already supported.
- **One-time credential setup, then it's just "add integration."** The first device you add asks for the AC14K_M CA cert + key (see Part 2). Every device after that reuses the same stored CA credentials — the config flow mints a fresh per-device leaf cert automatically and only asks for the host IP.
- **Standard HA entities**, not a hand-rolled dashboard: `sensor`, `binary_sensor`, `switch`, `number`, `select`, `button`, and `time` platforms, all backed by a single `DataUpdateCoordinator`-driven poller per device.
- **Capability registry, not a monolith.** Each appliance family's resources (power, kids lock, remote control, alarms, energy/water meters, cycle state, per-family settings) are declared once as `Capability` objects keyed on the stable OCF resource `href`, verified against live device dumps.
- **Stale-state resilience.** A failed poll doesn't blank out entities — the coordinator falls back to the last-known state rather than flapping devices to `unavailable`.
- **Your state stays on your LAN.** HA ↔ appliance is a direct DTLS session; Samsung's cloud sees nothing from this integration. *(The appliance still maintains its own connection to Samsung — that's appliance firmware behavior, not something this integration does or can prevent.)*
### Under the hood
### Supported appliance types
Each appliance runs an independent bridge built around three coordinated pieces over one persistent DTLS session: a `StateCache` (single source of truth for all reps), a `PollScheduler` (tiered adaptive polling — hot/warm/cold + a periodic `/device/0` sweep), and a `KeepaliveTask` (CoAP empty-CON ping for DTLS-layer liveness, with consecutive-failure detection for MQTT availability). Tier cadences are descriptor-declared and were calibrated against the empirically-measured per-firmware ceilings: dryer ~14 req/s, oven ~8 req/s. OBSERVE registrations (RFC 7641) are kept as an opportunistic freshness accelerator — when the appliance has internet and emits notifications, the cache absorbs them and the next-poll timer is reset for that resource; when it's air-gapped, polling alone carries the UX with no other code change. Token-stable Block2 (RFC 7959) handles multi-block reads. Writes are optimistically merged into the cache the moment the device 2.04-confirms, with the scheduler deferring that resource's next poll past the fetchback-revert window. Reconnect with exponential backoff on session errors.
| Type | Registry | Notable capabilities |
|---|---|---|
| Dryer | `by_type/dryer.py` | Power, kids lock, remote control, alarms, energy meter, operational state, door LED, sound mode, dryer settings/course, job-beginning status, diagnosis, firmware-update sensor |
| Oven | `by_type/oven.py` | Power, kids lock, remote control, alarms, cavity state, setpoint, mode, operational state, door, connectivity, firmware-update sensor |
| Dishwasher | `by_type/dishwasher.py` | Power, kids lock, remote control, alarms, energy + water meters, water filter, operational state, cycle options/settings, door LED, sound mode/volume, firmware-update sensor |
| Refrigerator | `by_type/refrigerator.py` | Power, kids lock, remote control, alarms, energy meter, water filter, status lock, door alert, icemaker (nighttime + generic per-compartment), flex zone, refrigeration mode, autofill, welcome/cabinet lighting, Sabbath mode, beverage zone, plus pattern-matched per-compartment temperature/setpoint/icemaker/door capabilities for multi-cavity fridges, firmware-update sensor |
Authentication uses a client cert keyed to the UUID published in Samsung's own wildcard cloud TLS cert. Every Samsung Tizen/RT-OCF appliance's factory ACL grants that UUID `perm=31` (full CRUDN) on `href=*`, so a single cert chain works across the whole fleet. Setup is one Python script.
Other Tizen RT / DAWIT-family appliances almost certainly speak the same protocol underneath (the auth path and CoAP primitives are shared across the fleet) — adding a new type is a new `by_type/<name>.py` registry file, not a protocol reverse-engineering project. See **Adding a new appliance type** below.
---
## Part 1 — Is your appliance compatible?
Check before anything else; if it's older firmware, this project doesn't target it.
```sh
# UDP scan for DTLS-CoAP ports
nmap -Pn -sU -p 49152-49160 "$APPLIANCE_IP"
```
Read the result:
- **`49154/udp` (or similar 4915x) open|filtered with a DTLS handshake responding** → newer firmware (Tizen RT 3.x with DAWIT 3.0). This is what the bridge talks to.
- **`49154/udp` or `49155/udp` open|filtered with a DTLS handshake responding** → newer firmware (Tizen RT 3.x, DAWIT 3.0+). This is what the integration talks to. The config flow probes both ports automatically — you don't need to know which one your device uses.
- **Only `8888/tcp` open (token-based HTTPS)** → older firmware (~2018–2022). **Not supported here.**
### Tested combinations
| Appliance class | Model family | Confirmed |
|---|---|---|
| Dryer | DV5000T (`DA_WM_TP2_20_COMMON`, `mnid=0AJT`) | All entities, ≤1s hot-tier poll (OBSERVE accelerates when online) |
| Oven | NV7000BS-class (`TP1X_DA-KS-OVEN-0107X`, `mnid=0AJT`) | All entities; hot-tier poll covers door + operational state regardless of cloud reachability |
Other appliances on the same firmware family (washers, dishwashers, AC units) almost certainly speak the same protocol — the auth path and read primitives are common. You'd write one new descriptor in `samsung_appliance/appliances/`.
---
## How the app keeps in sync with the appliance
## Part 2 — One-time: get the AC14K_M CA credentials
There are two parallel paths between the appliance and the app over the local CoAP-DTLS socket:
- **Push (OBSERVE).** When the appliance can reach Samsung's cloud, it emits a CoAP OBSERVE notification on the LAN socket within ~100ms of any state change — cycle start, door open, mode flip. The notification travels over the LAN; nothing about the push itself routes via Samsung. **But** the appliance's decision to emit it at all is gated inside its cloud-publish thread. Block the appliance from the internet and the LAN OBSERVE pushes stop, even though the LAN path itself is unaffected and the appliance still answers reads + accepts writes normally.
- **Polling.** The app always polls a small tier of hot resources (operational state, door, etc.) on a sub-second cadence, a warmer tier (mode, kidslock, alarms, …) every 15–30 s, and a full `/device/0` sweep every 5 minutes. This carries the UX regardless of whether OBSERVE is firing.
In normal operation both happen at once: an OBSERVE notification arrives first, the cache absorbs it, and the next-poll timer for that resource is reset. In an air-gapped LAN the app keeps working — only the worst-case freshness changes (from ~100 ms with push to ≤1 s on hot-tier resources via polling). Reads, writes, and HA entities behave identically.
Which path is doing the work is visible in Home Assistant. The bridge publishes per-appliance diagnostic entities including **Push Active** (on while OBSERVE is firing), **Last Update Source** (`observe` / `poll` / `sweep` / `optimistic`), **Last OBSERVE Age**, **Poll Max RTT**, **Slow Polls (window)**, **Poll Errors (window)**, and **Stalest Resource Age** — all under each device's Diagnostic section.
---
## Part 2 — Auth: get the identity cert
The bridge authenticates with a **client cert** signed by `AC14K_M`, an intermediate CA that has been public for years and remains in current firmware trust stores. The cert's Subject DN carries a UUID that the on-device ACL grants full access to.
You can read the UUID yourself out of the relevant server cert:
```sh
openssl s_client -connect <samsung-host>:443 -servername <samsung-host> \
-showcerts < /dev/null 2>/dev/null \
| openssl x509 -noout -subject
# subject=C=KR, O=Samsung Electronics, OU=uuid:<UUID>, CN=*.samsungiotcloud.com
```
The UUID lives in `OU=uuid:<UUID>`. The server cert is currently valid through **2035-04-09**.
This README doesn't pin the literal UUID — the setup script extracts it live each run, so it self-updates if upstream rotates.
### Why this works
- Every Samsung Tizen/RT-OCF appliance has a **factory-baked ACE** in `/oic/sec/acl` granting this UUID `perm=31` on `href=*`.
- TizenRT iotivity derives peerId from `memmem(subject_dn, "uuid:")` — RDN-agnostic. A cert with the UUID in CN authenticates the same as one with it in OU.
- We don't need the matching private key from the original keyholder — we mint our own key and have `AC14K_M` sign our leaf. Different key, same identity, same access.
### One-command setup
The integration authenticates with a client cert chained to `AC14K_M`, an intermediate CA that's been public for years and remains in current firmware trust stores. Every Samsung Tizen/RT-OCF appliance's factory ACL grants the identity in that chain full CRUDN access, so the same CA can mint a working cert for any appliance on your LAN — HA does the per-device minting itself once you give it the CA.
```sh
pip install -r requirements-bootstrap.txt
TARGET_IP=$APPLIANCE_IP python setup_cert.py --test
python setup_cert.py
```
What it does:
This fetches the AC14K_M CA cert + key + upstream chain from a public mirror and writes them to `./certs/ac14k_m.pem` and `./certs/ac14k_m.key`. Nothing device-specific happens at this step — no IP, no handshake needed. (Pass `--test` with `TARGET_IP=<appliance-ip>` set if you want to sanity-check connectivity against a real device before touching HA at all.)
1. Fetches the AC14K_M signing CA + private key + upstream chain (RemoteAccessCA → CECA → ROOTCA) from a public mirror.
2. Fetches the relevant server cert and extracts the current UUID from its subject DN.
3. Sanity-checks that the AC14K_M cert and key actually pair (modulus match) before signing anything.
4. Generates a fresh RSA-2048 key pair you own.
5. Builds a CSR with the UUID in OU + CN + SAN and signs it with `AC14K_M` (SHA-1, matching the on-device trust hierarchy).
6. Concatenates `leaf + AC14K_M + 3 upstream CAs` into the fullchain PEM.
7. With `--test`: opens a DTLS handshake against `$TARGET_IP:$TARGET_PORT` (default `49154`) and GETs `/oic/sec/acl` — a `2.05` reply proves the cert authenticated (anonymous peers get `4.01`).
If the live fetch fails, the script prints an inline workaround: supply `AC14K_M_CERT_BUNDLE=/path/to/cert.pem`, or point `BRAYSTORM_URL=<mirror>` at an alternate source.
Output in `./certs/`: `client_fullchain.pem` + `client.key`.
### Why this works
Neither the UUID nor the AC14K_M bundle is hardcoded in this repo — both are fetched live each run, so the script self-updates if upstream rotates. If either fetch fails, the script prints an inline workaround: supply the UUID via `UUID=<uuid>` env, or supply the AC14K_M bundle via `AC14K_M_CERT_BUNDLE=/path/to/cert.pem`. `BRAYSTORM_URL=<mirror>` points at a different bundle source.
### How durable is this?
Rotating the published UUID would require Samsung to re-issue TLS certs across their IoT cloud, push new ACLs to every device in the field, and update the on-device daemon identity — a multi-quarter change with a long backwards-compat tail. `AC14K_M` has been public for years and is still in 2026 firmware trust stores. Local access via this path is roughly as durable as cloud control of these appliances.
> **Legacy path:** earlier versions used a per-hub-UUID cert via an anonymous `/oic/sec/doxm` read escalation. That still works on the dryer-family firmware but isn't necessary — the cert minted here authenticates against every appliance and survives device resets. The old `bootstrap.py` for the legacy flow was removed when the package was renamed; see git history if you need it.
- Every Samsung Tizen/RT-OCF appliance has a factory-baked ACE in `/oic/sec/acl` granting the AC14K_M-chained identity `perm=31` on `href=*`.
- TizenRT iotivity derives the peer ID via `memmem(subject_dn, "uuid:")` — RDN-agnostic, so a cert with the UUID in any RDN authenticates the same way.
- You don't need the original keyholder's private key — the config flow mints its own key and has `AC14K_M` sign the leaf. Different key, same identity, same access.
---
## Part 3 — Configure your appliances
## Part 3 — Add the integration in Home Assistant
Copy `.env.example` to `.env` and fill in.
1. Copy `custom_components/localthings/` into your HA config's `custom_components/` directory (or install via a custom HACS repository — no `hacs.json` is checked in yet, so add this repo as a custom integration repository in HACS if you use it that way).
2. Restart HA.
3. **Settings → Devices & Services → Add Integration → Local Things.**
4. First device: paste the appliance's IP, plus the contents of `certs/ac14k_m.pem` and `certs/ac14k_m.key` from Part 2.
5. The flow fetches the current UUID from Samsung's cloud gateway, mints a leaf cert signed by your CA, probes ports `49154`/`49155`, and confirms the device answers `/device/0`. On success it creates the config entry and detects the device type automatically.
6. Every subsequent device only asks for the host IP — the stored CA credentials are reused to mint that device's leaf cert.
### Layered envs
The bridge config splits into:
- **Shared keys** (one per process): MQTT broker + creds, HA discovery prefix, cert paths, timer intervals.
- **Per-appliance keys** (one block per appliance) under `APPLIANCE_<n>_*` (1-indexed).
`APPLIANCE_COUNT` tells the bridge how many indexed blocks to read. Bump it as you add appliances.
```bash
APPLIANCE_COUNT=2
# Appliance 1 — dryer
APPLIANCE_1_CLASS=dryer
APPLIANCE_1_IP=192.168.1.100
APPLIANCE_1_OCF_PORT= # blank → descriptor default (49155 for dryer)
APPLIANCE_1_TOPIC=samsung_dryer
APPLIANCE_1_NAME=Samsung Dryer
# Appliance 2 — oven
APPLIANCE_2_CLASS=oven
APPLIANCE_2_IP=192.168.1.101
APPLIANCE_2_OCF_PORT= # blank → descriptor default (49154 for oven)
APPLIANCE_2_TOPIC=samsung_oven
APPLIANCE_2_NAME=Samsung Oven
```
Each `APPLIANCE_<n>_CLASS` must match a descriptor key in `samsung_appliance/appliances/__init__.py::DESCRIPTORS` — currently `dryer` and `oven`.
Entities appear under one HA device per appliance, named `Samsung Appliance (<ip>)` initially (rename freely — the config entry is keyed on the device's serial, not the name).
---
## Part 4 — Run it
## Development
### Docker (the real deployment)
### Docker Compose dev environment
```sh
docker compose up -d --build
docker compose up -d
docker compose logs -f
```
Container name `smartthings-local`. Outbound-only — no ports exposed. Needs egress to each appliance's IP/port (UDP) and to your MQTT broker. The certs in `./certs/` (or whatever `APPDATA_DIR` points to via the volume mount) are read-only mounted at `/config`.
Runs the official `home-assistant/home-assistant:stable` image with `network_mode: host` (required — DTLS is UDP and won't traverse Docker's bridge NAT to reach LAN appliances) and `custom_components/localthings/` bind-mounted read-only into `ha_config/custom_components/`. Bump `custom_components.localthings` to `debug` in `ha_config/configuration.yaml` for verbose protocol logging.
### Deploying to a remote Linux host (Unraid, etc.)
```sh
# Once: upload the cert + key onto the remote.
ssh "$SSH_HOST" mkdir -p "$APPDATA_DIR"
scp certs/client_fullchain.pem certs/client.key "$SSH_HOST:$APPDATA_DIR/"
# Each deploy: ship source + .env, rebuild container on the host.
./deploy.sh
```
Set `SSH_HOST`, `REMOTE_DIR`, `APPDATA_DIR` in `.env`. `deploy.sh` extracts those three keys via `grep` rather than `source .env`, so values containing spaces (like `APPLIANCE_1_NAME=Samsung Dryer`) don't break it.
### Bare metal (first test / debugging)
### Tests
```sh
python3 -m venv .venv
.venv/bin/pip install -r requirements.txt
.venv/bin/python main.py
.venv/bin/pip install -r requirements-dev.txt
.venv/bin/pip install pytest-homeassistant-custom-component homeassistant
.venv/bin/pytest tests/ -q
```
### Expected first-run logs
```
14:08:42 INFO samsung_appliance SmartThings-Local Bridge starting (2 appliances)
14:08:42 INFO samsung_appliance broker = <broker-ip>:1883 (user=<mqtt-user>)
14:08:42 INFO samsung_appliance [1] dryer @ <dryer-ip>:49155 (DTLS) → topic samsung_dryer/*
14:08:42 INFO samsung_appliance [2] oven @ <oven-ip>:49154 (DTLS) → topic samsung_oven/*
14:08:42 INFO samsung_appliance MQTT connected → <broker-ip>:1883
14:08:43 INFO dryer DTLS connected — subscribing 11 paths
14:08:44 INFO dryer.<dryer-serial> identified — serial=…
14:08:44 INFO dryer.<dryer-serial> seeded → 25 links; sensors live
14:08:44 INFO oven DTLS connected — subscribing 11 paths
14:08:46 INFO oven.<oven-serial> identified — serial=…
14:08:46 INFO oven.<oven-serial> seeded → 16 links; sensors live
```
In HA: **Settings → Devices & Services → MQTT** should show both devices populated.
`requirements-dev.txt` pins `smartthings-local` the same way `manifest.json` does, so tests exercise the real published protocol layer rather than a vendored copy.
---
## Per-appliance notes
## Repo layout
### Dryer
| Capability | Works? | Notes |
|---|---|---|
| Read all state | ✅ | Machine state, job state, energy (W + kWh), course, dry level, completion time, remote control, child lock, alarms |
| Wrinkle Prevent toggle | ✅ | Persists |
| Start / Pause / Stop | ✅ | Via `/operational/state/vs/0`; needs Remote Control on |
| Change course | ✅ | Via `/st/dryercourse/vs/0`; needs Remote Control on. **Not exposed by the SmartThings cloud HA integration.** |
| Power on/off | ❌ | Accepted (2.04) but reverts within seconds — hardware-mirrored |
| Child Lock / Remote Control toggle | ❌ | Same — hardware-mirrored physical buttons |
The dryer's `/operational/state/vs/0` is on the bridge's hot poll tier (1s idle / 0.5s while a cycle is active) and also accepts OBSERVE registration. When the appliance has internet it pushes notifications within ~100ms of any state change and the cache absorbs them as fast freshness; when air-gapped the hot-tier poll carries the same UX with worst-case lag of one tier interval.
### Oven
| Capability | Works? | Notes |
|---|---|---|
| Read state | ✅ | Cavity state, current/target temp, door, mode, alarms, firmware-update-available |
| Lamp (light entity) | ✅ | Binary On/Off only — High/Low/Dim values are accepted (2.04) but silently coerced back. Works regardless of Remote Control. |
| Sound, Fast preheat | ⚠️ | Wired but untested RC-gated. |
| Setpoint slider | ⚠️ | Wired but untested RC-gated. |
| Mode select | ⚠️ | Wired but untested RC-gated. |
| Stop button | ✅ | |
| **Kitchen timer (`⏲` icon)** | ❌ | **The oven's panel kitchen timer is not exposed via CoAP at all.** Confirmed by full `/device/0` dump — `UpperTimer*` fields in `/mode/vs/0` only populate when set via the API, not from the panel. |
**The oven doesn't push OBSERVE on `/mode/vs/0` writes** (the dryer does). The bridge handles this transparently because state freshness comes from polling rather than from OBSERVE:
1. **Optimistic publish** — the moment a POST returns 2.04, the bridge merges the write body into the cache and publishes to MQTT. HA reflects the new value instantly.
2. **Scheduler reconciliation** — the PollScheduler defers polling the just-written resource for ~4s (past Samsung's fetchback-revert window), then refreshes it on its tier cadence. If the device silently coerced the value, the corrected state is republished and HA reverts.
3. **Periodic `/device/0` sweep** — every 5 minutes the scheduler's sweep tier re-fetches the whole device tree, bounding worst-case drift on any resource the per-tier polls don't cover.
```
custom_components/localthings/
manifest.json Requirements (incl. the smartthings-local PyPI dep), version, domain
__init__.py async_setup_entry / async_unload_entry
config_flow.py UUID fetch, leaf cert minting, port probing, config entry creation
coordinator.py DataUpdateCoordinator: polling, stale-state fallback, write dispatch
const.py Domain, config keys, probe ports
entity.py Base entity wiring capability registry -> HA entity
sensor.py / binary_sensor.py / switch.py / number.py / select.py / button.py / time.py
One module per HA platform
strings.json / translations/ Config-flow copy + entity state translations
ocf/
batch.py /device/0 batch response parsing
registry/
capability.py Capability dataclass (href, entities, transforms)
entities.py Per-platform entity descriptor dataclasses
discovery.py Binds a device's live resources to registered capabilities
adapter.py Flattens bound entities into HA-ready state
identity.py Reads device identity (serial, oneUiVersion) for type detection
capabilities/ Shared + per-family Capability definitions (common, dryer, oven,
dishwasher, fridge, laundry, operational)
by_type/ One DeviceRegistry per appliance type, composed from capabilities/
tests/ 80+ tests: registry composition, discovery, entity descriptors,
golden-file regression against captured device dumps
setup_cert.py One-shot AC14K_M CA bundle fetcher (Part 2)
requirements-bootstrap.txt Deps for setup_cert.py only
requirements-dev.txt Test deps, including the smartthings-local package
docker-compose.yml / ha_config/ Local HA dev environment
```
---
## Reference
## Adding a new appliance type
### Config keys
1. Capture the appliance's `/device/0` response to see what resources/fields it exposes — an authenticated `DtlsCoapSession` from `smartthings_local.protocol.dtls_session` GET is enough; `local-tools/probe_device.py` wraps this.
2. Reuse existing `Capability` objects from `ocf/registry/capabilities/` wherever the resource matches one already declared (most `common.py` capabilities — power, kids lock, remote control, alarms, energy/water meters — are shared verbatim across families); add new ones only for resources unique to the new type.
3. Create `ocf/registry/by_type/<name>.py` with a `DeviceRegistry(name=..., capabilities=_build([...]))`. Use `pattern_capabilities` instead of `capabilities` for any resource whose `href` isn't fixed (e.g. per-compartment fridge resources) — see `refrigerator.py` for the pattern.
4. Register it in `_REGISTRY_BY_KEY` in `ocf/registry/by_type/__init__.py`, keyed on the lowercased, space/hyphen-to-underscore-converted suffix of the device's `oneUiVersion` string (see `_type_key()` in that file for the exact transform).
5. Add golden-file coverage in `tests/` against a captured `/device/0` dump for the new type.
| Key | Meaning |
|---|---|
| `APPLIANCE_COUNT` | Number of `APPLIANCE_<n>_*` blocks to read (1-indexed) |
| `APPLIANCE_<n>_CLASS` | Descriptor name: `dryer`, `oven` |
| `APPLIANCE_<n>_IP` | LAN IP of the appliance |
| `APPLIANCE_<n>_OCF_PORT` | Optional override (blank → descriptor default: dryer=49155, oven=49154) |
| `APPLIANCE_<n>_TOPIC` | MQTT topic prefix (also the HA device identifier — changing it re-keys the device) |
| `APPLIANCE_<n>_NAME` | Friendly name on the HA device card |
| `MQTT_BROKER` / `MQTT_PORT` / `MQTT_USER` / `MQTT_PASS` | Broker config |
| `HA_DISCOVERY_PREFIX` | HA discovery topic root (default `homeassistant`) |
| `CERT_PATH` / `KEY_PATH` | Override cert lookup (auto-detects `/config/` then `./certs/`) |
| `HEALTH_INTERVAL_S` | Seconds between `<prefix>/bridge/health` publishes (default 60) |
| `PING_INTERVAL_S` | CoAP empty-CON ping cadence; three consecutive failures publish `availability=offline` (default 25). Tier polling cadences are descriptor-declared, not env-tunable. |
| `SSH_HOST` / `REMOTE_DIR` / `APPDATA_DIR` | Used by `deploy.sh` only |
### MQTT topics — outgoing (bridge → broker)
Per appliance, where `<prefix>` is its `APPLIANCE_<n>_TOPIC`.
| Topic | Retain | When |
|---|---|---|
| `<prefix>/availability` | ✓ | `online` after seed; `offline` on disconnect (LWT for appliance #1) |
| `<prefix>/remote_available` | ✓ | `online` iff bridge is up AND Remote Control on the appliance is on. Gates the control entities. |
| `<prefix>/state` | ✓ | JSON sensor dict; published only when sensors actually diff |
| `<prefix>/bridge/health` | ✓ | Every `HEALTH_INTERVAL_S` — connect_count, error_count, notif_count, poll_count, poll_error_count, ping_count, ping_fail_count, reachable, last_change_age_s, last_seed_age_s, session_age_s, stalest_href, stalest_age_s, serial |
| `<ha_prefix>/{sensor,binary_sensor,switch,light,number,select,button}/<prefix>/.../config` | ✓ | HA MQTT discovery, republished on every MQTT (re)connect |
### MQTT topics — incoming (bridge subscribes)
`<prefix>/cmd/#`. **The MQTT user must have READ permission on this subtree** — without it the broker silently drops the TCP connection shortly after SUBSCRIBE. Check broker logs if writes never land.
Dryer:
| Suffix | Payloads | Effect |
|---|---|---|
| `cmd/wrinkle_prevent` | `On`, `Off` | POST `/washer/vs/0` |
| `cmd/operational_state` | `Run`, `Pause`, `Ready` | POST `/operational/state/vs/0` — requires RC |
| `cmd/dryer_mode` | Course name (e.g. `Cotton`) | Translated to `Course_HH` then POST `/st/dryercourse/vs/0` — requires RC |
Oven:
| Suffix | Payloads | Effect |
|---|---|---|
| `cmd/lamp` | `On`, `Off` | RMW of `/mode/vs/0 .options[UpperLamp_*]` |
| `cmd/sound` | `On`, `Off` | RMW of `/mode/vs/0 .options[Sound_*]` |
| `cmd/fastpreheat` | `On`, `Off` | RMW of `/mode/vs/0 .options[fastpreheat_*]` |
| `cmd/setpoint` | Integer °C (30–270, step 5) | RMW of `/temperatures/vs/0 .items[0].desired` — requires RC |
| `cmd/mode` | Mode name (e.g. `Convection`, `LargeGrill`) | POST `/mode/vs/0 {modes: [<name>]}` — requires RC |
| `cmd/stop` | (button press) | POST `/operational/state/vs/0 {state: Ready}` |
### Entity counts (approximate, per appliance)
| Type | Dryer | Oven |
|---|---|---|
| `sensor` | 17 | 17 |
| `binary_sensor` | 4 | 7 |
| `switch` | 1 (wrinkle) | 2 (sound, fastpreheat) |
| `light` | — | 1 (lamp) |
| `number` | — | 1 (setpoint slider) |
| `select` | 1 (course) | 1 (mode) |
| `button` | 3 (start/pause/stop) | 1 (stop) |
Gated control entities use HA's `availability_mode: all` against `<prefix>/availability` AND `<prefix>/remote_available`. Flip Remote Control on the appliance's front panel and those entities un-grey in HA.
### Repo layout
```
main.py Entry point — loads config, spawns one PushBridge per appliance
setup_cert.py One-shot cert minting script (live-fetches AC14K_M + UUID)
samsung_appliance/ The bridge package
__init__.py
config.py SharedConfig + ApplianceConfig dataclasses
logger.py Tagged logger helpers
bridge.py PushBridge — one DTLS session per appliance, descriptor-driven
coap_dtls.py DTLS-CoAP session: handshake, token-stable Block2 GET, POST, OBSERVE
sensors.py /device/0 link-dict indexer (shared util)
appliances/
__init__.py DESCRIPTORS registry + get_descriptor()
base.py ApplianceDescriptor dataclass + HA discovery helpers
dryer.py Dryer descriptor (paths, flatten, discovery, commands)
oven.py Oven descriptor
Dockerfile Container build (python:3.11-slim + 3 deps)
docker-compose.yml One service: smartthings-local
deploy.sh tar + ssh + docker compose up --build
.env.example Template — copy to .env, fill in
```
`certs/` is gitignored. Drop the privileged client cert + key there; the container mounts that directory read-only at `/config`.
No config-flow or coordinator changes needed — device-type detection and entity wiring are fully driven by the registry.
---
## Adding a new appliance class
## Known DTLS behavior
The bridge is appliance-agnostic. Adding e.g. a washer is mechanical:
Samsung's RT-OCF DTLS stack occasionally closes sessions actively, usually right after a Block2 GET or in the seconds after a POST. Retry/retransmit bounds and inter-request pacing live in the `smartthings-local` protocol layer (tuned against measured per-firmware request-rate ceilings); reconnect-with-backoff and stale-state fallback live in this repo's `coordinator.py`. From HA's perspective a brief reconnect looks like an entity holding its last value for one poll cycle rather than going `unavailable`.
1. Capture the appliance's `/device/0` to see what resources/fields it exposes. Use the GET helpers in `samsung_appliance/coap_dtls.py` against your authenticated session.
2. Create `samsung_appliance/appliances/washer.py` with:
- `OBSERVE_PATHS` — list of `[seg, …]` paths to subscribe to (only `/<x>/vs/0` resources push; the OCF-standard `/<x>/0` siblings register but never fire)
- `flatten(links) -> dict` — map link dict to the flat sensor dict that goes on MQTT
- `build_discovery(prefix, ha_prefix, name) -> [(topic, payload), …]` — HA discovery configs
- `command_handlers() -> {suffix: fn(payload, links)}` — MQTT commands → `(path_segs, body_dict)`
- A module-level `WASHER = ApplianceDescriptor(name='washer', default_observe_port=…, …)`
3. Add `WASHER` to `DESCRIPTORS` in `samsung_appliance/appliances/__init__.py`.
4. Add `APPLIANCE_<n>_CLASS=washer` to `.env`, bump `APPLIANCE_COUNT`, redeploy.
For a new appliance class also declare a `poll_tiers: list[PollTier]` and (optionally) an `is_active(links) -> bool` predicate on the descriptor. Hot-tier resources are whatever needs sub-second freshness for HA UX; warm covers everything else that's not static; the `/device/0` sweep tier catches anything you forgot. The descriptor pattern handles everything else — DTLS, MQTT, HA discovery, optimistic writes, Block2 reads, OBSERVE accelerator, reconnect, liveness pings.
---
## Traps to avoid
These each looked like obvious improvements at some point. Each one broke something.
- **Don't add OBSERVE subscriptions on OCF-standard `/<x>/0` paths.** They register successfully but never push. Use the Samsung `/<x>/vs/0` siblings (which do).
- **Don't assume OBSERVE silence means the appliance is broken.** When the appliance can't reach Samsung's cloud, its OBSERVE notify dispatch goes quiet even though the local DTLS session, GETs, POSTs, and the cache continue to work normally (measured at `~14 req/s` dryer / `~8 req/s` oven with 200/200 GETs successful while firewalled). The polling tiers are the structural answer to this; treat OBSERVE strictly as an optional accelerator.
- **Don't touch `/oic/sec/*` (doxm, pstat, cred, acl).** The bridge doesn't, and you shouldn't from helper scripts either — those resources have wedge/brick risk on Samsung's RT-OCF security stack. The bridge surfaces are strictly `/<x>/vs/0` and `/device/0`.
- **Don't run two clients against the same appliance simultaneously.** Samsung's RT-OCF DTLS allows one active session per peer; a second handshake will get the device to drop the new socket. If HA seems to flap, check whether you've got `main.py` running locally AND the Docker container up.
- **Don't expect parity from every write surface.** Samsung's firmware accepts a lot of writes with `2.04 Changed` but only some of them stick — power, child-lock, and remote-control writes are accepted-then-reverted because they're hardware-mirrored. The bridge's optimistic-publish-then-verify pattern handles this transparently: HA briefly shows the new value, the 3s fetch-back republishes the actual value, HA reverts.
---
## Known DTLS flakiness
Samsung's RT-OCF DTLS stack occasionally closes sessions actively — usually right after a Block2 GET or in the seconds after a POST. The bridge handles this with exponential reconnect (1s → 30s) and a re-seed on each new session. From HA's perspective the entity briefly goes offline then comes back; from the bridge's perspective you'll see lines like:
```
oven.… DTLS recv: Unexpected EOF
oven.… reconnect in 1s
oven.… DTLS connected — subscribing 11 paths
oven.… seeded → 16 links; sensors live
```
If reconnects become persistent (e.g. >10 in a minute) something's actually wrong — check the appliance's Wi-Fi link first, then look for a competing DTLS client on the LAN.
If reconnects become persistent (e.g. more than a handful per minute) something's actually wrong — check the appliance's Wi-Fi link first, then look for a competing DTLS client on the LAN (Samsung's RT-OCF DTLS allows only one active session per peer).
---
@@ -387,8 +161,8 @@ If reconnects become persistent (e.g. >10 in a minute) something's actually wron
Patches welcome — especially:
- New appliance descriptors (washer, dishwasher, AC, fridge, etc.) on the same Tizen RT 3.x firmware family.
- Confirmation/refutation on additional dryer or oven models. `nmap` + `/device/0` dump + `/oic/d` GET is enough to know if you're on the same firmware family.
- A proper HA custom component wrapping the bridge so there's a config flow instead of YAML/env editing.
- New `by_type/` registries for appliance families not yet covered (washer, AC, microwave, etc.) on the same Tizen RT 3.x firmware family.
- Confirmation/refutation on additional models within an already-supported type.
- Protocol-level fixes belong upstream in [`smartthings-local`](https://github.com/QuiteYellow/SmartThings-Local); HA-side fixes (entities, config flow, coordinator, registry) belong here.
If you submit a PR, please don't include real device UUIDs, MACs, serials, IPs, or bearer tokens — use the placeholders from `.env.example`.
If you submit a PR, please don't include real device UUIDs, MACs, serials, IPs, or CA private key material — use the placeholders from the config-flow form.
custom_components/localthings/config_flow.py
+1 -1
View File
@@ -123,7 +123,7 @@ def _mint_leaf_cert(ca_cert_pem: str, ca_key_pem: str, uuid: str) -> tuple[str,
def _probe_and_validate(host: str, ca_cert_pem: str, ca_key_pem: str) -> dict:
"""Fetch UUID, mint leaf cert, probe each port. Returns config entry data dict."""
import cbor2
from .ocf.coap_dtls import DtlsCoapSession
from smartthings_local.protocol.dtls_session import DtlsCoapSession
from .ocf.batch import parse_device0_batch
_LOGGER.debug("Fetching Samsung cloud UUID from %s", _SAMSUNG_CLOUD_HOST)
custom_components/localthings/coordinator.py
+2 -1
View File
@@ -13,8 +13,9 @@ from homeassistant.core import HomeAssistant
from homeassistant.helpers.update_coordinator import DataUpdateCoordinator, UpdateFailed
from homeassistant.helpers.device_registry import DeviceInfo
from smartthings_local.protocol.dtls_session import DtlsCoapSession
from .ocf.batch import parse_device0_batch
from .ocf.coap_dtls import DtlsCoapSession
from .ocf.registry.by_type import for_device
from .ocf.registry.discovery import discover, BoundEntity
from .ocf.registry import CAPABILITIES
custom_components/localthings/manifest.json
+5 -1
View File
@@ -4,7 +4,11 @@
"version": "0.1.0",
"config_flow": true,
"iot_class": "local_polling",
"requirements": ["cbor2>=5.4.6", "pyOpenSSL>=22.0.0"],
"requirements": [
"cbor2>=5.4.6",
"pyOpenSSL>=23.0",
"smartthings-local>=0.1.0"
],
"dependencies": [],
"codeowners": []
}
custom_components/localthings/ocf/coap_dtls.py
-745
View File
@@ -1,745 +0,0 @@
"""CoAP-over-DTLS client for Samsung RT-OCF appliances (RFC 7252 + 6347).
Replaces the TLS-over-TCP transport used in the original dryer bridge.
Both the oven (UDP/49154) and the dryer (UDP/49155) speak CoAP-over-DTLS
with the ECDHE-ECDSA-AES128-GCM-SHA256 cipher and ab0b0ac4 client cert.
Wire-level details that matter (from local-tools/oven-findings.md §17):
* DTLS ciphertext MTU must be 1200; otherwise OpenSSL fragments the
client cert across two datagrams and TizenRT drops the second.
* Samsung's RT-OCF uses ACK+separate-CON for the larger responses.
The reader MUST correlate by (token, mid) — not arrival order —
or interleaved one-shot / OBSERVE traffic mis-attributes.
* Multi-block GET requires the SAME CoAP token across every block
of the response ("token-stable Block2"). Fresh-token-per-block
is silently dropped by the server.
Reader thread owns the UDP socket. Callers issue get()/post() and block
on a per-token Event the reader signals. OBSERVE notifications are
delivered via the on_notification callback.
"""
import os
import socket
import struct
import threading
import time
from pathlib import Path
from OpenSSL import SSL
_OCF_ROOT_CA = str(Path(__file__).parent / 'ocf_root_ca.pem')
import logging
logger = logging.getLogger(__name__)
import re as _re
_PEM_CERT_RE = _re.compile(
rb'-----BEGIN CERTIFICATE-----.*?-----END CERTIFICATE-----',
_re.DOTALL,
)
def _load_pem_chain(ctx: SSL.Context, cert_pem: str, key_pem: str) -> None:
"""Load a PEM cert chain and private key into an SSL context in memory.
Parses all certificate blocks from cert_pem: the first is the leaf
(use_certificate), the rest are intermediates (add_extra_chain_cert).
No temp files are written.
"""
from OpenSSL import crypto
certs = _PEM_CERT_RE.findall(cert_pem.encode())
if not certs:
raise ValueError("No certificates found in cert_pem")
ctx.use_certificate(crypto.load_certificate(crypto.FILETYPE_PEM, certs[0]))
for extra in certs[1:]:
ctx.add_extra_chain_cert(
crypto.load_certificate(crypto.FILETYPE_PEM, extra)
)
ctx.use_privatekey(crypto.load_privatekey(crypto.FILETYPE_PEM, key_pem.encode()))
ctx.check_privatekey()
# Diagnostic logging — when DEBUG_BRIDGE=1 in env, the bridge dumps
# every received CoAP frame, every /operational/state/vs/0 + /oven/vs/0
# + /power/vs/0 + /mode/vs/0-options rep change, the full link tree at
# seed time, and the /oic/res directory. Useful for reverse-engineering
# new resources and field semantics; otherwise quiet.
DEBUG_BRIDGE = os.environ.get('DEBUG_BRIDGE') == '1'
# CoAP option numbers (RFC 7252 + 7641 + 7959)
URI_PATH = 11
URI_QUERY = 15
OBSERVE = 6
CONTENT_FORMAT = 12
ACCEPT = 17
BLOCK2 = 23
SIZE2 = 28
# CoAP message types
TYPE_CON = 0
TYPE_NON = 1
TYPE_ACK = 2
TYPE_RST = 3
# CoAP method codes
METHOD_GET = 0x01
METHOD_POST = 0x02
# CoAP content-format value for application/cbor
CF_CBOR = b'\x3c'
# OBSERVE option values (RFC 7641 §2)
OBSERVE_REGISTER = b'' # register / refresh
OBSERVE_DEREGISTER = bytes([1]) # deregister
# Block2 SZX=6 → 1024-byte blocks. The largest size Samsung's RT-OCF
# will honour and the only one the probes have validated end-to-end.
BLOCK_SZX = 6
# Per-block retransmission: send up to this many times before giving up.
# Each attempt waits at most _BLOCK_ACK_TIMEOUT seconds (capped by the
# overall deadline). Matches RFC 7252 CON retransmit behaviour.
_BLOCK_MAX_ATTEMPTS = 3
_BLOCK_ACK_TIMEOUT = 4.0
# Inter-request pacing: minimum seconds between CoAP CON sends on one session.
# Samsung's RT-OCF stacks drop requests when hit faster than their firmware
# ceiling (dryer ~14 req/s, oven ~8 req/s, dishwasher unknown). 5 req/s
# (200 ms) is conservative enough for all tested devices; tune per device
# once the ceiling is measured empirically.
_DEFAULT_RATE_LIMIT_RPS = 5.0
def _vlen(v):
"""Variable-length integer encoder used in option deltas + lengths."""
if v < 13: return v, b''
if v < 269: return 13, bytes([v - 13])
return 14, struct.pack('>H', v - 269)
def encode_options(opts):
"""Encode a list of (option_number, value_bytes) tuples."""
out = b''
prev = 0
for n, val in sorted(opts, key=lambda x: x[0]):
d, dx = _vlen(n - prev)
l, lx = _vlen(len(val))
out += bytes([(d << 4) | l]) + dx + lx + val
prev = n
return out
def parse_coap(data):
"""Decode a CoAP datagram. Returns (mtype, code, mid, token,
options, payload). options is a list of (num, value_bytes)."""
mt = (data[0] >> 4) & 0x03
tkl = data[0] & 0x0F
code = data[1]
mid = int.from_bytes(data[2:4], 'big')
tok = data[4:4 + tkl]
i = 4 + tkl
opts = []
prev = 0
payload = b''
while i < len(data):
b = data[i]
if b == 0xFF:
payload = data[i + 1:]
break
d_nib, l_nib = b >> 4, b & 0x0F
i += 1
if d_nib == 13:
delta = 13 + data[i]; i += 1
elif d_nib == 14:
delta = 269 + int.from_bytes(data[i:i + 2], 'big'); i += 2
elif d_nib == 15:
raise ValueError("reserved option delta nibble 15")
else:
delta = d_nib
if l_nib == 13:
length = 13 + data[i]; i += 1
elif l_nib == 14:
length = 269 + int.from_bytes(data[i:i + 2], 'big'); i += 2
elif l_nib == 15:
raise ValueError("reserved option length nibble 15")
else:
length = l_nib
num = prev + delta
opts.append((num, data[i:i + length]))
i += length
prev = num
return mt, code, mid, tok, opts, payload
def build_coap(mtype, code, mid, token, options, payload=b''):
"""Build a CoAP datagram. mtype: CON/NON/ACK/RST. token: bytes (may
be empty for ACK). options: list of (num, value_bytes)."""
tkl = len(token)
hdr = bytes([(1 << 6) | (mtype << 4) | tkl, code,
(mid >> 8) & 0xFF, mid & 0xFF])
body = hdr + token + encode_options(options)
if payload:
body += b'\xFF' + payload
return body
def block_value(num, more, szx):
"""Encode a CoAP Block-N option value."""
v = (num << 4) | ((more & 1) << 3) | (szx & 7)
if v <= 0xFF: return bytes([v])
if v <= 0xFFFF: return struct.pack('>H', v)
return struct.pack('>I', v)[1:]
def fmt_code(c):
"""0x45 → '2.05', 0x84 → '4.04'. Used in log lines."""
return f"{c >> 5}.{c & 0x1F:02d}"
def _split_dtls(buf):
"""Split a UDP datagram that contains one-or-more DTLS records.
OpenSSL sometimes hands the BIO multiple records back-to-back; we
must send each as its own UDP datagram or TizenRT drops them."""
o, out = 0, []
while o + 13 <= len(buf):
L = int.from_bytes(buf[o + 11:o + 13], 'big')
end = o + 13 + L
if end > len(buf):
break
out.append(buf[o:end])
o = end
return out
class DtlsCoapSession:
"""Single sustained DTLS-CoAP session.
Caller drives lifecycle:
sess = DtlsCoapSession(host, port, cert, key)
sess.connect()
sess.start_reader()
sess.subscribe([...], on_notification=cb) # OBSERVE
code, body = sess.get(['device', '0']) # Block2 fetch
code, _ = sess.post(['mode','vs','0'], cbor)
sess.close()
"""
HANDSHAKE_TIMEOUT_S = 12.0
READER_RECV_TIMEOUT_S = 1.0 # short so stop_event propagates quickly
MAX_BLOCKS = 32 # safety bound for Block2 fetches
def __init__(self, host, port, cert_pem, key_pem,
on_notification=None, mtu=1200,
rate_limit_rps: float = _DEFAULT_RATE_LIMIT_RPS):
self.host = host
self.port = port
self.cert_pem = cert_pem
self.key_pem = key_pem
self.on_notification = on_notification # fn(href, payload_bytes)
self.mtu = mtu
self._min_req_interval = 1.0 / rate_limit_rps
self.sock = None
self.conn = None
self.dest = None
self._send_lock = threading.Lock()
# Randomize MID and token counter starting points so reconnects
# don't reuse identifiers from previous sessions — Samsung's
# RT-OCF appears to remember observer state across DTLS
# sessions, and re-registering with a token it still thinks is
# active is silently no-ops.
self._mid = int.from_bytes(os.urandom(2), 'big')
self._tok_counter = int.from_bytes(os.urandom(4), 'big')
# OBSERVE tokens are 1-byte (Samsung silently drops TKL>1
# OBSERVE registrations). Pick a random starting byte in the
# 0x40..0xff range so each session uses fresh values.
self._observe_tok_counter = 0x40 + (os.urandom(1)[0] & 0xBF)
# token (bytes) → (Event, container_dict)
self._pending = {}
# token (bytes) → href (str)
self._observe_tokens = {}
self._stop = threading.Event()
self._reader_thread = None
def pace(self) -> None:
"""Sleep one rate-limit interval. Uses _stop so session teardown wakes it."""
self._stop.wait(self._min_req_interval)
# ---- lifecycle ---------------------------------------------------
def connect(self):
"""DTLS handshake. Blocks up to HANDSHAKE_TIMEOUT_S. Raises
ConnectionError / TimeoutError on failure."""
ctx = SSL.Context(SSL.DTLS_METHOD)
ctx.load_verify_locations(_OCF_ROOT_CA)
ctx.set_verify(SSL.VERIFY_PEER, lambda conn, cert, err, depth, ok: ok)
# @SECLEVEL=0 permits SHA-1 in Samsung's server cert chain (AC14K_M
# intermediate is SHA-1 signed). This is the only channel that reaches
# the OpenSSL instance cryptography bundles — ctypes and cffi bindings
# do not expose SSL_CTX_set_security_level on this build.
ctx.set_cipher_list(b'ECDHE-ECDSA-AES128-GCM-SHA256:@SECLEVEL=0')
_load_pem_chain(ctx, self.cert_pem, self.key_pem)
conn = SSL.Connection(ctx, None)
conn.set_connect_state()
conn.set_ciphertext_mtu(self.mtu)
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.settimeout(2.0)
dest = (self.host, self.port)
logger.debug(
"DTLS handshake starting to %s:%d (timeout=%.1fs)",
self.host, self.port, self.HANDSHAKE_TIMEOUT_S,
)
t0 = time.time()
iterations = 0
while time.time() - t0 < self.HANDSHAKE_TIMEOUT_S:
iterations += 1
try:
conn.do_handshake()
logger.debug(
"DTLS handshake succeeded after %d iterations", iterations,
)
break
except SSL.WantReadError:
pass
except SSL.Error as e:
logger.debug("DTLS SSL.Error on iter %d: %s", iterations, e)
sock.close()
raise ConnectionError(f"DTLS handshake error: {e}") from e
try:
o = conn.bio_read(65535)
if o:
for r in _split_dtls(o):
sock.sendto(r, dest)
except SSL.WantReadError:
pass
try:
d, _ = sock.recvfrom(65535)
if d:
conn.bio_write(d)
except socket.timeout:
pass
time.sleep(0.05)
else:
logger.debug(
"DTLS handshake timeout after %d iterations, elapsed=%.2fs",
iterations, time.time() - t0,
)
sock.close()
raise TimeoutError(
f"DTLS handshake timeout to {self.host}:{self.port}")
self.sock = sock
self.conn = conn
self.dest = dest
self._stop.clear()
def start_reader(self):
"""Spawn the reader thread. Must be called after connect()."""
if self.sock is None:
raise RuntimeError("connect() before start_reader()")
t = threading.Thread(target=self._reader_loop,
daemon=True, name='dtls-reader')
t.start()
self._reader_thread = t
def join(self):
"""Block until the reader thread exits (i.e. socket dies)."""
if self._reader_thread is not None:
self._reader_thread.join()
def _send_observe_dereg(self, tok, path_segs):
"""Send a single OBSERVE deregister GET (Observe option = 1)
on the existing token. Best-effort — caller swallows errors."""
if self.conn is None:
return
mid = self._next_mid()
opts = [(URI_PATH, s.encode()) for s in path_segs]
opts.append((OBSERVE, OBSERVE_DEREGISTER))
opts.append((ACCEPT, CF_CBOR))
self._send_dgram(
build_coap(TYPE_CON, METHOD_GET, mid, tok, opts))
def close(self):
"""Tear down session. Sends best-effort OBSERVE deregisters
first so Samsung's RT-OCF cleans up its observer table —
without this, the per-cert observer state survives DTLS close
and a quick reconnect with the same tokens silently no-ops."""
# Send dereg for every active observation while the conn is
# still healthy. Tiny sleep lets the records reach the wire
# before we shut DTLS down.
if self.conn is not None and self._observe_tokens:
for tok, href in list(self._observe_tokens.items()):
segs = [s for s in href.split('/') if s]
try:
self._send_observe_dereg(tok, segs)
except Exception as e:
logger.warning("dereg %s: %s", href, e)
time.sleep(0.1)
self._stop.set()
if self.conn is not None:
try:
self.conn.shutdown()
except Exception:
pass
if self.sock is not None:
try:
self.sock.close()
except Exception:
pass
for tok, (ev, container) in list(self._pending.items()):
container.setdefault('err', 'socket closed')
ev.set()
self._pending.clear()
self._observe_tokens.clear()
self.sock = None
self.conn = None
# ---- send / receive plumbing -------------------------------------
def _next_mid(self):
self._mid = (self._mid + 1) & 0xFFFF
return self._mid
def _next_tok(self):
self._tok_counter = (self._tok_counter + 1) & 0xFFFFFFFF
# 4-byte tokens — fits within tkl=8 cap with headroom and
# avoids collisions across long-running OBSERVE subscriptions.
return self._tok_counter.to_bytes(4, 'big')
def _next_observe_tok(self):
# Single-byte tokens for OBSERVE registrations. Samsung
# RT-OCF accepts these but silently drops TKL=4 OBSERVE
# registrations. Counter is randomly seeded per session so
# reconnects don't collide with stale observer state Samsung
# may still be holding from the previous run.
self._observe_tok_counter = (self._observe_tok_counter + 1) & 0xFF
# Avoid 0x00 — some CoAP stacks treat an all-zero token as
# equivalent to "no token" / empty (TKL=0).
if self._observe_tok_counter == 0:
self._observe_tok_counter = 1
return bytes([self._observe_tok_counter])
def _send_dgram(self, datagram):
"""Send a CoAP datagram. Holds the send lock for the
BIO-drain so two writers can't interleave records."""
with self._send_lock:
if self.conn is None:
raise ConnectionError("DTLS session closed")
try:
self.conn.send(datagram)
while True:
o = self.conn.bio_read(65535)
if not o:
break
for r in _split_dtls(o):
self.sock.sendto(r, self.dest)
except SSL.WantReadError:
pass
def _reader_loop(self):
"""Pump UDP socket → DTLS BIO → CoAP parser. Demuxes to pending
/ observe handlers. Exits on socket error or stop event."""
sock = self.sock
conn = self.conn
sock.settimeout(self.READER_RECV_TIMEOUT_S)
try:
while not self._stop.is_set():
try:
d, _ = sock.recvfrom(65535)
except socket.timeout:
continue
except (OSError, ValueError):
return
if not d:
continue
# pyOpenSSL's SSL.Connection is not thread-safe — the
# same SSL object must not be touched by multiple
# threads concurrently. Drain decrypted records into a
# local list under _send_lock so the reader never races
# a sender's conn.send()/bio_read(). Dispatch happens
# AFTER releasing the lock because _dispatch_coap may
# call _send_dgram (auto-ACK for CON frames), which
# re-acquires the lock — holding it across dispatch
# would deadlock.
packets = []
exit_reader = False
with self._send_lock:
try:
conn.bio_write(d)
except SSL.Error as e:
logger.warning("DTLS bio_write: %s", e)
return
while True:
try:
pl = conn.recv(65535)
except SSL.WantReadError:
break
except SSL.ZeroReturnError:
logger.info("DTLS peer closed connection")
exit_reader = True
break
except SSL.Error as e:
logger.warning("DTLS recv: %s", e)
exit_reader = True
break
if not pl:
break
packets.append(pl)
for pl in packets:
try:
self._dispatch_coap(pl)
except Exception as e:
logger.warning("dispatch: %s", e)
if exit_reader:
return
finally:
# Make sure pending waiters don't hang if the reader dies.
for tok, (ev, container) in list(self._pending.items()):
container.setdefault('err', 'reader exited')
ev.set()
def _dispatch_coap(self, datagram):
try:
mt, code, mid, tok, ropts, payload = parse_coap(datagram)
except Exception as e:
logger.debug("malformed CoAP: %s", e)
return
if DEBUG_BRIDGE:
kind = ['CON', 'NON', 'ACK', 'RST'][mt]
logger.info("rx %s code=%s mid=%04x tok=%s opts=%d pl=%d",
kind, fmt_code(code), mid, tok.hex() or '-',
len(ropts), len(payload))
# ACK back any CON from the device to suppress retransmits.
# RFC 7252 §4.2 — ACK is a bare frame (token len 0, code 0).
if mt == TYPE_CON:
try:
self._send_dgram(build_coap(TYPE_ACK, 0, mid, b'', []))
except Exception as e:
logger.warning("ACK send: %s", e)
# Empty ACK with no options & no payload = "separate response
# coming" — used by Samsung's RT-OCF for the larger reads. Stop
# the retransmit timer on the client side and wait for the CON.
if mt == TYPE_ACK and code == 0 and not payload and not ropts:
return
# Pending one-shot? Resolve and return.
rec = self._pending.get(tok)
if rec is not None:
ev, container = rec
container['code'] = code
container['mtype'] = mt
container['mid'] = mid
container['options'] = ropts
container['payload'] = payload
ev.set()
return
# OBSERVE notification?
href = self._observe_tokens.get(tok)
if href is not None:
if code != 0x45:
logger.warning("observe %s: non-2.05 %s",
href, fmt_code(code))
return
cb = self.on_notification
if cb is not None:
try:
cb(href, payload)
except Exception as e:
logger.warning("notification callback %s: %s",
href, e)
return
# Stale token (post-reconnect or unknown) — drop quietly.
logger.debug(
"stale CoAP response: code=%s tok=%s mid=%04x",
fmt_code(code), tok.hex() or '-', mid,
)
# ---- request primitives ------------------------------------------
def get(self, path_segs, query=(), timeout=10.0):
"""Token-stable Block2 GET. Returns (code, payload_bytes).
Reuses one CoAP token across every block of a multi-block
response — Samsung's server keys per-transfer state on the
token, and dropping a fresh token on block 1+ silently drops
the request."""
if self.conn is None:
raise ConnectionError("DTLS session closed")
tok = self._next_tok()
logger.debug(
"GET %s /%s token=%s timeout=%.1fs",
self.host, '/'.join(path_segs), tok.hex(), timeout,
)
blob = b''
num = 0
szx = BLOCK_SZX # server may negotiate down; track per-transfer
last_code = None
last_opts = []
deadline = time.time() + timeout
while True:
if num > 0:
self.pace()
container = {}
for attempt in range(_BLOCK_MAX_ATTEMPTS):
ev = threading.Event()
container = {}
self._pending[tok] = (ev, container)
try:
mid = self._next_mid()
opts = [(URI_PATH, s.encode()) for s in path_segs]
for q in query:
opts.append((URI_QUERY, q.encode()))
opts.append((ACCEPT, CF_CBOR))
if num > 0:
opts.append((BLOCK2, block_value(num, 0, szx)))
self._send_dgram(
build_coap(TYPE_CON, METHOD_GET, mid, tok, opts))
per_wait = min(_BLOCK_ACK_TIMEOUT,
max(0.1, deadline - time.time()))
if ev.wait(per_wait):
break # got a response
remaining = deadline - time.time()
if remaining <= 0 or attempt == _BLOCK_MAX_ATTEMPTS - 1:
logger.debug(
"GET %s /%s block %d: timed out after %d attempt(s)",
self.host, '/'.join(path_segs), num, attempt + 1,
)
raise TimeoutError(
f"GET /{'/'.join(path_segs)} block {num} timeout")
logger.debug(
"GET %s /%s block %d: attempt %d/%d timeout, retrying",
self.host, '/'.join(path_segs), num,
attempt + 1, _BLOCK_MAX_ATTEMPTS,
)
finally:
self._pending.pop(tok, None)
code_seen = container.get('code', 0)
# 4.01 = OCF cert/ACL rejection — surface at WARNING
# so it's visible without debug logging.
if code_seen == 0x81:
logger.warning(
"GET /%s → 4.01 Unauthorized",
'/'.join(path_segs),
)
else:
logger.debug(
"GET %s /%s block %d: %s (%d bytes)",
self.host, '/'.join(path_segs), num,
fmt_code(code_seen),
len(container.get('payload', b'')),
)
if 'err' in container:
raise ConnectionError(container['err'])
code = container['code']
payload = container['payload']
ropts = container['options']
last_code = code
last_opts = ropts
blob += payload
# 4.xx / 5.xx responses don't carry Block2 continuation —
# bail with whatever we got. Caller decides if 4.xx is fatal.
if code >> 5 != 2:
return code, blob
b2 = [v for n, v in ropts if n == BLOCK2]
more = 0
if b2:
bv = int.from_bytes(b2[0], 'big')
more = (bv >> 3) & 1
server_szx = bv & 0x07
if server_szx != szx:
logger.debug(
"GET /%s: server negotiated SZX %d→%d (%d-byte blocks)",
'/'.join(path_segs), szx, server_szx, 1 << (server_szx + 4),
)
szx = server_szx
if not more:
break
num += 1
if num > self.MAX_BLOCKS:
raise ConnectionError(
f"GET /{'/'.join(path_segs)}: >{self.MAX_BLOCKS} "
f"blocks, aborting")
return last_code, blob
def post(self, path_segs, body_cbor, timeout=8.0):
"""Single-frame POST with a CBOR-encoded body. Returns
(code, payload_bytes). body_cbor must already be encoded."""
if self.conn is None:
raise ConnectionError("DTLS session closed")
tok = self._next_tok()
mid = self._next_mid()
opts = [(URI_PATH, s.encode()) for s in path_segs]
opts.append((CONTENT_FORMAT, CF_CBOR))
opts.append((ACCEPT, CF_CBOR))
datagram = build_coap(TYPE_CON, METHOD_POST, mid, tok, opts,
body_cbor)
ev = threading.Event()
container = {}
self._pending[tok] = (ev, container)
try:
self._send_dgram(datagram)
if not ev.wait(timeout):
raise TimeoutError(
f"POST /{'/'.join(path_segs)} timeout")
if 'err' in container:
raise ConnectionError(container['err'])
return container['code'], container['payload']
finally:
self._pending.pop(tok, None)
def ping(self):
"""RFC 7252 §4.4 CoAP Ping — empty CON, no token, no payload.
Peer MUST respond with an RST sharing the same Message ID.
We don't block waiting for the RST here; the reader thread
sees it, finds nothing in _pending/_observe_tokens for an
empty token, and drops it quietly — which is the documented
behaviour for unsolicited RST.
Sole purpose is keepalive: gives Samsung's RT-OCF stack a
visible "client still here" signal so it doesn't expire our
OBSERVE subscriptions (symptom of expiry: POSTs still get
2.04 but OBSERVE notifications stop arriving)."""
if self.conn is None:
raise ConnectionError("DTLS session closed")
mid = self._next_mid()
# Empty message: ver=01, type=CON, tkl=0, code=0.00, mid, no
# token, no options, no payload. build_coap with empty token
# and no options yields exactly that.
self._send_dgram(build_coap(TYPE_CON, 0, mid, b'', []))
return mid
def subscribe(self, path_segs):
"""Register an OBSERVE on the given path. The initial 2.05
notification and all subsequent state-change notifications
will fire on_notification(href, payload_bytes).
Returns the token used (in case the caller wants to deregister
later)."""
if self.conn is None:
raise ConnectionError("DTLS session closed")
tok = self._next_observe_tok()
href = '/' + '/'.join(path_segs)
# Register the token BEFORE sending — otherwise the device
# could respond between send() and the dict insert, and the
# reader thread would drop the initial 2.05 as "stale".
self._observe_tokens[tok] = href
mid = self._next_mid()
opts = [(URI_PATH, s.encode()) for s in path_segs]
opts.append((OBSERVE, OBSERVE_REGISTER))
opts.append((ACCEPT, CF_CBOR))
self._send_dgram(
build_coap(TYPE_CON, METHOD_GET, mid, tok, opts))
return tok
custom_components/localthings/ocf/observe_refresh.py
-50
View File
@@ -1,50 +0,0 @@
"""Periodic OBSERVE re-subscribe.
CoAP OBSERVE (RFC 7641) has no built-in TTL, but real-world peers age
out observer state on their own schedule — Samsung's RT-OCF is known
to silently drop notify delivery during cloud auth blips even though
the DTLS session stays healthy. Without a re-subscribe, recovery from
such a blip requires a full session reconnect.
This task derregisters the current observer tokens and re-subscribes
every `interval_s`. Cheap (one register CON per path), idempotent
(Samsung silently no-ops a register on an already-active token), and
resilient — individual subscribe failures are logged but don't abort
the task.
"""
from __future__ import annotations
import threading
from typing import Optional
from .coap_dtls import DtlsCoapSession
class ObserveRefreshTask:
def __init__(self,
session: DtlsCoapSession,
paths,
interval_s: float = 6 * 3600.0,
logger=None):
self.session = session
self.paths = [list(p) for p in paths]
self.interval_s = interval_s
self.log = logger
self._refresh_count = 0
@property
def refresh_count(self) -> int:
return self._refresh_count
def run_forever(self, stop: threading.Event) -> None:
while not stop.wait(self.interval_s):
try:
self.session.refresh_observes(self.paths)
self._refresh_count += 1
if self.log:
self.log.info("OBSERVE refresh #%d (%d paths)",
self._refresh_count, len(self.paths))
except Exception as e:
if self.log:
self.log.warning("OBSERVE refresh: %s", e)
custom_components/localthings/ocf/ocf_root_ca.pem
-15
View File
@@ -1,15 +0,0 @@
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
requirements-dev.txt
+1
View File
@@ -1 +1,2 @@
pytest>=8.0
smartthings-local>=0.1.0