factory_data.md

Using ESP32 Factory Data Provider

By default applications uses test-mode or default commissionable data provider, device attestation credentials provider, and device instance info provider.

To use different values for them you can use the ESP32 Factory Data Provider.

Configuration Options

Enable config option CONFIG_ENABLE_ESP32_FACTORY_DATA_PROVIDER to use ESP32 specific implementation of CommissionableDataProvider and DeviceAttestationCredentialsProvider.

[Component config → CHIP Device Layer → Commissioning options → Use ESP32 Factory Data Provider]

Enable config option CONFIG_ENABLE_ESP32_FACTORY_DATA_PROVIDER to use ESP32 specific implementation of DeviceInstanceInfoProvider.

[Component config → CHIP Device Layer → Commissioning options → Use ESP32 Device Instance Info Provider]

ESP32 implementation reads factory data from nvs partition, chip-factory data must be flashed into the configured nvs partition. Factory partition can be configured using CONFIG_CHIP_FACTORY_NAMESPACE_PARTITION_LABEL option, default is "nvs".

Generate NVS Binary Image

scripts/tools/generate_esp32_chip_factory_bin.py script generates the chip-factory NVS binary image partition.bin.

Supported data

Script supports adding following data to the NVS binary image:

• Commissionable data

  • Discriminator
  • Spake2p verifier, salt, and iteration count

• Device attestation data

  • Device attestation key and certificate
  • Product attestation intermediate certificate
  • Certificate declaration

• Device instance information

  • Vendor id and name
  • Product id and name
  • Hardware version and version string
  • Serial Number
  • Unique identifier

Please check help for available options, scripts/tools/generate_esp32_chip_factory_bin.py

Dependency

Script has dependency on spake2p for generating spake2p parameters.

Build spake2p:

cd path/to/connectedhomeip
gn gen out/host
ninja -C out/host
cd -

Add spake2p to $PATH environment variable

export PATH=$PATH:path/to/connectedhomeip/out/host

Usage

Below mentioned command generates the nvs image with test DAC with VID:0xFFF2 and PID:8000 and some examples values for other fields.

./generate_esp32_chip_factory_bin.py -d 3434 -p 99663300 \
                                    --product-name ESP-lighting-app --product-id 0x8000 \
                                    --vendor-name Test-vendor --vendor-id 0xFFF2 \
                                    --hw-ver 1 --hw-ver-str DevKit \
                                    --dac-cert path/to/connectedhomeip/credentials/test/attestation/Chip-Test-DAC-FFF2-8001-0008-Cert.der \
                                    --dac-key path/to/connectedhomeip/credentials/test/attestation/Chip-Test-DAC-FFF2-8001-0008-Key.der \
                                    --pai-cert path/to/connectedhomeip/credentials/test/attestation/Chip-Test-PAI-FFF2-8001-Cert.der \
                                    --cd path/to/connectedhomeip/credentials/test/certification-declaration/Chip-Test-CD-FFF2-8001.der \

Flashing the generated NVS image

Use the following command to flash the NVS image. 0x9000 is default address for nvs partition.

esptool.py -p <port> write_flash 0x9000 factory_partition.bin

NOTE: Above command uses the default NVS address, please flash the NVS image at appropriate address.

Securing NVS binary image with NVS Encryption

Please check Flash and NVS encryption guide