NervesKey (nerves_key v1.3.0)

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This is a high level interface to provisioning and using the NervesKey or any ATECC508A/608A that can be configured similarly.

Summary

Types

Which device/signer certificate pair to use

Which type of device to use

Functions

Clear out the auxiliary certificates

Create a signing key pair

Return default provisioning info for a NervesKey

Detect if a NervesKey is available on the transport

Read the device certificate from the slot

Return the settings block as a binary

Return all of the setting stored in the NervesKey as a map

Check whether the auxiliary certificates were programmed

IEEE EUI-48 MAC address that can be used as a unique identifier in LAN networking This is only available on :trust_and_go

Read the manufacturer's serial number

Return the max length of settings

Provision a NervesKey in one step.

Provision the auxiliary device/signer certificates on a NervesKey.

Check whether the NervesKey has been provisioned

Store raw settings on the Nerves Key

Sign a SHA256 digest

Read the signer certificate from the slot

Return ssl_opts for using the NervesKey

Provision a NervesKey for the volatile key config in one step.

Types

certificate_pair()

@type certificate_pair() :: :primary | :aux

Which device/signer certificate pair to use

device_type()

@type device_type() :: :nerves_key | :trust_and_go

Which type of device to use

Functions

clear_aux_certificates(transport)

@spec clear_aux_certificates(ATECC508A.Transport.t()) :: :ok

Clear out the auxiliary certificates

This function overwrites the auxiliary certificate slots with

create_signing_key_pair(opts \\ [])

@spec create_signing_key_pair(keyword()) ::
  {X509.Certificate.t(), X509.PrivateKey.t()}

Create a signing key pair

This returns a tuple that contains a new signer certificate and private key. It is compatible with the ATECC508A certificate compression.

Options:

  • :years_valid - how many years this key is valid for

default_info(transport)

Return default provisioning info for a NervesKey

This function is used for pre-programmed NervesKey devices. The serial number is a Base32-encoded version of the ATECC508A/608A's globally unique serial number. No additional care is needed to keep the number unique.

detected?(transport)

@spec detected?(ATECC508A.Transport.t()) :: boolean()

Detect if a NervesKey is available on the transport

device_cert(transport, which \\ :primary, type \\ :nerves_key)

Read the device certificate from the slot

The device must be programmed for this to work.

Examples:

iex> NervesKey.device_cert(transport, :primary, :nerves_key)
{:OTPCertificate, ...}

iex> NervesKey.device_cert(transport, :primary, :trust_and_go)
{:OTPCertificate, ...}

get_raw_settings(transport, device_type \\ :nerves_key)

@spec get_raw_settings(ATECC508A.Transport.t(), device_type()) ::
  {:ok, binary()} | {:error, atom()}

Return the settings block as a binary

get_settings(transport, device_type \\ :nerves_key)

@spec get_settings(ATECC508A.Transport.t(), device_type()) ::
  {:ok, map()} | {:error, atom()}

Return all of the setting stored in the NervesKey as a map

has_aux_certificates?(transport)

@spec has_aux_certificates?(ATECC508A.Transport.t()) :: boolean()

Check whether the auxiliary certificates were programmed

manufacturer_mac(transport, atom)

IEEE EUI-48 MAC address that can be used as a unique identifier in LAN networking This is only available on :trust_and_go

manufacturer_sn(transport, type \\ :nerves_key)

@spec manufacturer_sn(ATECC508A.Transport.t(), device_type()) :: binary()

Read the manufacturer's serial number

max_settings_len(atom)

@spec max_settings_len(device_type()) :: integer()

Return the max length of settings

provision(transport, info, signer_cert, signer_key)

Provision a NervesKey in one step.

See the README.md for how to use this. This function locks the ATECC508A down, so you'll want to be sure what you pass it is correct.

This function does it all. It requires the signer's private key so handle that with care. Alternatively, please consider sending a PR for supporting off-device signatures so that HSMs can be used.

provision_aux_certificates(transport, signer_cert, signer_key, type \\ :nerves_key)

@spec provision_aux_certificates(
  ATECC508A.Transport.t(),
  X509.Certificate.t(),
  X509.PrivateKey.t(),
  device_type()
) :: :ok

Provision the auxiliary device/signer certificates on a NervesKey.

This function creates and saves the auxiliary certificates. These are only needed if the ones written by provision/4 are not usable. They are not used unless explicitly requested. See the README.md for details.

You may call this function multiple times after the ATECC508A has been provisioned.

provisioned?(transport)

@spec provisioned?(ATECC508A.Transport.t()) :: boolean()

Check whether the NervesKey has been provisioned

put_raw_settings(transport, raw_settings, device_type)

@spec put_raw_settings(ATECC508A.Transport.t(), binary(), device_type()) :: :ok

Store raw settings on the Nerves Key

This overwrites all of the settings and should be used with care since there's no protection against race conditions with other users of this API.

put_settings(transport, settings, device_type \\ :nerves_key)

@spec put_settings(ATECC508A.Transport.t(), map(), device_type()) :: :ok

Store settings on the NervesKey

This overwrites all of the settings that are currently on the key and should be used with care since there's no protection against a race condition with other NervesKey users.

sign_digest(transport, digest)

@spec sign_digest(ATECC508A.Transport.t(), binary()) ::
  {:ok, binary()} | {:error, atom()}

Sign a SHA256 digest

signer_cert(transport, which \\ :primary, type \\ :nerves_key)

Read the signer certificate from the slot

ssl_opts(transport, which \\ :primary, type \\ :nerves_key)

Return ssl_opts for using the NervesKey

Pass an engine and optionally which certificate that you'd like to use.

volatile_provision(transport, info, signer_cert, signer_key, activation_key, encryption_key)

Provision a NervesKey for the volatile key config in one step.

See the README.md for how to use this. This function locks the ATECC508A down, so you'll want to be sure what you pass it is correct. Ensure you have the activation key in safe storage, it will be required to use the NervesKey.

This function does it all. It requires the signer's private key so handle that with care. Alternatively, please consider sending a PR for supporting off-device signatures so that HSMs can be used.