NXP Manufacturing data#

By default, the example application is configured to use generic test certificates and provisioning data embedded with the application code. It is possible for a final stage application to generate its own manufacturing data using the procedure described below.

1. Prerequisites#

Generate build files from Matter root folder by running:

gn gen out

Build chip-cert tool:

ninja -C out chip-cert

Build spake2p tool:

ninja -C out spake2p

2. Generate#

a. Certificates#

To generate the different certificates, NXP provides a Python script scripts/tools/nxp/generate_certs.py. This script will always generate the PAI and DAC certificates/keys. It can also generate the Certification Declaration and the PAA certificate/key depending on the parameters.

Parameter	Description	Type	Required
`--chip_cert_path`	Path to chip-cert executable	string	Yes
`--output`	Output path to store certificates	string	Yes
`--vendor_id`	Vendor Identification Number	integer or hex integer	Yes
`--product_id`	Product Identification Number	integer or hex integer	Yes
`--vendor_name`	Human-readable vendor name	string	Yes
`--product_name`	Human-readable product name	string	Yes
`--gen_cd`	Use this option to enable Certificate Declaration generation	boolean	No
`--cd_type`	Type of generated Certification Declaration: `0` - development, `1` - provisional, `2` - official	integer	No
`--device_type`	The primary device type implemented by the node	int	No
`--paa_cert`	Path to the Product Attestation Authority (PAA) certificate. Will be generated if not provided.	string	No
`--paa_key`	Path to the Product Attestation Authority (PAA) key. Will be generated if not provided.	string	No
`--valid_from`	The start date for the certificate’s validity period.	string	No
`--lifetime`	The lifetime for the certificates, in whole days.	string	No

You can also run the following command to get more details on the parameters and their default value (if applicable):

python scripts/tools/nxp/generate_certs.py --help

Example of a command that will generate CD, PAA, PAI and DAC certificates and keys in both .pem and .der formats:

python scripts/tools/nxp/generate_certs.py --gen_cd --cd_type 1 --chip_cert_path ./out/chip-cert --vendor_id 0x1037 --product_id 0xA220 --vendor_name "NXP Semiconductors" --product_name all-clusters-app --device_type 65535 --output .

Note: the commands provided in this guide are just for the example and shall be adapted to your use case accordingly

c. Provisioning data#

Generate new provisioning data and convert all the data to a binary (unencrypted data):

python3 ./scripts/tools/nxp/factory_data_generator/generate.py -i 10000 -s UXKLzwHdN3DZZLBaL2iVGhQi/OoQwIwJRQV4rpEalbA= -p 14014 -d 1000 --vid 0x1037 --pid 0xA220 --vendor_name "NXP Semiconductors" --product_name "Lighting app" --serial_num "12345678" --date "2023-01-01" --hw_version 1 --hw_version_str "1.0" --cert_declaration ./Chip-Test-CD-1037-A220.der --dac_cert ./Chip-DAC-NXP-1037-A220-Cert.der --dac_key ./Chip-DAC-NXP-1037-A220-Key.der --pai_cert ./Chip-PAI-NXP-1037-A220-Cert.der --spake2p_path ./out/spake2p --unique_id "00112233445566778899aabbccddeeff" --out ./factory_data.bin

Same example as above, but with an already generated verifier passed as input:

python3 ./scripts/tools/nxp/factory_data_generator/generate.py -i 10000 -s UXKLzwHdN3DZZLBaL2iVGhQi/OoQwIwJRQV4rpEalbA= -p 14014 -d 1000 --vid "0x1037" --pid "0xA220" --vendor_name "NXP Semiconductors" --product_name "Lighting app" --serial_num "12345678" --date "2023-01-01" --hw_version 1 --hw_version_str "1.0" --cert_declaration ./Chip-Test-CD-1037-A220.der --dac_cert ./Chip-DAC-NXP-1037-A220-Cert.der --dac_key ./Chip-DAC-NXP-1037-A220-Key.der --pai_cert ./Chip-PAI-NXP-1037-A220-Cert.der --spake2p_path ./out/spake2p --spake2p_verifier ivD5n3L2t5+zeFt6SjW7BhHRF30gFXWZVvvXgDxgCNcE+BGuTA5AUaVm3qDZBcMMKn1a6CakI4SxyPUnJr0CpJ4pwpr0DvpTlkQKqaRvkOQfAQ1XDyf55DuavM5KVGdDrg== --unique_id "00112233445566778899aabbccddeeff" --out ./factory_data.bin

Generate new provisioning data and convert all the data to a binary (encrypted data with the AES key). Add the following option to one of the above examples:

--aes128_key 2B7E151628AED2A6ABF7158809CF4F3C

Here is the interpretation of the required parameters:

-i                 -> SPAKE2+ iteration
-s                 -> SPAKE2+ salt (passed as base64 encoded string)
-p                 -> SPAKE2+ passcode
-d                 -> discriminator
--vid              -> Vendor ID
--pid              -> Product ID
--vendor_name      -> Vendor Name
--product_name     -> Product Name
--hw_version       -> Hardware Version as number
--hw_version_str   -> Hardware Version as string
--cert_declaration -> path to the Certification Declaration (der format) location
--pai_cert         -> path to the PAI (der format) location
--spake2p_path     -> path to the spake2p tool
--out              -> name of the binary that will be used for storing all the generated data

Here is the interpretation of the optional parameters:

--dac_cert              -> path to the DAC certificate (der format) location
--dac_key               -> path to the DAC key (der format) location
--EL2GO_bin             -> path to the EdgeLock 2Go binary (bin format) location
--EL2GO_DAC_KEY_ID      -> DAC key ID configured into EdgeLock 2Go as hex value
--EL2GO_DAC_CERT_ID     -> DAC certificate ID configured into EdgeLock 2Go as hex value
--dac_key_password      -> Password to decode DAC key
--dac_key_use_sss_blob  -> Used when --dac_key contains a path to an encrypted blob, instead of the
                           actual DAC private key. The blob metadata size is 24, so the total length
                           of the resulting value is private key length (32) + 24 = 56. False by default.
--spake2p_verifier      -> SPAKE2+ verifier (passed as base64 encoded string). If this option is set,
                           all SPAKE2+ inputs will be encoded in the final binary. The spake2p tool
                           will not be used to generate a new verifier on the fly.
--aes128_key            -> 128 bits AES key used to encrypt the whole dataset. Please make sure
                           that the target application/board supports this feature: it has access to
                           the private key and implements a mechanism which can be used to decrypt
                           the factory data information.
--date                  -> Manufacturing Date (YYYY-MM-DD format)
--part_number           -> Part number as string
--product_url           -> Product URL as string
--product_label         -> Product label as string
--serial_num            -> Serial Number
--unique_id             -> Unique id used for rotating device id generation
--product_finish        -> Visible finish of the product
--product_primary_color -> Representative color of the visible parts of the product
--hw_params             -> Use application factory data from Hardware Parameters component

3. Write provisioning data#

platform	tool	command	details
`k32w0x1`	`DK6Programmer.exe` or `dk6prog`	`DK6Programmer.exe -Y -V2 -s <COM_PORT> -P 1000000 -Y -p FLASH@0x9D600="factory_data.bin"`	NA
`k32w1`	`JLink`	`loadfile factory_data.bin 0xFE080`	NA
`mcxw71`	`JLink`	`loadfile factory_data.bin 0xFE080`	NA
`rw61x`	`JLink`	`loadfile factory_data.bin 0xBFFF000`	Here, `0xBFFF000` is the value of symbol `__FACTORY_DATA_START` from the corresponding `.map` file
`rt1060`	`MCUXpresso Flash Tool GUI`	NA	The address is given by the `__FACTORY_DATA_START` symbol in the `.map` file
`rt1170`	`MCUXpresso Flash Tool GUI`	NA	The address is given by the `__FACTORY_DATA_START` symbol in the `.map` file

4. Build app and usage#

Use nxp_use_factory_data=true when compiling to enable factory data usage.

Run chip-tool with a new PAA:

./chip-tool pairing ble-thread 2 hex: $hex_value 14014 1000 --paa-trust-store-path /home/ubuntu/certs/paa

Here is the interpretation of the parameters:

--paa-trust-store-path -> path to the generated PAA (der format)

paa-trust-store-path must contain only the PAA certificate. Avoid placing other certificates in the same location as this may confuse chip-tool.

PAA certificate can be copied to the chip-tool machine using SCP for example.

This is needed for testing self-generated DACs, but likely not required for “true production” with production PAI issued DACs.

5. Useful information/Known issues#

Implementation of manufacturing data provisioning has been validated using test certificates generated by OpenSSL 1.1.1l.

Also, demo DAC, PAI and PAA certificates needed in case nxp_use_factory_data=true is used can be found in ./scripts/tools/nxp/demo_generated_certs.

6. Increased security for DAC private key#

6.1 SSS-based with EdgeLock2go support#

EdgeLock2go services could be used to securely provisioned DAC key/cert during manufacturing.

Prior to the generation of the factory data binary. EL2GO data needs to be generated following EL2GO process.

For the factory data generation following option need to be added:

--EL2GO_bin ~/secure_objects.bin containing EL2GO information including encrypted DAC private key and certificate. --EL2GO_DAC_KEY_ID 1234 containing corresponding to the ID of the DAC key chosen during EL2GO key generation. --EL2GO_DAC_CERT_ID 4321 containing corresponding to the ID of the DAC certification chosen during EL2GO key generation.

Reference factory data generation command:

python3 ./scripts/tools/nxp/factory_data_generator/generate.py -i 10000 -s UXKLzwHdN3DZZLBaL2iVGhQi/OoQwIwJRQV4rpEalbA= -p ${passcode} -d ${discriminator} --vid "0x$VID" --pid "0x$PID" --vendor_name "NXP Semiconductors" --product_name "Thermostat" --serial_num "12345678" --date "$DATE" --hw_version 1 --hw_version_str "1.0" --cert_declaration $FACTORY_DATA_DEST/Chip-Test-CD-$VID-$PID.der --EL2GO_bin ~/secure_objects.bin --EL2GO_DAC_KEY_ID 1234 --EL2GO_DAC_CERT_ID 4321 --pai_cert $FACTORY_DATA_DEST/Chip-PAI-NXP-$VID-$PID-Cert.der --spake2p_path ./out/spake2p --unique_id "00112233445566778899aabbccddeeff" --out $FACTORY_DATA_DEST/factory_data.bin

Supported platforms:

rw61x

In addition to the GN flag nxp_use_factory_data=true, a Matter application needs to be built with nxp_enable_secure_EL2GO_factory_data=true to allow loading of EdgeLock2go data to the secure element.

In this mode EdgeLock2go keys will always remain encrypted and only usable by the SSS. In this case, all operations that requires DAC private access will be transferred to the SSS.

6.2 SSS-based without EdgeLock2go support for DAC private key secure storage#

Supported platforms:

k32w1
mcxw71
rw61x

For platforms that have a secure subsystem (SSS), the DAC private key can be converted to an encrypted blob. This blob will overwrite the DAC private key in factory data and will be imported in the SSS by the factory data provider instance.

In this architecture, outside of the manufacturing flow, the DAC private will always remain usable only by the SSS. In this case, all operations that requires DAC private access will be transferred to the SSS.

The application will check at initialization whether the DAC private key has been converted or not and convert it if needed. However, the conversion process should be done at manufacturing time for security reasons.

Reference factory data generation command:

python3 ./scripts/tools/nxp/factory_data_generator/generate.py -i 10000 -s UXKLzwHdN3DZZLBaL2iVGhQi/OoQwIwJRQV4rpEalbA= -p 14014 -d 1000 --vid "0x1037" --pid "0xA221" --vendor_name "NXP Semiconductors" --product_name "Lighting app" --serial_num "12345678" --date "2023-01-01" --hw_version 1 --hw_version_str "1.0" --cert_declaration ./Chip-Test-CD-1037-A221.der --dac_cert ./Chip-DAC-NXP-1037-A221-Cert.der --dac_key ./Chip-DAC-NXP-1037-A221-Key.der --pai_cert ./Chip-PAI-NXP-1037-A221-Cert.der --spake2p_path ./out/spake2p --unique_id "00112233445566778899aabbccddeeff" --hw_params --out ./factory_data.bin

There is no need for an extra binary.

Write factory data binary.
Build the application with nxp_use_factory_data=true set.
Write the application to the board and use it as usual.

Factory data should now contain a corresponding encrypted blob instead of the DAC private key.

If an encrypted blob of the DAC private key is already available (e.g. obtained previously, using other methods), then the conversion process shall be skipped. Instead, option --dac_key_use_sss_blob can be used in the factory data generation command:

python3 ./scripts/tools/nxp/factory_data_generator/generate.py -i 10000 -s UXKLzwHdN3DZZLBaL2iVGhQi/OoQwIwJRQV4rpEalbA= -p 14014 -d 1000 --vid "0x1037" --pid "0xA221" --vendor_name "NXP Semiconductors" --product_name "Lighting app" --serial_num "12345678" --date "2023-01-01" --hw_version 1 --hw_version_str "1.0" --cert_declaration ./Chip-Test-CD-1037-A221.der --dac_cert ./Chip-DAC-NXP-1037-A221-Cert.der --dac_key ./Chip-DAC-NXP-1037-A221-Key-encrypted-blob.bin --pai_cert ./Chip-PAI-NXP-1037-A221-Cert.der --spake2p_path ./out/spake2p --unique_id "00112233445566778899aabbccddeeff" --dac_key_use_sss_blob --out ./factory_data_with_blob.bin

Please note that --dac_key now points to a binary file that contains the encrypted blob.

The user can use the DAC private in plain text instead of using the SSS by adding the following gn argument chip_use_plain_dac_key=true (not supported on rw61x).

NXP Manufacturing data

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