Interface with Home Connect appliances in Python

This is a very, very beta interface for Bosch-Siemens Home Connect devices through their local network connection. Unlike most IoT devices that have a reputation for very bad security, BSG seem to have done a decent job of designing their system, especially since they allow a no-cloud local control configuration. The protocols seem sound, use well tested cryptographic libraries (TLS PSK with modern ciphres) or well understood primitives (AES-CBC with HMAC), and should prevent most any random attacker on your network from being able to take over your appliances to mine cryptocurrency.

WARNING: This tool not ready for prime time and is still beta!

Setup

To avoid running into issues later with your default python installs, it's recommended to use a py virtual env for doing this. Go to your desired test directory, and:

python3 -m venv venv
source venv/bin/activate
git clone https://github.com/hcpy2-0/hcpy
cd hcpy
pip3 install -r requirements.txt

Install the Python dependencies; the sslpsk one is a little weird and we might need to revisit it later.

Alternatively an environment can be built with docker and/or docker-compose which has the necessary dependencies.

For Mac Users

Installing sslpsk needs some extra steps:

1. The openssl package installed via brew: brew install openssl, and
2. Install sslpsk separately with flags: LDFLAGS="-L$(brew --prefix openssl)/lib" CFLAGS="-I$(brew --prefix openssl)/include" pip3 install sslpsk
3. Rest of the requirements should be fine with pip3 install -r requirements.txt

Authenticate to the cloud servers

hc-login.py $USERNAME $PASSWORD config/devices.json

or

docker-compose -f compose.yaml build
docker-compose -f compose.yaml run -T app /app/hc-login.py $USERNAME $PASSWORD config/devices.json

The hc-login.py script perfoms the OAuth process to login to your Home Connect account with your usename and password. It receives a bearer token that can then be used to retrieves a list of all the connected devices, their authentication and encryption keys, and XML files that describe all of the features and options.

This only needs to be done once or when you add new devices; the resulting configuration JSON file should be sufficient to connect to the devices on your local network, assuming that your mDNS or DNS server resolves the names correctly.

Home Connect to MQTT

Use the following ./config/config.ini example:

devices_file = "./config/devices.json"
mqtt_host = "localhost"
mqtt_username = "mqtt"
mqtt_password = "password"
mqtt_port = 1883
mqtt_prefix = "homeconnect/"
mqtt_ssl = False
mqtt_cafile = None
mqtt_certfile = None
mqtt_keyfile = None
mqtt_clientname="hcpy"
ha_discovery = True  # See section on "Home Assistant autodiscovery"

hc2mqtt.py --config config/config.ini

or

docker-compose -f compose.yaml up

This tool will establish websockets to the local devices and transform their messages into MQTT JSON messages. The exact format is likely to change; it is currently a thin translation layer over the XML retrieved from cloud servers during the initial configuration.

Dishwasher

The dishwasher has a local HTTPS port open, although attempting to connect to the HTTPS port with curl results in a cryptic protocol error due to the non-standard cipher selection, ECDHE-PSK-CHACHA20-POLY1305. PSK also requires that both sides agree on a symetric key, so a special hacked version of sslpsk is used to establish the connection and then hand control to the Python websock-client library.

Example message published to homeconnect/dishwasher:

{
    "state": "Run",
    "door":  "Closed",
    "remaining": "2:49",
    "power": true,
    "lowwaterpressure": false,
    "aquastop": false,
    "error": false,
    "remainingseconds": 10140
}

Clothes washer

The clothes washer has a local HTTP port that also responds to websocket traffic, although the contents of the frames are AES-CBC encrypted with a key derived from HMAC(PSK,"ENC") and authenticated with SHA256-HMAC using another key derived from HMAC(PSK,"MAC"). The encrypted messages are send as binary data over the websocket (type 0x82).

Example message published to homeconnect/washer:

{
    "state": "Ready",
    "door": "Closed",
    "remaining": "3:48",
    "power": true,
    "lowwaterpressure": false,
    "aquastop": false,
    "error": false,
    "remainingseconds": 13680
}

Coffee Machine

Example message published to homeconnect/coffeemaker:

Posting to the appliance

Whereas the reading of the status is very beta, this is very very alpha. There is some basic error handling, but don't expect that everything will work.

In your config file you can find items that contain readWrite or writeOnly, some of them contain values so you know what to provide, ie:

"539": {
    "name": "BSH.Common.Setting.PowerState",
    "access": "readWrite",
    "available": "true",
    "refCID": "03",
    "refDID": "80",
    "values": {
        "2": "On",
        "3": "Standby"
    }
},

With this information you can build the JSON object you can send over mqtt to change the power state

Topic: homeconnect/[devicename]/set, ie homeconnect/coffeemaker/set

Payload:

{"uid":539,"value":2}

As for now, the results will be displayed by the script only, there is no response to an mqtt topic.

There are properties that do not require predefined values, debugging is required to see what is needed. Here are some of those values found through debugging:

Set the time:

{"uid":520,"value":"2023-07-07T15:01:21"}

Synchronize with time server, false is disabled

{"uid":547,"value":false}

Starting a Program

The MQTT client listens on /{prefix}/{devicename}/activeProgram for a JSON message to start a program. The JSON should be in the following format:

{"program":{uid},"options":[{"uid":{uid},"value":{value}}]}

To start a dishwasher on eco mode (Dishcare.Dishwasher.Program.Eco50):

{"program":8196}

To start a dishwasher on eco mode in 10 miuntes (BSH.Common.Option.StartInRelative):

{"program":8196,"options":[{"uid":558,"value":600}]}

Notes

• Sometimes when the device is off, there is the error ERROR [ip] [Errno 113] No route to host
• There is a lot more information available, like the status of a program that is currently active. This needs to be integrated if possible. For now only the values that relate to the config.json are published

Home Assistant autodiscovery

It's possible to allow Home Assistant to automatically discover the device using MQTT auto-discovery messages. With ha_discovery = True in config.ini or by passing --ha-discovery on the commandline, hcpy will publish HA discovery messages for each recognised property of your devices.

Limitations

Discovery messages currently only contain a state topic, not a command topic, so autodiscovered devices will be read-only. You can still use the method described in Posting to the appliance above.

Customising the discovery messages

hcpy will make some attempt to use the correct component and for some devices set an appropriate device class. You can customise these by editing your devices.json to add or edit the discovery section for each feature. For example:

[
    { // ...
        "features": {
            // ...
            "549": {
                "name": "BSH.Common.Option.RemainingProgramTimeIsEstimated",
                "discovery": {
                    "component_type": "binary_sensor",
                    "payload_values": {
                        "payload_on": true,
                        "payload_off": false
                    }
                }
            }
        }
    }
]

You may include arbitrary payload_values that are included in the MQTT discovery messages published when hcpy starts. Default values are set in HADiscovery.py for known devices/attributes. No validation is performed against these values.