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Custom properties

You can provision custom parameters to devices.

Parameter names:

  • Must be unique.
  • Must not include the mbed prefix.

Property names are case sensitive; the device code and any server code must match the name exactly when attempting to use the property. For example, if you use MyApp.DLMS as a key for a custom certificate, then this name should be precisely used in all configuration files in all FCU installations (if you have multiple production lines) and in your client code on the device. myapp.dlms will not work correctly.

Custom certificate

FCU parameter name Item with type certificate under custom-properties section
Name on the device Defined by user
Details You may use several custom certificates or certificate chains.
Note: If the item is a certificate chain, the corresponding data or data-file field may contain a chain of certificates in PEM format only.
FCU configuration source Configuration file
KCM type Certificate
Format in KCM DER
Validations in FCU Valid certificate according to the supported crypto-scheme in DER/PEM format (for certificate chains- only PEM format is supported).

Note: If the custom certificate is a certificate chain, every certificate in the chain is validated with those validations.
Validations in FCC Valid certificate in DER format.

Note: If the custom certificate is a certificate chain, each certificate in the chain is checked to be signed by its predecessor (previous certificate in the chain).

Custom private key

FCU parameter name Item with type private-key under custom-properties section
Name on the device Defined by user
Details You can use several custom private keys
FCU configuration source Configuration file
KCM type Private key
Format in KCM DER
Validations in FCU Valid ECC private key in DER/PEM format
Validations in FCC Valid DER format and private key format

Custom public key

FCU parameter name Item with type public-key under custom-properties section
Name on the device Defined by user
Details You can use several custom public keys
FCU configuration source Configuration file
KCM type Public key
Format in KCM DER
Validations in FCU Valid public key in DER/PEM format
Validations in FCC Valid public key in DER format

Custom generated certificate key pair

FCU parameter name Item with type generated-certificate-key-pair under custom-properties section
Name on the device Defined by user
Details You can use several custom parameters
FCU configuration source Configuration file
KCM type Configuration parameter
Format in KCM Bytes (length may vary)
Validations in FCU Supported types: dictionary in the following format:
certificate:
subject:
common-name: string
organization-name: string
organizational-unit-name: string
locality-name: string
state-or-province-name: string
country-name: string (two letters)
key-usage:
digital-signature: boolean
non-repudiation: boolean
key-cert-sign: boolean
extended-key-usage:
any-extended-key-usage: boolean
server-auth: boolean
client-auth: boolean
code-signing: boolean
email-protection: boolean
time-stamping: boolean
ocsp-signing: boolean
validity-period-months: int (1-360)
chain-depth-on-device: int (1-10)
(optional- required when FCU signs with certificate chain)
private-key-storage: 'device' (default) - Generate and store key in the device's default storage; or, 'secure_element' - Generate and store key on secure element.
public-key-storage: 'device' (default) - Generate and store key in the device's default storage; or, 'secure_element' - Generate and store key on secure element; or, 'not_stored' - Do not store key.
Validations in FCC N/A

Custom configuration parameter

FCU parameter name Item with type general-data under custom-properties section
Name on the device Defined by user
Details You can use several custom parameters.
FCU configuration source Configuration file
KCM type Configuration parameter
Format in KCM int - 64-bit integer
string and bytes - Bytes (length may vary)
Validations in FCU Supported types: int, string, bytes.
The size is limited to 5000 bytes.
Validations in FCC N/A